WO2005005439A1

WO2005005439A1 - Benzothiazino indoles

Info

Publication number: WO2005005439A1
Application number: PCT/IN2004/000200
Authority: WO
Inventors: Venkata Satya Nirogi Ramakrishna; Rama Satri Kambhampati; Vikas Shreekrishna Shirsath; Venkateswarlu Jasti
Original assignee: Suven Life Sciences Limited
Priority date: 2003-07-09
Filing date: 2004-07-07
Publication date: 2005-01-20

Abstract

This invention particularly relates to novel benzothiazinoindole derivatives represented by the general formula (I), given below: wherein R1, R2, R3, R4, R5, R6,, R7, R8, R9, R10, R11, R12, R13 and R14, may be same or different and each independently represent hydrogen, halogen, oxo, thio, perhaloalkyl, hydroxy, amino, nitro, cyano, formyl, amidino, guanidino, substituted or unsubstituted groups selected from linear or branched (Cl-C,12)alkyl, (C2-C12)alkenyl, C2-C12)alkynyl, (C3-C7)cycloalkyl, (C3-C7)cycloalkenyl, bicycloalkyl, bicycloalkenyl, C1-C12)alkoxy, cyclo(C3-C7)alkoxy, aryl, aryloxy, aralkyl, aralkoxy, heterocyclyl, heteroaryl, heterocyclylalkyl, heteroaralkyl, heteroaryloxy, heteroaralkoxy, heterocyclylalkyloxy, acyl, acyloxy, acylamino, monoalkylamino, dialkylamino, arylamino, diarylamino, aralkylamino, alkoxycarbonyl, aryloxycarbonyl, aralkoxycarbonyl, heterocyclylalkoxycarbonyl, heteroaryloxycarbonyl, hydroxyalkyl, aminoalkyl, monoalkylaminoalkyl, dialkylaminoalkyl, alkoxyalkyl, aryloxyalkyl, aralkoxyalkyl, alkylthio, thioalkyl, alkoxycarbonyamino, aryloxycarbonylamino, dialkylaminocarbonylamino, alkylamidino, alkylguanidino, dialkylguanidino, hydrazino, hydroxylamino, carboxylic acid and its derivatives, sulfonic acids and its derivatives, phosphoric acid and its derivatives; or two adjacent groups may form 'cyclic structures', for example, R1 and R2, R2 and R3, R5 and R6, R6, and R7, R7 and R8 together with the adjacent carbon atoms to which they are attached may form a 5, 6, or 7 membered ring, which may further optionally contain one or more double bonds and/or one or more heteroatoms such as the group 'Oxygen', 'Nitrogen' 'Sulfur' or 'Selenium' and combinations of double bond and heteroatoms; or R9 and R10 or R11 and R12 or R13 and R14 together represent double bond attached to 'Oxygen' or 'Sulfur'; or two adjacent groups may form 'cyclic structures' for example, R11 and R12, Ril and R13, R11 and R14, R13 and R14 together with the carbon atom/s to which they are attached may form a 3, 4, 5, or 6 membered ring, which may further optionally 10 contain one or more double bonds, and/or one or more heteroatoms such as the group 'Oxygen', 'Nitrogen', 'Sulfur' or 'Selenium' and also includes combination of one or more double bonds with 'heteroatoms', as above defined, R15 and R16 may be same or different and each independently represents hydrogen, substituted or unsubstituted groups selected from linear or branched (C1-C12)alkyl, (C2-C12)alkenyl, (C2-C12)alkynyl, (C3-C7)cycloalkyl, (C3-C7)cycloalkenyl, bicycloalkyl, bicycloalkenyl, aryl, aralkyl, heteroaryl, heterocyclylalkyl; optionally R15 and R16 along with the nitrogen atom may form a 3, 4, 5, 6 or 7 membered heterocyclic ring, which may further optionally contain one or more double bonds, and may include additional one or more heteroatoms such as the group 'Oxygen', 'Nitrogen', 'Sulfur' or 'Selenium' and also includes combination of one or more double bonds with 'heteroatoms', as above defined; 'n' ranges from 0 to 4, wherein the carbon chains which 'n' represents may be either linear or branched.

Description

BENZOTHIAZINO INDOLES

Field of Invention The present invention describes novel benzothiazinoindole derivatives, represented below as compounds with the general formula (I):

GENERAL FORMULA (I)

wherein R^ R₂, R₃, R₄, R5, Re, R7, Re, R9, R10, Ru, R12, 13 and R₁₄, may be same or different and each independently represent hydrogen, halogen, oxo, thio, perhaloalkyl, hydroxy, amino, nitro, cyano, formyl, amidino, guanidino, substituted or unsubstituted groups selected from linear or branched (C₁-C₁₂)alkyl, (C₂-C₁₂)alkenyl, (C₂-C₁₂)alkynyl (C₃-C₇)cycloalkyl, (C₃-C₇)cycloalkenyl, bicycloalkyl, bicycloalkenyl, (C-ι-C₁₂)alkoxy cycio(C₃-C₇)alkoxy, aryl, aryloxy, aralkyl, aralkoxy, heterocyclyl, heteroaryl heterocyclylalkyl, heteroaralkyl, heteroaryloxy, heteroaralkoxy, heterocyclylalkyloxy acyl, acyloxy, acylamino, monoalkylamino, dialkylamino, arylamino, diarylamino aralkylamino, alkoxycarbonyl, aryloxycarbonyl, aralkoxycarbonyl heterocyclylalkoxycarbonyl, heteroaryloxycarbonyl, hydroxyalkyl, aminoalkyl monoalkylaminoalkyl, dialkylaminoalkyl, alkoxyalkyl, aryloxyalkyl, aralkoxyalkyl alkylthio, thioalkyl, alkoxycarbonylamino, aryloxycarbonylamino aralkyloxycarbonylamino, aminocarbonylamino, alkylaminocarbonylamino dialkylaminocarbonylamino, alkylamidino, alkylguanidino, dialkylguanidino, hydrazino hydroxylamino, carboxylic acid and its derivatives, sulfonic acids and its derivatives phosphoric acid and its derivatives; or two adjacent groups may form "cyclic structures", for example, Ri and R₂, R₂ and R₃, R₅ and R₆, R₆ and R₇, R₇ and R₈ together with the adjacent carbon atoms to which they are attached may form a 5, 6, or 7 membered ring, which may further optionally contain one or more double bonds and/or one or more heteroatoms such as the group "Oxygen", "Nitrogen", "Sulfur" or "Selenium" and combinations of double bond and heteroatoms; or R₉ and R₁₀ or Ru and R₁₂ or R₁₃ and R₁₄ together represent double bond attached to "Oxygen" or "Sulfur"; or two adjacent groups may form "cyclic structures" for example, Ru and R₁₂, Rn and R₁₃, Ru and R₁₄, Rι₃ and R₁₄ together with the carbon atom/s to which they are attached may form a 3, 4, 5, or 6 membered ring, which may further optionally contain one or more double bonds, and/or one or more heteroatoms such as the group "Oxygen", "Nitrogen", "Sulfur" or "Selenium" and also includes combination of one or more double bonds with "heteroatoms", as above defined R₁₅ and R₁₆ may be same or different and each independently represents hydrogen, substituted or unsubstituted groups selected from linear or branched (C C₁₂)alkyl, (C₂-C₁₂)alkenyl, (C₂-C₁₂)alkynyl, (C₃-C₇)cycloalkyl, (C₃-C₇)cycloalkenyl, bicycloalkyl, bicycloalkenyl, aryl, aralkyl, heteroaryl, heterocyclylalkyl; optionally R ₅ and Ri₆ along with the nitrogen atom may form a 3, 4, 5, 6 or 7 membered heterocyclic ring, which may further optionally contain one or more double bonds, and may include additional one or more heteroatoms such as the group "Oxygen", "Nitrogen", "Sulfur" or "Selenium" and also includes combination of one or more double bonds with "heteroatoms", as above defined and "n" ranges from 0 to 4, wherein the carbon chains which "n" represents may be either linear or branched. The invention also envisages that certain tautomeric forms, stereoisomers, geometric forms, N-oxides, polymorphs, isotopically radiolabelled derivatives, salts, solvates, bio-active metabolites or any combination of above derivatives; may possess a beneficial physico-chemical, pharmacological characteristics having distinct major/minor advantageous over their corresponding compounds of general formulae (I), hence making them equally useful in either the therapy or experimental procedures (such as radioligand binding studies) as a substitute. The present invention also provides method to prepare the compounds of general formula (I), and their related derivatives such as salts. Other chemical derivatives, such as N-oxides, bio-active metabolites, isotopically radiolabelled compounds, pharmaceutically acceptable salts and pharmaceutically acceptable solvates, can be prepared according to the known literature. Whenever the chemistry of compound of formula (I) provides certain specialized derivatives such as tautomers, stereoisomers, geometric isomers and polymorphs, the compound can be prepared as a mixture containing variable proportions of individual compositions or individual compounds can be isolated. . There are variety of methods to administer the compounds of general formula (I), and such suitable pharmaceutically-acceptable dosage forms and the use of such compounds and compositions in either therapy or diagnosis also form the part of this invention.

Background of the Invention The compounds of this invention are useful in modulating the function of G- protein-coupled receptors (GPCRs). Majority of drugs exert their action by interacting with GPCRs which result into pharmacologically beneficial effect. The mode and general functioning of GPCR is well understood and can be found in the literature. (References : Bohm S. K., and et. al., Biochem. J. (1997), 322, 1 - 18; McConalogue, Karen, and NigelW. Bunnett, G-Protein-Coupled Receptors in Gastrointestinal Physiology. II. Regulation of neuropeptide receptors in enteric neurons. Am. J. Physiol. 274 (Gastrointest. Liver Physiol. 37): G792-G796, 1998.) The compounds of general formulae (i), are useful in treating neuropsychiatric diseases which involve receptors, modulated by ligands such as 5-HT (Serotonin), melatonin and dopamine, in order to obtain the desired therapeutic effect. International Patent Publications WO 04/000205, WO 04/000845, WO 04/000849, (Suven Lifesciences Limited) describes a few of related prior art. These PCT applications and the references reported therein are all incorporated herein. The compounds of general formula (I) are useful in treating the psychotic, affective, vegetative and psychomotor symptoms of schizophrenia and the extrapyramidal motor side effects of other antipsychotic drugs; neurodegenerative disorders like Alzheimer's disease, Parkinson's and Huntington's chorea and chemotherapy-induced vomiting; and in modulation of eating behavior and thus are useful in reducing the morbidity and mortality associated with excess weight. International Patent Publication WO 03/066056 A1 reports that antagonism of 5-HT₆ receptor could promote neuronal growth within the central nervous system of a mammal. Definition / Summary of the Invention The present invention describes novel benzothiazinoindole derivatives, represented below as compounds with the general formula (I):

GENERAL FORMULA (I)

The invention also includes certain tautomeric forms, stereoisomers, geometric forms, N-oxides, polymorphs, isotopically radiolabelled derivatives, biologically active metabolites, biologically active derivatives, pharmaceutically acceptable salts, pharmaceutically acceptable solvates or hydrates of the compounds or any combination of above derivatives; which may possess a beneficial physico-chemical, pharmacological characteristics having distinct major/minor advantageous over their corresponding compounds of general formulae (I), hence making them equally useful in either the therapy or experimental procedures (such as radioligand binding studies) as a substitute. The compounds of general formula (I) are defined as follows,

General Formula (I) wherein R-i, R₂, R₃, R₄, R₅, R₆, R_7, R₉, R₁₀, Ru, R₁₂, ι₃ and R₁₄, may be same or different and each independently represent hydrogen, halogen, oxo, thio, perhaloalkyl, hydroxy, amino, nitro, cyano, formyl, amidino, guanidino, substituted or unsubstituted groups selected from linear or branched (C_rC₁₂)alkyl, (C₂-C₁₂)alkenyl, <C₂-C₁₂)alkynyl, (C₃-C₇)cycloalkyl, (C₃-C₇)cycloalkenyl, bicycloalkyl, bicycloalkenyl, (C C₁₂)alkoxy cyclo(C₃-C₇)alkoxy, aryl, aryloxy, aralkyl, aralkoxy, heterocyclyl, heteroaryl heterocyclylalkyl, heteroaralkyl, heteroaryloxy, heteroaralkoxy, heterocyclylalkyloxy acyl, acyloxy, acylamino, monoalkylamino, dialkylamino, arylamino, diarylamino aralkylamino, alkoxycarbonyl, aryloxycarbonyl, aralkoxycarbonyl heterocyclylalkoxycarbonyl, heteroaryloxycarbonyl, hydroxyalkyl, aminoalkyl monoalkylaminoalkyl, dialkylaminoalkyl, alkoxyalkyl, aryloxyalkyl, aralkoxyalkyl alkylthio, thioalkyl, alkoxycarbonylamino, aryloxycarbonylamino aralkyloxycarbonylamino, aminocarbonylamino, alkylaminocarbonylamino dialkylaminocarbonylamino, alkylamidino, alkylguanidino, dialkylguanidino, hydrazino hydroxylamino, carboxylic acid and its derivatives, sulfonic acids and its derivatives phosphoric acid and its derivatives; or two adjacent groups may form "cyclic structures", for example, R₁ and R₂, R₂ and R₃, R₄ and R₅, R₅ and R₆, R₆ and R₇ together with the adjacent carbon atoms to which they are attached may form a 5, 6 or 7 membered ring, which may further optionally contain one or more double bonds and/or one or more heteroatoms such as the group "Oxygen", "Nitrogen", "Sulfur" or "Selenium" and combinations of double bond and heteroatoms; or R₉ and R₁₀ or Ru and R₁₂ or R₁₃ and Rι₄ together represent double bond attached to "Oxygen" or "Sulfur"; or two adjacent groups may form "cyclic structures" for example, R_g and R₁₀, Ru and Rι₂, Ru and R₁₃, Ru and R₁₄, R₁₃ and R₁₄ together with the carbon atom/s to which they are attached may form a 3, 4, 5, or 6 membered ring, which may further optionally contain one or more double bonds, and/or one or more heteroatoms such as the group "Oxygen", "Nitrogen", "Sulfur" or "Selenium" and also includes combination of one or more double bonds with "heteroatoms", as above defined. R-₁5 and R₁₆ may be same or different and each independently represents hydrogen, substituted or unsubstituted groups selected from linear or branched (C-r Cι₂)alkyl, (C₂-C₁₂)alkenyl, (C₂-C₁₂)alkynyl, (C₃-C₇)cycloalkyl, (C₃-C₇)cycloalkenyl, bicycloalkyl, bicycloalkenyl, aryl, aralkyl, heteroaryl, heterocyclylalkyl; optionally R₁₅ and R₁₆ along with the nitrogen atom may form a 3, 4, 5, 6 or 7 membered heterocyclic ring, which may further optionally contain one or more double bonds, and may include additional one or more heteroatoms such as the group "Oxygen", "Nitrogen", "Sulfur" or "Selenium" and also includes combination of one or more double bonds with "heteroatoms", as above defined. "n" ranges from 0 to 4, wherein the carbon chains which "n" represents may be either linear or branched. Partial list of such compounds represented by general formula (I) is as follows:

3-(N,N-Dimethylaminoethyl)-2,5-dimethyl-1 ,2-benzothiazino-[2,3,4-ab]indole-S,S- dioxide;

3-(N,N-Dimethylaminoethyl)-5-chloro-2-methyl-1 ,2-benzothiazino-[2,3,4-ab]indole-S,S- dioxide;

3-(N,N-Dimethylaminoethyl)-2-methyl-5-fluoro-1 ,2-benzothiazino-[2,3,4-ab]indole-S,S- dioxide;

3-(N,N-Dimethylaminoethyl)-2-methyl-5-methoxy-1 ,2-benzothiazino-[2,3,4-ab]indole-

S,S-dioxide; 3-(N,N-Dimethylaminoethyl)-2-methyl-8-methoxy-1 ,2-benzothiazino-[2,3,4-ab]indoIe-

S,S-dioxide;

3-(N,N-Dimethylaminoethyl)-2,5-dimethyl-8-methoxy-1 ,2-benzothiazino-[2,3,4- ab]indole-S,S-dioxide;

3-(N,N-Dimethylaminoethyl)-5-chloro-2-methyl-8-methoxy-1 ,2-benzothiazino-[2,3,4- ab]indole-S,S-dioxide;

3-(N,N-Dimethylaminoethyl)-2-methyl-5-fluoro-8-methoxy-1 ,2-benzothiazino-[2,3,4- ab]indole-S,S-dioxide;

3-(N,N-Dimethylaminoethyl)-2-methyl-5,8-dimethoxy-1 ,2-benzothiazino-[2,3,4- ab]indo!e-S,S-dioxide; 3-(N,N-Dimethylaminoethyl)-8-fIuoro-1,2-benzothia∑ino-[2,3,4-ab]indole-S,S-dioxide;

3-(N,N-Dimethylaminoethyl)-8-isopropyl-1 ,2-ben∑othia∑ino-[2,3,4-ab]indole-S,S- dioxide;

3-(N,N-Dimethylaminoethyl)-8-chloro-1 ,2-benzothiazino-[2,3,4-ab]indole-S,S-dioxide;

3-(N,N-Dimethylaminoethyl)-8-methyl-1 ,2-benzothiazino-[2,3,4-ab]indole-S,S-dioxide; 3-(N,N-Dimethylaminoethyl)-1 ,2-benzothiazino-[2,3,4-ab]indole-S,S-dioxide;

3-(N,N-DimethyIaminoethyl)-5-fluoro-8-methyl-1 ,2-benzothiazino-[2,3,4-ab3indole-S,S- dioxide; 3-(N,N-Dimethylaminoethyl)-5-chloro-8-fluoro-1 ,2-benzothiazino-[2,3,4-ab]indole-S,S- dioxide; 3-(N,N-Dimethylaminoethyl)-5-chloro-8-methyl-1 ,2-benzothiazino-[2,3,4-ab]indole-S,S- dioxide; 3-(N,N-Dimethylaminoethyl)-5,8-difluoro-1 ,2-benzothiazino-[2,3,4-ab]indole-S,S- dioxide; 3-(N,N-Dimethylaminoethyl)-5-fluoro-1 ,2-benzothiazino-[2,3,4-ab]indole-S,S-dioxide; 3-(N,N-Dimethylaminoethyl)-8-methoxy-2-benzothiazino-[2,3,4-ab]indole-S,S-dioxide; 3-(N,N-Dimethylaminoethyl)-5-fluoro-8-methoxy-1 ,2-benzothiazino-[2,3,4-ab]indole- S,S-dioxide;

3-(N,N-Dimethylaminoethyl)-5-fluoro-8-chloro-1 ,2-benzothiazino-[2,3,4-ab]indole-S,S- dioxide;

3-(N,N-Dimethylaminoethyl)-5-methyl-8-fluoro-1,2-benzothiazino-[2,3,4-ab]indole-S,S- dioxide;

3-(N,N-Dimethylaminoethyl)-5-methyl-1 ,2-benzothiazino-[2,3,4-ab]indole-S,S-dioxide;

3-(N,N-Dimethylaminoethyl)-5,8-dimethyl-1 ,2-benzothiazino-[2,3,4-ab]indole-S,S- dioxide;

3-(N,N-Dimethylaminoethyl)-5-methyl-8-methoxy-2-benzothiazino-[2,3,4-ab]indole-S,S- dioxide;

3-(N,N-Dimethylaminoethyl)-5,8-dichloro-2-benzothiazino-[2,3,4-ab]indole-S,S-dioxide;

3-(N,N-Dimethylaminoethyl)-5-fluoro-9,10-dichloro-2-benzothiazino-[2,3,4-ab]indole-

S,S-dioxide;

3-(N,N-Dimethylaminoethyl)-5,9,10-trichloro-2-benzothiazino-[2,3,4-ab]indole-S,S- dioxide;

3-(N,N-Dimethylaminoethyl)-5-chloro-2-benzothiazino-[2,3,4-ab]indole-S,S-dioxide;

3-(N,N-Dimethylaminoethyl)-9,10-dichloro-2-benzothiazino-[2,3,4-ab] indole-S,S- dioxide;

3-(N,N-Dimethylaminoethyl)-5-chloro-8-methoxy-2-benzothiazino-[2,3,4-ab]indole-S,S- dioxide;

3-(N,N-Dimethylaminoethyl)-5-methyl-8-isopropyl-2-benzothiazino-[2,3,4-ab]indole-

S,S-dioxide; 3-(N,N-Dimethylaminoethyl)-5-fluoro-8-isopropyl-2-benzothiazino-[2,3,4-ab]indole-S,S- dioxide; 3-(N,N-Dimethylaminoethyl)-8,10-difluoro-2-benzothiazino-[2,3,4-ab] indole-S,S- dioxide; 3-(N,N-Dimethylaminoethyl)-5,8,10-trifluoro-2-benzothiazino-{2,3,4-ab]indole-S,S- dioxide; 3-(N,N-Dimethylaminoethyl)-5-methyl-9,10-dichloro-2-benzothiazino-[2,3,4-ab]indole- S,S-dioxide; 3-(N,N-Dimethylaminoethyl)-5-methoxy-2-benzothiazino-[2,3,4-ab] indole-S,S-dioxide; 3-(N,N-Dimethylaminoethyl)-6-methoxy-2-benzothiazino-[2,3,4-ab] indole-S,S-dioxide; 3-(N,N-Dimethylaminoethyi)-5,8-methoxy-2-benzothiazino-{2,3,4-ab] indole-S,S- dioxide; 3-(N,N-Dimethylaminoethyl)-5-methoxy-8-chloro-2-benzothiazino-{2,3,4-ab]lndole-S,S- dioxide; 3-(N,N-Dimethylaminoethyl)-5-methoxy-8-fluoro-2-benzothiazino-[2,3,4-ab]indole-S,S- dioxide;

3-(N,N-Dimethylaminoethyl)-5-methoxy-8-bromo-2-benzothiazino-[2,3,4-ab]indole-S,S- dioxide; 3-(N,N-Dimethylaminoethyl)-5-methoxy-8-methyl-2-benzothiazino-[2,3,4-ab]indole-S,S- dioxide;

3-(N,N-Dimethylaminoethyl)-5-methoxy-8-isopropyl-2-benzothiazino-[2,3,4-ab]indole-

S,S-dioxide;

3-(2-N,N-Dimethylaminopropyl)-5-methoxy-2-benzothiazino-[2,3,4-ab]indole-S,S- dioxide;

3-(2-N,N-Dimethylaminopropyl)-6-methoxy-2-benzothiazino-[2,3,4-ab]indole-S,S- dioxide;

3-(2-N,N-Dimethylaminopropyl)-5,8-methoxy-2-benzothiazino-[2,3,4-ab]indole-S,S- dioxide; 3-(2-N,N-Dimethylaminopropyl)-5-methoxy-8-chloro-2-benzothiazino-[2,3,4-ab]indole-

S,S-dioxide;

3-(2-N,N-Dimethylaminopropyl)-5-methoxy-8-fluoro-2-benzothiazino-[2,3,4-ab]indole-

S,S-dioxide;

3-(2-N,N-Dimethylaminopropyl)-5-methoxy-8-bromo-2-benzothiazino-[2,3,4-ab]indole- S,S-dioxide;

3-(2-N,N-Dimethylaminopropyl)-5-methoxy-8-methyl-2-benzothiazino-[2,3,4-ab]indole-

S,S-dioxide;

3-(2-N,N-Dimethylaminopropyl)-5-methoxy-8-isopropyl-2-benzothiazino-[2,3,4-ab] indole-S,S-dioxide; 3-(N,N-Dimethylaminoethyl)-5-chloro-8,10-difluoro-2-benzothiazino-[2,3,4-ab]indole- S,S-dioxide; 3-(N,N-Dimethylaminoethyl)-5-methyl-8-chloro-2-benzothiazino-[2,3,4-ab]indole-S,S- dioxide; 3-(N,N-Dimethylaminoethyl)-5-chloro-8-isopropyl-2-benzothiazino-[2,3,4-ab]indole-S,S- dioxide; 3-(N,N-Dimethylaminoethyl)-5-methyl-8,10-difluoro-2-benzothiazino-[2,3,4-ab]indole- S,S-dioxide; 3-(N,N-Dimethylaminoethyl)-7-trifluoromethyl-10-chloro-2-benzothiazino-[2,3,4- ab]indole-S,S-dioxide; 3-(N,N-Dimethylaminoethyl)-5-fluoro-7-trifluoromethyl-10-chloro-2-benzothiazino- [2,3,4-ab]indole-S,S-dioxide; 3-(N,N-Dimethylaminoethyl)-5,10-dichloro-7-trifluoromethyl-2-benzothiazino-[2,3,4- abjindole-S,S-dioxide;

3-(N,N-Dimethylaminoethyl)-5-chloro-9-trifluoromethyl-2-benzothiazino-[2,3,4- ab]indole-S,S-dioxide and 3-(N,N-Dimethylaminoethyl)-9-trifluoromethyl-2-benzothiazino-[2,3,4-ab]indole-S,S- dioxide and includes, tautomeric forms, stereoisomers, geometric forms, N-oxides, polymorphs, isotopically radiolabelled derivatives, biologically active metabolites, biologically active derivatives, pharmaceutically acceptable salt, pharmaceutically acceptable solvate or hydrate of the compound or any combination of above derivatives. The present invention also provides method to prepare the compounds of general formula (I), and their related derivatives for example, salts, solvates. Other chemical derivatives, such as pharmaceutically acceptable salts, pharmaceutically acceptable solvates, N-oxides, bio-active metabolites, isotopically radiolabelled compounds and can be prepared according to the known literature. Whenever the chemistry of compound of formula (I) provides certain specialized derivatives such as tautomers, stereoisomers, geometric isomers and polymorphs, the compound can be prepared as a mixture containing variable proportions of individual compounds or individual compounds can be isolated. Suitable pharmaceutically acceptable acid addition salts of compounds- of the general formula (I) can be prepared of the aforementioned base compounds of this invention are those which form non-toxic acid addition salts, includes, salts containing pharmacologically acceptable anions, such as the hydrochloride, hydrobromide, hydroiodide, nitrate, sulfate, bisulfate, phosphate, acid phosphate, acetate, lactate, citrate, acid citrate, tartrate, bitartrate, succinate, maleate, fumarate, gluconate, saccharate, benzoate, methanesulfonate, ethanesulfonate, benezenesulfonate, p- tolunesulfonate, palmoate and oxalate. Pharmaceutically acceptable salts forming part of this invention are intended to define but not limited to the above list. Suitable pharmaceutically acceptable base addition salts of compounds of the general formula (I) can be prepared of the aforementioned acid compounds of this invention are those which form non-toxic base addition salts, includes, salts containing pharmaceutically acceptable cations, such as Lithium, sodium, potassium, calcium and magnesium, salts of organic bases such as lysine, arginine, guanidine, diethanolamine, choline, tromethamine and the like; ammonium or substituted ammonium salts.- ■ Pharmaceutically acceptable salts forming part of this invention are intended to define but not limited to the above list. In addition, pharmaceutically acceptable salts of the compound of general formula (I) can be obtained by converting derivatives which have tertiary amino groups into the corresponding quarternary ammonium salts in the methods known in the literature by using quarternizing agents. Possible quarternizing agents are, for example, alkyl halides such as methyl iodide, ethyl bromide and n-propyl chloride, including arylalkyl halides such as benzyl chloride or 2-phenylethyl bromide. In the addition to pharmaceutically acceptable salts, other salts are included in the invention. They may serve as intermediates in the purification of the compounds, in the preparation of other salts, or in the identification and characterization of the compounds or intermediates. The pharmaceutically acceptable salts of compounds of formula (I) may exist as solvates, such as with water, methanol, ethanol, dimethylformamide, ethyl acetate, and the like. Mixtures of such solvates can also be prepared. The source of such solvate can be from the solvent of crystallization, inherent in the solvent preparation or crystallization, or adventitious to such solvent. Such solvates are within the scope of this invention. The present invention also relates to radio-labeled isotopes, which are identical to those defined in the general formula (I) but for the fact that one or more atoms are replaced by an atom having an atomic mass or mass number different from the atomic mass or mass number found usually in nature. Examples of isotopes that can be incorporated into compounds of the invention include isotopes of hydrogen, carbon, nitrogen, oxygen, phosphorus, fluorine, chlorine, iodine, bromine and mTecnitium, exemplified by ²H, ³H, ¹¹C, ¹³C, ¹⁴C, ¹³N, ¹⁵N, ¹⁵0, ¹⁸F, ^99mTc, ³¹P, S, ¹²³l and ¹²⁵l. Those compounds of general formula (I) as described earlier containing the aforementioned isotopes and/or other isotopes of other atoms are within the scope of this invention. The term "nitrogen oxide" or "N-oxide" refers to the oxidation of at least one of the two nitrogens in the compounds of general formula (I), (e.g., mono- or di-oxide). The nitrogen mono-oxides may exist as a single positional isomer, a mixture of 2° positional isomers or oxide of aromatic nitrogen. In the case of the compounds of general formula (I) where tautomerism may exist, the present invention relates to all of the possible tautomeric forms and the possible mixture thereof. The stereoisomers as a rule are generally obtained as racemates that can be separated into the optically active isomers in a manner known per se. In the case of the compounds of general formula (I) having an asymmetric carbon atom the present invention relates to the D-form, the L-form and D,L- mixture's and in the case of a number of asymmetric carbon atoms, the diastereomeric forms and the invention extends to each of these stereoisomeric forms and to mixtures thereof including racemates. Those compounds of general formula (I) which have an asymmetric carbon and as a rule are obtained as racemates can be separated one from the other by the usual methods, or any given isomer may be obtained by stereospecific or asymmetric synthesis. However, it is also possible to employ an optically active compound from the start, a correspondingly optically active or diastereomeric compound then being obtained as the final compound. In the case of the compounds of general formula (I) containing geometric isomerism the present invention relates to all of these geometric isomers. The method to identify and prepare polymorph/s of the compounds of general formula (I) involve multiple approaches and are discussed elsewhere. During the preclinical / clinical studies it is possible to identify and fully characterize a biologically active metabolite of the compound of general formula (I). Such compounds wherever they are not part of the compounds of general formulae (I), yet would be considered part of this invention. Dependi ng upon the chemical structure and its chemistry, it is possible to prepare such "bio-actr ve" compounds in a laboratory, Similarly, when needed, a "biological derivatr ve" of compounds of general formula (I) would be synthesized in order to improve the therapeutic effect and/or ease of administration of such compounds. These derivatives have distinct advantages over their counter-parts, such as a different pharmacokinetic profile than the parent, enabling easier absorption across the mucosal epithelium, better salt formation, or solubility, and/or improved systemic stability (an increase in the plasma half-life, for example). These biological derivatives whenever are not coming under the definition of compounds of general formula (I) will form the part of this invention. Generally these biological derivatives would be for example, 1. Ester or amide derivatives which may be cleaved by esterases or lipases; _ 2. Peptides which may be recognized by specific or nop-specific proteases; 3. N-glycosyl or O-glycosyl derivatives; 4. Derivatives that accumulate at a site of action through membrane selection of a prodrug from or a modified prodrug form; or 5. PEG (polyethylene giycol) is covalently bonded to the compound of formula (I); 6. any combination of 1 to 5, above. A "biological derivative" is a drug which has been chemically modified and may be in-active as such in-vitro or at the site of action, but which lϊpon degradtion in body via chemical or enzymatic means or as such (in case of PEG) may give beneficial effect. One such reference is H. Bundgard, Design of prodrugs, (1985). Another aspect of the present invention comprises of a pharmaceutical composition, containing at least one of the compounds of general formula (I) as defined earlier elsewhere in the specification or a derivatives such as salt, solvate, pharmaceutically acceptable salts, pharmaceutically acceptable solvates, N-oxides, bio-active metabolites, isotopically radiolabelled compound, tautomers, stereoisomers, geometric isomers, polymorphs; either in pure or impure forms forming an active ingredient, together with pharmaceutically employed carriers, auxiliaries and the like. An effective amount of a compound of general formula (I), or their derivatives as defined above can be used to produce a medicament, along with conventional pharmaceutical auxiliaries, carriers and additives. Such pharmaceutically acceptable compositions containing compounds of formula (I) form the part of this invention. The use of compounds and compositions defined are useful in therapy and are the part of this invention. The compounds of general formula (I) of this invention are useful in the treatment and/ or prophylaxis of a condition wherein modulation of 5-HT activity is desired. The compounds of general formula (I) of this invention are useful in the treatment and/ or prophylaxis of a condition wherein modulation of melatonin activity is desired. The compounds of general formula (I) of this invention are useful in the treatment and/ or prophylaxis of a condition wherein modulation of 5-HT and / or melatonin activities gives desired effect. The present invention provides the compounds of general formula (I), to prepare the medicaments useful in the treatment and/ or prophylaxis of certain disorders such as psychosis, paraphrenia, anxiety, depression, mania, schizophrenia, schizophreniform disorders, migraine headache, drug addiction, convulsive disorders, personality disorders, hypertension, autism, post-traumatic stress syndrome, alcoholism, panic attacks, obsessive-compulsive disorders, chronobiological abnormalities and circadian rhythms, cognitive memory disorders e.g. Alzheimer's disease and age-related cognitive decline, ADHD (Attention Deficient Disorder/ Hyperactivity Syndrome), amylotrophic lateral sclerosis, withdrawal from drug abuse such as cocaine, ethanol, nicotine and benzodiazepines, panic attacks, and also disorders associated with spinal trauma and / or head injury s^*uch as hydrocephalus. Other conditions where there are low endogenous melatonin levels benefits may be obtained in cases of osteoporosis, ischemic stroke, SIDS in young infants, reproduction, glaucoma and sleep disorders. Compounds of this invention are expected to be of use in the treatment of mild cognitive impairment and other neurodegenerative disorders like Alzheimer's disease, Parkinsonism and Huntington's chorea. The compounds of this invention could be of use in the treatment of certain Gl (Gastrointestinal) disorders such as IBS (Irritable bowel syndrome) or chemotherapy induced emesis. Also these compounds can help in modulation of eating behavior and thereby reduce morbidity and mortality associated with the excess weight. The present invention provides a method for the treatment of a human or a animal subject suffering from disorders such as, anxiety, depression, convulsive disorders, obsessive-compulsive disorders, migraine headache, cognitive memory disorders e.g. Alzheimer's disease and age-related cognitive decline, ADHD (Attention Deficient Hyperactivity Disorder), personality disorders, psychosis, paraphrenia, psychotic depression, mania, schizophrenia, schizophreniform disorders, withdrawal from drug abuse such as cocaine, ethanol, nicotine and benzodiazepines, panic attacks, chronobiological abnormalities, circadian rhythms, anxiolytic, osteoporosis, ischemic stroke, lower the risk of SIDS in young infants with low endogenous melatonin levels, reproduction, glaucoma, sleep disorders (including disturbances of Circadian rhythm) and also disorders associated with spinal trauma and /or head injury such as hydrocephalus. Compounds of the invention are further expected to be of use in the treatment of mild cognitive impairment and other neurodegenerative disorders like Alzheimer's disease, Parkinsonism and Huntington's chorea. Compounds of the present invention may be administered in combination with other pharmaceutical agents, such as apo-B/MTP inhibitors, MCR-4 agonists, CCK-A agonists, monoamine reuptake inhibitors, sympathomimetic agents, adrenergic receptor agonists, dopamine agonists, melanocyte-stimulating hormone receptor analogs, cannabinoid 1 receptor antagonists, melanin concentrating hormone antagonists, leptins, leptin analogs, leptin receptor agonists, galanin antagonists, lipase inhibitors, bombesin agonists, neuropeptide-Y antagonists, thyromimetic agents, dehydroepiandrosterone or analogs thereof, glucocortioord ^"receptor ^"agonists ^" or^" antagonists, orexin receptor antagonists, urocortin binding protein antagonists, glucagon-like peptide-1 receptor agonists, ciliary neurotrophic factors, AGRPs (human agouti-related proteins), ghrelin receptor antagonists, histamine" 3 receptor antagonists or reverse agonists, neuromedin U receptor agonists, and the like, in a therapeutically effective amount via a suitable, pharmaceutical composition, to achieve the desired effect in mammals as well as humans. Such therapy includes multiple choices: for example, administering two compatible compounds simultaneously in a single dosage form or administering each compound individually in a separate dosage; or if required at some time interval or separately in order to maximize the beneficial effect or minimize the potential side- effects of the drugs according to the known principles of pharmacology. The phrase "pharmaceutically acceptable" indicates that the substance or composition must be compatible chemically and/or toxicologically, with the other ingredients comprising a formulation, and/or the mammal being treated therewith. The terms "treating", "treat", or "treatment" embrace all the meanings such as preventative, prophylactic and palliative. The term "compounds of the present invention" (unless specifically identified otherwise) refer to compounds of Formulae (I), nitrogen oxides thereof, prodrugs of the compounds or nitrogen oxides, pharmaceutically acceptable salts of the compounds, nitrogen oxides, and/or prodrugs, and hydrates or solvates of the compounds, nitrogen oxides, salts, is and/or prodrugs, as well as, all stereoisomers (including diastereoisomers and enantiomers), tautomers and isotopically labeled compounds. Detailed Description of the Invention The present invention relates to compounds of general formula (I), are described in the summary above. Suitable groups represented by Ri, R₂, R₃, R , R5, Re, R7, R9, R10, u, R12, R13 and R-₁₄ wherever applicable may be selected from halogen atom such as fluorine, chlorine, bromine or iodine; perhaloalkyl particularly

such as fluoromethyl, difluoromethyl, trifluoromethyl, trifluoroethyl, fluoroethyl, difluoroethyl and the like; substituted or unsubstituted

group, especially, linear or branched (C₁-C₈)alkyl group, such as methyl, ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl, t-butyl, n-pentyl, iso-pentyl, hexyl, iso-hexyl, heptyl, octyl and the like; substituted or unsubstituted (C₂-Cι₂)alkenyl group such as ethylene, n-propylene pentenyl, hexenyl, heptynyl, heptadienyl and the like; (C₂-C₁₂)alkynyl substituted or unsubstituted (C₂- Cι₂)alkynyl group such as acetylene and the like; cyclo(C₃-C₇)alkyl group such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, the cycloalkyl group may be substituted; cyclo(C₃-C₇)alkenyl group such as cyclopentenyl, cyclohexenyl, cycloheptynyl, cycloheptadienyl, cycloheptatrienyl and the like, the cycloalkenyl group may be substituted; (CrC₁₂)alkoxy, especially, (C₁-C₆)alkoxy gYoup such as methoxy, ethoxy, propyloxy, butyloxy, iso-propyloxy and the like, which may be substituted; cyclo(C₃-C₇) alkoxy group such as cyclopropyloxy, cyclobutyloxy, cyclopentyloxy, cyclohexyloxy, cycloheptyloxy and the like, the cycloalkoxy group may be substituted; aryl group such as phenyl or naphthyl, the aryl group may be substituted; aralkyl group such as benzyl, phenethyl, C₆H₅CH₂CH₂CH₂, naphthylmethyl and the like, the aralkyl group may be substituted and the substituted aralkyl is a group such as CH₃C₆H₄CH₂, Hal-C₆H₄CH₂, CH₃OC₆H₄CH₂, CH₃OC₆H₄CH₂CH₂ and the like; aralkoxy group such as benzyloxy, phenethyloxy, naphthylmethyloxy, phenylpropyloxy and the like, the aralkoxy group may be substituted; heterocyclyl groups such as aziridinyl, pyrrolidinyl, morpholinyl, piperidinyl, piperazinyl and the like, the heterocyclyl group may be substituted; heteroaryl group such as pyridyl, thienyl, furyl, pyrrolyl, oxazolyl, imidazolyl, oxadiazolyl, tetrazolyl, benzopyranyl, benzofuranyl and the like, the heteroaryl group may be substituted; heterocyclo(Cι-C₆)alkyl, such as pyrrolidinylalkyl, piperidinylalkyl, morpholinylalkyl, thiomorpholinylalkyl, oxazolinylalkyl and the like, the heterocyclo(C₁-C₆)alkyl group may be substituted; heteroaralkyl group such as furanylmethyl, pyridinylmethyl, oxa∑olylmethyl, oxazolylethyl and the like, the heteroaralkyl group may be substituted; heteroaryloxy, heteroaralkoxy, heterocycloalkoxy, wherein heteroaryl, heteroaralkyl, heterocycloalkyl and heterocyclylalkyl moieties are as defined earlier and may be substituted; acyl groups such as acetyl, propionyl or benzoyl, the acyl group may be substituted; acyloxy group such as CH₃COO, CH₃CH₂COO, C₆H₅COO and the like which may optionally be substituted, acylamino group such as CH₃CONH, CH₃CH₂CONH, C₃H₇CONH, C₆H₅CONH which may be substituted, (C C₆)monoalkylamino group such as CH₃NH, C₂H₅NH, C₃H₇NH, C₆H₁₃NH and the like, which may be substituted, (C C₆)dialkylamino group such as N(CH₃)₂, CH₃(C₂H₅)N and the like, which may be substituted; arylamino group such as C₆H₅NH,

C₆H₄(CH₃)NH, NH-C₆H - Hal and the like, which may be substituted; arylalkylamino group such as C₆H₅CH₂NH, C₆H₅CH₂CH₂NH, C₆H₅CH₂NCH₃ and the like, which may be substituted; hydroxy(C C₆)alkyl which may be substituted, amino(C₁-C₆)alkyl which may be substituted; mono(C₁-C₆)alkylamino(C₁-C₆)alkyl, di(C₁-C₆)alkylamino(C₁-C₆)alkyl group which may be substituted, alkoxyalkyl group such as methoxymethyl, ethoxymethyl, methoxyethyl, ethoxyethyl and the like, which may be substituted; aryloxyalkyl group such as C₆H₅OCH₂, C₆HsOCH₂C-H₂, naphthyloxymethyl and the Hike, which- may-be substituted;- aralkoxyalkyl group such as C₆H₅CH₂OCH₂, C₆H₅CH₂θCH₂CH₂ and the like, which may be substituted; (C C₆)alkylthio, thio(CrC₆)alkyl which may be substituted alkoxycarbonylamino group such as C₂H₅OCONH, CH₃OCONH and the like which may be substituted; aryloxycarbonylamino group as C₆H₅OCONH, C₆H₅OCONCH₃ C₆H₅OCONC₂H₅, C₆H₄CH₃OCONH, C₆H₄(OCH₃)OCONH and the like which may be substituted; aralkoxycarbonylamino group such C₆H₅CH₂OCONH

C₆H₅CH₂CH₂OCONH, C₆H₅CH₂OCON(CH₃), C₆H₅CH₂OCON(C₂H₅)

C₆H₄CH₃CH₂OCONH, C₆H₄OCH₃CH₂OCONH and the like, which may be substituted aminocarbonylamino group; (Cι-C₆)alkylaminocarbonylamino group, di(C C₆)alkylaminocarbonylamino group; (CrC₆)alkylamidino group, (C₁-C₆)alkylguanidino di(Cι-C₆)alkylguanidino groups, hydrazino and hydroxylamino groups; carboxylic acid or its derivatives such as amides, like CONH₂, alkylaminocarbonyl like CH₃NHCO (CH₃)₂NCO, C₂H₅NHCO, (C₂H₅)₂NCO, arylaminocarbonyl like PhNHCO NapthylNHCO and the like, aralkylaminocarbonyl such as PhCH₂NHCO PhCH₂CH₂NHCO and the like, heteroarylaminocarbonyl and heteroaralkylamino carbonyl groups where the heteroaryl groups are as defined earlier heterocyclylaminocarbonyl where the heterocyclyl group is as defined earlier carboxylic acid derivatives such as esters, wherein the ester moieties are alkoxycarbonyl groups such as unsubstituted or substituted phenoxycarbonyl naphthyloxycarbonyl and the like; aralkoxycarbonyl group such as benzyloxycarbonyl phenethyloxycarbonyl, naphthylmethoxycarbonyl and the like, heteroaryloxycarbonyl heteroaralkoxycarbonyl, wherein the heteroaryl group is as defined earlier heterocycloxycarbonyl where heterocycle is as defined earlier and these carboxylic acid derivatives may be substituted; sulfonic acid or its derivatives such as S0₂NH₂, S0₂NHCH₃, S0₂N(CH₃)₂, S0₂NHCF₃, S0₂NHCO(C C₆)alkyl, S0₂NHCOaryl where the aryl group is as defined earlier and the sulfonic acid derivatives may be substituted; phosphoric acid and its derivatives as P(0)(OH)₂, P(0)(OCrC₆-alkyl)₂, P(0)(0-aryl)₂ and the like. Suitable "cyclic structures" formed by the two adjacent groups like for example, R_T and R₂, R₂ and R₃, R₄ and R₅, R₅ and R₆, R₆ and R₇, R₉ and R₁₀, Ru and R₁₂, R-n .and R₁₃, R^ and R₁₄, R₁₃ and R₁₄ together with the adjacent carbon atoms to which they are attached contain 3, 4, 5, 6 or 7 ring atoms as defined earlier, which may optionally contain one or more heteroatoms selected from oxygen, nitrogen or sulfur and optionally contain one or more double bonds and optionally contain combination of double bond and hetero atoms as described earlier. The cyclic structures may be optionally substituted phenyl, naphthyl, pyridyl, furanyl, thienyl, pyrrolyl, imidazolyl, pyrimidinyl, pyrazinyl and the like. Suitable substituents on the 'cyclic structures' as defined above includes hydroxy, halogen atom such as chlorine, bromine and iodine; nitro, cyano, amino, formyl, <CrC₃)alkyl, (C C^alkoxy, thioalkyl, alkylthio, phenyl or benzyl groups. R₁₅ and R₁₆ preferably represents hydrogen, substituted or unsubstituted linear or branched (Cι-C₁₂)alkyl. like methyl, ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl, pentyl, hexyl, octyl and the like; aryl group such as phenyl or naphthyl, the aryl group may be substituted; cyclo(C₃-C₇)alkyl group such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, the cycloalkyl group may be substituted; the aralkyl group may be substituted and the substituted aralkyl is a group such as CH₃C₆H₄CH₂, Hal-C₆H₄CH₂, CH₃OC₆H₄CH₂, CH₃OC₆H₄CH₂CH₂ and the like; (C₃- C₇)cycloheteroalkyl with heteratoms like "Oxygen", "Nitrogen", "Sulfur" or "Selenium" optionally containing one or two double or triple bonds. Suitable hetero cyclic rings formed between Rι₅ and Rι₆ along with "Nitrogen atom" be such as pyrrolyl, pyrrolidinyl, piperidinyl, pyridinyl, 1 ,2,3,4-Tetrahydro- pyridinyl, imidazolyl, pyrimidinyl, pyrazinyl, piperazinyl, diazolinyl and the like; the heterocyclyl group may be substituted; heteroaryl group such as pyridyl, imidazolyl, tetrazolyl and the like, the heteroaryl group may be substituted; heterocyclo(d- C₆)alkyl, such as pyrrolidinealkyl, piperidinealkyl, morpholinealkyl, thiomorpholinealkyl, oxazolinealkyl and the like, the heterocyclo(Cι-C₆)alkyl group may be substituted; heteroaralkyl group such as furanmethyl, pyridinemethyl, oxazolemethyl, oxazolethyl and the like, the heteroaralkyl group may be substituted; heteroaryloxy, heteroaralkoxy, heterocycloalkoxy, wherein heteroaryl, heteroaralkyl, heterocycloalkyl and heterocyclylalkyl moieties are as defined earlier and may be further substituted. Compounds of general formula (I) can be prepared by any of the methods described below. The present invention also provides processes for preparing compounds of general formula (I) as defined above, including salts, solvates, pharmaceutically acceptable salts and pharmaceutically acceptable solvates. In the following description and reaction schemes R_{1 ?} R₂, R₃, R , R₅, Re, R₇, R₉, Rio, Ru, R₁₂, Rι₃, Ru, i5, R-_I6 and n are as defined previously for the compounds of general formula (I). The . method to synthesize tryptamines, 3- substitutedindolylalkylamines is very well described in the literature.

Scheme - 1 : Compounds of general formula (I), may be prepared by cyclizing a compound of formula (II) given below,

wherein X is halogen such chloro, bromo or iodo, Ri, R₂, R₃, R₄, R₅, R₆, R₇, R₃, R₉, R₁₀, Ru, R₁₂, Rι₃, R₁₄ Ri5, Rι₆ and "n" are as defined previously, using a Pd(0) or Pd (II) derivative as a catalyst, for example tetrakis triphenylphosphine palladium, (Bis-tri- o-tolylphosphine) palladium(ll) chloride and the like; and thereafter if necessary: i) converting a compound of the formula (I) into another compound of the formula (I); and/or ii) removing any protecting groups; and/or iii) forming a pharmaceutically acceptable salt, solvate, polymorph or prodrug thereof. This cyclization reaction can be achieved using variety of palladium catalysts. The reaction may be affected in the presence of a base such as CH₃COOK. This reaction may be carried out in the presence of solvents such as THF, DMF, DMSO, DMA, DME, acetone and the like and preferably using Dimethylacetamide. The inert atmosphere may be maintained by using inert gases such as N₂, Ar or He. The reaction temperature may range from 50 °C to 200 °C based on the choice of solvent and preferably at a temperature of 160 °C. The duration of the reaction may range from 1 to 24 hours, preferably from 10 to 20 hours.

Scheme - 2 : Compounds of general formula (I), may be prepared by reacting a compound of formula (III) given below,

(ill) wherein R^ R₂, R₃, R₄, R₅, R₆, R₇, Re, R₉, R_10l Ru, ι₂, Rι₃, R_M and "n" are as defined previously, with a suitable alkylating agent such as R₁₅ X or R₁₆ X or XR₁₅R₁₆X in successive steps or in one step, wherein X is good leaving group such as^* halogen and the like. The reaction is preferably carried in an organic solvent inert to the conditions of the reaction, such as acetone, THF or DMF and the like or mixtures thereof. The inert atmosphere may be maintained by using inert gases such as N₂, Ar or He. The reaction may be affected in the presence of a base such as K₂C0₃, Na₂C0₃, TEA or mixtures thereof. The reaction temperature may range from 20 °C to 200 °C based on the solvent employed and preferably at a temperature in the range from 30 °C to 150 °C. The duration of the reaction may range from 1 to 24 hours, preferably from 2 to 6 hours.

Scheme - 3 : Compounds of general formula (I), may be prepared by reacting a compound of formula (IV) given below,

wherein R^ R₂, R₃, R , R₅, R₆, R₇ and R₈ are as defined previously, with formaldehyde and a compound of formula (V) given below,

(V) wherein R₁₅ and R₁₆ are as defined earlier. The above reaction is preferably carried out at a temperature of 50 °C to 150 °C. The formaldehyde can be in the form of as aqueous solution i.e. 40 % formalin solution, or a polymeric form of formaldehyde such as paraformaldehyde or trioxymethylene. When such polymeric forms are used, a molar excess of mineral acid, for example hydrochloric acid, is added to regenerate the free aldehyde from the polymer. The reaction is preferably carried in an organic solvent inert to the conditions of the reaction, such as methanol, ethanol or 3-methylbutanol and the like or a mixture thereof, and preferably using either acetone or DMF. The inert atmosphere may be maintained by using inert gases such as N₂, Ar or He. The reaction temperature may range from 20 °C to 150 °C based on the choice of solvent and preferably at a temperature in the range from 30 °C to 100 °C. The duration of the reaction may range from 1 to 24 hours, preferably from 2 to 6 hours.

Scheme - 4 : The pharmaceutically acceptable salts forming a part of this invention may be prepared by treating the compound of formula (I) with 1-6 equivalents of a base such as Lithium, ammonia, substituted ammonia, sodium hydride, sodium methoxide, sodium ethoxide, sodium hydroxide, potassium t-butoxide, calcium hydroxide, calcium acetate, calcium chloride, magnesium hydroxide, magnesium chloride and the like. Solvents such as water, acetone, ether, THF, methanol, ethanol, t-butanol, dioxane, isopropanol, isopropyl ether or mixtures thereof may be used. Organic bases such lysine, arginine, methyl benzylamine, ethanolamine, diethanolamine, tromethamine, choline, guanidine and their derivatives may be used. Acid addition salts, wherever applicable may be prepared by treatment with acids such as tarta c acid, mandelic acid, fumaric acid,^" maleic acid, lactic acid, salicyclic acid, citric acid, ascorbic acid, benzene sulfonic acid, p-toluene sulfonic acid, hydroxynaphthoic acid, methane sulfonic acid, malic acid, acetic acid, benzoic acid, succinic acid, palmitic acid, oxalic acid, hydrochloric acid, hydrobromic acid, sulfuhc acid, nitric acid and the like in solvents such as water, alcohols, ethers, ethyl acetate, dioxane, DMF or a lower alkyl ketone such as acetone, or the mixtures thereof. During any of the above synthetic sequences it may be necessary and/or desirable to protect sensitive or reactive groups on any of the molecules concerned. This may be achieved by means of conventional protecting groups, such as those described in Protective Groups in Organic Chemistry, Ed J. F. W. McOmie, Plenum Press, 1973; and T. W. Greene & P. G. M. Wuts Protective Groups in Organic Synthesis, John Wiley & Sons, 1991. For example, suitable protecting groups for the piperazine group include BOC, COCCI₃, COCF₃. The protecting groups may be removed according to the standard procedures. The protecting groups may be removed at a convenient subsequent stage using methods known from the art. The stereoisomers of the compounds of the present invention may be prepared by one or more ways presented below: i) One or more of the reagents may be used in their optically active form, ii) Optically pure catalyst or chiral ligands along with . metal catalyst may be employed in the reduction process. The metal catalyst may be Rhodium, Ruthenium, Indium and the like. The chiral ligands may preferably be chiral phosphines (Principles of Asymmetric synthesis, J. E. Baldwin Ed., Tetrahedron series, 14, 311-316). iii) The mixture of stereoisomers may be resolved by conventional methods such as forming a diastereomeric salts with chiral acids or chiral amines, or chiral amino alcohols, chiral amino acids. The resulting mixture of diastereomers may then be separated by methods such as fractional crystallization, chromatography and the like, which is followed by an additional step of isolating the optically active product by hydrolyzing the derivative (Jacques et. al., "Enantiomers, Racemates and Resolution", Wiley Interscience, 1981). iv) The mixture of stereoisomers may be resolved by conventional methods such as microbial resolution, resolving the diastereomeric salts formed with chiral acids or chiral bases. Chiral acids that can be employed may be tartaric acid, mandelic acid, lactic acid, camphorsulfonic acid, amino acids and the like. Chiral bases that can be employed may be cinchona alkaloids, brucine or a basic amino acid such as iysine, arginine and the like. Different polymorphs may be prepared by crystallization of compounds of general formula (I) under different conditions such as different solvents or solvent mixtures in varying proportions for recrystallizatroτr, various ways ofcrystaiiization sirclr as slow cooling, fast cooling or a very fast cooling or a gradual cooling during crystallization. Different polymorphs may also be obtained by heating the compound, melting the compound and solidification by gradual or fast cooling, heating or melting under vacuum or under inert atmosphere and cooling under either vacuum or inert atmosphere. The various polymorphs may be identified by either one or more of the following techniques such as differential scanning calorimeter, powder X-ray diffraction, IR spectroscopy, solid probe NMR spectroscopy and thermal microscopy. Isotopically labelled compounds of the present invention are useful in drug and/or substrate tissue distribution and target occupancy assays. For example, isotopically labelled compounds are particularly useful in SPECT (single photon emission computed tomography) and in PET (positron emission tomography). The pharmaceutical compositions of the present invention may be formulated in a conventional manner using one or more pharmaceutically acceptable carriers. Thus, the active compounds of the invention may be formulated for oral, buccal, intranasal, parental (e.g., intravenous, intramuscular or subcutaneous) or rectal administration or a form suitable for administration by inhalation or insufflation. The dose of the active compounds can vary depending on factors such as the route of administration, age and weight of patient, nature and severity of the disease to be treated and similar factors. Therefore, any reference herein to a pharmacologically effective amount of the compounds of general formula (I) refers to the aforementioned factors. For oral administration, the pharmaceutical compositions may take the form of, for example, tablets or capsules prepared by conventional means with pharmaceutically acceptable excipients such as binding agents (e.g., pregelatinised maize starch, polyvinylpyrrolidone or hydroxypropyl methylcellulose); fillers (e.g., lactose, microcrystalline cellulose or calcium phosphate); lubricants (e.g., magnesium stearate, talc or silica); disintegrants (e.g., potato starch or sodium starch glycolate); or wetting agents (e.g., sodium lauryl sulphate). The tablets may be coated by methods well known in the art. Liquid preparations for oral administration may take the form of, for example, solutions, syrups or suspensions, or they may be presented as a dry product for constitution -with water or other suitable vehicle before use. Such liquid preparations may be prepared by conventional means with pharmaceutically acceptable additives such as suspending agents (e.g., sorbitol syrup, methyl cellulose or hydrogenated edible fats); emulsifying agents (e.g., lecithin or acacia); non-aqueous vehicles (e.g., almond oil, oily esters or ethyl alcohol); and preservatives (e.g., methyl or propyl p-hydroxybenzoates or sorbic acid). For buccal administration, the composition may take the form of tablets or lozenges formulated in conventional manner. The active compounds of the invention may be formulated for parenteral administration by injection, including using conventional catheterization techniques or infusion. Formulations for injection may be presented in unit dosage form, e.g., in ampoules or in multi-dose containers, with an added preservative. The compositions may take such forms as suspensions, solutions or emulsions in oily or aqueous vehicles, and may contain formulating agents such as suspending, stabilizing and/or dispersing agents. Alternatively, the active ingredient may be in powder form for reconstitution with a suitable vehicle, e.g., sterile pyrogen-free water, before use. The active compounds of the invention may also be formulated in rectal compositions such as suppositories or retention enemas, e.g., containing conventional suppository bases such as cocoa butter or other glycerides. For intranasal administration or administration by inhalation, the active compounds of the invention are conveniently delivered in the form of an aerosol spray from a pressurized container or a nebulizer, or from a capsule using a inhaler or insufflator. In the case of a pressurized aerosol, a suitable propellant, e.g., dichlorodifluoromethane, trichlorofluoromethane, dichlorotetrafluoroethane, carbon dioxide or other suitable gas and the dosage unit may be determined by providing a valve to deliver a metered amount. The medicament for pressurized container or nebulizer may contain a solution or suspension of the active compound while for a capsule it preferably should be in the form of powder. Capsules and cartridges (made, for example, from gelatin) for use in an inhaler or insufflator may be formulated containing a powder mix of a compound of the invention and a suitable powder base such as lactose or starch. A proposed dose of the active compounds of this invention, for either oral, parenteral, nasal or buccal administration, to an average adult human, for the treatment of the conditions referred to above, is 0.1 to 200 mg of the active ingredient per unit dose which could be administered, for example, 1 to 4 times per day. Aerosol formulations for treatment of the conditions referred to above (e.g., migraine) in the average adult human are preferably arranged so that each metered dose or "puff of aerosol contains 20 μg to 1000 μg of the compound of the invention. The overall daily dose with an aerosol will be within the range 100 μg to 10 mg. Administration may be several times daily, for example 2, 3, 4 or 8 times, giving for example, 1 , 2 or 3 doses each time. Radioligand binding assays for various receptor sub-types : International Patent Publication WO 04/000205, i/O 04/000845, WO 04/000849, (Suven Lifesciences Limited) gives detailed list of methods used for Radioligand assays and related prior art, all of which is incorporated herein along with the references.

Preparation of compounds: The following description illustrates the method of preparation of variously substituted compounds of general formula (I), according to the methods described herein. These are provided by the way of illustration only and therefore should not be construed to limit the scope of the invention. Commercial reagents were utilized without further purification. Room temperature refers to 25 - 30 °C. Melting points are uncorrected. IR spectra were taken using KBr and in solid state. Unless otherwise stated, all mass spectra were carried out using ESI conditions. 1 H NMR spectra were recorded at 400 MHz on a Bruker instrument. Deuterated chloroform (99.8 % D) was used as solvent. TMS was used as internal reference standard. Chemical shift values are expressed in are reported in parts per million (δ)-values. The following abbreviations are used for the multiplicity for the NMR signals: s=singlet, bs=broad singlet, d=doublet, t=triplet, q=quartet, qui=quintet, h=heptet, dd=double doublet, dt=double triplet, tt=triplet of triplets, m=multiplet. NMR, mass were corrected for background peaks. Specific rotations were measured at room temperature using the sodium D (589 nm). Chromatography refers to column chromatography performed using 60 - 120 mesh silica gel and executed under nitrogen pressure (flash chromatography) conditions.

Description 1 {2-[1 -(2-Bromobenzenesulfonyl)-2,5-dimethyl-1 H-indol-3-yl]ethyl}dimethylamine

(D1) [2-(2,5-Dimethyl-1H-indol-3-yl)ethyl]dimethylamine (2.16 g, 0.01 moles) in DMF ( 30 mL) was added slowly to a suspension of potassium hydride (1.47 g, 30 %suspension in mineral oil, 0.011 moles) in DMF ( 10 mL) maintaining the temperature below 10 °C. The mixture was 'stirred for 1 hr at 25 °C. and 2-Bromobenzenesulfonyl chloride (2.55 g, 0.01 moles) was added at 10 °C drop-wise to the reaction mixture. The reaction mixture was further stirred for 1 hr at 25 ° C. After the completion of reaction (TLC), the reaction mixture was poured onto ice-water mixture and extracted with ethyl acetate (20 mL x 2). The combined organic extracts were washed with water and brine and dried over sodium sulfate. Volatile impurities were distilled off under reduced pressure to obtain the crude residue. The residue obtained was purified by flash chromatography (silica gel, EtOAc/TEA, 9.9/0.1) to afford the compound, which was identified by IR, fiMR and mass spectral analyses as the title compound. All the other intermediates were prepared in the similar manner and their cyclization to the final compounds of formula - I is as described in the following examples.

Example - 1 : 3-(N,N-Dimethylaminoethyl)-2,5-dimethyl-1,2-benzothiazino- [2,3,4-ab]indole-S,S-dioxide {2-[1-(2-Bromophenylsulfonyl)-2,5-dimethyl-1H-indol-3-yl)ethyl}dimethylamine (0.286 mmoles) was taken in a 100 mL 3 necked round bottomed flask, along with N,N-dimethyl acetamide (40 mL), potassium acetate (0.286 mmoles, 0.0281 g.) and Tetrakis triphenyl phosphine palladium (0.0143 mmoles, 0.0165 g.). The reaction mixture was maintained under nitrogen atmosphere and was heated to 160 °C with stirring for 5 hrs. After the completion of reaction (TLC), excess of dimethyl acetamide was distilled off under reduced pressure. The residue obtained was purified by silica gel column chromatography using 20 % methanol in ethyl acetate as an eluent, to afford the title compound, which was identified by IR, NMR and mass spectral analyses. The final desired compound of general formula (I) can be further purified by preparation of their acid addition salts. Mass (m/z) : 355 (M+H)⁺ .

Example - 2 : 3-(N,N-Dimethylaminoethyl)-5-chloro-2-methyl-1,2- benzothiazino-[2,3,4-ab]indole-S,S-dioxide Using essentially the same procedure as described in example 1 , above derivative was prepared. Mass (m/z) : 375 (M+H)⁺ .

Example - 3 : 3-(N,N-Dimethylaminoethyl)-2-methyl-5-fluoro-1,2- benzothiazino-[2,3,4-ab]indole-S,S-dioxide Using essentially the same procedure as described in example 1 , above derivative was prepared. Mass (m/z) : 359 (M+H)⁺ ; ¹H-NMR (δ, ppm) : 2.36 (6H, s), 2.48 - 2.57 (2H, m), 2.76 (3H, s), 2.84 - 3.0 (2H, m), 7.27 - 8.25 (6H, m).

Example - 4 : 3-(N,N-Dimethylaminoethyl)-2-methyl-5-methoxy-1,2- benzothiazino-[2,3,4-ab]indole-S,S-dioxide Using essentially the same procedure as described in example 1 , above derivative was p^'repareα'. ^' Mass (m/z) : 371 (M+H)⁺ . Example - 5 : 3-(N,N-Dimethylaminoethyl)-2-methyl-8-methoxy-1,2- benzothiazino-[2,3,4-ab]indole-S,S-dioxide Using essentially the same procedure as described in example 1 , above derivative was prepared. Mass (m/z) : 371 (M+H)⁺ ; ¹H-NMR (δ, ppm) : 2.37 (6H, s), 2.38 (3H, s), 2.43 - 2.57 (2H, m), 2.80 - 2.96 (2H, m), 3.34 (3H, s), 7.06 - 7.49 (6H, m).

Example - 6 : 3-(N,N-Dimethylaminoethyl)-2,5-dimethyI-8-methoxy-1,2- benzothiazino-[2,3,4-ab]indole-S,S-dioxide Using essentially the same procedure as described in example 1 , above derivative was prepared. Mass (m/z) : 385 (M+H)⁺ .

Example - 7 : 3-(N,N-Dimethylaminoethyl)-5-chloro-2-methyl-8-methoxy-1,2- benzothiazino-[2,3,4-ab]indole-S,S-dioxide Using essentially the same procedure as described in example 1 , above derivative was prepared. Mass (m/z) : 405 (M+H)⁺ .

Example - 8 : 3-(N,N-Dimethylaminoethyl)-2-methyl-5-fluoro-8-methoxy-1,2- benzothiazino-[2,3,4-ab]indole-S,S-dioxide Using essentially the same procedure as described in example 1 , above derivative was prepared. Mass (m/z) : 389 (M+Hf ; ¹H-NMR (δ, ppm) : 2.34 (6H, s), 2.46 - 2.54 (2H, m), 2.74 (3H, s), 2.82 - 2.9 (2H, m), 3.98 (3H, s), 7.1 - 8.16 (5H, m).

Example - 9 : 3-(N,N-DimethylaminoethyI)-2-methyl-5,8-dimethojc -1,2- ben∑othiazino-[2,3,4-ab]indole-S,S-dioxide Using essentially the same procedure as described in example 1 , above derivative was prepared. Mass (m/z) : 401 (M+H)⁺ .

Example - 10 : 3-(N,N-Dimethylaminoethyl)-8-fluoro-1,2-benzothiazino-[2,3,4- ab]indole-S,S-dioxide Using essentially the same procedure as described in example 1 , above derivative was prepared. I.R. (KBr, cm^"1) : 2930, 1602, 1463, 1323, 1173, 633; Mass (m/z) : 345.3 (M+H)⁺ ; ¹H-NMR (δ, ppm) : 2.38 (6H, s), 2.6- 2.72 (2H, t), 3.0 -3.04 (2H, t), 7.31 -7.32(1 H, m), 7.485 -7.523 (1 H, t, J= 7.8), 7.596 (1 H, s), 7.76 - 7.78 (d, 1 H, J = 7.72), 7.81 - 7.84 (1 H, dd, J = 9.64, 2.48), 7.89 - 7.91 (1 H, d, J = 7.68), 8.226 - 8.261 (1 H, dd, J = 6.8, 5.28). Example - 11 : 3-(N,N-Dimethylaminoethyl)-8-isopropyl-1,2-benzothiazino- [2,3,4-ab]indole-S,S-dioxide Using essentially the same procedure as described in example 1 , above derivative was prepared. Mass (m/z) : 369.4 (M+H)⁺ ; ¹H-NMR (δ, ppm) : 1.355 - 1.372 (6H, d, J = 6.96), 2.35 (6H, s), 2.69 - 2.73 (2H, m), 2.97 - 3.01 (2H, m), 3.09 - 3.12 (1H, septet, J = 6.92), 7.459 - 7.498 (2H, m), 7.586 (1H, s), 7.7 - 7.72 (dd, 1H, J = 7.8), 7.98 - 7.99 (1 H, d, J = 7.64), 8.00 - 8.01 (1 H, d, J = 1.52), 8.13 - 8.16 (1 H, d, J = 8.24).

Example - 12 : 3-(N,N-Dimethylaminoethyl)-8-chloro-1,2-benzothiazino-[2,3,4- ab]indole-S,S-dioxide Using essentially the same procedure as described in example 1 , above derivative was prepared. Mass (m/z) : 361.6(M+H)⁺ ; ¹H-NMR (δ, ppm) : 2.35 (6H, s), 2.68 - 2.72 (2H, t),^" 2.97 -3.01 (2H, t), 7.48 - 7.6 (2H, m), 7.75 - 7.77 (1H, d, J = 7.8), 8.14 - 8.175 (2H, m), 7.92 - 7.94 (1H, d, J = 7.68).

Example - 13 : 3-(N,N-Dimethylaminoethyl)-8-methyl-1,2-benzothiazino-[2,3,4- ab|indole-S,S-dioxide Using essentially the same procedure as described in example 1 , above derivative was prepared. Mass (m/∑) : 341.2 (M+H)⁺ ; ¹H-NMR (δ, ppm) : 2.36 (6H, s),

2.56 (3H, s), 2.69 - 2.73 (2H, t), 2.97 - 3.018 (2H, t), 7.41 - 7.49 (2H, m), 7.585 (1 H, s),

7.7 - 7.72 (d, 1H, J=7.8), 7.94 - 7.96 (d, 1H, J = 7.68), 7.981 (1H, s), 8.1 - 8.12 (d, 1 H, J = 8.12).

Example - 14 : 3-(N,N-Dimethylaminoethyl)-1,2-benzothiazino-[2,3,4-ab]indole- S,S-dioxide Using essentially the same procedure as described in example 1 , above derivative was prepared. I.R. (KBr, cm^"1) : 2982, 1594, 1328, 1173, 1128, 756; Mass (m/z) : 327.2 (M+H)⁺ ; ¹H-NMR (δ, ppm) : 2.35 (6H, s), 2.69 - 2.72 (2H, m), 2.97 - 3.01 (2H, m), 7.46 - 7.5 (1 H, m), 7.59 - 7.64 (1 H, m), 7.71 - 7.73 (1 H^", d, J = 7.72), 7.779 (1H, bm), 7.95 - 7.97 (1H, d, J = 7.68), 8.17 - 8.19 (1H, d, J = 7.92), 8.22 - 8.24 (1H, dd, J = 8.0, 0.96).

Example - 15 : 3-(N,N-Dimethylaminoβthyl)-5-fluoro-8-methyl-1,2- benzothiazino-[2,3^~4-ab3indόle-S,S-dioxide Using essentially the same procedure as described in example 1 , above derivative was prepared. M.P : 215 -218 °C ;I.R. (KBr, crrf¹) : 2921 , 1602, 1473,

1316, 1171 , 1136, 533; Mass (m/z) : 359.2 (M+H)⁺ ; ¹H-NMR (δ, ppm) : 2.43 (6H, s),

2.56 (3H, s), 2.76 - 2.8 (2H, m), 2.99 -3.03 (2H, m), 7.41 -7.47(3H, m), 7.62 -7.72 (2H, m), 7.87 (1 H, s), 8.09 - 8.11 (1 H, d, J = 7.88).

Example - 16 : 3-(N,N-Dimethylaminoethyl)-5-chloro-8-fluoro-1 ,2- benzothiazino-[2,3,4-ab]indole-S,S-dioxide Using essentially the same procedure as described in example 1 , above derivative was prepared. I.R. (KBr, cm^"1) : 2763, 1603, 1330, 1174, 1126, 865, 551;

Mass(m/z) : 379.2 (M+Hf ; ¹H-NMR (δ, ppm) : 2.34 (6H, s), 2.66 - 2.7 (2H, t), 2.93 -

2.96 (2H, m), 7.34 -7.38 (1 H, m), 7.63 (1 H, s), 7.723 - 7.727 (1H, d, J = 1.52), 7.77 -

7.8(1 H, dd, J = 9.4), 7.863 - 7.866 (1 H, d, J = 1.28), 8.22 - 8.26 (1 H, dd, J = 8.6).

Example - 17 : 3-(N,N-Dimethylaminoethyl)-5-chloro-8-methyl-1,2- benzothiazino-[2,3,4-ab]indole-S,S-dioxide Using essentially the same procedure as described in example 1 , above derivative was prepared. Melting range: 155 - 160 °C ;I.R. (KBr, cm^"1) : 2923, 1332,

1166, 1136, 810.67; Mass(m/∑) : 375.1 (M+H)⁺ ; ¹H-NMR (δ, ppm) : 2.46 (3H, s), 2.57 (6H, s), 3.03 (2H, bm), 3.049 (2H, bm), 7.46 - 7.48 (1 H, bd, J = 7.72), 7.61 (1 H, s),

7.71-7.73 (1 H, bm), 7.92-7.94 (2H, bm), 8.1 - 8.12 (1 H, d, J = 8.16).

Example - 18 : 3-(N,N-Dimethylaminoethyl)-5,8-difluoro-1,2-benzothia∑ino- [2,3,4-ab]indole-S,S-dioxide Using essentially the same procedure as described in example 1 , above derivative was prepared. Melting range ( °C):150 - 152.5; I.R. (KBr, cm¹) : 2976, 1602, 1474, 1336, 1173, 1134, 860, 662, 539; Mass(m/z) : 363.3 (M+H)⁺ ; ¹H-NMR (δ, ppm) : 2.34 (6H, s), 2.66 - 2.7 (2H, m), 2.92 - 2.96 (2H, m), 7.358 (1 H, m), 7.43 - 7.45 (1 H, dd, J = 8.52), 7.59 - 7.62 (1 H, dd, J=9.6), 7.64 (1 H, s), 7.72 - 7.75 (1 H, dd, J = 9.4), 8.22 - 8.26 (dd, 1 H, J = 8.8).

Example - 19 : 3-(N,N-Dimethylaminoethyl)-5-fluoro-1,2-benzothiazino-[2,3,4- ab]indole-S,S-dioxide Using essentially the same procedure as described in example 1 , above derivative was prepared. Melting range (°C): 126 -129 ;I.R. (KBr, cm^"1) : 2953, 1461 , 1333, 1173, 1138, 765, 561 ; Mass (m/z) : 345.3 (M+H)⁺ ; ¹H-NMR (δ, ppm) : 2.35 (6H, s), 2.67 - 2.71 (2H, m), 2.92 -2.96 (2H, m), 7.38 - 7.41 (1 H, dd, J = 8.56, 2.08), 7.64 - 7.69 (3H, m), 7.78 - 7.8 (1 H, m), 8.09 - 8.11 (1H, d, J = 7.92),*8.22 - 8.25 (1 H, dd, J = 7.92, 1.00).

Example - 20 : 3-(N,N-DimethyIaminoethyl)-8-methoxy-2-benzothiazino-[2,3,4- ab]indole-S,S-dioxide Using essentially the same procedure as described in example 1 , above derivative was prepared. Melting range (°C) : 154 -158; I.R.(KBr, cm¹) : 2933, 1595, 1468, 1318, 1166, 1132, 858; Mass(m/∑) : 357.1 (M+H)⁺ ; ¹H-NMR (δ, ppm) : 2.35 (6H, s), 2.68 - 2.72 (2H, m), 2.96 - 3.00 (2H, m), 7.1 - 7.13 (1 H, m), 7.44 -7.48 (1 H, t), 7.58 (1 H, s), 7.6 - 7.606 (1 H, d, J = 2.44), 7.7 -7.72 (1 H, d, J = 7.84), 7.9 - 7.92 (1 H, d, J = 7.64), 8.14 - 8.16 (d, 1 H, J = 8.92).

Example - 21 : 3-(N,N-Dimethylaminoethyl)-5-fluoro-8-methoxy-1,2- benzothiazino-[2,3,4-ab]indole-S.S-dioxide Using essentially the same procedure as described in example 1 , above derivative was prepared. Melting range (°C) : 186 -187.5 °C ; I.R. (KBr, cm^"1) : 2946, 1597, 1411 , 1327, 1168, 1126, 857, 501 ; Mass(m/z) : 375.3 (M+H)⁺ ; ¹H-NMR (δ, ppm) : 2.34 (6H,s), 2.66 - 2.7 (2H, m), 2.91 - 2.95 (2H, m), 7.13-7.16 (1H, dd, J = 8.88, 2.44), 7.38 - 7.4(1 H, dd, J = 8.56), 7.5 - 7.506 (1H, d, J = 2.4), 7.6 - 7.63 (2H, m), 8.14 - 8.16 (d, 1H, J = 8.88).

Example - 22 : 3-(N,N-Dimethylaminoethyl)-5-fluoro-8-chloro-1,2- benzothiazino-[2,3,4-ab]indole-S,S-dioxide Using essentially the same procedure as described in example 1 , above derivative was prepared. Melting range (°C) : 152 -153.4; I.R. KBr, cm^"1) : 2948, 1333, 1175, 1132, 894, 627; Mass(m/z) : 379.1 (M+H)⁺ ; ¹H-NMR (δ, ppm) : 2.348 (6H, s), 2.66 - 2.7 (2H, m), 2.92 -2.96 (2H, m), 7.42 - 7.45 (1 H, dd), 7.616 - 7.659 (3H, m, J = 8.48), 8.05 - 8.06 (d, 1 H, J = 1.96), 8.15 - 8.176 (1 H, d, J = 8.48)

Example - 23 : 3-(N,N-Dimethylaminoethyl)-5-methyl-8-fluoro-1,2- benzothiazino-[2,3,4-ab]indole-S,S-dioxide Using essentially the same procedure as described in example 1 , above derivative was prepared. I.R.(KBr, cm¹) : 2921 , 1327, 1176, 786, 762; Mass(m/z) : 359.4 (M+H)⁺ ;^{" 1}Η-NMR (DO Oppmj : 2.35 (6H, s), 2.68 - 2.72^'(2H; m), 2.96 - 3.00 (2H, m), 7.1 - 7.13 (1 H, m), 7.44 - 7.48 (1 H, t), 7.58 (1 H, s), 7.60 - 7.606 (1 H, d, J = 2.44), 7.7 - 7.72 (1 H, d, J = 7.84), 7.9 - 7.92 (1 H, d, J = 7.64), 8.14 - 8.16 (1 H, d, J = 8.92).

Example - 24 : 3-(N,N-Dimethylaminoethyl)-5-methyl-1,2-benzothiazino-[2,3,4- ab]indole-S,S-dioxide Using essentially the same procedure as described in example 1 , above derivative was prepared. I.R. (KBr, cm^"1) : 2919, 1338, 1175, 1127, 786, 763;

Mass(m/z) : 341.4 (M+H)⁺ ; ¹H-NMR (δ, ppm) : 2.4 (6H, s), 2.6 (3H, s), 2.75 - 2.77

(2H, m), 2.99 (2H, m), 7.52 (1 H, s), 7.53 (1 H, s), 7.59 - 7.63 (1 H, m), 7.75 -7.79 (2H, m), 8.16 - 8.18 (1 H, d, J = 7.88), 8.21 - 8.23 (1 H, dd, J = 9.08)

Example - 25 : 3-(N,N-Dimethylaminoethyl)-5,8-dimethyl-1,2-benzothiazino- [2,3,4-ab]indole-S,S-dioxide Using essentially the same procedure as described in example 1 , above derivative was prepared. I.R. (KBr, cm^"1) : 2918, 1463, 1327, 1174, 1139, 807, 607,

527; Mass(m/z) : 355.5 (M+H)⁺ ; H-NMR (δ, ppm) : 2.4 (6H, s), 2.56 (3H, s), 2.59 (3H, s), 2.73 - 2.77 (2H, m), 2.98 - 3.02 (2H, m), 7.4 - 7.42 (1 H, m), 7.51 - 7.52 (2H, m),

7.77 (1 H, s), 7.96 (1H, s), 8.09 - 8.11 (d, 1H, J = 8.16).

Example - 26 : 3-(N,N-Dimethylaminoethyl)-5-methyl-8-methoxy-2- benzothiazino-[2,3,4-ab]indole-S,S-dioxide Using essentially the same procedure as described in example 1 , above derivative was prepared. I.R (KBr, cm¹) : 2918, 1596, 1323, 1303, 1240, 1169, 811 ,

533; Mass(m/z) : 370.7 (M+Hf ; ¹ H-NMR (δ, ppm) : 2.41 (6H, s), 2.75 - 2.79 (2H, m), 2.98 - 3.29 (2H, m), 3.99 (3H, s), 7.09 - 7.12 (1 H, dd, J = 8.84, 2.44), 7.51 - 7.52 (2H, m), 7.57 - 7.58 (1 H, d, J = 2.4), 7.72 (1 H, s), 8.12 - 8.15 (1 H, d, J = 8.8).

Example - 27 : 3-(N,N-Dimethylaminoethyl)-5,8-dichloro-2-benzothiazino-[2,3,4- ab]indole-S,S-dioxide Using essentially the same procedure as^' described in example 1 , above derivative was prepared. Melting range (°C) : 101 - 108; I.R (KBr, cm¹) : 2982, 2769, 1329, 1178, 1150, 851 , 791 , 619, 529; Mass(m/z) : 395, 397, 399 (M+H)⁺ ; ¹H-NMR (δ, ppm) : 2.35 (6H, s), 2.67 - 2.71 (2H, m), 2.93 - 2.97 (2H, m), 7.61 - 7.64 (2H, m), 7.72 - 7.727 (2H, d, J = 1.64), 7.89 - 7.90 (1H, d, J = 1.52), 8.09 - 8.10 (1 H, d, J = 1.56), 8.15 - 8.17 (1 H, d, J = 8.56). Example - 28 : 3-(N,N-Dimethylaminoethyl)-5-fIuoro-9,10-dichloro-2- benzothiazino-[2,3,4-ab]indole-S,S-dioxide Using essentially the same procedure as described in example 1 , above derivative was prepared. Melting range (°C) : 207 - 210; I.R (KBr, cm¹) : 2918, 1454, 1340, 1175, 1163, 838, 581 ; Mass(m/z) : 413.2, 415.2 (M+H)⁺ ; ¹H-NMR (δ, ppm) : 2.35 (6H, s), 2.66 - 2.70 (2H, m), 2.92 - 2.96 (2H, m), 7.41 - 7.44 (1 H, dd, J = 8.4, 2.12), 7.59 - 7.62 (1 H, dd, J = 9.98, 2.0), 7.68 (1 H, s), 7.83 - 7.85 (1 H, d, J = 8.78), 7.97 - 7.99 (1 H, d, J = 8.78).

Example - 29 : 3-(N,N-Dimethylaminoethyl)-5,9,10-trichloro-2-benzothia∑ino- [2,3,4-ab]indole-S,S-dioxide Using essentially the same procedure as described in example 1 , above derivative was prepared. Melting range (°C) : 210.4 - 214.9; I.R (KBr, cm¹) : 2946,

1445, 1339, 1163, 838, 594, 568; Mass(m/z) : 429.1 , 431.1 , 432.9 (M+H)⁺ ; ¹H-NMR (δ, ppm) : 2.35 (6H, s), 2.67 - 2.71 (2H, m), 2.93 - 2.97 (2H, m), 7.66 (1H, s), 7.70 -

7.71 (1 H, d, J = 1.48), 7.83 - 7.86 (2H, m), 8.01 - 8.03 (1 H, d, J = 8.76).

Example - 30 : 3-(N,N-Dimethylaminoethyl)-5-chloro-2-benzothiazino-[2,3,4- ab]indole-S,S-dioxide Using essentially the same procedure as described in example 1 , above derivative was prepared. Melting range (°C) : 133 - 136.3; I.R (KBr, cm¹) : 2962, 1331 , 1169, 1124, 826, 766, 749; Mass(m/z) : 361 , 363 (M+H)⁺ ; ¹H-NMR (δ, ppm) : 2.35 (6H, s), 2.67 - 2.71 (2H, m), 2.93 - 2.97 (2H, m), 7.62 - 7.69 (3H, m), 7.78 - 7.80 (1H, m), 7.92 - 7.93 (1 H, d. J = 1.56), 8.12 - 8.14 (1 H, d), 8.22 - 8.24 (1 H, dd, J = 8.0, 1.08).

Example - 31 : 3-(N,N-Dimethylaminoethyl)-9,10-dichloro-2-benzothiazino- [2,3,4-ab] indole-S,S-dioxide Using essentially the same-procedure as described in example 1 , above derivative was prepared. Melting range (°C) : > 240; I.R (KBr, cm¹) .: 2940, 1448, 1329, 1165, 793, 600; Mass(m/z) : 394.9, 397 (M+H)⁺ ; ¹H-NMR (δ, ppm) : 2.37 (6H, s), 2.71 - 2.75 (2H, m), 3.00 - 3.03 (2H, m), 7.45 - 7.49 (1 H, t), 7.74 - 7.76 (1 H, -d, J = 7.72), 7.81 - 7.83 (1 H, d, J = 8.76), 7.89 - 7.91 (1 H, d, J = 7.76), 8.08 - 8.10 (1 H, d, J = 8.72).

Example - 32 : 3-(N,N-Dimethylaminoethyl)-5-chloro-8-methoxy-2- benzothiazino-[2,3,4-ab] indole-S.S-dioxide Using essentially the same procedure as describes in example 1 , above derivative was prepared. Melting range (°C) : 176.6 - 1S3; I.R (KBr, cm¹) : 2980, 1596, 1311 , 1167, 850, 573, 534; Mass(m/z) : 391.1 (M+H)⁺ ; ¹H-NMR (δ, ppm) : 2.36 (6H, s), 2.67 - 2.71 (2H, m), 2.93 - 2.97 (2H, m), 4.0 (3H, s), 7.13 - 7.16 (1H, dd, J = 8.84, 2.36), 7.52 - 7.53 (1 H, d, J = 2.36), 7.61 (1 H, s), 7.68 - 7.687 (1 H, d, J = 1.56), 7.86 - 7.87 (1 H, d, J = 1.56), 8.13 - 8.16 (1 H, d, J = 8.84).

Example - 33 : 3-(N,N-Dimethylaminoethyl)-5-methyl-8-isopropyl-2- ben∑othiazino-[2,3,4-ab] indole-S.S-dioxide Using essentially the same procedure as described in example 1 , above derivative was prepared. Melting range (°C) : 86.5 - 93.5; I.R (KBr, cm¹) : 2957, 1599, 1458, 1322, 1174; Mass(m/z) : 383 (M+H)⁺ ; ¹H-NMR (δ, ppm) : 1.35 - 1.38 (6H, d), 2.36 (6H, s), 2.61 (3H, s), 2.68 - 2.72 (2H, m), 2.94 - 2.98 (2H, m), 3.09 - 3.12 (1 H, sep.), 7.46 - 7.48 (1 H, dd, J = 8.24, 1.32), 7.49 (1 H, s), 7.53 (1 H, s), 7.79 (1 H, s), 7.98 - 7.99 (1 H, d, J = 1.61), 8.12 - 8.14 (1H, d, J = 8.28).

Example - 34 : 3-(N,N-Dimethylaminoethyl)-5-fluoro-8-isopropyl-2- benzothiazino-[2,3,4-ab] indole-S,S-dioxide Using essentially the same procedure as described in example 1 , above derivative was prepared. Melting range (°C) : 117 - 124; I.R (KBr, cm¹) : 2917, 1598, 1344, 1178, 1128, 796, 661 ; Mass(m/z) : 387 (M+H)⁺ ; ¹ H-NMR (δ, ppm) : 1.35 - 1.37 (6H, d), 2.36 (6H,s), 2.68 - 2.72(2H, m), 2.93 - 2.97 (2H, m), 3.1 - 3.13(1 H, sep), 7.38 - 7.4 (1 H, dd, J = 8.56, 2.1), 7.51 - 7.53 (1 H, dd, J =8.28, 1.56), 7.63 (1 H, s), 7.68 - 7.71 (1H, dd, J = 9.9,2.08), 7.914 - 7.918 (1H, d, J = 1.48), 8.14 - 8.16 (1H, d, J = 8.28).

Example - 35 : 3-(N,N-Dimethylaminoethyl)-8,10-difluoro-2-benzothiazino- [2,3,4-ab] indole-S.S-dioxide ^• Using essentially the same procedure as described in example 1 , above derivative was prepared. Melting range (°C) : 155 - 160; I.R (KBr, cm¹) : 2963, 1612, 1331 , 1261, 1173, 1111 , 855, 797, 512; Mass(m/z) : 363.1 (M+H)⁺ ; ¹H-NMR {δ, ppm) : 2.41 (6H,s), 2.74 - 2.78(2H, m), 3.02 - 3.06 (2H, m), 7.04 - 7.1 (1 H, m), 7.47 - 7.53 (1 H, t), 7.62 (1 H, s), 7.67 - 7.71 <1H, m), 7.8 - 7.82 (1 H, d, J = 7.76),7.87 - 7.89 (1H, d, J = 7.72). Example - 36 : 3-(N,N-Dimethylaminoethyl)-5,8,10-trifluoro-2-benzothiazino- [2,3,4-ab] indole-S,S-dioxide Using essentially the same procedure as described in example 1 , above derivative was prepared. Melting range (°C) : 140 - 144(dec); I.R {KBr, cm¹) : 2917, 1579, 1462, 1339, 1173, 1094, 857, 799, 529; Mass(m/z) : 380.7 (M+H)⁺ ; ¹H-NMR (δ, ppm) : 2.38 (6H,s), 2.7 - 2.74(2H, m), 2.95 - 2.99 (2H, m), 7.08 - 7.14 (1 H, m), 7.47 -

7.5 (1 H, dd,J=8.4,2.04), 7.58 - 7.61 (2H,dd,J=9.84), 7.67 (1 H, s).

Example - 37 : 3-(N,N-Dimethylaminoethyl)-5-methyl-9,10-dichloro-2- benzothiazino-[2,3,4-ab] indole-S,S-dioxide Using essentially the same procedure as described in example 1 , above derivative was prepared. I.R (KBr, cm¹) : 2936, 1460, 1333, 1175, 1132, 816, 609,

594; Mass(m/z) : 409, 411 (M+H)⁺ ; ¹H-NMR (δ, ppm) : 2.37 (6H, s), 2.70 - 2.74 (2H, m), 2.96 - 3.00 (2H, m), 7.53 (1 H, s), 7.58 (1 H, s), 7.70 (1 H, s), 7.79 - 7.81 (1 H, d, J = 8.8), 8.06 - 8.08 (1H, d, J = 8.82).

Example - 38 : 3-(N,N-Dimethylaminoethyl)-5-methoxy-2-benzothiazino-[2,3,4- ab] indole-S,S-dioxide Using essentially the same procedure as described in example 1 , above derivative was prepared. I.R (KBr, cm¹) : 2934, 1595, 1460, 1320, 1170, 1130, 860; Mass(m/z) : 357.1 (M+H)⁺ .

Example - 39 : 3-(N,N-Dimethylaminoethyl)-6-methoκy-2-benzothiazino-[2,3,4- ab] indole-S,S-dioxide Using essentially the same procedure as described in example 1 , above derivative was prepared. I.R (KBr, cm¹) : 2932, 1596, 1460, 1322, 1171 , 1129, 865; Mass(m/z) : 357.1 (M+H)⁺ .

Example - 40 : 3-(N,N-Dimethylaminoethyl)-5,8-methoxy-2-benzothiazino-[2,3,4- ab] indole-S,S-dioxide Using essentially the same procedure as described in example 1 , above derivative was prepared. I.R (KBr, cm¹) : 2934, 1592, 1462, 1322, 1171 , 1130, 864; Mass(m/z) : 387 (M+H)⁺ . Example - 41 : 3-(N,N-Dirheth^"ylaminoethyl) 5-methoxy-8-chloro-2- benzothiazino-[2,3,4-ab] indole-S,S-dioxide Using essentially the same procedure as described in example 1 , above derivative was prepared. I.R (KBr, cm¹) : 2934, 1595, 1460,*1320, 1170, 1130, 860; Mass(m/z) : 391.1 , 393 (M+H)⁺ .

Example - 42 : 3-(N,N-Dimethylaminoethyl)-5-methoxy-8-fluoro-2- benzothiazino-[2,3,4-ab] indole-S,S-dioxide Using essentially the same procedure as described in example 1, above derivative was prepared. Mass(m/z) : 375.2 (M+H)⁺ .

Example - 43 : 3-(N,N-DimethyIaminoethyl)-5-methoxy-8-bromo-2- benzothiazino-[2,3,4-ab] indole-S,S-dioxide Using essentially the same procedure as described in example 1 , above derivative was prepared. Mass(m/z) : 436, 438 (M+H)⁺ .

Example - 44 : 3-(N,N-DimethylaminoethyI)-5-methoxy-8-methyl-2- benzothiazino-[2,3,4-ab] indole-S,S-dioxide Using essentially the same procedure as described in example 1 , above derivative was prepared. Mass(m/z) : 371 (M+H)⁺ .

Example - 45 : 3-(N,N-Dimethylaminoethyl)-5-methoxy-8-isopropyl-2- benzothiazino-[2,3,4-ab] indole-S,S-dioxide Using essentially the same procedure as described in example 1 , above derivative was prepared. Mass(m/∑) : 399 (M+H)⁺ .

Example - 46 : 3-(2-N,N-Dimethylaminopropyl)-5-methoxy-2-benzothiazino- [2,3,4-ab] indole-S.S-dioxide Using essentially the same procedure as described in example 1 , above derivative was prepared. I.R (KBr, cm¹) : 2934, 1595, 1460, 1320, 1170, 1130, 860; Mass(m/z) : 371 (M+H)⁺ .

Example - 47 : 3-(2-N,N-Dimethylaminopropyl)-6-methoxy-2-benzothiazino- [2,3,4-ab] indole-S,S-dioxide Using essentially the same procedure as described in example 1 , above derivative was prepared. I.R (KBr, cm¹) : 2932, 1596, 1460, 1322, 1171 , 1129, 865; Mass(m/z) : 371 (M+H)⁺ . Example - 48 : 3-(2-N,N-Dimethylaminopropyl)-5,8-methoxy-2-benzothiazino- [2,3,4-ab] indole-S,S-dioxide Using essentially the same procedure as described in example 1 , above derivative was prepared. I.R (KBr, cm¹) : 2934, 1592, 1462, 1322, 1171 , 1130, 864; Mass(m/z) : 401 (M+H)⁺ .

Example - 49 : 3-(2-N,N-Dimethylaminopropyl)-5-methoxy-8-chloro-2- benzothiazino-[2,3,4-ab] indole-S,S-dioxide Using essentially the same procedure as described in example 1 , above derivative was prepared. I.R (KBr, cm¹) : 2934, 1595, 1460, 1320, 1170, 1130, 860; Mass(m/z) : 405, 407(M+H)⁺ .

Example - 50 : 3-(2-N_sN-Dimethylaminopropyl)-5-methoxy-8-fluoro-2- benzothiazino-[2,3,4-ab] indole-S,S-dioxide Using essentially the same procedure as described in example 1 , above derivative was prepared. Mass(m/z) : 389 (M+H)⁺ .

Example - 51 : 3-(2-N,N-Dimethylaminopropyl)-5-methoxy-8-bromo-2- benzothiazino-[2,3,4-ab] indole-S,S-dioxide Using essentially the same procedure as described in example 1 , above derivative was prepared. Mass(m/z) : 450, 452 (M+H)⁺ .

Example - 52 : 3-(2-N,N-Dimethylaminopropyl)-5-methoπy-8-methyl-2- benzothiazino-[2,3,4-ab] indole-S,S-dioxide Using essentially the same procedure as described in example 1 , above derivative was prepared. Mass(m/z) : 385 (M+H)⁺ .

Example - 53 : 3-(2-N,N-Dimethylaminopropyl)-5-methoxy-8-isopropyl-2- benzothiazino-[2,3,4-ab] indole-S,S-dioxide Using essentially the same procedure as described in example 1 , above derivative was prepared. Mass(m/z) : 413 (M+H)⁺ .

Example - 54 : 3-(N,N-Dimethylaminoethyl)-5-chloro-8,10-difluoro-2- benzothiazino-[2,3,4-ab]indole-S,S-dioxide Using essentially the same procedure as described in example 1 , above derivative was prepared. I.R (KBr, cm¹) : 2917, 1339, 1172, 1123, 757; Mass(m/z) : 397.1 , 399 (M+H)⁺ ; ¹H-NMR (00 ppm) : 2.42 (6H, s), 2.74 - 2.78 (2H, m), 2.99 - 3.03 (2H, m), 7.08 - 7.14 (1 H, m), 7.63 - 7.66 (2H, m), 7.78 - 7.784 (1 H, d, J = 1.32), 7.85 - 7.854 (1 H, d, J = 1.32).

Example - 55 : 3-(N,N-DimethylaminoethyI)-5-methyl-8-chloro-2-benzothiazino- [2,3,4-ab]indole-S,S-dioxide Using essentially the same procedure as described in example 1 , above derivative was prepared. I.R (KBr, cm¹) : 2918, 2762, 1330, 1177, 1096, 790;

Mass(m/z) : 375, 376.9 (M+H)⁺ ; ¹H-NMR (δ, ppm) : 2.37 (6H, s), 2.60 (3H, s), 2.69 - 2.73 (2H, m), 2.96 - 3.00 (2H, m), 7.53 - 7.58 (3H, m), 7.74 (1 H, s), 8.12 - 8.15 (2H, m).

Example - 56 : 3-(N,N-Dimethylaminoethyl)-5-chloro-8-isopropyl-2- benzothiazino-[2,3,4-ab]indole-S,S-dioxide Using essentially the same procedure as described in example 1 , above derivative was prepared. I.R (KBr, cm¹) : 2963, 1457, 1406, 1336, 1178, 1126, 827; Mass(m/z) : 403.2, 405.2 (M+H)⁺ ; ¹H-NMR (δ, ppm) : 1.382 - 1.399 (6H, d, J = 6.8), 2.37 (6H, s), 2.65 - 2.73 (2H, m), 2.94 - 2.98 (2H, m), 3.12 - 3.15 (1H, sep.), 7.53 - 7.56 (1 H, dd, J = 8.28), 7.63 (1 H, s), 7.694 - 7.699 (1 H, d, J = 1.68), 7.96 - 7.967 (2H, m), 8.15 - 8.17 (1 H, d, J = 8.24).

Example - 57 : 3-(N,N-Dimethylaminoethyl)-5-methyl-8,10-difluoro-2- henzofhiazino-[2,3,4-ab]indole-S,S-dioxide Using essentially the same procedure as described in example 1 , above derivative was prepared. I.R (KBr, cm¹) : 2918, 2849, 1619, 1332, 1170, 853, 802; Mass(m/z) : 377.1 (M+H)⁺ ; ¹H-NMR (δ, ppm) : 2.45 (6H, s), 2.-60 (3H, s), 2.75 - 2.83 (2H, m), 3.10 - 3.60 (2H, m), 7.02 - 7.08 (1 H, m), 7.56 - 7.70 (4H, m).

Example - 58 : 3-(N,N-Dimethylaminoethyl)-7-trifluoromethyl-10-chloro-2- ' benzothiazino-[2,3,4-ab]indole-S,S-dioxide Using essentially the same procedure as described in example 1 , above derivative was prepared. I.R (KBr, cm¹) : 2917, 1348, 1297, 1170, 1142, 753; Mass(m/z) : 429.1 , 431 (M+H)⁺ ; ¹H-NMR (δ, ppm) : 2.37 (6H, s), 2.72 - 2.76 (2H, m), 2.99 - 3.04 (2H, m), 7.48 - 7.58 (2H, m), 7.72 - 7.82 (2H, m), 8.20 - 8.60 (2H, m).

Example - 59 : 3-(N,N-Dimethylaminoethyl)-5-fluoro-7-trifluoromethy!-10- chloro-2-benzothiazino-[2,3,4-ab]indole-S,S-dioxide Using essentially the same procedure as described in example 1 , above derivative was prepared. I.R (KBr, cm¹) : 2943, 1435, 1349, 1298, 1170, 868;

Mass(m/z) : 447.2, 449.2 (M+H)⁺ ; ¹H-NMR (δ, ppm) : 2.36 (6H, s), 2.69 - 2 3 (2H, m), 2.94 - 2.98 (2H, m), 7.46 - 7.49 (1 H, dd, J = 8.0, 2.1), 7.54 (1 H, s), 7.76 - 7.78 (1 H, d,

J = 8.72), 7.79 - 7.82 (1 H, dd), 8.04 - 8.07 (1 H, d, J = 8.60).

Example - 60 : 3-(N,N-Dimethylaminoethyl)-5,10-dichloro-7-trifluoromethyl-2- benzothiazino-[2,3,4-ab]indole-S,S-dioxide Using essentially the same procedure as described in example 1 , above derivative was prepared. I.R (KBr, cm¹) : 2926, 1356, 1297, 1173, 1130, 795; Mass(m/z) : 463, 465 (M+H)⁺ ; ¹H-NMR (δ, ppm) : 2.45 (6H, s), 2.79 - 2.83 (2H, m), 3.03 - 3.10 (2H, m), 7.538 - 7.549 (1 H, s), 7.76 - 7.78 (1 H, d, J = 8.64), 7.80 - 7.804 (1H, d, J = 1.4), 8.03 (1 H, bs), 8.05 - 8.07 (1 H, d, J = 8.60).

Example - 61 : 3-(N,N-Dimethylaminoethyl)-5-chloro-9-trifluoromethyl-2- benzothiazino-[2,3,4-ab]indoIe-S,S-dioxide Using essentially the same procedure as described in example 1 , above derivative was prepared. I.R (KBr, cm¹) : 2941 , 1328, 1175, 1128, 811 , 573; Mass(m/z) : 429.1 , 431.2 (M+H)⁺.

Example - 62 : 3-(N,N-Dimethylaminoethyl)-9-trifluoromethyl-2-benzothiazino- [2,3,4-ah]indole-S,S-dioxide Using essentially the same procedure as described in example 1 , above derivative was prepared. I.R (KBr, cm¹) : 2917, 1329, 1175, 1134, 751 , 597; Mass(m/z) : 395 (M+H)⁺.

Claims

We Claim:

1. A compound of the general formula (I),

GENERAL FORMULA (I) wherein R_{1 (} R₂, R₃, R₄, R5, Rε, R7, Rs, R9, R10. Ru, R12, R13 and R₁₄, may be same or different and each independently represent hydrogen, halogen, oxo, thio, perhaloalkyl, hydroxy, amino, nitro, cyano, formyl, amidino, guanidino, substituted or unsubstituted groups selected from linear or branched (C C₁₂)alkyl, (C₂-C₁₂)alkenyl, (C₂-C₁₂)alkynyl (C₃-C₇)cycIoalkyl, (C₃-C )cycloalkenyl, bicycloalkyl, bicycloalkenyl, (d-C₁₂)alkoxy cyc!o(C₃-C₇)alkoxy, aryl, aryloxy, aralkyl, aralkoxy, heterocyclyl, heteroaryl heterocyclylalkyl, heteroaralkyl, heteroaryloxy, heteroaralkoxy, heterocyclylalkyloxy acyl, acyloxy, acylamino, monoalkylamino, dialkylamino, arylamino, diarylamino aralkylamino, alkoxycarbonyl, aryloxycarbonyl, aralkoxycarbonyl heterocyclylalkoxycarbonyl, heteroaryloxycarbonyl, hydroxyalkyl, aminoalkyl monoalkylaminoalkyl, dialkylaminoalkyl, alkoxyalkyl, aryloxyalkyl, aralkoxyalkyl alkylthio, thioalkyl, alkoxycarbonylamino, aryloxycarbonylamino aralkyloxycarbonylamino, aminocarbonylamino, alkylaminocarbonylamino dialkylaminocarbonylamino, alkylamidino, alkylguanidino, dialkylguanidino, hydrazino hydroxylamino, carboxylic acid and its derivatives, sulfonic acids and its derivatives phosphoric acid and its derivatives; or two adjacent groups may form "cyclic structures", for example, R^ and R₂, R₂ and R₃, R₅ and R₆, R₆ and R₇, R₇ and R₈ together with the adjacent' carbon atoms to which they are attached may form a 5^ 6, or 7 membered ring, which may further optionally contain one or more double bonds and/or one or more heteroatoms such as the group "Oxygen", "Nitrogen", "Sulfur" or "Selenium" and combinations Of double bond and heteroatoms; or R₉ and R₁₀ or Rn and R₁₂ or R₁₃ and R₁₄ together represent double bond attached to "Oxygen" or "Sulfur"; or two adjacent groups may form "cyclic structures" for example, Ru and R ₂, Ru and Rι₃, Ru and R₁₄, R₁₃ and R₁₄ together with the carbon atom/s to which they are attached may form a 3, 4, 5, or 6 membered ring, which may further optionally contain one or more double bonds, and/or one or more heteroatoms such as the group "Oxygen", "Nitrogen", "Sulfur" or "Selenium" and also includes combination of one or more double bonds with "heteroatoms", as above defined; R₁₅ and R₁₆ m3y be same or different and each independently represents hydrogen, substituted or unsubstituted groups selected from linear or branched (C₁-C₁₂)alkyl, (C₂-C₁₂)alkenyl, (C₂-C₁₂)alkynyl, (C₃-C₇)cycloalkyI, (C₃-C₇)cycloalkenyl, bicycloalkyl, bicycloalkenyl, aryl, aralkyl, heteroaryl, heterocyclylalkyl; optionally R₁₅ and R₁₆ along with the nitrogen atom may form a 3, 4, 5, 6 or 7 membered heterocyclic ring, which may further optionally contain one or more double bonds, and may include additional one or more heteroatoms such as the group "Oxygen", "Nitrogen", "Sulfur" or "Selenium" and also includes combination of one or more double bonds with "heteroatoms", as above defined; "n" ranges from 0 to 4, wherein the carbon chains which "n" represents may be either linear or branched.

2. A compound according to Claim 1 which is selected from :

3-(N,N-DimethyIaminoethyl)-2,5-dimethyl-1 ,2-benzothiazino-[2,3,4-ab]indole-S,S- dioxide;

3-(N,N- Dl imethylaminoethyl)-5-chloro-2-methyl-1 ,2-benzothiazino-[2,3,4-ab]indole-S,S- dioxide

3-(N,N- Dimethylaminoethyl)-2-methyl-5-fluoro-1 ,2-benzothiazino-[2,3,4-ab]indole-S,S- dioxide

S,S-dioxide; 3-(N,N-Dimethylaminoethyl)-2-methyl-8-methoxy-1 ,2-benzothiazino-[2,3,4-ab]indole-

S,S-dioxide; 3-(N,N-Dimethylaminoethyl)-2,5-dimethyl-8-methoxy-1 ,2-benzothiazino-[2,3,4- ab]indole-S,S-dioxide; 3-(N,N-Dimethylaminoethyl)-5-chloro-2-methyl-8-methoxy-1 ,2-benzothiazino-[2,3,4- ab]indole-S,S-dioxide; 3-(N,N-Dimethylaminoethyl)-2-methyl-5-fluoro-8-methoxy-1 ,2-benzothiazino-[2,3,4- ab]indole-S,S-dioxide; 3-(N,N-Dimethylaminoethyl)-2-methyl-5,8-dimethoxy-1 ,2-benzothiazino-[2,3,4- ab]indole-S,S-dioxide; 3-(N,N-Dimethylaminoethyl)-8-fluoro-1 ,2-benzothiazino-{2,3,4-ab]indole-S,S-dioxide 3-(N,N-Dimethylaminoethyl)-8-isopropyl-1 ,2-benzothiazino-[2,3,4-ab]indole-S,S- dioxide;

3-(N,N-Dimethylaminoethyl)-8-methyl-1 ,2-benzothiazino-[2,3,4-ab]indole-S,S-dioxide;

3-(N,N-Dimethylaminoethyl)-1 ,2-benzothiazino-[2,3,4-ab]indole-S,S-dioxidø;

3-(N,N-Dimethylaminoethyl)-5-fluoro-8-methyl-1 ,2-benzothiazino-[2,3,4-ab]indole-S,S- dioxide;

3-(N,N- -DC imethylaminoethyl)-5-chloro-8-fluoro-1 ,2-benzothiazino-[2,3,4-ab]indole-S,S- dioxide;

3-(N,N- D[ imethylaminoethyl)-5-chloro-8-methyl-1 ,2-benzothiazino-[2,3,4-abjindole-S,S- dioxide;

3-(N,N- Dimethylaminoethyl)-5,8-difluoro-1,2-benzothiazino-[2,3,4-ab]indole-S,S- dioxide;

3-(N, N-Dimethylaminoethy )-5-fluoro-1 ,2-benzothiazino-[2,3,4-ab]indole-S,S-dioxide;

3-(N,N-Dimethylaminoethyl )-8-methoxy-2-benzothiazino-[2,3,4-ab]indole-S,S-dioxide; 3-(N,N-Dimethylaminoethyl )-5-fluoro-8-methoxy-1 ,2-benzothiazino-[2,3,4-ab]indole-

S,S-dioxide;

3-(N,N-Dimethylaminoethy )-5-fluoro-8-chloro-1,2-benzothiazino-[2,3,4-ab]indole-S,S- dioxide;

3-(N, -Dimethylaminoethy: )-5-methyl-8-fluoro-1 ,2-benzothiazino-[2,3,4-ab]indole-S,S- dioxide;

3-(N , N-Dimethylaminoethy! )-5-methyl-1 ,2-benzothiazino-[2,3,4-ab]indole-S,S-dioxide;

3-(N,N-Dimethylaminoethyl )-5,8-dimethyl-1 ,2-benzothiazino-[2,3,4-ab]indole-S,S- dioxide;

3-(N,N-Dimethylaminoethyl )-5-methyl-8-methoxy-2-benzothiazino-[2,3,4-ab]indole-S,S- dioxide;

3-(N, N-Dimethylaminoethy )-5,8-dichloro-2-benzothiazino-[2,3,4-ab]indole-S,S-dioxide;

3-(N, N-Dimethylaminoethy )-5-fluoro-9,10-dichloro-2-benzothiazino-[2,3,4-ab]indole-

S,S-dioxide;

3-(N, N-Dimethylaminoethy )-5,9, 10-trichloro-2-benzothiazino-[2,3,4-ab]indole-S,S- dioxide; 3-(N,N-Dimethylaminoethyl )-5-chloro-2-benzothiazino-[2,3,4-ab]indole-S,S-dioxide; 3-(N, N-Dimethylaminoethyl )-9,10-dichloro-2-benzothiazino-[2,3,4-ab] indole-S,S- dioxide; 3-(N, N-Dimethylaminoethy )-5-chloro-8-methoxy-2-benzothiazino-[2,3,4-ab]indole-S,S- dioxide; 3-(N, N-Dimethylaminoethy )-5-methyl-8-isopropyl-2-benzothiazino-[2,3,4-ab]indole- S,S-dioxide;

3-(N,N-Dimethylaminoethyl)-5-fluoro-8-isopropyl-2-benzothiazino-[2,3,4-ab]indole-S,S- dioxide;

3-(N,N-Dimethylaminoethyl)-8, 10-difluoro-2-benzothiazino-[2,3,4-ab] tndole-S.S- dioxide;

3-(N,N-Dimethylaminoethyl)-5,8,10-trifluoro-2-benzothiazino-[2,3,4-ab]indole-S,S- dioxide;

3-(N,N-Dimethylaminoethyl)-5-methyl-9,10-dichloro-2-benzothiazino-[2,3,4-ab]indole- S,S-dioxide; 3-(N,N-Dimethylaminoethyl)-5-methoxy-2-benzothiazino-{2,3,4-ab] indole-S.S-dioxide; 3-(N,N-Dimethylaminoethyl)-6-methoxy-2-benzothiazino-[2,3,4-ab] indole-S.S-dioxide; 3-(N,N-Dimethylaminoethyl)-5,8-methoxy-2-benzothiazino-[2,3,4-ab] indole-S,S- dioxide;

3-(N,N -Dimethylaminoethyl)-5-methoxy-8-chloro-2-benzothiazino-[2,3,4-ab]indole-S,S- dioxide 3-(N,N- Dimethylaminoethyl)-5-methoxy-8-fluoro-2-benzothiazino-[2,3,4-ab]indole-S,S- dioxide 3-(N,N- Dimethylaminoethyl)-5-methoxy-8-bromo-2-benzothiazino-[2,3,4-ab]indole-S,S- dioxide 3-(N,N- Dimethylaminoethyl)-5-methoxy-8-methyl-2-benzothiazino-[2,3,4-ab]indole-S,S- dioxide;

S,S-dioxide;

3-(2-N,N-Dimethylaminopropyl)-5-methoxy-2-ben∑othiazino-[2,3,4-ab]indole-S,S- dioxide; 3-(2-N,N-Dimethylaminopropyl)-6-methoxy-2-benzothiazino-[2,3,4-ab]indole-S,S- dioxide; 3-(2-N,N-Dimethylaminopropyl)-5,8-methoxy-2-benzothiazino-[2,3,4-ab]indole-S,S- dioxide; 3-(2-N,N-Dimethylaminopropyl)-5-methoxy-8-chloro-2-benzothiazino-[2,3,4-ab]indole- S,S-dioxide; 3-(2-N,N-Dimethylaminopropyl)-5-methoxy-8-fluoro-2-benzothiazino-[2,3,4-ab]indole- S,S-dioxide; 3-(2-N,N-Dimethylaminopropyl)-5-methoxy-8-bromo-2-benzothiazlno-[2,3,4-ab]indoIe- S,S-dioxide; 3-(2-N,N-Dimethylaminopropyl)-5-methoxy-8-methyl-2-benzothiazino-{2,3,4-ab]indole- S,S-dioxide;

3-(2-N,N-Dimethylaminopropyl)-5-methoxy-8-isopropyl-2-benzothiazino-[2,3,4-ab] indole-S.S-dioxide;

3-(N,N-Dimethylaminoethyl)-5-chloro-8,10-difluoro-2-benzothiazino-[2,3,4-cϊb]indole- S,S-dioxide;

3-(N,N-Dimethylaminoethyl)-5-methyl-8-chloro-2-benzothiazino-[2,3,4-ab]indole-S,S- dioxide;

3-(N,N-Dimethylaminoethyl)-5-chloro-8-isopropyl-2-benzothiazino-[2,3,4-ab]indole-S,S- dioxide; 3-(N,N-Dimethylaminoethyl)-5-methyl-8,10-difluoro-2-benzothiazino-[2,3,4-ab]indole-

S,S-dioxide;

3-(N,N-Dimethylaminoethyl)-7-trifluoromethyl-10-chioro-2-benzothiazino-[2,3,4- ab]indole-S,S-dioxide;

3-(N,N-Dimethylaminoethyl)-5-fluoro-7-trifluoromethyl-10-chloro-2-benzothiazino- [2,3,4-ab]indole-S,S-dioxide;

3-(N,N-Dimethylaminoethyl)-5,10-dichloro-7-trifluoromethyl-2-benzothiazino-[2,3,4- ab]indole-S,S-dioxide;

3-(N,N-Dimethylaminoethyl)-5-chloro-9-trifluoromethyl-2-ben∑othiazino-[2,3,4- ab]indole-S,S-dioxide and 3-(N,N-Dimethylaminoethyl)-9-trifluoromethyl-2-benzothiazino-[2,3,4-ab]indole-S,S- dioxide, and includes, tautomeric form, stereoisomers, geometric forms, N-oxides, polymorphs, isotopically radiolabelled derivatives, biologically active metabolites, biologically active derivatives, pharmaceutically acceptable salt, pharmaceutically acceptable solvate or hydrate of the compound or any combination of above derivatives.

3. A process for the preparation of a compound of general formula (I)

GENERAL FORMULA (I)

wherein R^ R₂, R₃, R₄, R₅, R₆, R_7ι R₈, R₉, R₁₀, Ru, Rι₂, R₁₃ and R₁₄, may be same or different and each independently represent hydrogen, halogen, oxo, thio, perhaloalkyl, hydroxy, amino, nitro, cyano, formyl, amidino, guanidino, substituted or unsubstituted groups selected from linear or branched (C.,-G₁₂)alkyl, (C₂-C-ι₂)alkenyl, (C₂-C₁₂)alkynyl (C₃-C )cycloalkyI, (C₃-C₇)cycloalkenyl, bicycloalkyl, bicycloalkenyl, (C C₁₂)alkoxy cyclo(C₃-C₇)alkoxy, aryl, aryloxy, aralkyl, aralkoxy, heterocyclyl, heteroaryl heterocyclylalkyl, heteroaralkyl, heteroaryloxy, heteroaralkoxy, heterocyclylalkyloxy acyl, acyloxy, acylamino, monoalkylamino, dialkylamino, arylamino, diarylamino aralkylamino, alkoxycarbonyl, aryloxycarbonyl, aralkoxycarbonyl heterocyclylalkoxycarbonyl, heteroaryloxycarbonyl, hydroxyalkyl, aminoalkyl monoalkylaminoalkyl, dialkylaminoalkyl, alkoxyalkyl, aryloxyalkyl, aralkoxyalkyl alkylthio, thioalkyl, alkoxycarbonylamino, aryloxycarbonylamino aralkyloxycarbonylamino, aminocarbonylamino, alkylaminocarbonylamino dialkylaminocarbonylamino, alkylamidino, alkylguanidino, dialkylguanidino, hydrazino hydroxylamino, carboxylic acid and its derivatives, sulfonic acids and its derivatives phosphoric acid and its derivatives; or two adjacent groups may form "cyclic structures", for example, Ri and R₂, R₂ and R₃, R₅ and R₆, R₆ and R₇, R₇ and R₈ together with the adjacent carbon atoms to which they are attached may form a 5, 6, or 7 membered ring, which may further optionally contain one or more double bonds and/or one or more heteroatoms such as the group "Oxygen", "Nitrogen", "Sulfur" or "Selenium" and combinations of double bond and heteroatoms; or R_g and R₁₀ or Ru and R₁₂ or R₁₃ and R ₄ together represent double bond attached to "Oxygen" or "Sulfur"; or two adjacent groups may form "cyclic structures" for example, Ru and R₁₂, Ru and R-i₃, R and R₁₄, R₁₃ and R^" ₁₄ together with the carbon atom/s to which they are attached may form a 3, 4, 5, or 6 membered ring, which may further optionally contain one or more double bonds, and/or one or more heteroatoms such as the group ^" "Oxygen", "Nitrogen", "Sulfur" or "Selenium" and also includes combination of one or more double bonds with "heteroatoms", as above defined; R₁₅ and R₁₆ may be same or different and each independently represents hydrogen, substituted or uftsubstituted groups selected from linear or branched -(Cι-C ₂)alkyl, (C₂-C₁₂)alkenyl, (C₂-Cι₂)alkynyl, (C₃-C₇)cycloalkyl, (C₃-C₇)cycloalkenyl, bicycloalkyl, bicycloalkenyl, aryl, aralkyl, heteroaryl, heterocyclylalkyl; optionally R ₅ and Rι_B along with the nitrogen atom may form a 3, 4, 5, 6 or 7 membered heterocyclic ring, which may further optionally contain one or more double bonds, and may include additional one or more heteroatoms such as the group "Oxygen", "Nitrogen", "Sulfur" or "Selenium" and also includes combination of one or more double bonds with "heteroatoms", as above defined; "n" ranges from 0 to 4, wherein the carbon chains which "n" represents may be either linear or branched which comprises cyclizing a compound of formula (II)

wherein X is halogen such chloro, bromo or iodo; R_{1 t} R₂, R₃, R₄, R₅, R₆, R₇, R₉, R₁₀, Ru, R1₂, Ri3, ₁₄ Ri5_> R₁6 and "n" are as defined previously, using a Pd(0) or Pd (II) derivative as a catalyst, for example tetrakis triphenylphosphine palladium, (Bis-tri-o- tolylphosphine) palladium(ll) chloride;

4. A process for the preparation of a compound of General formula

GENERAL FORMULA (I)

wherein R^ R₂, R₃, R , R₅, R₆, R₇, R₈, R₉, Rio, Ru, R1₂, R₁3 and R₁₄, may be same or different and each independently represent hydrogen, halogen, oxo, thio, perhaloalkyl, hydroxy, amino, nitro, cyano, formyl, amidino, guanidino, substituted or unsubstituted groups selected from linear or branched (C C₁₂)alkyl, (C₂-C₁₂)alkenyl, (C₂-C₁₂)aikynyl (C₃-C₇)cycloalkyl, (C₃-C₇)cycloalkenyl, bicycloalkyl, bicycloalkenyl, (C C₁₂)alkoxy cyclo(C₃-C₇)alkoxy, aryl, aryloxy, aralkyl, aralkoxy, heterocyclyl, heteroaryl heterocyclylalkyl, heteroaralkyl, heteroaryloxy, heteroaralkoxy, heterocyclylalkyloxy acyl, acyloxy, acylamino, monoalkylamino, dialkylamino, arylamino, diarylamino aralkylamino, alkoxycarbonyl, aryloxycarbonyl, aralkoxycarbonyl heterocyclylalkoxycarbonyl, heteroaryloxycarbonyl, hydroxyalkyl, aminoalkyl monoalkylaminoalkyl, dialkylaminoalkyl, alkoxyalkyl, aryloxyalkyl, aralkoxyalkyl alkylthio, thioalkyl, alkoxycarbonylamino, aryloxycarbonylamino aralkyloxycarbonylamino, aminocarbonylamino, alkylaminocarbonylamino dialkylaminocarbonylamino, alkylamidino, alkylguanidino, dialkylguanidino, hydrazino hydroxylamino, carboxylic acid and its derivatives, sulfonic acids and its derivatives phosphoric acid and its derivatives; or two adjacent groups may form "cyclic structures", for example, R^ and R , R₂ and R₃, R₅ and R₆, R₆ and R₇, R₇ and R₈ together with the adjacent carbon atoms to which they are attached may form a 5, 6, or 7 membered ring, which may further optionally contain one or more double bonds and/or one or more heteroatoms such as the group "Oxygen", "Nitrogen", "Sulfur" or "Selenium" and combinations of double bond and heteroatoms; or R₉ and R ₀ or Rn and R₁₂ or R₁₃ and R₁₄ together represent double bond attached to "Oxygen" or "Sulfur"; or two adjacent groups may form "cyclic structures" for example, R^ and R₁₂, Ru and R₁₃, Ru and R₁ , R₁₃ and R₁₄ together with the carbon atom/s to which they are attached may form a 3, 4, 5, or 6 membered ring, which may further optionally contain one or more double bonds, and/or one or more heteroatoms such as the group "Oxygen", "Nitrogen", "Sulfur" or "Selenium" and also includes combination of one or more double bonds with "heteroatoms", as above defined; R₁₅ and R₁₆ may be same or different and each independently represents hydrogen, substituted or unsubstituted groups selected from linear or branched (d-C₁₂)alkyl, (C₂-C₁₂)alkenyl, (C₂-C₁₂)alkynyl, (C₃-C₇)cycloalkyl, (C₃-C₇)cycloalkenyl, bicycloalkyl, bicycloalkenyl, aryl, aralkyl, heteroaryl, heterocyclylalkyl; optionally R₁₅ and R₁₆ along with the nitrogen atom may form a 3, 4, 5, 6 or 7 membered heterocyclic ring, which may further optionally contain one or more double bonds, and may include additional one or more heteroatoms such as the group "Oxygen", "Nitrogen", "Sulfur" or "Selenium" and also includes combination of one or more double bonds with "heteroatoms", as above defined; "n" ranges from 0 to 4, wherein the carbon chains which "n" represents may be either linear or branched which comprises reacting a compound of formula (III)

(in) wherein R-,, R₂, R₃, R₄, R₅, R₆, R₇, R₉, R₁₀, Ru, R₁₂, R₁₃, R₁₄ and "n" are as defined previously, with a suitable alkylating agent such as R₁₅ X or Rι₆ X or XR₁₅R₁₆X in successive steps or in one step, wherein X is good leaving group such as halogen;

5. A process for the preparation of compound of formula

GENERAL FORMULA (I)

wherein R-t, R₂, R₃, R₄, R₅, R₆, R₇, R₈, R₉, R10, Ru, R12, R13 and R₁ , may be same or different and each independently represent hydrogen, halogen, oxo, thio, perhaloalkyl, hydroxy, amino, nitro, cyano, formyl, amidino, guanidino, substituted or unsubstituted groups selected from linear or branched (C C₁₂)alkyl, (C₂-C₁₂)alkenyl, (C₂-C₁ )alkynyl (C₃-C₇)cycloalkyl, (C₃-C₇)cycloalkenyl, bicycloalkyl, bicycloalkenyl, (C C₁₂)alkoxy cyclo(C₃-C₇)alkoxy, aryl, aryloxy, aralkyl, aralkoxy, heterocyclyl, heteroaryl heterocyclylalkyl, heteroaralkyl, heteroaryloxy, heteroaralkoxy, heterocyclylalkyloxy acyl, acyloxy, acylamino, monoalkylamino, dialkylamino, arylamino, diarylamino aralkylamino, alkoxycarbonyl, aryloxycarbonyl, aralkoxycarbonyl heterocyclylalkoxycarbonyl, heteroaryloxycarbonyl, hydroxyalkyl, aminoalkyl monoalkylaminoalkyl, dialkylaminoalkyl, alkoxyalkyl, aryloxyalkyl, aralkoxyalkyl alkylthio, thioalkyl, alkoxycarbonylamino, aryloxycarbonylamino aralkyloxycarbonylamino, aminocarbonylamino, alkylaminocarbonylamino dialkylaminocarbonylamino, alkylamidino, alkylguanidino, dialkylguanidino, hydrazino hydroxylamino, carboxylic acid and its derivatives, sulfonic acids and its derivatives phosphoric acid and its derivatives; or two adjacent groups may form "cyclic structures", for example, R₁ and R₂, R₂ and R₃, R₅ and R₆, R₆ and R₇, R₇ and R₈ together with the adjacent carbon atoms to which they are attached may form a 5, 6, or 7 membered ring, which may further optionally contain one or more double bonds and/or one or more heteroatoms such as the group "Oxygen", "Nitrogen", "Sulfur" or "Selenium" and combinations of double bond and heteroatoms; or R_g and R₁₀ or Ru and R₁₂ or R₁₃ and R₁₄ together represent double bond attached to Oxygen" or "Sulfur"; or two adjacent groups may form "cyclic structures" for example, Ru and R₁₂, Ru and R ₃, R^ and R₁₄, R₁₃ and R₁ together with the carbon atom/s to which they are attached may form a 3, 4, 5, or 6 membered ring, which may further optionally contain one or more double bonds, and/or one or more heteroatoms such as the group "Oxygen", "Nitrogen", "Sulfur" or "Selenium" and also includes combination of one or more double bonds with "heteroatoms", as above defined; R₁₅ and R₁₆ may be same or different and each independently represents hydrogen, substituted or unsubstituted groups selected from linear or branched (C Cι₂)alkyl, (C₂-C₁₂)alkeny), (C₂-C₁₂)alkynyl, (C₃-C₇)cycloalkyl, (C₃-C₇)cycloalkenyl, bicycloalkyl, bicycloalkenyl, aryl, aralkyl, heteroaryl, heterocyclylalkyl; optionally R₁₅ and R₁₆ along with the nitrogen atom may form a 3, 4, 5, 6 or 7 membered heterocyclic ring, which may further optionally contain one or more double bonds, and may include additional one or more heteroatoms such as the group "Oxygen", "Nitrogen", "Sulfur" or "Selenium" and also includes combination of one or more double bonds with "heteroatoms", as above defined; "n" ranges from 0 to 4, wherein the carbon chains which "n" represents may be either linear or branched, which comprises reacting a compound of formula (IV)

wherein Ri, R₂, R₃, R₄, R₅, R₆ and R₇ are as defined previously, with formaldehyde and a compound of formula (V) NHR₁₅Rιe (V) wherein R₁₅ and R₁₆ are as defined earlier.

6. A process according to any one of claims 3 to 5 further including one or more of the following optional steps: i) removing any protecting group; ii) resolving the racemic mixture into pure enantiomers by the known methods and iii) preparing a pharmaceutically acceptable salt of a compound of formula (I) and/or iv preparing a pharmaceutically acceptable a prodrug thereof.

7. A pharmaceutical composition comprising either of a pharmaceutically acceptable carrier, diluent, excipients or solvate along with a therapeutically effective amount of a compound according to Claim-1, and also tautomeric form, stereoisomers, geometric forms, N-oxides, polymorphs, isotopically radiolabelled derivatives, . biolog cally active metabolites, biologically active derivatives, pharmaceutically acceptable salt, pharmaceutically acceptable solvate or hydrate of the compound or any combination of above derivatives.

8.A pharmaceutical composition of compounds of general formula (I) according to Claim 5, in the form of a tablet, capsule, powder, syrup, injectable, solution or suspension.

9. Use of the compounds as claimed in Claim 1 , in combination with other pharmaceutical agents, such as apo-B/MTP inhibitors, MCR-4 agonists, CCK-A agonists, monoamine reuptake inhibitors, sympathomimetic agents, adrenergic receptor agonists, dopamine agonists, melanocyte-stimulating hormone receptor analogs, cannabinoid 1 receptor antagonists, melanin concentrating hormone antagonists, leptins, leptin analogs, leptin receptor agonists, galanin antagonists, lipase inhibitors, bombesin agonists, neuropeptide-Y antagonists, thyromimetic agents, dehydroepiandrosterone or analogs thereof, glucocorticoid receptor agonists or antagonists, orexin receptor antagonists, urocortin binding protein antagonists, glucagon-like peptide-1 receptor agonists, ciliary neurotrophic factors, AGRPs (human agouti-related proteins), ghrelin receptor antagonists, histamine 3 receptor antagonists or reverse agonists, neuromedin U receptor agonists, in a therapeutically effective amount via a suitable pharmaceutical composition, to achieve the desired effect in mammals as well as humans.

10. Use of compound of general formula (I), as defined in Claim 1 or a pharmaceutical composition as defined in Claim 3 for preparing the medicaments.

11. Use of a compound as claimed in Claim 1 for the treatment and/or prevention of clinical conditions such as anxiety, depression, convulsive disorders, obsessive- compulsive disorders, migraine headache, cognitive memory disorders, ADHD (Attention Deficient Disorder/ Hyperactivity Syndrome), personality disorders, psychosis, paraphrenia, psychotic depressron,τπaπia, schizophrenia, sc iizσphreniform ^' disorders, withdrawal from drug abuse, panic attacks, chronobiological abnormalities, circadian rhythms, anxiolytic, Osteoporosis, ischemic stroke, lower the risk of SIDS in young infants with low endogenous melatonin levels, reproduction, glaucoma, sleep disorders and also disorders associated with spinal trauma and /or head injury.

12. Use of a compound as claimed in Claim 1 for the treatment of mild cognitive impairment and other neurodegenerative disorders like Alzheimer's disease, Parkinsonism and Huntington's chorea.

13. Use of a compound as claimed in Claim 1 for the treatment of certain Gl (Gastrointestinal) disorders such as IBS (Irritable bowel syndrome) or chemotherapy induced emesis.

14. Use of a compound as claimed in Claim 1 to reduce morbidity and mortality associated with the excess weight.

15. Use of a radiolabelled compound as claimed in Claim 1 , as a diagnostic tool for modulating 5-HT and/or Melatonin receptor function.