EP0607329A1

EP0607329A1 - New derivatives of fluoro-quinoline carboxylic-3 acid and preparation thereof

Info

Publication number: EP0607329A1
Application number: EP92922225A
Authority: EP
Inventors: Christophe Daubie; Jean-Jacques Legrand; Clive Pemberton
Original assignee: Laboratoire Roger Bellon SA
Current assignee: Laboratoire Roger Bellon SA
Priority date: 1991-10-10
Filing date: 1992-10-08
Publication date: 1994-07-27
Also published as: TW224093B; EP0538100A1; NO941244D0; NO301640B1; FR2682378A1; IL103403A; DE69232406D1; ES2176185T3; RU2109014C1; KR100249637B1; CZ284595B6; PT538100E; NO941244L; HU9401004D0; CA2119757A1; KR940702846A; US5442070A; FI105400B; HU214955B; NZ244646A

Abstract

New fluoro-3-quinolinecarboxylic acid derivatives of general formula (I), in which R is a hydrogen atom or an alkyl radical and Hal is a halogen atom, and its salts where such exist, their preparation and their use as synthetic intermediates. <IMAGE>

Description

NOVEL DERIVATIVES OF FLUORO QUINOLEINE CARBOXYLIC-3 ACID AND THEIR

PREPARATION

The present invention relates to new derivatives of fluoro quinoline carboxylic acid-3 of general formula:

in which R is a hydrogen atom or an alkyl radical and Hal is a halogen atom, as well as its salts when they exist.

In US patent 4,970,213, 6-fluoro-quinoline carboxylic acids have been described with a structure:

in which Hal is a fluorine or chlorine atom, useful as intermediates for the preparation of benzonaphthyridines-1, 8 having antimicrobial activity.

The new quinoline derivatives according to the present invention are also useful for the preparation of benzonaphthyridine derivatives-1, 8 antimicrobials, but allow to obtain improved yields and thus avoid carrying out the process in passing intermediate by unstable products.

In the general formula (I) when R represents an alkyl radical, the latter is straight or branched and contains 1 to 4 carbon atoms; moreover, the symbol Hal is advantageously chosen from chlorine or fluorine.

According to the present invention, the new quinoline derivatives of general formula (I) can be prepared by cyclization in an acid reducing medium of a nitro derivative of general formula: in which Hal is defined as above, R- _| is defined as R with the exception of representing a hydrogen atom, and R2 is defined as R- _j or represents a carbamoyl or cyano radical, optionally followed by the release of the acid function if it is desired to obtain a quinoline derivative for which R is a hydrogen atom.

The treatment in an acid medium is carried out in the presence of iron, at a temperature between 0 and 130 ° C., by means of any organic or mineral acid which does not alter the rest of the molecule. By way of example, the procedure is carried out using acetic acid or formic acid, it is also possible to operate using dilute hydrochloric acid or dilute sulfuric acid in a hydro-alcoholic medium. . It is understood that the choice of acid depends on the expected product. In the case where it is desired to obtain the acid of general formula (I), it is advantageous to operate in a stronger acid, under conditions where the hydrolysis of the ester takes place simultaneously; it may also be advantageous to operate from the product of general formula (II) for which 2 is cyano. It is well understood that in the cases where the ester has been obtained and where the acid of general formula (I) is to be obtained for which R is a hydrogen atom, the hydrolysis of the ester can also be used after the cyclization reaction, by any known method for obtaining an acid from an ester without affecting the rest of the molecule.

Where appropriate, the hydrolysis of the ester is carried out in an acid medium, for example in the presence of hydrochloric acid, sulfuric acid or ethanesulfonic acid. It can also be carried out in a basic hydroalcoholic medium (soda, potash for example).

The nitro derivative of general formula (II) can be prepared by the action of a malonic acid derivative of general formula: 2-CH2-C00R-! (III) in which R- _j and 2 are defined as above, on a nitrobenzaldehyde derivative of general formula:

in which Hal is defined as above.

The reaction is generally carried out in a basic medium [for example in the presence of an alkaline bicarbonate (sodium bicarbonate), a hydride (sodium hydride) or an alcoholate at a temperature between 0 and 150 ° C, in an organic solvent such as an anhydride (acetic anhydride for example) or such as an ide (dimethylformamide, N-methylpyrrolidone for example) by operating in the presence of molecular sieves or any other drying agent or in a mixture of solvents such as a polar aprotic solvent / acetic anhydride mixture (dimethylformamide / acetic anhydride, N-methyl pyrrolidone / acetic anhydride for example). It is also possible to operate in a two-phase environment. It is not essential to isolate the product of general formula (II) in order to use it in the following reaction.

The fluoronitrobenzaldehyde of general formula (IV) is obtained by nitration of the fluorobenzaldehyde of general formula:

in which Hal is defined as above.

the reaction is advantageously carried out with concentrated nitric acid in the form of a sulfonitric mixture, or of a nitric acid / acetic acid mixture, at a temperature between 0 and 90 ° C. 4-Chloro-3-fluoro-benzaldehyde can be prepared according to the method described in European application EP 289 942.

According to the invention, the new fluoro quinoline derivatives of general formula (I) are useful as synthesis intermediates for the preparation of benzo [b] naphthyridine-1, 8 derivatives of general formula:

in which either R3 (which represents an alkyl, fluoroalkyl, cycloalkyl radical containing 3 to 6 carbon atoms, alkyloxy or alkyllamino) and Het (which is a nitrogen heterocyclyl radical), are as defined for the substituents in position -1 and -8, in European application EP 431 991 and US Pat. No. 5,004,745, either R3 is a hydrogen atom or an alkyl, fluoroalkyl, carboxyalkyl, cycloalkyl radical containing 3 to 6 carbon atoms, fluorophenyl, difluorophenyl, alkyloxy or alkyllamino, and Het is an azetidinyl-1 radical substituted [in position -3 by a radical R4 which may be a hydrogen atom or a hydroxy, amino, alkylamino radical in which the alkyl part is optionally substituted by a radical amino or hydroxy or can represent a dialkoylamino radical whose alkyl parts can optionally form with the nitrogen atom to which they are attached, a 5 or 6-membered heterocycle containing possibly Another heteroatom chosen from nitrogen, oxygen or sulfur, or may represent a cycloalkylamino radical containing 3 to 6 members, or an alkanoylamino, N-alkyl N-alkanoyl amino or aminoalkyl phenylamino radical, and substituted in positions -2 and -3 by identical or different radicals R5 and Rg which represent hydrogen atoms, alkyl, alkenyl radicals containing 2 to 4 carbon atoms, phenyl, phenyl substituted by a halogen atom, or by an alkyl, alkyloxy, hydroxy, ni- radical tro, amino, alkyllamino, dialkoylamino or halogenoalkyl, or substituted in position -2 by radicals R5 and Rg which represent alkyl radicals], it being understood that the alkyl and alkanoyl radicals mentioned above are straight or branched and contain 1 to 4 carbon atoms.

These benzonaphthyridine derivatives are useful as antimicrobials.

The quinoline derivatives according to the present invention are also useful for the preparation of intermediates of general formula (XI) defined below which are the precursors of benzonaphthyridine derivatives of general formula (VI).

According to the invention, the benzo [b] naphthyridines-1, 8 of general formula (VI) can be obtained from the products according to the invention by operating as follows:

A chloro fluoro ester of general formula is prepared:

in which Hal and R are defined as above, by chloration of the fluoroquinoline carboxylic acid derivative of general formula (I), the acid function of which, where appropriate, is previously protected (when R is a hydrogen atom).

Chlorination is carried out using known chlorinating agents which do not alter the rest of the molecule. In particular, the operation is carried out by the action of phosphoryl chloride, sulfuryl chloride or phosphorus pentachloride at a temperature between 0 and 150 ° C.

When it is desired to obtain the acid of general formula (VII) in which R is a hydrogen atom, the ester obtained is hydrolyzed by any known method which does not alter the rest of the molecule. The protection and the elimination of the protective radical can be carried out by any compatible group and the placing of which implementation and elimination do not alter the rest of the molecule. In particular, one operates according to the methods described by TW GREENE, Protective Groups in Organic Synthesis, A. iley Interscience Publication (1981), or by Me OMIE, Protective Groups in Organic Chemistry, Plenum Press (1973).

The benzonaphthyridine derivative of general formula (VI) can be obtained from chloro fluoro quinoline carboxylic acid of general formula (VII) in which R is a hydrogen atom, according to or by analogy with the method described in European application EP 431 991 and the patent US 5,004,745 or US 4,970,213.

The benzonaphthyridine derivative of general formula (VI) can also be obtained from the ester of general formula (VII) by operating as follows:

An amine of general formula:

R3-NH-CH2-CH2-R7 (VIII)

in which R3 is defined as above and R is an alkyloxycarbonyl, cyano, carbamoyl, alkylcarbamoyl, benzylcarbamoyl, hydroxyethylcarbamoyl, dialkoylaminoethylthycarbamoyl or dialkoylcarbamoyl radical in which the alkyl parts may optionally form with the nitrogen atom to which they are attached a 5 or 6-membered heterocycle optionally containing another heteroatom chosen from oxygen, sulfur or nitrogen and optionally substituted on nitrogen by an alkyl radical, (the alkyl radicals being straight or branched and containing 1 to 4 atoms carbon), is condensed on the chloro fluoro quinoline of general formula (VII) in which R is an alkyl radical, so as to obtain a fluoro ester of general formula:

in which Hal, R, R3 and R7 are defined as above.

Condensation takes place in a basic medium in an organic solvent such as an aromatic hydrocarbon (toluene for example), an amide (dimethylformamide, N-methyl pyrrolidone for example), an ether (tetrahydrofuran for example), a sulfoxide (di ethyl sulfoxide for example), a chlorinated solvent (dichloromethane, dichloroethane, chlorobenzene for example) or an alcohol at a temperature between -10 and 120 ° C.

By way of example, the bases used can be chosen from alkali carbonates (sodium or potassium carbonate), alcoholates or an alkali hydride (sodium hydride).

It is understood that, in the alternative where the symbol R3 represents a carboxyalkyl radical, the latter is protected before the reaction. The removal of the protective radical is preferably carried out after the oxidation reaction, on the benzonaphthyridine derivative of general formula (XI) described below. The protection and the release of the acid function are carried out according to the usual methods which do not alter the rest of the molecule. In particular according to the methods which have been mentioned previously.

The fluoro quinoline of general formula (IX) is cyclized in a basic medium to prepare tetrahydro-1,2,3,4 benzo [b] naphthyridine-1, 8 of general formula:

in which Hal, R3 and R are defined as above.

The reaction is carried out at a temperature between -70 and 120 ° C in the presence of a base such as an alcoholate (sodium ethylate, sodium methylate, potassium t.butylate for example), a hydride alkaline (sodium hydride for example), or an alkali hydroxide by operating by phase transfer. It is advantageously carried out in a polar aprotic solvent (for example dimethylformamide, tetrahydrofuran) or in an alcohol (ethanol, methanol for example) in a glyme or in a glycol (ethylene glycol for example). When the reaction is carried out by phase transfer, it is advantageously carried out in a chlorinated solvent such as methylene chloride, the base being in solution in the. aqueous phase.

2,3,4,4-tetrahydro benzo [b] naphthyridine-1, 8 of general formula (X) is oxidized to prepare benzo [b] naphthyridine-1, 8 of general formula:

in which Hal, R3 and 7 are defined as above.

Oxidation is carried out with hydrogen peroxide, optionally in the presence of potassium iodide, in an organic solvent such as an alcohol

(ethanol for example), at a temperature between 0 and 120 ° C.

It is also possible to operate in a two-phase medium in a water / chlorinated solvent mixture (dichloromethane, dichloroethane ...).

The Het heterocycle is condensed on the benzo [b] naphthyridine-1, 8 of general formula (XI) or the corresponding acid to prepare a benzonaphthyridine derivative of general formula (VI), operating according to or by analogy with the methods described in European application EP 431 991 and US Pat. No. 5,004,745 then, if necessary, by transformation of the ester, of the amide or of the nitrile obtained into an acid of general formula (VI). The benzonaphthyridine derivatives of general formula (VI) are antimicrobials whose activities have been described in the European application and the American patent cited above. Benzonaphthyridine derivatives of formula general (VI) for which Het is an azetidinyl radical also have antibacterial properties. They show remarkable activity in vitro and in vivo on gram positive bacteria and also on gram negative bacteria. In vitro, they are active at a concentration between 0.06 and 4 μg / crn ^ on staphylococcus aureus IP 8203 and at a concentration between 0.25 and 20 μg / crn ^ on Escherichia coli strain NIHJ JC2. In vivo, they are active on experimental infections of mice with staphylococcus aureus IP 8203 at doses between 10 and 200 mg / kg orally.

The new products according to the present invention, as well as the products to which they lead, can optionally be purified by physical methods such as crystallization or chromatography.

The new intermediates of general formula (I) for which R is a hydrogen atom can be converted into metal salts or into addition salts with nitrogenous bases according to the methods known per se. These salts can be obtained by the action of a metal base (for example alkaline or alkaline-earth), ammonia or an amine on a product according to the invention in »an appropriate solvent such as an alcohol, a ether or water or by exchange reaction with a salt of an organic acid. The salt formed precipitates after optional concentration of its solution, it is separated by filtration, decantation or lyophilization.

As examples of salts, there may be mentioned the salts with alkali metals (sodium, potassium, lithium) or with alkaline earth metals (magnesium, calcium), the ammonium salt, the salts of nitrogenous bases (ethanolamine, diethanolamine, triethylamine, triethylamine, ethylamine, propylamine, diisopropylamine, NN-dimethylethanolamine, benzylamine, dicyclohexylamine, N-benzyl phenethylamine, NN'-diben- zylethylenediamine, diphenylenediamine, benzhydrylamine, quinine, choline, arginine, lysine, leucine, lysine) addition salts with mineral acids (hydrochlorides, bromhy- drates, sulfates, nitrates, phosphates) or organic (succinates, fumarates, maleates, methanesulfonates, p.toluenesulfonates, isethionates).

The following examples, given without limitation, illustrate the present invention.

EXAMPLE

To a solution of 56.5 g of 3,4-difluoro-6 nitro-6 benzaldehyde in 92 cm ³ of acetic anhydride, 62.8 g of ethyl malonate and 51 g are added in ten minutes. sodium bicarbonate. • _j O The suspension is kept for 1 hour at around 20 ° C and then heated for 3 hours at a temperature of around 75 ° C. At this temperature, 400 cm 3 of glacial acetic acid are poured in 30 minutes, then 65 cπv- ³ . of water. The temperature is allowed to stabilize at around 50 ° C. and the mixture is stirred for another 30 minutes at this temperature. 39 g of powdered iron are added, in portions, over 2 hours to the reaction mixture. The temperature rises to approximately 85 ° C. and the suspension is maintained for an additional hour at this temperature. Iron salts formed are esso¬ res at 80 ° C, then washed with 2 times 150 cm ³ of glacial acid ac ^é tick. The filtrate and the acid washing phases are combined and 0 3 added to 700 cm of water, the precipitate obtained is drained at 20 ° C.

3 approximately and washed with 3 times 500 cm of water. The wet product obtained is dried under reduced pressure (20 JcPa) at approximately 50 ° C. 53.5 g of 3-ethoxycarbonyl-difluoro-6.7 carbostyril are obtained in the form of a cream solid, melting at 242 ° C.

5 3,4-Difluoro-6 nitro-6 benzaldehyde is prepared as follows:

3 At 520 cm of sulfuric acid, with stirring, cooled to 0 ° C., 60 cm of fuming nitric acid are added over 30 minutes. To the solution obtained, 100 g of difluoro-3,4 benzaldehyde are added over 30 minutes at approximately 0 ° C. The temperature is allowed to rise to about 20 ° C and stirred for another 3 hours at this temperature. After cooling to approximately 5 ° C., the reaction mixture is poured over 30 minutes under strong agitation, in 1200 g of crushed ice. We leave the temperature

3 go up to around 20 ° C and extracted with 2 times 600 cm of toluene. The combined organic extracts are washed with 3 times 1000 cm ³ of water, and concentrated under reduced pressure (20kPa) at 50 ° C. 113 g of 3,4-difluoro-6-nitro-benzaldehyde are obtained in the form of a brown oil which is used as it is in subsequent syntheses. A purified sample of 3,4-difluoro-6 nitro-benzaldehyde gives the following characteristics:

PE (6.66 Pa) = 46 ° C. NMR spectrum (400 MHz, DMSO, T = 298 ° K)

10.20 ppm (1H, 1s); 8.5 ppm (1H, 1q); 8.05 ppm (1H, 1q)

The products according to the invention can be used in the following manner:

Usage example 1

To 200 cm ³ of phosphoryl chloride, 50 g of ethoxycarbonyl-3 difluoro-6,7 carbostyrile are added over 10 minutes, with stirring, at 20 ° C. The suspension is heated to a temperature in the region of 70 ° C. and kept at this temperature for 3 hours. After cooling to approximately 10 ° C, the solution obtained is poured, with stirring, into a mixture of 1000 cm ³ of water and 1000 g of crushed ice. The temperature is allowed to rise to about 20 ° C and extracted with 2 times 500 cm ³ of dichloromethane. The combined organic extracts are washed with 1000 cm ³ of water, 1000 cm ³ of water supplemented with sodium bicarbonate until pH = 7, dried over sodium sulfate, filtered and concentrated to dryness under reduced pressure (20 kPa) at around 40 ° C. 45.6 g of 2-chloro-3-ethoxycarbonyl-difluoro-6,7 quinoline are obtained in the form of a beige solid melting at 108 ° C. which is used without further purification for the subsequent steps. 2-chloro-3-ethoxycarbonyl difluoro-6,7 quinoline is converted to 2-chloro-difluoro-6,7 quinoline carboxylic-3 according to the usual methods and can thus lead to benzo [b] naphthyridin-1,8 derivatives described in US Patent 4,970,213. Example cTntilisatipn 2

Preparation of 3-ethoxycarbonyl-6,7-difluoro (N-methyl. N-b ethoxycarbonylethyl) 2-aminoquinoline:

To a solution of 72 g of 2-chloro-3-ethoxycarbonyl-difluoro-6,7 quinoline prepared as described in use example 1 and

45.1 g of N-methyl, Nb ethoxycarbonylethyl amine in 750 cm ³ of toluene, 56.2 g of sodium carbonate are added. The suspension obtained is heated to approximately 90 ° C. and then stirred for 4 hours at this temperature. The reaction mixture is then cooled to approximately 20 ° C. and then washed with 3 times 400 cm of water. The organic phase is concentrated to dryness under reduced pressure (20kPa) at around 50 ° C. 94 g of 3-ethoxycarbonyl-6,7-difluoro (N-methyl Nb ethoxycarbonylethyl) 2-aminoquinoline are obtained in the form of an oil used without further purification for the subsequent steps.

Preparation of 3-ethoxycarbonyl-7,8-difluoro-1 methyl-4-oxo-tetrahydro-1,2,3,4 benzo [b] naphthyridin-1, 8:

To a solution of 26.6 g of sodium ethylate brought to reflux in

3,900 cm of absolute ethanol, a solution of

94 g of 3-ethoxycarbonyl-6,7-difluoro (N-methyl Nb ethoxy¬ carbonylethyl) 2-amino quinoline in 300 cm ³ of absolute ethanol. The suspension obtained, still at reflux, is stirred for 15 minutes

3 additional. Then poured, in 30 minutes, 38 cm of glacial acé¬ tick. The reaction mixture is stirred for an additional 15 minutes.

3 shutters then pour in 45 minutes, still at reflux, 500 cm of water. The suspension obtained is cooled to approximately 20 ° C. The precipitate is

3 wrung at around 20 ° C and washed with 2 times 300 cm of water. The wet product is dried under reduced pressure (20 kPa) at around 60 ° C. Is isolated 71.5 g of 3-ethoxycarbonyl-7,8-difluoro-1-methyl-4-oxo-1,2,3,4 benzo [b] aphtyridine-1,8 in the form of a melting yellow solid at 188 ° C.

Preparation of 3-ethoxycarbonyl-7,8-difluoro-1-methyl-4-oxo-1,4-dihydro benzo [b] naphthyridin-1, 8: To a suspension of 71 g of 3-ethoxycarbonyl-7,8-methyl-difluoro

3 oxo-4 tétrahydro-1, 2,3,4 benzo [b] naphthyridin-1, 8 in 1000 cm of ethanol, a solution of stirring is added at approximately 20 ° C.

3.78 g of potassium iodide in 20 cm of water. The suspension is heated to 77 ° C. and 30 cm 3 of hydrogen peroxide at 33% by weight is added at this temperature over 60 minutes. The reaction mixture is maintained at reflux for another 30 minutes and then is cooled to approximately 20 ° C. At this temperature, a solution of 11.4 g of sodium thiosulfate in 50 cm ³ of water is poured over 5 minutes. The precipitate obtained is drained at approximately 20 ° C and washed with 2 times 300 cm ³ of water. The wet product obtained is dried under reduced pressure

(20 kPa) at around 60 ° C. 73 g of 3-ethoxy-7.8-difluoro-1 methyl-4-oxo-1,4-dihydro-benzo [b] naphthyridin-1, 8 are isolated in the form of a white solid melting at a temperature above 270 ° C. .

Example of use 3

Preparation of 3-ethoxycarbonyl-6,7-difluoro (N-ethyl N-b ethoxycarbonylethyl) 2-amino quinoline:

To a solution of 10 g of 2-chloro-3-ethoxycarbonyl-6,7-difluoro-quinoline prepared as described in Example 1 and 9.7 g of N-ethyl, Nb ethoxycarbonylethyl amine in 120 cm ³ of toluene, 7.8 g of sodium carbonate are added. The suspension obtained is heated to approximately 90 ° C. and then stirred for 4 hours at this temperature. The reaction mixture is then cooled to approximately 20 ° C. and then washed with 3 times 100 cm ³ of water. The organic phase is concentrated to dryness under reduced pressure (20 kPa) at around 50 ° C. 13 g of 3-ethoxycarbonyl-6,7-difluoro (N-ethyl Nb ethoxycarbonylethyl) 2-aminoquinoline are obtained in the form of an oil which is used without further purification for the subsequent steps.

Preparation of 3-ethoxycarbonyl-7,8-difluoro-1-ethyl-4-oxo-tetrahydro-1, 2,3,4 benzo [b] naphthyridin-1, 8:

A solution of 16.1 g of sodium ethylate brought to reflux in 600 cm ³ of absolute ethanol is poured, in 60 minutes, a solution of 68 g 3-ethoxycarbonyl-6,7-difluoro (N-ethyl Nb ethoxycarbonylé¬ thyl) 2-amino quinoline in 200 cm ³ of absolute ethanol. The suspension obtained, still at reflux, is stirred for an additional 60 minutes. Then 20 cm ³ of glacial acetic acid are poured in over 30 minutes. The reaction mixture is stirred for an additional 15 minutes, then 400 cm ³ of water are poured in over 45 minutes, still at reflux. The suspension obtained is cooled to approximately 20 ° C. The precipitate obtained is drained at around 20 ° C and washed with twice 200 cm ³ of water. The wet product is dried under reduced pressure (20 kPa) at around 50 ° C. 52.4 g of 3-ethoxycarbonyl-7.8 difluoro-1 ethyl-4-oxo-tetrahydro-1,2,3,4-benzo [b] naphthyridin-1, 8 are isolated in the form of a golden yellow solid melting at 152 ° C.

Preparation of 3-ethoxycarbonyl-7,8-difluoro-1-ethyl-4-oxo-1,4-dihydro-benzo [b] naphthyridin-1, 8:

To a suspension of 33 g of 3-ethoxycarbonyl-7,8-difluoro-1 ethyl-4-oxo-tetrahydro-1, 3, benzo [b] naphthyridin-1, 8 in 1000 cm ³ of ethanol with stirring at about 20 ° C a solution of 1.7 g of potassium iodide in 10 cm ³ of water. The suspension is heated to 77 ° C. and 12.7 cm ³ of oxygenated water at 33% by weight are poured at this temperature over 30 minutes. The reaction mixture is kept at reflux for a further 30 minutes and then is cooled to about 20 ° C. At this temperature, a solution of 6 g of sodium thiosulfate in 20 cm ³ of water is poured in 5 minutes. The precipitate obtained is drained at approximately 20 ° C and washed with twice 150 cm ³ of water. The wet product obtained is dried under reduced pressure (20 kPa) at around 50 ° C. 28.7 g of 3-ethoxy-7.8-difluoro-1 ethyl-4-oxo-1,4 dihydro-1,4 ben-zo [b] naphthyridin-1, 8 are isolated in the form of a light yellow solid melting at 270 °. vs.

Example of use 4

Preparation of 3-ethoxycarbonyl-6,7-difluoro (N-cyclopropyl N- b ethoxycarbonylethyl) 2-amino quinoline: To a solution of 3.48 g of 2-chloro-3-ethoxycarbonyl-6,7-difluoro-quinoline prepared as described in the example of use, 1 and 3 g of N-cyclopropyl Nb ethoxycarbonylethyl ine in 10 cm ³ of toluene, 3 g of sodium carbonate are added. The suspension obtained is heated to reflux and then stirred for 15 hours at this temperature. The reaction mixture is then cooled to approximately 20 ° C. and then 30 cm ³ of water and 4.5 cm ³ of acetic acid are added. After decantation, the reaction mixture is washed with 2 times 10 cm ³ of water. The organic phase is concentrated to dryness under reduced pressure (20 kPa) at around 50 ° C. 3.3 g of 3-ethoxycarbonyl-6,7-difluoro (N-cyclopropyl Nb ethoxycarbonylethyl) 2-aminoquinoline quinoline are obtained in the form of an oil which is used without further purification for the subsequent step.

Preparation of 3-ethoxycarbonyl-7,8-difluoro-1-cyclopropyl-4-oxo-tetrahydro-1,2,3,4 benzo [b] naphthyridin-1, 8:

To a solution of 1.6 g of sodium ethylate brought to reflux in 40 cm ³ of absolute ethanol is added, in 60 minutes, a solution of 3-ethoxycarbonyl-difluoro-6,7 (N-cyclopropyl Nb ethoxycarbo¬ nylethyl) 2-amino quinoline in 20 cm ³ of absolute ethanol. The solution obtained is stirred for an additional 60 minutes at reflux. 2.6 cm ³ of glacial acetic acid are then poured in 10 minutes. The reaction mixture is stirred for an additional 15 minutes, then 26 cm ³ of water are poured in over 5 minutes, still at reflux. The suspension obtained is cooled to approximately 20 ° C. The precipitate is drained at approximately 20 ° C. and washed with twice 10 cm ³ of water. The wet product is dried under reduced pressure (20 kPa) at around 60 ° C. 1.25 g of ethoxycarbonyl-3, difluoro-7,8 cyclopropyl-1 oxo-4, tetrahydro-1,2,3,4 benzo [b] naphthyridin-1, 8 are isolated in crude form as a yellow solid melting at 172 ° C.

Preparation of 3-ethoxycarbonyl-7,8-difluoro-1-cyclopropyl-4-oxo-1,4-dihydro-benzo [b] naphthyridin-1, 8:

To a suspension of 1 g of 3-ethoxycarbonyl-7,8-difluoro-1-cyclopropyl-4-oxo-1,2,3,4-benzo [b] naphthyridine-1, 8 in 14 cm ³ of etha- nol, a solution of 0.053 g of potassium iodide in 0.5 cm ³ of water is added with stirring at approximately 20 ° C. The suspension is heated to 77 ° C. and 0.5 cm ³ of oxygenated water at 33% by weight is poured at this temperature over 5 minutes. The reaction mixture is maintained at reflux for an additional 60 minutes and then cooled to approximately 20 "C. At this temperature, 1.06 cm ³ of a 1N solution of sodium thiosulfate is poured in over 5 minutes. The precipitate obtained is drained at 20 ° C approximately and washed with 2 times 10 cm ³ of water The wet product obtained is dried under reduced pressure (20 kPa) at approximately 60 ° C. 0.7 g of 3-ethoxy-7,8-difluoro cyclopropyl is isolated -1 oxo-4 dihydro-1,4 ben¬ zo [b] naphthyridine-1,8, crude in the form of an ocher white solid melting at 210 ° C.

Example of use 5

Ethoxycarbonyl-3 difluoro-6,7 (N-methyl N-b-cyanoethyl amino) -2 quinoline is prepared in the following way:

To a solution of 16.3 g of 2-chloro-3-ethoxycarbonyl-difluoro-6,7 quinoline prepared as described in the example of use 1 and 10 g of N-methyl Nb-cyanoethyl amino in 160 cm ³ of toluene, 19.08 g of sodium carbonate are added. The suspension obtained is heated to reflux and then stirred for 4 hours at this temperature. The reaction mixture is then cooled to approximately 20 ° C. and then washed with 3 times 50 cm ³ of water. The organic phase is concentrated to dryness under reduced pressure (20 kPa) at around 50 ° C. 19.17 g of 3-ethoxycarbonyl-difluoro-6.7 (N-methyl Nb-cyanoethyl amino) -2 quinoline are obtained in the form of an oil which is used without further purification for the subsequent steps.

Cyano-3, difluoro-7,8 methyl-1 oxo-4, tetrahydro-1,2,3,4 ben¬ zo [b] naphthyridin-1, 8 is prepared as follows:

A solution of 8.74 g of potassium terbutylate in 200 cm ³ of tetrahydrofuran cooled to -10 ° C is poured, in 60 minutes, a solution of 19.17 g of 3-ethoxycarbonyl-difluoro-6.7 (N-methyl Nb-cyano-noethyl amino) -2 quinoline in 50 cm ³ of tetrahydrofuran. The suspension obtained is always stirred at -10 ° C for 30 minutes additional. Then pour 4 cm ³ of glacial acetic acid. The tetrahydrofuran is evaporated under reduced pressure (20 kPa). The crude reaction mixture is taken up in 200 cm ³ of an ethanol / water hydroalcoholic mixture (70/30 vol / vol). The precipitate obtained is filtered, washed twice with 50 cm3 of water, then dried under reduced pressure (20 kPa). 16.1 g of cyano-3, difluoro-7,8 methyl-1, oxo-4, tetrahydro-1,2,3,4, benzo [b] naphthyridin-1, 8 are isolated in the form of a golden yellow fondant solid. at 144 ° C.

Cyano-3 difluoro-7,8 methyl-1 oxo-4 dihydro-1,4 benzo [b] naphthyridin-1,8 is prepared in the following manner:

To a suspension of 8.6 g of cyano-3, difluoro-7.8, methyl-1, oxo-4, tetrahydro-1,2,3,4, benzo [b] naphthyridine-1, 8 in 350 cm ³ of ethanol , a solution of 0.47 g of potassium iodide in 5 cm ³ of water is added with stirring at approximately 20 ° C. The suspension is heated to 77 ° C. and added to this temperature, over 10 minutes, of 4 cm ³ of hydrogen peroxide at 33% by weight. The reaction mixture is maintained at reflux for another 30 minutes and then is cooled to approximately 20 ° C. At this temperature, 10 cm ³ of a 1N sodium thiosulfate solution are added over 5 minutes. The precipitate obtained is drained at around 20 ° C and washed with twice 20 cm ³ of water. The wet product obtained is dried under reduced pressure (20 kPa) at around 50 ° C. 8 g of cyano-3 difluoro-7,8 methyl-1 oxo-4 dihydro-1,4 benzo [b] naphthyridin-1,8 are isolated in the form of a light yellow solid melting at 380 ° C.

Cyano-3 fluoro-7 methyl-1 (methyl-4 piperazinyl-1) -8 oxo-4 dihyro-1,4-benzo [b] naphthyridine-1, 8 is prepared in the following way:

A suspension of 2.1 g of cyano-3 difluoro-7,8 methyl-1 oxo-4 dihy-dro-1,4 benzo [b] naphthyridine-1, 8 in 100 cm ³ of dimethyl sulfoxide is heated to 80 ° C in the presence of 2 cm ³ of N-methyl piperazine. The reaction mixture is maintained at this temperature for 8 hours. The solution obtained is cooled to room temperature and stirred at this temperature for 15 hours. The precipitate formed is filtered, washed with 3 times 20 cm ³ of water, and dried under vacuum (20 kPa) at 50 ° C. We obtains 2.6 g of cyano-3 fluoro-7 methyl-1 (methyl-4 piperazinyl-1) -8 oxo-4 benzo [b] naphthyridine-1, 8 in the form of a yellow precipitate melting at 335 ° C.

Fluoro-7 methyl-1 (4-methyl piperazinyl-1) -8 oxo-4 dihydro-1,4 benzo [b] naphthyridin-1, 8 carboxylic-3-acid is prepared in the following manner:

A suspension of 2 g of cyano-3 fluoro-7 methyl-1 (4-methyl-piperazinyl-1) -8 oxo-4 dihydro-1,4 benzo [b] naphthyridine-1,8 is heated to reflux in 40 cm ³ of 12N hydrochloric acid. The reaction mixture is kept at this temperature for 15 hours. The solution obtained is cooled to room temperature. The product which crystallizes is filtered, washed with water until neutral, and dried under reduced pressure (20 kPa) at 50 ° C. 1.5 g of fluoro-7 methyl-1 (4-methyl-piperazinyl-1) -8-4-oxo-1,4-dihydro-benzo [b] naphthyridin-1, 8-carboxylic-3-monohydrochloride are obtained in the form of crystals. yellows melting at 290 ° C (decomposition).

Example of use 6

3-ethoxycarbonyl-difluoro-6,7 [N-methyl N-b (N ', N'-dimethylamino-carbonylethyl) amino) -2 quinoline is prepared in the following manner:

To a solution of 26 g of 2-chloro-3-ethoxycarbonyl-difluoro-6,7 qui¬ nolein prepared as described in the example of use 1 and 25 g of N-methyl Nb (N ', N'-dimethylaminocarbonylethyl) amino in 300 cm ³ of toluene, 31 g of sodium carbonate are added. The suspension obtained is heated to reflux and then stirred for 2 hours 30 minutes at this temperature. The reaction mixture is then cooled to approximately 20 ° C. and then washed with 3 times 100 cm ³ of water. The organic phase is concentrated to dryness under reduced pressure (20 kPa) at around 50 ° C. 35 g of 3-ethoxycarbonyl-6,7 [N-methyl Nb (N ', N'-dimethylaminocarbonyl ethyl) amino] -2 quinoline are obtained in the form of an oil which is used without further purification for the subsequent steps . N, N-dimethyl difluoro-7,8 methyl-1 oxo-4 tétrahydro-1, 2,3,4 ben¬ zo [b] naphthyridine-1, 8 carboxamide-3 is prepared in the following way:

To a solution of 15.7 g of potassium terbutylate in 150 cm ³ of tetrahydrofuran cooled to 0 ° C. is added, in 75 minutes, a solution of 35 g of 3-ethoxycarbonyl-difluoro-6.7 N-methyl Nb (N ', N' ~ dimethylaminocarbonyl ethyl) 2-amino quinoline in 150 cm ³ of té¬ trahydrofuran. The suspension obtained is then stirred at 0 ° C for an additional 30 minutes and then 8 cm ³ of glacial acetic acid are added. The tetrahydrofuran is evaporated under reduced pressure (20 kPa). The crude reaction mixture is taken up in 200 cm ³ of an alcoholic ethanol / water mixture (70/30 vol / vol). The precipitate obtained is filtered, washed 3 times with 100 cm ³ of water, then dried under vacuum (20 kPa). 25 g of N, N-dimethyl difluoro-7,8 methyl-1 oxo-4, tetrahydro-1,2,3,4 benzo [b] naphthyridin-1, 8 carboxamide-3 are isolated in the form of a lemon yellow solid melting at 206 ° C.

N, N-dimethyl difluoro-7,8 methyl-1 oxo-4 1,4-dihydro-1,4-benzo [b] naphthyridine-1, 8 carboxamide-3 is prepared in the following way:

To a suspension of 25 g of N, N-dimethyl difluoro-7,8 methyl-1 oxo-4 tétrahydro-1, 2,3,4 benzo [b] naphthyridine-1, 8 carboxamide-3 in 1000 cm ³ of ethanol, a solution of 1.35 g of potassium iodide in 10 cm ³ of water is added with stirring at approximately 20 ° C. The suspension is heated to 77 ° C. and 25 cm ³ of hydrogen peroxide at 33% by weight are poured at this temperature over 20 minutes. The reaction mixture is maintained at reflux for an additional 1 hour 30 minutes and then is cooled to approximately 20 ° C. At this temperature, 30 cm ³ of a 1N sodium thiosulfate solution are poured in 5 minutes. The precipitate obtained is drained at approximately 20 ° C and washed with twice 60 cm ³ of water. The wet product obtained is dried under reduced pressure (20 kPa) at around 50 ° C. 19.5 g of N, N-dimethyl-7.8-difluoro-1 methyl-4-oxo-1,4-dihydro-benzo [b] naphthyridin-1, 8 carboxamide-3 are isolated in the form of a light yellow solid melting at 324 ° C. A suspension of 2.96 g of difluoro-7.8 N, N-dimethyl oxo-4 methyl-1 dihydro-1,4 benzo [b] naphthyridine-1, 8 carboxamide-3, of 1.12 g of me¬ 1-thyl piperazine and 1.55 g of potassium carbonate in 100 cm ³ of dimethyl sulfoxide is heated for 5 hours, with stirring, to approximately 80 ° C. After cooling to about 20 ° C, the reaction mixture is added with 100 cm ³ of water; the insoluble material is drained, washed with 2 times 30 cm ³ of water and 2 times 30 cm ³ of ethanol.

Obtained 2.3 g of N, N dimethyl fluoro-7 methyl-1 (4-methyl-piperazinyl-1) -8 oxo-4 1,4-dihydro-1,4 benzo [b] naphthyridine-1, 8 carboxamide-3 in form of a yellow solid decomposing at 275 ° C.

A solution of 0.5 g of N, N-dimethyl-fluoro-7 methyl-1 (4-methyl-piperazinyl-1) -8 4-oxo-1,4-dihydro-benzo [b] aphtyridine-1, 8 carboxamide- 3 in 10 cm ³ of 6N aqueous hydrochloric acid is heated, with stirring to about 95 ° C, for 5 hours. After cooling to around 20 ° C, the insoluble material is drained, washed with 3 times 20 cm ³ of water and 2 times 10 cm ³ of ethanol.

The product obtained is suspended in 30 cm ³ of water; 0.6 cm ³ of aqueous potassium hydroxide N are added and the mixture is stirred for 1 hour at approximately 20 ° C. The insoluble material is drained, washed with 2 times 20 cm ³ of water and 2 times 10 cm ³ of ethanol. After recrystallization from 15 cm ³ dimethylformamide, 0.15 g of 7-fluoro-methyl-1 (4-methyl-piperazinyl-1) -8 oxo-4-1,4-dihydro-1,4-benzo [bnaphthyridin-1, 8 carboxylic acid] is obtained. 3 in the form of a yellow solid decomposing at 354 ° C.

Example of use 7

Ethoxycarbonyl-3 difluoro-6,7 (N-methyl N-b aminocarbonylethyl amino) -2 quinoline is prepared as follows:

To a solution of 4 g of 2-chloro-3-ethoxycarbonyl-difluoro-6,7 qui¬ nolein prepared as described in the use example 1 and 3 g of N-methyl Nb-aminocarbonylethyl amine in 40 cm ³ of toluene, 4.4 g of sodium carbonate are added. The suspension obtained is heated to reflux and then stirred for 2 hours 30 minutes at this temperature. The reaction mixture is then cooled to approximately 20 ° C. and then washed with 3 times 25 cm ³ of water. The organic phase is concentrated to dryness under reduced pressure (20 kPa) at around 50 ° C. 4.7 g of 3-ethoxycarbonyl-difluoro-6.7 (N-methyl Nb-amino-carbonbonylethyl amino) -2 quinoline are obtained in the form of an oil which is used without further purification for the subsequent steps.

The carboxamide-3 difluoro-7,8 methyl-1 oxo-4 tétrahydro-1, 2,3,4 ben¬ zo [b] naphthyridine-1, 8 is prepared in the following way:

To a solution of 1.8 g of potassium terbutylate in 50 cm ³ of tetrahydrofuran cooled to 0 ° C. is added, in 30 minutes, a solution of 4.23 g of 3-ethoxycarbonyl-difluoro-6.7 ( N-methyl Nb- amino¬ carbonylethyl amino) -2 quinoline in 20 cm ³ of tetrahydrofuran. The suspension obtained is then stirred at 0 ° C for an additional 30 minutes and then 2 cm ³ of glacial acetic acid are poured. The tetrahydrofuran is evaporated under reduced pressure (20 kPa). The crude reaction product is taken up in 10 cm ³ of a hydroalcoholic ethanol / water mixture (70/30 vol / vol). The precipitate obtained is filtered, washed 3 times with 10 cm ³ of water, then dried under reduced pressure (20 kPa). 1.6 g of carboxamide-3, difluoro-7,8 methyl-1 oxo-4, tetrahydro-1,2,3,4 benzo [b] naphthyridin-1, 8 are isolated in the form of a yellow solid, melting at 182 ° C.

The carboxamide-3 difluoro-7,8 methyl-1 oxo-4 dihydro-1,4 benzo [b] naphthyridine-1, 8 is prepared in the following way:

To a suspension of 1.3 g of carboxamide-3 difluoro-7,8 methyl-1 oxo-4 tetrahydro-1,2,3,4 benzo [b] naphthyridine-1, 8 in 25 cm ³ of ethanol, we add with stirring at about 20 ° C a solution of 0.1 g of potassium iodide in 1 cm ³ of water. The suspension is heated to 77 ° C and added at this temperature, in 5 minutes, 1.5 cm ³ of hydrogen peroxide at 33% by weight. The reaction mixture is maintained at reflux for an additional 1 hour 30 minutes then is cooled to approximately 20 ° C. At this temperature, 1 cm ³ of a 1N sodium thiosulfate solution is added. The precipitate obtained is drained at approximately 20 ° C. and washed with twice 5 cm ³ of water. The wet product obtained is dried under reduced pressure (20 kPa) at around 50 ° C. 1.1 g of carboxamide-3 difluoro-7,8 methyl-1 oxo-4 dihydro-1,4 benzo [b] naphthyridin-1,8 are isolated in the form of an orange solid melting at 318 ° C.

A suspension of 1.3 g of difluoro-7,8 methyl-1 oxo-4 dihydro-1,4 benzo [b] naphthyridine-18 carboxamide-3, of 0.54 g of methyl-1 piperazine and 0 , 75 g of potassium carbonate in 25 cm ³ of dimethyl sulfoxide is heated to about 80 ° C for 6 hours. After cooling to a temperature in the region of 20 ° C., the reaction mixture is added with 100 cm ³ of water. The insoluble material is drained, washed with 2 times 20 cm ³ of water and 2 times 20 cm ³ of ethanol.

The product obtained is chromatographed on 20 g of silica gel (0.063-0,200 mm) suspended in a mixture of dichloromethane with 10% methanol. Reaction impurities are removed by elution with 500 cm ³ of this mixture of solvents. The expected product is then eluted with 500 cm ³ of the same mixture of solvents. After concentrating to dryness, under reduced pressure (20 kPa) at about 40 ° C., the solid residue is recrystallized from 25 cm ³ of dimethylformamide, drained and washed with 2 times 30 cm ³ of ethanol at approximately 70 ° C.

0.6 g of fluoro-7 methyl-1 (4-methyl-piperazine-1) -8 4-oxo-1,4 dihydro-benzo [b] naphthyridin-1, 8 carboxamide-3 is obtained in the form of a yellow solid decomposing at 265 ° C.

Fluoro-7 (4-methyl-piperazinyl-1) -8-methyl-4-oxo-1,4-dihydro-1,4-benzo [1], 8-naphthyridine-1, 8-carboxylic acid-3 is prepared under the conditions of example. use 2, but from 0.3 g of fluoro-7 methyl-1 (4-methyl-piperazinyl-1) -8 oxo-4 dihydro-1,4 ben¬ zo [b] naphthyridine-1, 8 carboxamide-3 . After cooling to about 20 ° C, the reaction mixture is added with 50 cm ³ of water; the insoluble material is drained and washed with 2 times 10 cm ³ of water.

The product obtained is suspended in 20 cm ³ of water, added with 0.4 cm ³ of an aqueous potassium hydroxide solution N and stirred for 1 hour at approximately 20 ° C. The insoluble material is wrung out, washed with 3 times 10 cm ³ of water, twice 10 cm ³ of ethanol and recrystallized from 20 cm ³ of dimé¬ thylformamide.

0.17 g of fluoro-7 methyl-1 (4-methyl-piperazinyl-1) - 8 oxo-4 dihydro-1,4 benzo [b] naphthyridin-1, 8 carboxylic-3 is obtained, in the form of a yellow solid decomposing at 354 ° C.

Claims

EVENTS

1- A new derivative of fluoro quinoline carboxylic-3 of general formula:

in which R is a hydrogen atom or an alkyl radical and Hal is a halogen atom, as well as its metal salts or its addition salts with nitrogenous bases when they exist.

2- A new derivative of fluoro quinoline carboxylic acid-3 according to claim 1, characterized in that the symbol Hal is chlorine or fluorine.

3- Ethoxycarbonyl-3 difluoro-6,7 carbostyril.

4- A process for the preparation of a quinoline derivative according to claim 1, characterized in that a nitro derivative of general formula is cyclized in acid medium:

in which Hal is defined as in claim 1, R- is defined as R in claim 1 except for representing a hydrogen atom, and 2 is defined as R- _] or represents a carbamoyl or cyano radical, optionally followed by the release of the acid function if it is desired to obtain a quinoline derivative for which R is a hydrogen atom and optionally the transformation of the product obtained into a salt.

5- 3,4-Difluoro-6-nitro-benzaldehyde. 6- Use of a product according to claim 1, for the preparation of a benzo [b] naphthyridine-1, 8 derivative of general formula:

in which either R3 is an alkyl, fluoroalkyl, cycloalkyl radical containing 3 to 6 carbon atoms, alkyloxy or alkylamino and Het is a heterocyclyl nitrogen radical, or R3 is a hydrogen atom or an alkyl radical, fluoroalkyl, carboxyalkyl, cycloalkyl containing 3 to 6 carbon atoms, fluorophenyl, difluorophenyl, alkyloxy or alkylamino, and Het is a azetidinyl-1 radical substituted [in position -3 by a radical R4 which can be a hydrogen atom or a hydroxy radical, amino, amino alkyl, the alkyl part of which is optionally substituted by an amino or hydroxy radical or can represent a dialkoylamino radical, the alkyl parts of which can optionally form, with the nitrogen atom to which they are attached, a 5 or 6-membered heterocycle optionally containing another heteroatom chosen from nitrogen, oxygen or sulfur, or may represent a cycloalkylamino radical containing 3 to 6 members, or a alkanoyl-amino radical, N-alkyl N-alkanoyl amino or aminoalkylphenylamino, and substituted in positions -2 and -3 by identical or different radicals R5 and Rg which represent hydrogen atoms, alkyl and alkenyl radicals containing 2 with 4 carbon atoms, phenyl, phenyl substituted by a halogen atom, or by an alkyl, alkyloxy, hydroxy, nitro, amino, alkyllamino, dialcoylamino or halogenoalkyl radical, or else substituted in position -2 'by radicals R ₅ and Rg which represent alkyl radicals], the alkyl and alkanoyl radicals mentioned above being straight or branched and containing 1 to 4 carbon atoms. 7- Use of a quinoline derivative according to claim 1, for the preparation of a benzonaphthyridine derivative of general formula:

in which Hal is defined as in claim 1, R3 represents a hydrogen atom or an alkyl, fluoroalkyl, carboxyalkyl, cycloalkyl radical containing 3 to 6 carbon atoms, fluorophenyl, difluorophenyl, alkyloxy or alkylamino and R7 is an alkoxyalkylcarbonyl, cyano, carbamoyl, alkylcarbamoyl, benzylcarbamoyl, hydroxyethylcarbamoyl, dialkoylaminoethylcarbamoyl or dialkoylcarbamoyl in which the alkyl parts may optionally form with the nitrogen atom to which they are attached, a hetero or 6 ring links optionally containing another heteroatom chosen from oxygen, sulfur or nitrogen and optionally substituted on nitrogen by an alkyl radical, the alkyl radicals being straight or branched and containing 1 to 4 carbon atoms.