CA2074816A1 - Therapeutic agents - Google Patents

Abstract

Compounds of formula (I), in which R1 represents hydrogen, cyano, C2-6 alkanoyl, C2-6 alkoxycarbonyl, CONH2, or R1 represents C1-6 alkyl or C2-6 alkenyl both of which may be substituted by cyano, halo, trifluoromethyl, hydroxy, benzoyl, C2-6 alkanoyloxy, C3-8 cycloalkoxycarbonyl, a 5-7 membered non-aromatic heterocyclic group containing 2 oxygen heteroatoms, CONR9R9', phenoxy or C1-6 alkoxy, in which C1-6 alkoxy may be further substituted by halo, hydroxy, C1-6 alkoxy or C2-6 alkanoyloxy; R2 represents hydrogen or chloro; R3 represents chloro or trifluoromethyl; or R2 and R3 are joined to form a fused benz ring; R4 represents hydrogen, C1-6 alkyl, C1-6 alkoxy or halo; R9 and R9', which may be the same or different represent hydrogen, C1-6 alkyl or benzyl, for use as immunomodulatory agents.

Description

, WO91/12255 2D7 ~ PCT/EP91/U0153 THERAPEUTIC AGENTS

; The present invention relates to novel therapeutic agents, and in particular to r1]benzopyrano[4,3-cl-pyrazolesj to processes for their preparation, to pharmaceutical compositions containing them and to their therapeutic activity as immunomodulatorv agents.

The present invention relates to novel compounds of formula I
,Rl ~ ~ R2 in which R1 represents hydrogen, cyano, C2 6 alkanoyl, C2 6 alkoxycarbonyl, CONH2, or R1 represents C1 6 alkyl or C2 6 alkenyl both of which may be substituted bv cyano, halo, trifluoromethyl~ hydroxy, benzoyl, C2 6 alkanoyloxy, C3 8 cycloalkoxycarbonyl, a 5-7 membered non-aromatic heterocyclic group containing 2 oxygen heteroatoms, CONRgRgl~ phenoxy or C1 6 alkox~, in which C1 6 alkoxy may be further substituted by halo, hydroxy, C1 6 alkoxy or C2 6 alkanoyloxy;

. R2 represents hydrogen or chloro;

R3 represents chloro or trifluoromethyl;

or R2 and R3 are joined to form a fused benz ring;

R4 represents hydrogen, C1 6 alkyl, C1 6 alkoxy or halo;

.

:

Wos1/122ss 2074~ 2 - PCT/EP91/0~15~--Rg and R9, , which may be the same or different, represent hydrogen, C1 6 alkyl or benzyl, or pharmaceutically acceptable salts thereof.

It will be understood that a group containing a S chain of 3 or more carbon atoms may be straight o~
branched, for example propyl includes n-propyl and isopropyl, and butyl includes n-butyl, sec-butyl, isobutyl and tert-butyl. The term "halo" includes fluoro, chloro or bromo.

Preferably R1 represents hydrogen, cyano, carbamoyl, C2 4 alkanovl ~for example acetyl), C2 4 alkoxycarbonyl (for example methoxycarbonyl or ethoxycarbonyl), or -CH2Rlo in which R10 represents hydrogen, cyano, trifluoro-methyl, halo, hydroXY, C3_g cycloalkoxycarbonyl (preferablv cyclobutoxycarbonyl), benzoyl, CONHR9 (for example carbamoyl, methylcarbamoyl, ethylcarbamoyl or propylcarbamoyl) or a 5-7 membered non-aromatic heterocyclic group containin~ two oxygen heteroatoms (for example 1,3-dioxolan-2-yl or 1,3-dioxan-2-yl; or Rlo represents C1 4 alkyl, (for example methyl, ethyl or propyl, more preferably methyl or ethyl) or C2 4 alkenyl (for example vinyl) both optionally substituted with hydroxy, cyano, trifluoromethyl, halo ~preferably chloro or bromo), C1 6 alkoxy (preferably methoxy or ethoxy), C1 6alkoxy(C1_6)alkOXY (preferably 2-methoxyethoxy), C2-6alkanoyloxy(cl-6)alkoxy (preferably acetoxvethoxy), hydroxy(C1 6 alkoxy) (preferably 2-hydroxyethoxy), C2_6 alkanoyloxy (preferably acetoxy or propionyloxy), phenoxy, benzoyl, CONHRg (for example carbamoyl, methylcarbamoyl, . WO91/12255 ~ PCT/EP91/00153 ethylcarbamoyl or propylcarbamoyl) or a 5-7 membered non-aromatic heterocyclic group containing two oxygen heteroatoms (for example l,3-dioxolan-2-yl or 1,3-dioxan-2-yl).

S In preferred compounds, R~ represents (CH2) J in which J represents hydrogen, Cl 6 alkoxy, cyano, halo or carbamoyl, and p is 0, ~ or 2, particularly hydrogen, methyl, cyanomethyl, (CH2)2halo, carbamoylmethyl or Cl 4 alkoxyethyl.
lo Preferred substituents Rl are hydro~en, methyl, ethyl, propyl, butyi, allyl, 2-methoxyethyl, 2-ethoxyethyl, 2-ethoxypropyl, 2-(2-methoxyethoxy)ethyl 2-(2-acetoxyethoxy)ethyl, 2-(2-hydroxyethoxy)ethyl cyclobutyloxycarbonylmethyl, carbamoyl, methylcarbamoylmethyl, 2-carbamoylethyl,3-carbamoylpropyl ethylcarbamoylmethyl, propylcarbamoylmethyl, isopropylcarbamoylmethyl, benzyl(methyl)carbamoylmethyl, carbamoylmethyl, 2-hydroxyethyl, 3-hydroxypropyl 2-acetoxyethyl, cyano, cyanomethyl, 2-cyanoethyl, 2-phenoxyethyl, 2-chloroethyl, 2-bromoethyl, 2,2,2-trifluoroethyl 2-propionyloxyethyl, 1,3-dioxolan-2-ylmethyl, 2-(1,3-dioxan-2-yl)ethyl, 2-(1,3-dioxolan-2-yl)ethyl, acetyl, benzoylmethyl, ethoxycarbonyl.

In especially preferred compounds Rl represents methyl or 2-ethoxyethyl.

In preferred compounds of formula I, R2 represents hydrogen.

.

2 ~ 7 ~ PCT/EP91tOO153,~

In preferred compounds of formula I, R3 represents chloro or trifluoromethyl, more preferably trifluoromethyl.

In preferred compounds of formula I, R4 represents hydrogen, C1 4 alkyl, C1 4 alkoxy, fluoro, chloro, or bromo. More preferably R4 represents hydrogen, methyl, methoxy or ethoxy most preferabiy hydrogen or methoxy.

Preferably Rg represents hydrogen, methyl or ethyl or benzyl, especially hydrogen or methyl.

Preferably Rg, represents hydroge~ or benzyi.

Particular compounds of rormula I are the compounds listed in Table A provided in the specific Examples of the invention, or pharmaceutically acceptable salts thereof.

Compounds o~ formula I may contain one o~ more chiral centres and exist in different optically active forms. When compounds of formula I contain one chiral centre the compounds exist in two enantiomer c .orms and the present invention includes both enantiome s an~
mixtures of enantiomers. The enantiomers may be resolved by methods known to those skilled in the art, for example by formation of diastereoisomeric salts or complexes which may be separated, for example, by crystallisation; formation of diastereoisomeric derivatives which may be separated, for example, by crystallisation, gas-liquid or liquid chromatography;
selective derivatisation of one enantiomer by reaction with an enantiomer-specific reagent, for example enzymatic oxidation or reduction; or gas-liquid or liquid chromatography in a chiral environment, for WO91/12255 2 ~ 7 ~ PCT/EPgl/00153 example on a chiral support, for example silica with a bound chiral ligand or in the presence of a chiral solvent. Alternatively, specific enantiomers may be synthesised by asymmetric synthesis using optically active reagents, substrates, catalysts or solvents, or by converting one enantiomer into the other bv asymmetric transformation.

For example, the following compound may also exist in the R- or S- enantiomeric form:

4-(4-chlorophenyl)-2-(2-ethoxypropyl)[l]-benzopyrano[4,3-c]pyrazol-3(2H)-one.

When compounds o~ formula I contain more than one chiral centre, the compounds may exist in diastereoisomeric forms. The present invention includes each diastereoisomer and mixtures o' the diastereoisomers. The diastereoisomers mav be separated by methods known to those skilled in the art, for example by crystallisation or liquic chromatography.

Certain compounds of formula I may exist in different tautomeric forms or as different geometric isomers.

Certain compounds of formula I may exist in more than one crystal form and the present invention includes each crystal form and mixtures thereo'.

...

.
.~ '' '. ~. :

WO91/12255 2 ~ 7 ,!~ PCT/EP91/00153---Certain compounds of formula I may also e~ist in - the form of solvates, for example hydrates, and the present invention includes each solvate and mlxtures thereof.

S The present invention also includes pharmaceutical compositions containing a therapeutically effective amount of a compound of formula I togethe- with a pharmaceutically acceptable diluent or carrier.

As used hereinafter, the term "active compound"
deno~es a [1]benzopyrano[4,3-c~pyrazole of formula I.
In therapeutic use, the active compounc may be administerec orally, -ectally, ?a-enter~lly o-topically, preferably orally or topically. Thus the therapeutic compositions of the present invention take the form of any of the known pharmaceutical compositions for oral, rectal, parenteral o- topical administration. Pharmaceutically acceptable carriers suitable for use in such compositions a_e well known in the art of pharmacy. The compositions of the invention may contain 0.1-90% by weight of active compound. The compositions of the invention are generally prepared in unit dosage form. The excipients used in the preparation of these compositions are the excipients known in the pharmacist's art.

Compositions for oral administration are preferred compositions of the invention, and these are known pharmaceutical forms for such adminis~ration, for example tablets, capsules, syrups and aqueous or oily suspensions. Tablets may be prepared by mixlng the active compound with an inert diluent such as lactose ., : .
.~ ~ ' ' .
:\ . .

WO91/1225~ PCT/EP91/00153 or calcium phosphate in the presence of disintegratins agents, for example maize starch, and lubricating agents, for example magnesium stearate, and tableting the mixture by known methods. The tablets may be ; formulated in a manner known to those skilled in the art so as to give a sustained release of the compounds of the present invention. Such tablets may, ic desired, be provided with enteric coatings bv known methods, for example by the use of cellulose acetate phthalate. Similarly, capsules, for example hard or soft gelatin capsules, containing the active compound with or without added excipients, may be prepared b~
conventional means and, if desired, provided witn enteric coatings in a known manner. The tablets anc 15 capsules may conveniently each contain 0.1 to 500 mg cc the active compound. Other compositions for oral administration include, for example, aqueous suspensions containing the active compoun~ in ar.
aqueous medium in the presence of a non-toxic suspending agent such as sodium carboxymethylcellulose, and oily suspensions containing a compound o: the present invention in a suitable vegetable oil, fc~
example arachis oil.

Compositions for topical administration are also preferred compositions of the invention. The pharmaceutically active compound may be dispersed in a pharmaceutically acceptable cream, ointment or gel. A
suitable cream may be prepared by incorporating the active compound in a topical vehicle such as petrolatum and~or light liquid paraffin, dispersed in an aqueous medium using surfactants. An ointment may be prepared by mixing the active compound with a topical vehicle such as a mineral oil, petrolatum and/or a wax e.g.
paraffin wax or beeswax. A gel may be prepared by mixinq the active compound with a topical vehicle comprising a gelling agent e.g. basified Carbomer BP, WO91/12255 2 0 7 ~ PCTtEP91/00153-in the presence of water. Topically administrable compositions may also comprise a matrlx in which the pharmaceutically active comp~unds of the present invention are dispersed so that the compounds are held in contact with the skin in order to administer the compounds transdermally. A suitable transdermal composition mav be prepared by mixinc the pharmaceutically active compound with a topical vehicle, such as described above, together with a potential transdermal accelerant such as dimethyl sulphoxide or propylene glycol.

Compositions of the invention suitable for recta7 administration are known pharmaceulical forms fo- suc~
administration, for example suppositories with semi-synthetic glycerides or polyethylene glycol bases.

Compositions o. the invention suitable for parenteral administration are known pharmaceutical forms for such administration, for example sterile suspensions in aqueous and oily media or sterile solutions in a suitable solvent.

In some formulations it may be beneficial to use the compounds of the present invention in the form o' particles of very small size, for example as obtained by fluid energy milling.

In the compositions of the present invention the active compound may, if desired, be associated with other compatible pharmacologically active ingredients.

The compounds of formula I are indicated for use as immunomodulatory agents, and are generally immunosuppressants, but some compounds, in certain disease states, may exhibit immunostimulant activity.
The compounds according to the invention are useful in WO91/12255 ~ & ~ PCT/EP91/00153 g _ the treatment of diseases resulting from an aberrant immune reaction. Thus the pharmaceutical compositions containing a therapeutically effective amount of a compound of formula I may be used to treat diseases S with an immunological association for example tissue relection, such as kidney rejection; autoimmune diseases, such as rheumatoid arthritis and svstemic lupus erythematosus; cutaneous disorders, such as contact sensitivity, eczema and psoriasis; and neoplasia, such as melanoma.

In such treatment the amount of the compound of formula I administered per day will be such as to give a therapeutic effec~ and is generally in tne rance 0.' to 2000 mg, preferably 1 to 500 mg.

Accordingly, in another aspect, the present invention also includes a method of treating diseases with an immunological associatior., comprising the administration of a therapeutically effective amount o~
a compound of formula I.

The therapeutic activitv of compounds Oc formuia I
has been demonstrated b~ means of tests on standard laboratory animals. Such tests include, for example, the oral and parenteral administration of the compounds to BALB/c mice. Thus, compounds of formula I are useful as immunomodulatory agents. Whilst the precise amount of active compound administered will depend on a number of factors, for example the age of the patient, the severity of the condition and the past medical history and always lies within the sound discretion of the administering physician, a suitable dose for oral administration to mammals, including humans, is generally within the range 0.01-40 mg/kg/day, more usually 0.2-25 mg/kg/day given in single or divided doses. For parenteral administration, a suitable dose WO91/122~5 2 0 7 ~ o, l~j PCT/EP91/0015~--- I O

is generally within the range 0.001-4.0 mg/kg/day, more usually 0.005-l mg/kg/day given in single o~ divided doses or by continuous infusion. A suitable preparation for topical administration generally contains the active in~redient within the ranae 0.01-20~ by weight, more usually 0.05-5~ bv weigh .
Oral administration is preferred.

Processes for the preparation of compounds of formula I will now be described. These processes form a further aspect of the present invention.

Compounds of rormula I mav be prepared bv reactins a compound o formula II, ,R
. ~0 11 or a tautomer thereof with a compound of formula III

R2 ~ CR14R15 in which R14 represents (Q)2 or (SQ)2 and R15 lS represents OQ or SQ or NQ'2; R14 represents = NH and Rl;
represents OQ or SQ; or R14 represents = O and R15 .

WO91/12255 ~ rt?~i~ PCT/EP91/00153 1 1 _ represents hydrogen, halo or 1-imidazolyl; and Q and represent a C1 4 alkyl group or a benzyl group.

Compounds of formula I may be prepared by reacting compounds of formula IV

~OR16 . OR17 in which R16 representa hvdrogen, or 2 tau~ome~
thereof, or in which R16 represents a group COR18 wherein R18 represents hydrogen, a C1 4 alkvl group, a benzyl group or a group R5 and R17 represents COR5 in which R5 represents IIIa R2~
1¦ Illa R3~

with a base e.g. piperidine in a suitable solvent e.g ethanol.

Compounds of formula I may be prepared by reacting compounds of formula IV in which R1 and R16 represent COR18 and R17 represents hydrogen with a carboxylic acid chloride for example a substituted benzoyl chloride in the presence of a base for example triethylamine followed by heating in the presence of a base for example piperidine.

WO91/12255 ~ PCT/EP91/00153,--Compounds of formula I in which Rl represents an alkyl group or alkenyl group substituted as herein described may be prepared by alkylating correspondins compounds of formula I in which R1 represents hydrogen, ; for example by reaction with a compound Oc formula R1X
in which X represents halo in the presence of a base e.s. sodium hydride.

Compounds of formula I in which R1 represents C2 alkanoyl may be prepared by acylation of correspondlng compounds of formula I ln which ~ represents hyd-oger., for example by reaction with an acyl halide.

Compounds of for,~ula I in which R. re?resen.~
cyano may be prepared bv cyanation of cor-esponding compounds of formula I in which R1 represents hydroger., for example by reaction with cyanogen bromide in the presence of a base, for example sodium hydride.

Compounds of formula I in which R1 represents C2 6 alkoxycarbonyl may be prepared by the substitution o-corresponding compounds of formula I in whic~
represents hydrogen with a C2 6 alkoxycarbonyl grou~, for example by reaction with compounds of formula ~C2 6 alkoxycarbonyl)A where A is a leaving group, for example cyano or halo.

Compounds of formula I in which R1 represents carbamoylalkyl, e.g. carbamoylmethyl, may be prepared by the hydrolysis of corresponding compounds Oc formula I in which R1 represents cyanoalkyl, e.g. cyanomethyl.

Compounds of formula I in which R1 represents CONHR30 in which R30 represents a readily hydrolysable group for example chlorosulphonyl, may be prepared by reacting corresponding compounds of formula in which R1 represents hydrogen with an isocyanate cf . .

WO91/1225~ 2 3 ~ PCT/EP91/00153 formula R30N=C=O. Compounds of formula I in which Rl represents carbamoyl mav be prepared by hydrolysis, for example acid hydrolvsis, of corresponding compounds of formula I in which R~
S represents CONHR30.

Compounds of formula I in which Rl is substituted by a carboxylic amide group (CONRgRgt) may be prepared by reacting corresponding compounds of formula substituted by a group -COA where A represents a leaving group for example, hydroxyl, halo, Cl 6 alkoxy, aryloxy, arylmethoxy or Cl 6 acyloxy with a Cl 6 alcohol or amine (HNRgRg,)respectively, for example a.
0-250C, optionallv in the presence Or z~. organ-e liquid which is preferably a solvent for the reactants and optionally in the presence of a catalyst for the reaction.

Compounds of formula I in which Rl represents a group substituted by a hydroxyl group may be prepared by the hydrolysis of corresponding compounds of formula substituted by a C2 6 alkanoyloxy group, for example acetoxy.

Compounds of formula I in which Rl is substituted by a C2 6 alkanoyloxy group may be prepared by acylation of corresponding coMpounds of formula substituted by a hydroxy group.

Compounds of formula II may be prepared by reacting compounds of formula V

~,~ V
o WO91~122~5 ~ PCT/EP91/001~3~--., with a hydrazine of formula H2NN~Rt.

Compounds of formula III wherein R14 represents (Q)2 and R15 represents OQ mav be prepared for example a) by reacting compounds of formula R5CX3 in which X is halo with a sodium alkoxide of formula NaOQ in which Q
ls a Cl_4 alkyl group or a benzyl group, or b) by reacting compounds of formula R5CN with an alcohol of formula QOH in the presence of an anhydrous acid, for example hydrogen chloride, to qive compounds of formula R;C(=NH)OQ as their acid salts, e.g. hydrochloride salts, which are then reacted with further alcohol of rormula QO~.

Compounds oI formula IV in which R16 represents COR18 and R17 represents COR5 mav be prepared by acylation of compounds of formula IV in which R16 represents COR18 and R17 represents hydrogen, for example by reaction with an acid anhydride o' formula (R5CO)2O in the presence of a salt ~e.g. the sodium salt) of the corresponding acid or an acid halide e.a.
of formula R;COCl in the presence of a base e.g.
triethylamine.

Compounds of formula IV in which R16 represents COR18 and R17 represents hydrogen may be prepared by the acylation of compounds of formula II for example by reaction with an acid anhydride of formula (R18CO)2O in the presence of a salt (e.g. the sodium salt) of the corresponding acid.

Compounds of formula IV in which R17 represents COR5 and R16 represents hydrogen, or tautomers thereof, may be prepared by reacting a compound of formula IV in which R16 represents COR18 and R17 represents COR5 with a base e.g. piperidine ir. a suitable solvent e.g. ethanol.

WO91/1225~ PCT/EP91/001~3 - ~5 -Compounds of formula IV in which R1 and R16 represents COR18 in which R18 is as hereinbefore defined, and R17 represents hydrogen may be prepared by reacting compounds of formula II in which R1 represents hydrogen with an acid anhydride of formula (R18CO~2O in the presence of a salt (e.g. the sodium salt) o' the corresponding acid.

Compounds of formula V may be prepared bv reacting compounds of formula VI

R

~ OH

in which R23 represents hydrogen with malonic acld in the presence of an acid chloride e.g. phosphor~l chloride and a Lewis acid e.g. zinc chloride.

Compounds of formula V may be prepared bv reacting compounds of formula VI in which R23 represents an acetyl group with a base, for example sodium hydride, and a dialkyl carbonate of formula ~QO)2CO in which Q represents a C1 4 alkyl group or a benzyl group, e.g. dimethyl carbonate.

Compounds of formula V in which R4 represents C1 6 alkoxy may be prepared from compounds of formula VI
in which R4 represents halo e.g. fluoro, and R23 represents an acetyl group with a base for example sodium hydride, and a dialkyl carbonate of WO91/12255 2 ~ PCT/EP91/001~3--formula (Q0)2C0 in which Q represents a C~ 4 alkyl group or a benzyl group, e.g. dimethyl carbonate.

Certain intermediate compounds of formulae II, III, IV, V, and VI are believed to be novel compounds.
All novel compounds herein are claimed as a furthe_ aspect of the invention.

This invention is illustrated by the following non-llmitative Examples. In the Examples parts and percentages are by weight and compositions of mixed solvents are given by volume. Characterisation was by elemental analysis and one or more of the ~ollow~.g spectroscopic techniques: nuclear magneti- -~sonanc~, infra-red and mass spectroscopy.

Example 1 a) 2'-Fluoro-6'-hydroxyacetophenone (30 g) was added dropwise over 30 minutes to a stirred suspension o' sodium hydride (17.1 g, 60~ dispersion in mineral oil) in dry toluene (400 ml) which was boiling under reflux under nitrogen. After boiling for a further 20 minutes heating was continued while diethyl carbonate (50.8 g) was added dropwise over 10 minutes. The resulting mixture was stirred and heated under reflux for 20 hours. The reaction mixture was cooled to ambient temperature and water (150 ml) added dropwise. After separation, the aqueous phase was washed with ether and then acidi~ied with concentrated hydrochloric acid.
The precipitate was collected by filtration and washed with water to give, after drying and recrystallisation from ethyl acetate, S-ethoxy-4-hydroxycoumarin, m.p.
30 110-111C.

WO 91/12255 ~ rJ PCI/EP91/00153 Example 2 A stirred mixture of 4-hydroxycoumarin (10.0 g), ethylhydrazine oxalate (14.25 g) and triethylamine (24.0 ml) in dry toluene (50 ml) was heated unde_ reflux for 3 hours with removal of water formed in the reaction. The solid collected after filtraticn was partitioned between water and dichloromethane. The organic layer was dried and evaporated to give a solid which was recrystallised from butanol to give 1-ethyl-3-(2-hydroxyphenyl)-2-pyrazolin-5-one, m.p.
147-150C.

~xam~le 3 Hydrazine (32.3 g) was added dropwise during 0.25 hours to a stirred solution of 4-hydroxycoumarin (50.0 g) in absolute alcohol (1.2 l) and the reaction mixture was heated under reflux with stirring for 20 hours. The solution was cooled and acidified with glacial acetic acid ~154 ml) and the ethano1 was evaporated off under reduced pressure to leave an oil which was then poured into water ~1.5 l). The resulting solid was filtered of', washed with wate-, dried and recrystallised from isopropanol to give 3-(2-hydroxyphenyl)-2-pyrazolin-5-one, m.p. 205-207C.

Examp es 4 to 6 In a similar manner to that described in Example 3, a compound of formula II was prepared by reacting a compound of formula V, with a hydrazine of formula H2NNHR1, as summarized in Table A below in which substituents R4 and R1 are given.

.. '~

WO 91/12255 ~ i '3 Pcl/Ep9l/ool53r ~

OU ~ _ _ _ ~ C h O _ _ _ V _, CV~ o o '1:5 C u1 0 L~ 0 ~
C 00 ~ ~ C
~1 _ _ _ 0 'Vc 3 C 0 X C
O O m _ E u~
o . ~ Ll 0 E ~ 3 0 C
_ C~ E 3: 3 LO~ E
. H ~ Z O O au 0 U~ tU C) ~ 3 ~-1 cr~ ~ L~ 0-O ~ ,C Ll ~ aJ O
~c u~
c ~ .v 3 O u~ c c c . ~1 ~ ~ c) o O . ~ tn,/ v a) ~ I c o ~ c a~--a ~ c I :~ o v r _~ V ~ JJ C ~ U) 0 0 O X L~ X CL U~ 0 ~ C h~r c o ol a~ h E 0~
C ~:1 -- ~ Ln ~ 0 ~ ~ ~ ~ 0 1 0 C--O ~ ^ O c c 3 u~ E u~ O-r/
a) U ~ ~ h ~
,q ,~ ,:~ ~r~ = ~ _, v o ~ ~ :~
~i ~:; i~ ~ ~o ~ o ~ E
E~ ~ æ; ~~ ~- o -~ ~ c r ~ I v O ir --_ ~ ~ E''l x E ` Q,~ x o o.
C ~r ~ O 'C S O ~ O ~I E C! ~ _ o c~ ~o ~ o ~ v ).I c ~ _ O ~ . . . ~ ~ 0 ~ O
~ u~ ~ ~ ~ ~1 3 ,~
~; ~ ~ ~ ~ ,~
~ v ~. i C' s o ~: ~ v v ~n v 0 ~ v ~ a) - --, 0 0 U 3 au t)-rl ~ h ~ -1 3 3 _ 0 c 0 3 E a,~ --~ c r v v ~ v ~ _~ ~ ,1 h ~ V.
Z X--~ ~ X ~U 0--1 h 0 C-~ V
Z ~ ~ ~ u 3 0 o~ ,c ~ ~ aJ E r~ 3 ~
r i' ;_ ~r V U~ V :~ h U ~ ~ ~ 0 _I c 0 o aJ ~ 0 ,a a~ E 0 3 _I ~) E U c 3,c o 3 ~C,C ~ 0 C
U~ h a~ E v ~ X s o~ u~
v ~ u~ c o v 0 u 3 u a~ h ~1 h a~ 3 ,c E u r~ ' ~ Q~ ~) ~ c e h :~, O ~
~r U_i O h ~ O ~n C V 3 ~ ,c ~ ~ s ~ ¦ ~ i-- O U h ~ ,1 h V -l ~) ~ JJ I O ~ 3 a~ 3 -I ~ u ~ I 3 o ~_1 U
. a) . s v v ,c v i : ~ v . ~ ~. OJ O E-~
E o~ ~ ~ q) o h _ v c, ~ a~ u~ e v v D -- ~ h --V ~ g V ~ I C X ,C
In o u~ O

.

. .

WO91/1225~ PCT/EP91/00153 The compounds of formula II prepared in Examples 4-6 were as follows:

Example 4 3-~2-hydroxyphenyl)-1-methyl-2-pyrazolin-5-one ; Example 5 3-(2-hydroxy-6-methoxyphenyl)-1-methyl-2-pyrazolin-5-one Example 6 3-(2-hydroxy-6-methylphenyl)-1-methyl-2-pyrazolln-5-one ~xamDle 7 _ A solution of 4-trifluoromethylbenzonitrile (25 g) in dry ether (120 ml) and dry methanol (6 ml) was cooled at 0-5C and saturated with hydrogen chloride gas. The reaction mixture was allowed to stand lS overnight in a melting ice bath and the imidate salt which precipitated was collected by filtration, washed with ether and dried in a desiccator. This solid was added to AR methanol (78.3 ml) with stirring and the mixture stirred at ambient temperature for 5 days. The reaction mixture was filtered and the filtrate was evaporated under reduced pressure to give trimethyl ortho(4-trifluoromethylbenzoate) as an oil which was used without further purification.

ExamDle 8 a) A mixture of 4-hydroxy-5-methoxycoumarin (4.0 g) and hydrazine hydrate t3.0 ml) in industrial methylated spirit (84 ml) was boiled under reflux for 4.75 hours. On cooling, glacial acetic acid (13.3 ml) was added and the alcohol removed under reduced pressure. The residue was added to water and a gum separa~ed which solidified on the addition of a small 5 ~ 3,; PCT/EP91/001S~

amount of dichloromethane. The solid was collected by filtration to give 3-(2-hydroxy-6-methoxyphenyl)-2-pyrazolin-5-one, m.p. 208-210C.

b) A mixture of 3-(2-hydroxy-6-methoxyphenyl)-2-pyrazolin-5-one (2.06 g) and 1-(4-trifluorometh benzoyl)imidazole (5.04 g) in dry xylene (50 ml) was stirred and heated unde~ reflux under nitroger. fo-0.5 hours then cooled to ambient temperature. The solid formed was collected by filtration and then dissolved in boiling industrial methvlate~
spirit/dichloromethane (1:2). Dichloromethane was boiled off until a solid separated. The mixture w25 cooled to ambien~ tempe ature an~ filtere~ ~e cive 9-methoxy-4-(4-trifluoromethylphenyl)[1]benzopyrano-[4,3-c]pyrazol-3(2H)-one, m.p. >280C (with decomposition).

c) Sodium hydride (0.114 g, 60% dlspersion in mineral oil) was added to a suspension of 9-methoxy-4-~4-trifluoromethylphenyl)[l]benzopyrano[4,3-c]pyrazol-3(2H)-one (0.94 g) in dry N,N-dimethylformamide (55 ml). The mixture was st_rred ~ ambien~
temperature for 10 minutes, then 2-bromoethvl ethyi ether (0.36 ml, 90~) was added dropwise followed bv stirring at ambient temperature for 16h. The mixture was added to water containing a small amount of petroleum ether (b.p. 62-68C). The mlxture was acidified with 2M hydrochloric acid and filtered to give 2-(2-ethoxyethyl)-9-methoxy-4-(4-trifluoromethyl-phenyl)[1~benzopyrano[4,3-c]pyrazol-3(2H)-one, m.p. 164-168C.
Example 9 a) A mixture of 5-ethoxy-4-hydroxycoumarin (5.0 g) (Example 1) and methylhydrazine (2.2 g) in industrial WO91/1Z255 2 Q 7 ~ Q 1 S PCT/EPgl/0ols3 methylated spirit (60 ml) was heated under reflux for 20 hours. On cooling, the solvent was evaporated off under reduced pressure to give the crude product Methanol (50 ml) and concentrated hydrochloric acid (20 ml) were added to this crude product ar.~ the solution obtained was heated unde- reflux for 2 hours.
After evaporating of-^ the solvents under reduced pressure, the residue was triturated with water and the solid obtained collected by filtration and dried to 10 cive 3-(2-hydroxy-6-ethoxyphenyl)-1-methyl-2-pyrazolin-5-one.

b) The solid obtained in ~2) above (3.2 5) ar.~
trimethyl ortho(4-chlorobenzoate) (9.0 g) wera :saatec`
to~ether at 130-140C for 45 minutes. The mixtu-e was cooled to ambient temperature and hexane (50 ml) was added. The supernatant li~uid was decanted o'~ and ether (80 ml~ added to the residual oil to preci?itate a solid. The solid was collected by filtration, washed with ether, dried and then recrystallised from propan-20 2-ol to give 4-~4-chlorophenyl)-9-ethoxy-2-methyl[l]-benzopyrano[4,3-c]pyrazol-3~2H)-one, m.p. 19~-199C.

ExamDle 1 0 a) A mixture of 4-hydroxycoumari.. (3.6 g) and ~ 70~
aqueous solution o~ 2,2,2-trifluoroethylhydrazine (5.0 g) in toluene (27 ml) was heated under reflux for 4 hours with removal of water; The solid collected after cooling and filtration was extracted with hot dichloromethane, filtered and the filtrate was evaporated. The solid product was recrystallise~ from toluene and then from dichloromethane to give 3-(2-hydroxyphenyl)-1-(2,2,2-trifluoroethyl)-2-pyrazolin-5-one, m.p. 163-165C.

.

W091/12255 2 ~ pCT/EP91/0015~-b) The solid obtained in (a) above (1.2 g) and trimethyl ortho(4-chlorobenzoate) (3.0 g) were heated together at 125C for 10 minutes. The mixture was cooled, diluted with ether (10 ml) and the solid obtained was recrystallised from a mixture of N,N-dimethylformamide and methanol to give 4-(4-chloro-phenyl)-2-(2,2,2-t~ifluoroethyl)[l~benzpyrano~4,3-c]-pyrazol-3(2H)-one, m.p. 214-215C (decomposed).
Example 11 a) A mixture of 3-(2-hydroxyphenyl)-1-methyl-2-pyrazolin-5-one (3.8 g), prepared as in ~xampl~ 4, anhvdrous sodium acetate (1.64 g) and acetic anny~ride (30 ml) was stirred at ambient temperature for 1.5 hours. The reaction mixture was added to water (10 volumes) and extracted with ethyl acetate. The combined organic extracts were washed with water, dried and evaporated. The semi-crystalline residue was triturated with petroleum ether (b.2. 60-30C) and the solid collected by filtration and dried to give 3-(2-hydroxyphenyl)-1-methyl-5-pyrazolyl acetate, m.p. 113-116C.

b) A solution of 3,4-dichlorobenzoyl chloride ~4.4 g) in tetrahydrofuran (80 ml) was added over 10 minutes to a stirred solution of 3-(2-hydroxyphenyl)-1-methyl-;-25 pyrazolyl acetate (4.5 g) in tetrahydrofuran (100 ml) and triethylamine (3 ml) at 0-5C. The mixture was stirred for 18 hours at ambient temperature and then more 3,4-dichlorobenzoyl chloride (4.4 g) in tetrahydrofuran (80 ml) and triethylamine (3 ml) was added. After stirring for a further 24 hours, the reaction mixture was poured into water (1 1) and extracted with ethyl acetate. The combined organic extracts were dried and then concentrated until precipitation occurred. After filtration to remove WO91/1225~ 2 ~ 7 ~ PCT/EP91/001~3 3,4-dichlorobenzoic acid, the filtrate was evaporated under reduced pressure and the residue crystallised from ethyl acetate to give 2-(5-acetoxy-1-methyl-3-pyrazolyl~phenyl 3,4-dichlorobenzoate, m.p. 123C.

c) 2-(5-Acetoxy-1-methyl-3-pyrazolyl)phenyl 3,~-dichlorobenzoate (1.0 g) and piperidine (0.27 ml) were heated in ethanol (10 ml) under reflux for 2 hours.
The reaction mixture was cooled to 0C. The produc was collected by filtration and recrystalllsed from ethanol to give 4-(3,4-dichlorophenyl)-2-methyl[1]
benzopyrano[4,3-c]pyrazol-3t2H)-one, m.p. 193-l94C.
~xamDle 12 a) A solution of 3-(2-hydroxvphenyl)-1-methyl-5-pyrazolyl acetate (2.32 g), prepared as in Example 11a, in dry tetrahydrofuran (50 ml) was treated successively with triethylamine (1.5 ml) and 2-naphthoyl chloride (2.1 g) in dry tetrahydrofuran (10 ml) at 0-5C. The mixture was stirred at ambient temperature for 20 hours and then more triethylamine (0.75 ml) and 2-naphthoyl chloride (1.05 g) were added anc the mixtur~ was stirred for another 20 hours. The reaction mixture was poured into water (10 volumes) and extracted with ethyl acetate. The combined organic extracts were washed with saturated sodium carbonate solution, then water and then dried. After evaporation under reduced pressure the residue was tritur,ated with ether and the solid formed collected by filtration.

b) Part of the crude solid of stage (a) (2.43 g) and piperidine (0.63 ml) were boiled under reflux in absolute ethanol (l9 ml) for 30 minutes. On cooling, the mixture was filtered to give 2-(1-methyl-5-oxo-4,5-dihydro-3-pyrazolyl)phenyl 2-naphthoate, m.p.
207-210C.

WO91/1225~ PCT~EP91/00153--c) The filtrate was boiled under reflux for a further hour. The mixture was concentrated and then cooled.
The solid formed was collected by filtration to give 2-methyl-4-~2-naphthyl)[1]benzopyrano[4,3-c]pyrazo7- -5 3(2H)-one, m.p. 159-161C.

ExamDle 13 A stirred mixture of 3-(2-hydroxyphenyl)-2-pyrazolin-S-one (2.32 g) and triethyl ortho(4-chloro-benzoate) (10.2 g) was heated at 130-135C for 1 hour.
The mixture was cooled to ambient temperature, diluted with ether and the resulting solid filtered o'-, washe~
and dried. The solid was recrystallise~ fro~
industrial methylated spirit (charcoal used) to give 4-~4-chlorophenyl)~1]benzopyrano[4,3-c]pyrazol-3(2H)-15 one, m.p. 255-257C.

Examples 14 to_18 In a similar manner to that described in Example 13, a compound of formula I was prepared bv reacting a compound of formula II with a compound o formula III as summarized in Table B below in which substituents R1 and R4 in compound II are given. The compounds of formula III used were of the type R5C(OQ)3 in which R2 represents hydrogen and R3 and Q are as given in Table B.

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W O 91/12255 2 ~ 7 L~ p, ~ ~3 PC~r/EP91/00153--Example I 9 A mixture of 3-(2-hydroxyphenyl)-2-pyrazolin-5-one (16 g) and 1-(4-chlorobenzoyl)imidazole (37.5 g) in xylene (200 ml) was stirred and heated under reflux for 3 hours The mixture was allowed to cool to 70C and then 'iltered to give 4-(4-chlorophenyl)[l]-benzopyrano[4,3-c]pyrazol-3(2~)-one, m.p. 2;;-257C.

Exam~le 20 A mixture of trimethyl ortho(4-trifluoromethyl-benzoate) (5.5 g), prepared as in Example 7, and 3-(2-hydroxyphenvl)-2-pyrazolin-S-one (1.94 g) was heated a 135-140C for 4 hours. The mixture was cooled to 0C
and the solid formed filtered off and washed with ether. This solid was triturated with hot water and filtered to give 4-(4-tri'luoromethylphenyl)[1]benzo-pyrano[4,3-c~pyrazol-3(2H)-one, m.p. 271-273C.

Example 21 A mixture of 3-~2-hydroxyphenyl)-2-pvrazolin-;-one (30.2 g), 1-(4-trifluoromethylbenzoyl)imidazole (86.5 g) and xylene ~800 ml) was stirred and boiled under reflux for 4 hours under nitrogen. The reaction mixture was allowed to cool to 40C and filtered to give 4-(4-trifluoromethylphenyl)[1]benzopyranof4,3-c]-pyrazol-3~2H)-one, m.p. 270-272,C.

ExamDle 22 a) A mixture of 3-(2-hydroxyphenyl)-2-pyrazolin-5-one ~3.52 g) and sodium acetate (1.64 g) in acetic anhydride (30 ml) was stirred at ambient temperature for 3 hours. The mixture was poured into water and petroleum ether (b.p. 62-68C, 10:1) and the solid `

.:. ,. . ~ : .

WO91/12255 ~ ~ 7 R ,~ 5 PCTtEPg1/001~3 collected by filt_atior. to give crude l-acetyl-3-(2-hydroxyphenyl)-5-pyrazolyl acetate, m.p. 62-64C.

b) A mixture of crude l-acetyl-3-(2-hydroxy-phenyl)-5-pyrazolyl acetate ~1.53 g), triethylamine (2.1 ml) and dry tetrahydrofuran (25 ml) was stirred at 0-5C while 4-t-ifluoromethylbenzoyl chlo-ide (3.21 g) was added dropwise. The resultant mixture was stirred at ambien. temperature for 64 hours and then poured into water. The product was extracted lnto ethyl acetate and the combined extracts were washe~ with water, saturated sodium bicarbonate solution and finally water. After drying, the solver. was evaporated OCc unde- reduced pressure. The residue wzs digested with hot propan-2-ol then cooled and _iltered.
The filtrate was evaporated to give crude 2-(;-acetoxy-1-acetyl-3-pyrazolyl)phenyl 4-trifluoromethylbenzoate as an oil.

c) The oil from stage (b) and piperidine (0.7 ml) were boiled under reflux in absolute ethano' ~22 ml) for 1 hour. The mixture was cooled to 0-5C an~ then filtered to give the crude product which was pu-ified by preparative layer chromatographv on silica, using dichloromethane/methanol (9:1) as the mobile phase, to give 4-(4-trifluoromethylphenyl)[1~ benzopyrano-[4,3-c]pyrazol-3(2H)-one, m.p. 268-272C.
Example 23 A mixture of 3-(2-hydroxyphenyl)-2-pyrazolin-5-one (2.9 g) and potassium carbonate (3.2 g) in dry xylene (30 ml) was stirred and heated under reflux while 4-trifluoromethylbenzoyl chloride (6.9 g) was added dropwise over 15 minutes. The mixture was boiled and stirred for 2 hours then hot filtered. The solid collected was washed with toluene, water and rinally J j WO91/1225~ PCT/EP91/OOl~s-ether to give 4-~4-trifluoromethylphenyl~[1]benzo-pyrano[4,3-c]pyrazol-3(2H)-one, m.p. 259-263C.

Example 24 3-t2-Hydroxyphenyl)-l-methyl-2-pyrazolin-5-one 5 (Example 4) (1.90 g) W25 dissolved in warm toluene (100 ml) then cooled to ambient temperature and added over 5.25 hours to a stirred, boiling solution of 4-chlorobenzaldehyde (1,4 g) in dry toluene (50 ml) containing piperidine (1 ml), with removal o. water formed in the reaction. The reaction mixture was evaporated under reduced preSsurQ anc the residue triturated with ether ar.d recrystallised from ?ropan-2-ol to give 4-(4-chlorophenyl)-2-methyl~1]benzop~rano-[4,3-c]pyrazol-3(2H)-one, m.p. 204-205C.

Example 25 A mixture of 2-(2-chloroethoxy)ethyl acetate (16.7 g), sodium bromide (103 g), N,N-dimethyl-formamide (200 ml) and dibromomethane ~100 ml) was stirred and heated at 100C for 48 hours. The mixture 20 was poured into ether (300 ml~ and water (200 ml). The organic layer was separated, washed with water, dried and evaporated to give an oil. Distillatio.. under reduced pressure gave 2-(2-bromoethoxy)ethyl acetate, b.p. 100-103C (7mm Hg).

Example 26 Sodium hydride (0.60 g, 50% dispersion in mineral oil) was added to a stirred solution of 4-(4-chloro-phenyl)~l]benzopyrano[4,3-c]pyrazol-3(2H)-one (3.70 g), prepared as in Example 13, in dry N,N-dimethylformamide (145 ml) under nitrogen. The mixture was stirred at ambient temperature for 5 minutes and then 2-bromoethyl ~ J l `2 (~
WO91/122sa PCT/EP91/00153 acetate (1.38 ml) was added dropwise. The reaction mixture was stirred at ambient temperature for 16 hours and then poured into water and petrol (b.p. 60-80:
approx. 10:1 by volume). The mixture was cooled in an S ice bath and the deposited solid filtered o'f and washed to give 2-~4-(4-chlorophenyl)-3-oxo-2,3-dihydro-[l]benzopvrano~4,3-c]pyrazol-2-yl]ethyl acetate, m.p.
126-129C.

ExamDles 27 to 41 . . .
In a similar manner to Example 26, compounds of formula I were prepared bv reactir.g 4-(4-~hloro-phenyl)~l]benzo?yrano[4,3-~]pyrazol-3(2H)-one (~) ~xample 13) with compounds of formula RIX, in which X
is halo as summarized in Table C below.

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er U~ o WO91/12Z55 ~ 7 ~ ~5 ~J3 PCT/EP91/00153 -Notes for Table C

(1) The reaction mixture was added to water (2 1), acidified with concentrated hydrochloric acid and extracted with ethyl acetate. The combined extracts were washed with water, dried and concentrated until crystallisation occurred. On coolins, the ?roduct was obtained by filtration.

(2) The solid obtained was dissolved in a mixture of dichloromethane/ethanol and concentrated until crystallisation occurred. The product was collected by filtration.

(3) The quenched mixture was extracted with ethyl acetate. The combined extracts were washed with water, dried and concentrated until crystallisation occurred.
The product was collected by filtration.

(4) The reaction mixture was added to water (10 volumes) and acidified with 2M hydrochloric acid.
The solid formed was collected by filtration, dried and then dissolved in boiling industrial methylatec spirit/dichloromethane, 1:2. The dichloromethane was removed and the solution cooled in an ice bath. The solid formed was collected by filtration.

(5) The reaction mixture was added to water ~500 ml) and extracted with ethyl acetate. The combined extracts were washed with water, dried and evaporated.
The solid obtained was recrystallised from propan-l-ol, ~6) The reaction mixture was added to water and the solid formed collected by filtration and dried. This solid was triturated with acetone and filtered. The residue was triturated with boiling industrial methylated spirit then filtered and the residue .

WO91/12255 ~ PCT/EP91/00153 dissolved in warm dichloromethane, treated with charcoal and filtered. The filtrate was evaporated and the residue triturated with petrol and filtered to give the product, (7) The reaction mixture was quenched into water (300 ml) containing 2M hydrochloric acid (5 ml) and extracted with dichloromethane. The combined extracts were dried and evaporated. The residue was partitioned between ether and water, then separated. The aqueous layer was extracted with ether and the combined ether extracts dried and concentrated (to 10 ml). The solid formed was collected by filtration, washed with petroleum ether (b.p. 40-60C) and dried. After recrystallisation from ethanol the product was pu-ified by flash chromatography on silica using dichloromethane/methanol, 98:2 as the mobile phase.
The eluted material was recrystallised from ethanol to give the product.

(8) The reaction mixture was partitioned betwee~ 5M
hydrochloric acid (600 ml) and ether (300 ml). The aqueous layer was separated cff and washed with ether.
The combined ether extracts were washed weli with water, dried and evaporated. The residue was purified by flash chromatography on silica using dichloromethane~methanol, 97:3 as the mobile phase.
The solid obtained was recrystallised twice from a mixture of ether and ethyl acetate to give the product.

(10) The reaction mixture was added to water and acidified with 5M hydrochloric acid. The solid was , ~ 30 collected by filtration and recrystallised from N,N-dimethylformamide.

; .

WO91/1225~ PCT/EP91/0~153 (11) The reaction mi~ture was added to water. The solid obtained was collected by filtration and recrystallised from propan-2-ol.

(12) 60% dispersion of sodium hydride in mineral oi used.

~13) The reaction mixture was added to wate- (500 ml) and extracted with ether. The combined extracts were washed witX water, dried and evaporated. The solid obtained was recrystallised from ethanol.

(14) The reaction mixture was added to water t2 l), acidified with 5M- hydrochloric acid and extracted with ethyl acetate. The combined extracts were washed with water, dried and evaporated. The oil obtained was crystallised from ether.

ExamDle 42 In a similar manner to Example 26, a mi~ture of sodium hydride (0.74 5, 60~ dispersion in mineral oil), dry N,N-dimethylformamide (180 ml), 4-(4-chloro-phenyl)[l1benzopyrano[4,3-c]pyrazol-3(2H)-one ~Example 13) (5.0 g) and 2-bromomethyl-1,3-dioxolane (1.97 ml) was stirred at ambient temperature for 16 hours. More sodium hydride (0.74 g) was added in portions followed by more 2-bromomethyl-1,3-dioxolane (l.97 ml). The mixture was stirred at ambient temperature for 24 hours and then warmed at 70-80C for 1 hour. The mixture was cooled to ambient temperature and then added to water. The solid formed was collected by filtration, dried and recrystallised from ethanol/dichloromethane to give 4-(4-chlorophenyl)-2-(1,3-dioxolan-2-ylmethyl)[l]benzopyrano[4,3-c]-pyrazol-3(2H)-one, m.p. 230-231C.

WO91/12255 2 i~ ~ ~ X ~ pCT/EP91/00153 ExamPle 43 -In a similar manner to Example 26, a mixture of sodium hydride (0.44 g, 60% dispersion in mineral oil), dry N,N-dimethylformamide (100 ml), 4-(4-chloro-phenyl)[1~benzopyrano[4,3-c]pyrazol-3(2H)-one ~3.0 g) (Example 13 ) and 1-bromo-2-ethoxypropane (2.9 g) was stirred at ambient temperature for 16 hours. The mixture was warmed at about 60C for 1.5 hours then cooled to ambient temperature. The mixture was added to water and the product extracted into ether. The combined ether extracts were dried and evaporated. The residue was separated by flash chromatography or.
silica, using ethyl acetate/petroleum ethe~
(b.p. 80-100) (1:3) as the mobile phase, to give a red solid which was recrystallised from ethanol to give 4-(4-chlorophenyl)-2-(2-ethoxypropyl)~1]be~zopyrano-[4,3-c]pyrazol-3(2H)-one, m.p. 118-119C.

Example 44 In a similar manner to Example 26, a mixture o' sodium hydride ~1.82 g, 60~ dispersion in mineral oil), dry N,N-dimethylformamide (450 ml), 4-(4-trifluoromethylphenyl)r1]benzopyrano[4,3-c]pyrazol-3~H)-one (15.0 g) (Example 20) and 2-bromoethyl acetate (7.62 g) was stirred at ambient temperature for 48 hours. The mixture was added to water. The solid formed was filtered off and dissolved in ethyl acetate which was washed with water. The residue obtained, after removal of the ethyl acetate under reduced pressure, was recrystallised from propan-2-ol to give 2-t3-oxo-4-(4-trifluoromethylphenyl)-2,3-dihydro[1~-benzopyranot4,3-c]pyrazol-2-yl]ethyl acetate, m.p. 134-136C.

WO91/12255 î ~ PCT/EP91/Q0153.-ExamDle 45 In a similar manner to Example 26, a mixture of sodium hydride (0.74 g, 60~ dispersion in mineral oil), dry N,N-dimethylformamide t150 ml), 4-(4-chloro-phenyl)r1]~enzopyrano[4,3-c]pyrazol-3~2H)-one (5.0 g) and 2-(2-bromoethyl)-1,3-dioxane (2.52 ml) was stirred at ambient temperature for 42 hours. The reaction mixture was added to water. The product was extracted into ether and the extracts washed with water.
Evaporation of the ether left a solid residue which was recrystallised from ethanol to give 4-~4-chlorophenyl)-~-[2-(1,3-dioxan-2-yl)ethyl]r1]benzopyranor4,3-c~-pyrazol-3(2H)-one, m.p. 157-163C.

Example 46 1S A mixture of 2-[3-oxo-4-(4-trifluoromethylphenyl)-2,3-dihydro[1]benzopyrano[4,3-c]pyrazol-2-yl~ethyl acetate (17.93 g) (Example 44), 2M hydrochloric acid (22 ml) and industrial methylated spirit ~750 ml) was stirred and boiled under reflux for 18 hours. The mixture was cooled to 0C and the solid formed collected by filtr~tion to give 2-(2-hydroxyethyl)-4-(4-trifluoromethylphenyl)[1]benzopyrano[4,3-c]-pyrazol-3(2H)-one, m.p. 199-201C.

ExamDle 47 Dilute hydrochloric acid (2 ml) was added to a stirred suspension of 2-[4-(4-chlorophenyl)-3 -oxo- 2,3-dihydro[1]benzopyrano[4~3-c]pyrazol-2-yl]ethyl acetate (1.53 g), prepared as in Example 26, in industrial methylated spirit (80 ml) at ambient temperature. The mixture was heated under reflux for 6.5 hours. The solution was allowed to cool and was kept at ambient temperature for 16 hours. The resulting crystals were WO91/1225~ PCT/EP~1/00153 filtered off and washed with industrial methylated spirit to give 4-(4-chlorophenyl)-2-(2-hydroxyethyl)-[l]benzopyrano[4,3-c]pyrazol-3(2H)-one, m.p. 179-183C.

Exam~le 48 A mlxture Oc 3-[4-(4-chlorophenyl)-3-oxo-2,3-dihydro[l~benzopyrano[4,3-c]pyrazol-2-yl]propyl acetate (1.5 g) (Example 41), 2M hydrochloric acid (1.9 ml) and industrial methylated spirit (75 ml) was boiled under reflux for 5 hours. The mixture was cooled to room temperature and the solid formed collecte~ by filtration to give 4-(4-chlorophenyl)-2-(3-hvdroxy-propyl)[l~benzopyrano[4,3-c]pvrazol-3(2H)-one, m.p.
166-168C.

Example 49 A mixture Oc 2- t 2-[4-(4-chlorophenyl)-3-oxo-2,3-dihydro[l]benzopyrano[4,3-c]pyrazol-2-yl]ethoxy~ethyl acetate (11 g) (Example 39), 5M hydrochloric acid (100 ml) and water (100 ml) was stirred and boiled under reflux for 24 hours. The mixture was evaporated and the solid obtained was recrystallised from propan-2-ol ~100 ml) to give 4-(4-chlorophenyl)-2-[2-(2-hydroxyethoxy)ethyl~[l]benzopyrano[4,3-c]pyrazol-3(2H)-one, m.p. 110-112C.

Example 50 A mixture of 4-(4-chlorophenyl)-3-oxo-2,3-dihydro-[l]benzopyrano[4,3-c)pyrazole-2-acetonitrile (0.68 g), prepared as in Example 28, and concentrated sulphuric acid (6 ml) was heated at 120C for 0.5 hour. The reaction mixture was poured on to ice (10 volumes) and the solid product was collected, washed and dried to give WO91/12255 ~g 7 !~ PCT/EP91/00153-4-(4-chlorophenyl)-3-oxo-2,3-dihydro~l]benzo-pyrano[4,3-c]pyrazole-2-acetamide, m.p. 279-283c.
Exam~le 51 In a similar manner to Example 50, a mixture of 4-(4-chlorophenyl)-3-oxo-2,3-dihydro[l~benzopyrano-[4,3-c]pyrazole-2-propionitrile (1.0 g), prepared in Example 32, and concentrated sulphuric acid (10 ml) was heated at 120-125C for 15 minutes to give, after recrystallisation from industrial methylated spirit, 4-(4-chlorophenyl)-3-oxo-2,3-dihydro[l]benzopyrano-[4,3-c~pyrazole-2-propionamide, m.p. 264-266C.
Example 52 a) A stirred suspension of 4-(4-chlorophenyl)-3-oxo-2,3-dihydrotl]benzopyrano[4,3-c1pvrazole-2-acetic acid (2.16 g), prepared as in Example 31, in dichloromethane (50 ml) was treated with dry N,N-dimethylformamide (0.24 ml) and then thionyl chloride (1.51 ml). The mixture was stirred at ambient temperature for 16 hours and then evaporated unde-reduced pressure. The residue was triturated with dry ether and the solid collected by filtration to give 4-(4-chlorophenyl)-3-oxo-2,3-dihydro[1~benzo-pyranol4,3-c]pyrazole-2-acetyl chloride.

b) A portion of this acid chloride (1.08 g) in dry tetrahydrofuran (100 ml) was treated dropwise with an aqueous solution of ethylamine (0.43 ml, 70~ w/w). The mixture was stirred at 0-5C for 1.5 hours and then filtered. The filtrate was diluted with ether (100 ml), cooled in an ice-bath for 3 hours and the solid filtered off. On standing for several days a second crop of solid was obtaine~. The two combined crops were washed with water and then petroleum ether WO91~122~5 PCTtEP91/00153 ~b~p. 60-80C) to give 4-(4-chlorophenyl)-N-ethyl-3-oxo-2,3-dihydro[1]benzopyrano[4,3-c]pyrazole-2-acetamide, m.p. 238-239C.

Exam~1e 53 In a similar manner to ~xample 52(a) 4-(4-chlorophenyl)-3-oxo-~,3-dihydro[l]benzopyrano [4,3-c]pyrazole-2-acetic acid (1.87 g) was converted into the acid chloride (1.89 q) and then suspended in dry tetrahydrofuran (172 ml) at 0-5~C. Aqueous tO methylamine ~0.69 ml, 25/30~ w/v) was added d~opwise and the mixture stirred in a melting ice bath fo~
2.5 hours. The solid was filtered off, washed witn water and then ether to give 4-(4-chloropnenyl)-N-methyl-3-oxo-2,3-dihydro[1]benzopyrano[4,3-c]pvrazole-2-acetamide, m.p. 244-250C.

Example 54 A solution of propylamine ~0.2 ml) i~ drv tetrahydrofuran (10 ml) was added dropwise to a mixture of 4-(4-chlorophenyl)-3-oxo-2,3-dihvdro[1~-benzopyrano[4,3-c]pyrazole-2-acetyl chloride (1.07 g) tExample 52a) in dry tetrahydrofuran ~95 ml) with stirrinq at 0-5C. The mixture was stirred at 0-5C
for 50 minutes and then more propylamine ~0.1 ml) in dry tetrahydxofuran ~5 ml) was added. This mixture was stirred at 0-5C ~or 2.3 hours and then diluted with dry ether ~95 ml) and stirred at 0-5C for 1 hour. The mixture was filtered and the filtrate washed with water, dried and evaporated under reduced pressure.
The residue was separated on a Florisilc column using dichloromethane and then dichloromethane/methanol (95:5) as the mobile phase. The solid obtained was triturated with ether to give 4-~4-chlorophenyl)-3-- WO91/12255 ~ ; PCT/EP91/00153 -oxo-N-propyl-2,3-dihydrorl~benzopyrano[4,3-c]pyrazole-2-acetamide, m.p. 218-223C, Exam~le 55 A stirred mixture of 4-(4-chlorophenyl)[l]benzo-pyrano[4,3-c]pyrazol-3(2H)-one (Example 13) (1.0 g) in toluene (20 ml) was treated with chlorosulphonvl isocyanate (0.53 g) at ambient temperature. The mixture was heated to 70C and stirred at this temperature for 15 minutes. On cooling to 0C, the mixture was filtered and the residue washed with ether then suspended in glacial acetic acid (6 ml) and wate~
(3 ml). This mixture was heated at 60C for 15 mlnutes and then filtered. The residue was washed with water, dried and recrystallised from dichloromethane/methanol, 4:1, to give 4-(4-chlorophenyl)-3-oxo-2,3-dihyaro[1]-benzopyrano[4,3-c]pyrazole-2-carboxamide, m.p. 215-216C.

Example 56 Acetyl chloride (0.86 ml) was added dropwise to a stirred mixture of 4-(4-chlorophenyl)[1]benzopyrano-[4,3-c]pyrazol-3(2H)-one (Example 13) (3.0 g) and potassium carbonate (2.79 g) in AR acetone (20 ml) at ambient temperature. The mixture was stirred at ambient temperature for 42 hours. More potassium carbonate (6.98 g) was added followed by more acetyl chloride (3.6 ml) in AR acetone (15 ml). The mixture was stirred at ambient temperature for 18 hours. More potassium carbonate (2.79 g) and acetyl chloride , ' (1.44 ml) were added ahd the mixture stirred at ambient temperature for 2.25 hours. The mixture was then boiled under reflux for 1 hour, cooled to ambient temperature and then added to water. The solid formed was collected by filtration, dried and then .~
' . ~

WO91tl2255 PCTtEP91/00153 recrystallised from acetonitrile to give 2-acetyl-4-(4-chlorophenyl)[l]benzopyrano[4,3-c]pyrazol-3(2H)-one, m.p. 224-226C.

Exam~le 57 .
A stirred mixture of 4-(4-chlorophenyl)[l]benzo-pyrano[4,3-c]pvrazol-3(2H)-one (Example 13) (20 g) and ethyl chloroformate (200 ml) was boiled under reflux for 5 hours. More ethyl chloroformate (50 ml) was added and the mixture was stirred and boiled unde-reflux for 4 hours. The reaction mixture was cooled to ambient temperature and the solid was collected by filtration and recrystallised from acetonitrile. The crude product obtained was purified by flash column chromatography on silica using dichloromethane/methanol (9:1) as the mobile phase. Evaporation of the eluent gave a solid which was recrystallised from ethyl acetate to give ethyl 4-(4-chlorophenyl)-3-oxo-2,3-dihydro~l]benzopyrano[4,3-c]pyrazole-2-carboxylate, m.p. 187-188C.

Example 58 A stirred mixture of 4-(4-chlorophenyl)[l~benzo-pyrano[4,3-c]pyrazol-3(2H)-one (Example 13) (5 g) and ethyl cyanoformate (50 ml) was boiled under reflux for 3.5 hours. The reaction mixture was cooled to ambient temperature, diluted with petroleum ether (30 ml), filtered and dried to give ethyl 4-(4-chlorophenyl)-3-oxo-2,3-dihydro[l]benzopyrano[4,3-c]pyrazole-2-carboxy-late, m.p. 187-189C.

WO 91/1225~ r~ PCr/EP91/01)153 --Example 59 A stirred suspension of 4-(4-chlorophenyl)-3-oxo-2,3-dihydro[l]benzopyrano[4,3-c]pyrazole-2-acetyl chloride (0.97 gJ, prepared as in Example 52(a), in drv tetrahydrofuran (76 ml) was treated with a solution of cyclobutanol (0.7 g) in dry tetrahydrofuran (10 ml) followed by triethylamine (0.35 ml). The resulting mixture was stirred at ambient temperature for 2.67 hours and then filtered. The filtrate was diluted with ether, washed with water, dried and then evaporated under reduced pressure. The residue was purified by preparative layer chromatography on silic2 using dichloromethane/methanol (9:1) as the mobile phase. The fast running band was extracted with ethyl tS acetate. Evaporation under reduced pressure gave a gum which was triturated with ether/petroleum ether (b.p. 62-68C, 1:1) and filtered to give cyclobutyl 4-(4-chlorophenyl)-3-oxo-2,3-dihydrot1]benzopyrano-t4,3-c]pyrazole-2-acetate, m.p. 135-138C.

ExamDle 60 Sodium hydride (0.48 g, 60% dispersion in mineral oil) was added to a stirred solution of 4-(4-trifluoro-methylphenyl)[1]benzopyrano[4,3-c]pyrazol-3~2H)-one ~ 3.3 g), prepared as in Example 20, in dry N,N-dimethylformamide (60 ml) under nitrogen. The mixture was stirred at ambient temperature for 0.5 hours and then bromoacetonitrile (1.46 g) added in one portion.
The mixture was stirred at ambient temperature for 18 hours and then added to iced water. The mixture was extracted with ethyl acetate and the combined extracts washed with water, dried and evaporated to give a solid which was recrystallised from propanol to give 3-oxo-WO91~1225~ , ~J pCr/EP91/00153 4-(4-trifluoromethylphenyl)-2,3-dihydro[1]benzopyrano -[4,3-c]pvrazole-2-acetonitrile, m.p. 215-217C.

Example 61 In a similar manner to Example 60, 4-(4-trifluoromethylphenyl) [1~benzopyrano[4,3-c]pyrazol-3(2H)-one (1.35 g), sodium hydride (0.21 5, 50~
dispersion in mineral oil), 2-bromoethyl ethyl ether (0.77 g) and dry N,N-dimethylformamide t50 ml) wer~

mixed and stirred at ambient temperature for 42 hours.
10 The crude product obtained was purified by flash colums chromatographv on silica usina ethvl acelate as th~
mobile phase to give, after recrvstallisation from propan-2-ol, 2-(2-ethoxyethyl)-4-(4-trifluoromethy!-phenyl) ~11benzopyrano[4,3-c1pyrazol-3(2H)-one, m.p. 126-128C.

ExamDle 62 . _ 2-(2-Hydroxyethyl)-4-(4-t~ifluoromethylphenyl)-[1]benzopyrano[4,3-c]pyrazol-3(2H)-one (8.22 a) prepared as in Example 46 and 48% aqueous hydrobromic acid ~500 ml) were stirred and heated under reflux for 28 hours. The reaction mixture was cooled to 0C and the solid collected by filtration washed with water and then dried and recrystallised from acetonitrile to give 2-(2-bromoethyl)-4-(4-trifluoromethylphenyl) [1]benzo-pyrano~4,3-c]pyrazol-3(2H)-one, m.p. 145-147C.
Exam~le 63 a) In a similar manner to Example 60, 4-(4-trifluoro-methylphenyl) ~1~benzopyrano[4,3-c]pyrazol-3(2H)-one (5 g), sodium hydride (0.7 g, 60% dispersion in mineral 30 oil), ethyl 4-bromobutyrate (2.4 ml) and dry N,N-WO91/1225~ C~J~ '; PCT/EP91/001~3 -dimethylformamide (230 ml) were mixed and stirred at ambient temperature for 24 hours. The reactlon mixture was added to water (2.3 1) and petrol (b.p. 60-80C), acidified with 5M hydrochloric acid and the product formed was collected by filtration and dried to give ethyl 3-oxo-4-(4-trifluoromethylphenyl)-2,3-dihydroE~-benzopyrano[4,3-c]pyrazole-2-butyrate, m.p. ~12-t15C.

b) A mixture of ethyl 3-oxo-4-(4-trifluoromethyl-phenyl)-2,3-dihydro[l]benzopyrano~4,3-c]pyrazole-2-butyrate (3,0 g) and 5M hydrochloric acid (30 ml) was stirred and heated at 96-105C for 5 hours. The reaction mixture was allowed to cool and was keDt at am'oient temperature for 24 hours. The sol~d obtained was collected by filtration, washed with water and then ether, and dried to give 3-oxo-4-(4-trifluoro-methylphenyl)-2,3-dihydro[l]benzopyrano~4,3-c~-pyrazole-2-butyric acid, m.p. 197-200C with shrinking from 189C.

c) A stirred suspension of 3-oxo-4-(4-trifluoro-methylphenyl)-2,3-dihydro[11benzopyrano[4,3-c~pyrazol-2-butyric acid (1.8 g) in dichloromethane ~37 ml) was treated with N,N,-dimethylformamide (0.2 ml) and then thionyl chloride (1.2 ml). The mixture was stirred at ambient temperature for 24 hours and then evaporated under reduced pressure to give 3-oxo-4-~4-trifluoro-methylphenyl)-2,3-dihydro[l]benzopyrano[4,3-c]pyrazole-2-butyryl chloride.

d) A solution of the acid chloride from stage (c) in dry tetrahydrofuran (88 ml) was stirred at 0.5C and treated with concentrated aqueous ammonia solution (0.6 ml). The reaction mixture was stirred at 0-5C
for 1 hour. More concentrated ammonia solution (0.2 ml) was added and the mixture was stirred at 0-5C
for 0.75 hour. The solid formed was collected bv WO91/122S5 ~ i3 7 l~ PCT/EP91/001~3 fil.ration, washed with tetrahydrofuran and water, and dried to give 3-oxo-4-(4-trifluoromethylphenyl)-2,3-dihydro[l]-benzopyrano[4,3-c]pyrazole-2-butyramide, m.p. 218-221C.

S Example 64 4-(4-Chlorophenyl)-2-(2-hvdroxyethyl)[1lbenzo-pvrano[4,3-c]pyrazol-3(2H)-one (28 g), prepared as in Example 47, and thionyl chloride (300 ml) were stirred and boiled under reflux for 3.5 hours. Excess thionyl chloride was distilled of' under reduced pressure and the residue stirred with acetonitrile. The mixture was filtered and the solid collected was recrvstallised from dichloromethane to give 2-(2-chloroethyl)-4-(4-chlorophenyl)[l]benzopyrano[4,3-clpyrazol-3(2H)-one, l5 m.p. 169-170C.

Exam~le 65 In the preparation of capsules, 10 parts by weight of active compound and 240 parts by weight of lactose are de-aggregated and blended. The mixture is fillec into hard gelatin capsules, each capsule containina 10 mg active compound.

Example 66 In the preparation of capsules, 50 parts by weight of active compound, 300 parts by weight of lactose and 3 parts by weight of magnesium stearate are de-aggregated and blended. The mixture is filled into hard gelatin capsules, each capsule containing S0 mg of active ingredient.

.

WO91/1225S ~ ~ 1 s~;~ PCT/EP91/0015~r ~

Exam~le 67 ~ .
Tablets are prepared from the following ingredients.

Parts bv weicht S Active compound 10 Lactose 190 Maize starch 22 Polyvinylpyrrolidone 10 Magnesium stearate 3 The active compound, the lactose and some of the starch are de-aggreqated, blended and the resulting mixture is granulated with a solution of the polyvinylpyrrolidone in ethanol. The dry granulate is blended with magnesium stearate and the rest of the starch. The mixture is then compressed in a tableting machine to give tablets containing a) 10 mg, b) 100 ma and c) 500 mg of active compound.

Example 68 Tablets are prepared by the method of ~xample 67.
The tablets are enteric coated in a conventional manner using a solution of 20% cellulose acetate phthalate and 3% diethyl phthalate in ethanol:dichloromethane (1:1).

ExamDle 69 In the preparation of suppositories, 100 parts by weight of active compound is incorporated in 1300 parts by weight of semi-synthetic glycerides as the suppository base and the mixture formed into suppositories each contining 100 mg of active ingredient.

WO91/1225a _ 47 _ PC~/EP91/00153 Example 70 In the preparation of ointments the active compound is incorporated into the base bv thorough homogenization until the drug is evenly distributed.
The ointment is packed into 10 g amber jars with screw-capped lined lids.

Active compound 0.1 g White soft paraffin to 10 g The compounds of the invention are immuno-modulatory agents, especially immunosuppressantsand may show therapeutic activity at a dose of 200 mg/~g or lower. Preferred compouncs of the invention show activity at S0 mg/kg or lower. The therapeutic activity of the preferred compounds O r the present invention has been demonstrated by a cutaneous hypersensitivity test (CH test) in which the compounds are administered parenterally to BALB/c ~ice. This test was carried out in the following way.

Female BALB/c mice, weight range 16-24 g, were used in groups of eight. The abdomen of each mouse was shaved and 20 ul of a solution of a sensitising agent, 5% w/v 4-ethoxymethylene-2-phenyl-2-oxazolin-5-one ~oxazolone) in acetone:ethanol (1:1 by volume), was applied to the shaved area. Immediately after sensitisation, the test compound in one of the dosages listed below was injected intraperitoneally as a suspension in 1.5~ v/v sorbitan esters, under the trade name Tween 80, in sterile water (100 ~l). 100 ul of the same suspension was injected likewise every 24 hours for a further 7 days. The dosages used were WO91/12255 ~ PCT/EP91/~0153 selected from the following values: 50, 30, 10, 3, 1, 0.3, 0.1, 0.03 or 0.01 mg/kg.

Two groups of at least eight BALB/c mice were used as a control simultaneously with each test in a similar manner to that described above except that no test compound was included in the daily injections.

On the seventh day after sensitisation, 10 ~l of a solution of 1~ w/v oxazolone in acetone: olive oil (3:1 by volume) was applied to one ear (the challenged ear) of each of the test mice and the control mice. (~ more potent challenge dose of 1.5% w/v oxazolone i~
acetone:olive oil was employed in a few cases). Arte-24 hours the thickness of the challenged ear and the thickness of the non-challenged ear of the same animal were measured with an engineer's screw gauge micrometer, The difference in thickness between the challenged ear and the non-challenged ear in each animal is a measure of the response of that animal to oxazolone. A comparison between the response o mice treated wlth the test compound and mice treated with the control indicates the effectiveness o the tes~
compound as an immunomodulatory agent. The compoun~s were considered to be active at a particular dose if a 20~ or greater reduction in ear swelling, which was statistically significant (p <0.05) accordins to Dunnett's test, between treated and control groups was obtained in at least two out of three CH tests, (or, where more than three tests have been carried out, a majority of the tests) at that dose (see for example 30 Int. Arch. Allergy, 38, p246-259 (19701) Each of the compounds of formula I illustrated in Table A below was active at 50 mg/kg in at least two out of three tests at 50 mg/kg unless indicated otherwise (see Notes following the Table). The minimum .

~iJl'~

effective dose for each compound is given in Table A.
The Example (Ex) number or numbers listed adjacent to each compound indicates the process or processes illustrating the preparation of that compound in the Examples.

...

.
, WO91/1225~ ~3 7 4 ~; 1 ';J; PCT/EP91/001~3.-Table A

Ex Compound Name Minimum Effective Dose (mq/kg) 9-methoxy-4-(4-trifluoromethylphenyl)- ~3 8b [1]benzopyrano[4,3-c]pyrazol-3(2H)-one 2-(2-ethoxyethyl)-9-methoxy-4-(4- 3 8c trifluoromethylphenyl)~l~benzopyrano-[4,3-c]pyrazol-3(2H)-one 4-(4-chlorophenyl)-9-ethoxy-2-methyl- 50 9 [l]benzopyrano[4,3-c]pyrazol-3(2H)-one 4-(4-chlorophenyl)-2-(2,2,2-trifluoro- 50 1510 ethyl)[1]benzopyrano[4,3-c]pyrazol-3-(2H)-one 4-(3,4-dichlorophenyl)-2-methyl[ll- 50 11 benzopyrano[4,3-c]pyrazol-3(2H)-one 2-methyl-4-(2-naphthyl)[l]benzo- 50 2012 pyrano[4,3-c]pyrazol-3(2H)-one 4-(4-chlorophenyl)[l]benzopyrano- 3 13,19 [4,3-clpyrazol-3(2H)-one 4-(4-chlorophenyl)-2-methyl[l]benzo- 10 14,24 pyrano[4,3-c]pyrazol-3~2H)-one 4-(4-chlorophenyl)-2-ethyl[l]benzo- ~50 t5 pyrano[4,3-c]pyrazol-3(2H)-one .

WO91/12255 ~ Q ~ ~ B ~ PCTtEP91/00153 Ex Compound Name Minimum Effective Dose (mq/kq) 4-~4-chlorophenyl)-9-methoxy-2-methyl- 50 16 [l]benzopyrano[4,3-c]pyrazol-3(2H)-one 4-(4-chlorophenyl)-2,9-dimethyl[l]- 50 17 benzopyrano[4,3-c]pyrazol-3(2H)-one 2-methyl-4-(4-trifluoromethylphenyl)- 3 18 [l]benzopyrano[4,3-c]pyrazol-3(2H)-one 23,20 4-(4-trifluoromethylphenyl)[l]benzo- 3 21,22 pyrano[4,3-c]pyrazol-3(2H)-one 2-l4-(4-chlorophenyl)-3-oxo-2,3- So 26 dihydro[1]benzopyrano[4,3-c~pyrazol-2-yl]ethyl acetate 4-(4-chlorophenyl)-2-~2-methoxyethyl)- 10 27 [l]benzopyrano[4,3-c]pyrazol-3(2H)-one 4-(4-chlorophenyl)-3-oxo-2,3-dihydro ~50 28 [1]benzopyrano[4,3-c]pyrazole-2-acetonitrile 29 4-(4-chlorophenyl)-2-(2-phenoxyethyl)- 50 [l]benzopyrano[4,3-c]pyrazole-3(2H)-one 2-allyl-4-(4-chlorophenyl)[l]benzo- 50 pyrano[4,3-c]pyrazol-3(2H)-one WO91/12255 PCT/EP91/00153,---Ex Comound Name Minimum Effective Dose (mq/kg) 32 4-(4-chlorophenyl)-3-oxo-2,3-dihydro- 50 [1]benzopyrano[4,3-c]pyrazole-2-propionitrile 33 4-(4-chlorophenyl)-2-propyl[l]benzo- 50 pyrano[4,3-c]pyrazol-3(2H)-on~

34 4-14-chlorophenyl)-3-oxo-2,3-dihydro- ~30(a) [1]benzopyrano[4,3-c]pyrazole-2-carbonitrile 4-(4-chlorophenyl)-2-~2-ethoxyethyl)-[l]benzopyrano[4,3-c]pyrazol-3~2H)-one 36 2-butyl-4-(4-chlorophenyl)t1]benzo- 50 pyrano~4,3-c]pyrazol-3(2H)-one 37 4-(4-chlorophenyl)-2-[2-~2-methoxy- S0 ethoxy)ethyl][l]benzopyrano~4,3-c]-pyrazol-3~2H)-one 38 4-(4-chlorophenyl)-3-oxo-2,3-dihydro- 50 ~l]benzopyrano~4,3-c]pyrazole-2-acetophenone 39 2-~2-t4-(4-chlorophenyl)-3-oxo-2,3- 50 dihydro[1]benzopyrano[4,3-c]pyrazol-2-yl]ethoxy3ethyl acetate WO91/12255 2 ~ J~ ~ PCT/EP91/00153 ~x ComDound Name Minimum ~ffective Dose ~mq/kq) 4-(4-chlorophenyl)-2-~2-(1,3-dioxolan- 50 40 2-yl)ethyl~[1~benzopyrano[4,3-c~pyrazol-3(2H~-one 4-(4-chlorophenyl)-2-(1,3~dioxolan-2- 50 42 ylmethyl)[1]benzopyrano[4,3-c]pyrazol-3(2H)-one 4-(4-chlorophenyl)-2-(2-ethoxvpropyl)- 50 43 [1]benzopyrano[4,3-c]pyrazol-3(2H)-one 2-[3-oxo-4-~4-trifluoromethylphenyl)- 50 44 2,3-dihydro[1]benzopyrano~4,3-c]pyrazol-2-yllethyl acetate 4-(4-chlorophenyl)-2-~2-(1,3-dioxan-2- 50 45 yl)ethyl][1lbenzopyrano[4,3-c]pyrazol-3(2H)-one 2-(2-hydroxyethyl)-4-(4-trifluoro- 50 46 methylphenyl)[1]benzopyrano[4,3-c]-pyrazol-3(2H)-one 4-(4-chlorophenyl)-2-(2-hydroxyethyl)- 50 47 [1]benzopyrano[4,3-c]pyrazol-3(2H)-one 4-(4-chlorophenyl)-2-(3-hydroxypropyl)- 50 48 r1]benzopyrano[4,3-c]pyrazol-3(2H)-one 4-(4-chlorophenyl)-2-[2-(2-hydroxy- 50 49 ethoxy)ethyl][1]benzopyrano[4,3-c]-pyrazol-3(2H)-one wo 91/12255 2 ~ ~ ~ & ~ ~ PCT/EP9l/00153.-~

Ex Compound Name Minimum ~ffective Dose (mq/kg) 4-(4-chlorophenyl)-3-oxo-2,3-dihydro- 3 [1]benzopyrano[4,3-c]pyrazole-2-acetamide 4-(4-chlorophenyl)-3-oxo-2,3-dihydro- 50 51 [l]benzopyrano[4,3-c]pyrazole-2-propionamide 4-(4-chlorophenyl)-N-ethyl-3-oxo-2,3- 50 52 dihydro~1]benzopyrano[4,3-c]pyrazole-2-acetamide 4-(4-chlorophenyl)-N-methyl-3-oxo-2,3- 50 53 dihydro[1]benzopyrano[4,3-c]pvrazole-2-acetamide 4-(4-chlorophenyl)-3-oxo-N-propyl-2,3- 50 54 dihydro[l~benzopyrano[4,3-c]pyrazole-2-acetamide 4~(4-chlorophenyl)-3-oxo-2,3-dihydro- ~50 [l]benzopyrano[4,3-c]pyrazole-2-carbox-amide 2-acetyl-4-(4-chlorophenyl)[l]benzo- 50 56 pyrano[4,3-c]pyrazol-3(2H)-one Ethyl 4-(4-chlorophenyl)-3-oxo-2,3- 50 57,58 dihydro[l]benzopyrano[4,3-c]pyrazole-2-carboxylate WO91/1225~ PCTtEP91/00153 Ex Compound Name Minimum Effective Dose ~mq/kq) cyclobutyl 4-(4-chlorophenyl)-3-oxo- 50 59 2,3-dihydro[l]benzopyrano[4,3-c~-pyrazole-2-acetate 3-oxo-4-(4-trifluoromethylphenyl)-2,3- ~3 60 dihydro[l3benzopyrano[4,3-c]pyrazole-2-acetonitrile 2-(2-ethoxyethyl)-4-(4-trifluoromethyl- 3 61 phenyl)[l]benzopyranot4,3-c]pyrazol-3(2H)-one 2-(2-bromoethyl)-4-(4-trifluoromethyl- ~3 62 phenyl)[l]benzopyrano[4,3-c]pvrazol-3(2H)-one 3-oxo-4-(4-trifluoromethylphenyl)-2,3- ~S0 63 dihydro[l]benzopyrano[4,3-c]pyrazole-2-butyramide 2-(2-chloroethyl)-4-(4-chlorophenyl)- ~50 64 [1]benzopyrano[4,3-c~pyrazol-3~2H)-one The following compounds were prepared in an analogous manner and also found to be active in the above described CH test at 50 mg/kg.

2-[4-~4-chlorophenyl)-3-oxo-2,3-dihydro-[l]benzopyrano[4,3-c]pyrazol-2-yl]ethyl propionate, m.p. 112-114C.

., ~

WO91/1225~ PCTtEP9t/001~3 -Ex Compound Name 4-(4-chlorophenyl)-N-isopropyl-3-oxo-2,3-dihydro[1~benzopyrano[4,3-c~pyrazole-2-acetamide, m.p. 238-241 (decomposition) N-benzyl-4-(4-chlorophenyl)-N-methyl-3-oxo-2,3-dihydro[1]benzopyrano[4,3-c]-pyrazole-2-acetamide m.p. 182-183C

Notes (a) Active in each of two tests at 30 mg/kg.

The compounds of the present invention also show activity in a variety of other ln-vivo screens, which show the utility of the compounds as immunomodulants, particularly in suppressing the immune response.
Administration of the compounds has been ca-ried out orally, or parenterally. Some compounds have been found to be active in a test which determines their effects on humoral immunity by assaying the sera collected at the end of the oxazolone induced cutaneous hypersensitivity test described above (CH test) for changes in the amount of anti-ox,azolone antibody produced, and a Graft versus Host test similar to that used by Smith S R, Terminelli C, Xipilman C T and Smith Y., J. Immunopharmacology 1981;3(2),133-170.

For example, the compounds prepared in the following Examples were also found to be active in the above-described antibody test after parenteral administration at 50 mg/kg. A compound was deemed to WO91/12255 ` ~ ~ PCT/EP91/00153 be active, i~ at a dose of 50 mg/kg it caused a decrease in the relative serum anti-oxazolone antibodv concentration determined by an enzyme linked immunosorbent assay ~ELISA) by a factor of 0.5 or greater calculated by the following formula:-O.D.(C1) - O.D.(T1) O.D.(C1) - O.D.~C2) where O.D.(C1) is the optical density of the control serum at a dilution of 1/t28 O.D.(C2) is the optical density of the control serum at a dilution of 1/256 O.D.(T1) is the optical density of the test serum at a dilution of 1/t28 The control and test sera were diluted with phosphate bufered saline (pH 7.3) containing 0.05~ v/v Tween 20 (trade name).

Compounds active in above test:
Examples: 8b, 8c, 10-15, 18, 20, 26, 27, 30, 33, 35, 37, 38, 40, 42, 44-47, 49, 52, 55-64.

Claims (12)

1. A compound of formula I

in which R1 represents hydrogen, cyano, C2 6 alkanoyl, C2-6 alkoxycarbonyl, CONH2, or R1 represents C1-6 alkyl or C2-6 alkenyl both of which may be substituted by cyano, halo, trifluoromethyl, hydroxy, benzoyl, C2-6 alkanoyloxy, C3-8 cycloalkoxycarbonyl, a 5-7 membered non-aromatic heterocyclic group containing 2 oxygen heteroatoms, CONR9R9,, phenoxy or C1-6 alkoxy, in which C1-6 alkoxy may be further substituted by halo, hydroxy, C1-6 alkoxy or C2-6 alkanoyloxy;

R2 represents hydrogen or chloro;

R3 represents chloro or trifluoromethyl;

or R2 and R3 are joined to form a fused benz ring;

R4 represents hydrogen, C1-6 alkyl, C1-6 alkoxy or halo;

R9 and R9, , which may be the same or different, represent hydrogen, C1-6 alkyl or benzyl.

2. A compound according to claim 1 in which R2 represents hydrogen; R3 represents chloro or trifluoromethyl; R1 represents (CH2)PJ, J represents hydrogen, C1-6 alkoxy, carbamoyl, cyano or halo; R4 represents hydrogen or C1-6 alkoxy and p is 0, 1 or 2.

3. A compound according to claim 2 in which R1 represents hydrogen, methyl, cyanomethyl, (CH2)2halo, carbamoylmethyl or C1-4 alkoxyethyl.

4. A compound according to claim 3 in which R6 represents methyl or 2-ethoxyethyl.

5. A compound selected from:

2-(2-ethoxyethyl)-9-methoxy-4-(4-trifluoromethyl-phenyl)[1]benzopyrano[4,3-c]pyrazol-3(2H)-one 2-methyl-4-(4-trifluoromethylphenyl)[1]benzo-pyrano[4,3-c]pyrazol-3(2H)-one 2-(2-ethoxyethyl)-4-(4-trifluoromethylphenyl)[1]-benzopyrano[4,3-c]pyrazol-3(2H)-one

6. A pharmaceutical composition comprising a compound of formula I as claimed in any one of claims 1-5 together with a pharmaceutical carrier.

7. A pharmaceutical composition according to claim 6 in unit dosage form.

8. A method of treating diseases with an immunological association comprising the administration of a therapeutically effective amount of a compound of formula I as claimed in any one of claims 1-5.

9. A compound of formula I as claimed in any one of claims 1-5 for use as an immunomodulatory agent.

10. A compound of formula I as claimed in any one or claims 1-5 in the manufacture of a medicament for use in the treatment of diseases with an immunomological association.

11. A process to prepare a compound of formula I as claimed in claim 1:-a) comprising the reaction of a compound of formula II

II

or a tautomer thereof, with a compound of formula III

III

in which R14 represents (OQ)2 or (SQ)2 and R15 represents OQ or SQ or NQ'2; R14 represents =NH; and R15 represents OQ or SQ; or R14 represents =O and R15 represents hydrogen, halo or 1-imidazolyl; and Q
and Q' represent a C1 4 alkyl group or a benzyl group;
b) comprising the reaction of compounds of formula IV

IV

in which R16 represents hydrogen, or a tautomer thereof, or in which R16 represents a group COR18 wherein in R18 represents hydrogen, a C1-4 alkyl group, a benzyl group or a group R5 and R17 represent COR5 with a base;

12. A compound of formula II

II

in which R1 and R4 are as defined in claim 1.