IE61089B1 - New pyrrole derivatives, their preparation and pharmaceutical compositions which contain them - Google Patents

New pyrrole derivatives, their preparation and pharmaceutical compositions which contain them

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IE61089B1
IE61089B1 IE325287A IE325287A IE61089B1 IE 61089 B1 IE61089 B1 IE 61089B1 IE 325287 A IE325287 A IE 325287A IE 325287 A IE325287 A IE 325287A IE 61089 B1 IE61089 B1 IE 61089B1
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radical
naphthyridin
substituted
general formula
alkyl
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IE873252L (en
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Jean-Dominique Bourzat
Marc Capet
Claude Cotrel
Richard Labaudiniere
Philippe Pitchen
Gerard Roussel
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Rhone Poulenc Sante
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    • C07D401/00Heterocyclic compounds containing two or more hetero rings, having nitrogen atoms as the only ring hetero atoms, at least one ring being a six-membered ring with only one nitrogen atom
    • C07D401/02Heterocyclic compounds containing two or more hetero rings, having nitrogen atoms as the only ring hetero atoms, at least one ring being a six-membered ring with only one nitrogen atom containing two hetero rings
    • C07D401/04Heterocyclic compounds containing two or more hetero rings, having nitrogen atoms as the only ring hetero atoms, at least one ring being a six-membered ring with only one nitrogen atom containing two hetero rings directly linked by a ring-member-to-ring-member bond
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    • C07D471/02Heterocyclic compounds containing nitrogen atoms as the only ring hetero atoms in the condensed system, at least one ring being a six-membered ring with one nitrogen atom, not provided for by groups C07D451/00 - C07D463/00 in which the condensed system contains two hetero rings
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    • C07D487/02Heterocyclic compounds containing nitrogen atoms as the only ring hetero atoms in the condensed system, not provided for by groups C07D451/00 - C07D477/00 in which the condensed system contains two hetero rings
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    • C07D495/02Heterocyclic compounds containing in the condensed system at least one hetero ring having sulfur atoms as the only ring hetero atoms in which the condensed system contains two hetero rings
    • C07D495/04Ortho-condensed systems
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    • C07ORGANIC CHEMISTRY
    • C07DHETEROCYCLIC COMPOUNDS
    • C07D497/00Heterocyclic compounds containing in the condensed system at least one hetero ring having oxygen and sulfur atoms as the only ring hetero atoms
    • C07D497/02Heterocyclic compounds containing in the condensed system at least one hetero ring having oxygen and sulfur atoms as the only ring hetero atoms in which the condensed system contains two hetero rings
    • C07D497/04Ortho-condensed systems

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Abstract

Derivatives of formula (I), in which A forms with the pyrrole ring an isoindoline, 6,7-dihydro-5H-pyrrolo[3,4-b]pyrazine, 2,3,6,7- tetrahydro-5H-oxathiinno[1,4][2,3C]pyrrole or 2,3,6,7-tetrahydro-5H- dithiinno[1,4][2,3C]pyrrole nucleus and Het = naphthyridinyl, pyridyl or quinolyl which are unsubstituted or substituted by a halogen, alkyl (1-4 C), alkoxy (1-4 C), alkylthio (1-4 C) or CF3, and R = alkenyl (3- 10 C) with a straight or branched chain or alkyl which is unsubstituted or substituted by alkoxy, alkylthio, cycloalkyl (3-6 C), NH2, alkylamino, dialkylamino, alkylcarbonylamino (in which the amino part is optionally alkyl-substituted), 1- or 2-piperazinyl, piperidyl, piperidino, morpholino, pyrrolidinyl, 1-azetidinyl, carbamoyl, alkylcarbamoyl, dialkylcarbamoyl, (1-piperazinyl)carbonyl, piperidinocarbonyl, (1-pyrrolidinyl)carbonyl, phenyl, pyridyl, 1- imidazolyl, or else R = 2- or 3-pyrrolidinyl or 2-,3- or 4-piperidyl, it being understood that the alkyl radicals form a straight or branched chain and, unless specially mentioned, contain 1 to 10 C and that the piperazinyl, piperidino, piperidyl, pyrrolidinyl and azetidinyl radicals may be unsubstituted or substituted in any position by alkyl, alkylcarbonyl, benzyl or hydroxyalkyl or else may form a lactam functional group with the nitrogen atom of the ring, and, when they exist, their pharmaceutically acceptable salts and the optical isomers of the products of formula (I). <IMAGE> The products of formula (I) are useful as anxiolytics.

Description

The present invention relates to new pyrrole derivatives of general formula: in which A forms with the pyrrole ring an isoindoline ring-system. Het denotes a naphthyridinyl radical substituted with a halogen atom or a (1 to 4 C) alkyl or (1 to 4 C) alkyloxy radical and R denotes an alkyl radical which is unsubstituted or substituted with an alkyloxy or dialkylamino radical, with an alkylcarbonylamino radical (in which the amino portion can optionally foe substituted with an alkyl radical), or with a piperidyl or piperidine radical, or alternatively R denotes a 4-piperidyl radical, on the understanding that the alkyl radicals are straight- or branched-chain radicals and contain, except where specifically stated, 1 to 10 carbon atoms, and that the piperidino and piperidyl radicals can be unsubstituted or substituted at any position with an alkyl radical, as well as, where they exist, their pharmaceutically acceptable salts and the optical isomers of the products of formula (1).
Derivatives of isoindoline, of pyrrolo[3,4-bj~ pyrazine, of dithiinof2,3-c]pyrrole or of oxathiino[2,3-c]pyrrols which are described in French Patents FR 2,101,081 and 2,115,045 or British Patent GB 1,468,497 are known as products possessing tranquillising and anticonvulsant properties. In European Patent Application EP 91,241, products of similar structure possessing anxiolytic properties are described.
In European Patent Applications EP-A-274,929 and EP-A-274,930, compounds very closely related structurally to the products which form the subject of the present invention, and which possess the same type of activity, are described.
According to the invention, the products of general formula (I) in which Het is defined as above, with the exception of denoting a 1,8-naphthyridin-2~yl radical substituted at the 7-position with an alkyloxy radical, and the other symbols are defined as above, may be prepared by the action of an acid of general formula: R-COOH (II) or an alkali metal salt of this acid, in which R is defined as above, on a product of general formulas in which Het' has the meanings given above for Het, with the exception of denoting a 1,8-naphthyridin-2-yl radical substituted at the 7-position with an alkyloxy radical, and A is defined as above.
The reaction is generally performed in the presence of a condensing agent, such as 1,8-diasabicyclo[5.4. 0]undec-7-ene or l,5-diasabicyclo[5»3.0)non-5-ene, or a quaternary ammonium hydroxide, such as triethylbenzylammonium hydroxide. In an organic solvent such as dimethyl formamide at a temperature of between 20 and 100eC, or simply, when the alkali metal salt of the acid is used, in dimethyl formamide at a temperature of 20"C.
The products of general formula (III) may be prepared by chlorination of a product of general formula; (IV) in which A and Het are tie fined as above.
The reaction is generally performed in the presence of a chlorinating agent such as sulphinyl chloride or phosphorus oxychloride, in the presence of catalytic amounts of dimethylformamide, at a temperature between 20 °C and the refluxing temperature of the reaction mixture, or any other agent known to those versed in the art which enables a hydroxy radical to be converted to a chloro radical without affecting the remainder of the molecule.
The products of general formula (IV) may be prepared by application or adaptation of the methods described in Belgian Patents 815,019 or 835,325.
According to the invention, the products of general formula (I) may also be prepared by the action of a derivative of general formulas RCO-X (V) in which R is defined as above and X denotes a halogen atom such as a chlorine atom, or alternatively denotes an activated residue such as a 1-imidazolyl radical or a radical RCO-O- in which R denotes an alkyl radical, on a derivative of general formula (IV) defined as above.
The reaction is generally performed In an organic solvent such as chloroform or methylene chloride, or an ether such as tetrahydrofuran or dioxane, or alternatively in dimethylformamide at a temperature between 0°C and the refluxing temperature of the reaction mixture, in the presence of a base such as sodium hydride or an acceptor for acid such as triethylamine or pyridine.
According to the invention, the products of general formula (I) may also be prepared by the action of an alkali metal salt of an acid of general formula (II) on a product of general formulas 0-P(0R4)2 In which denotes a straight- or branched-chain alkyl radical containing 1 to 4 carbon atoms or a phenyl radical and A and Het are defined as above.
The reaction is generally performed in an organic solvent such as dimethylf ormamide at a temperature of between 0 and 25°C.
The products of general formula (VI) may be prepared by the action of a product of general formulas C1-P(OR4)2 B ' (VIT) in which RA denotes a straight- or branched-chain alkyl radical containing 1 to 4 carbon atoms or a phenyl radical/ on a product of general formula (IV) in which Het and A are defined as above.
The reaction is generally performed in an organic solvent such as dimethyIformamide, in the presence of a base such as an alkali metal hydride, e.g. sodium hydride at a temperature of between ~5 and +25 °C» Xt is not necessary to isolate the product of general formula (VI) in order to carry out the process according to the invention. It is sufficient to perform the condensation of the products of general formula (VII) and (IV) as has just been stated, and then to add the alkali metal salt of the acid of general formula (II) to the reaction mixture.
As may be realized by those versed in the art, some radicals falling within the definition of the symbol R are incompatible with the reactants employed during the reactions, and must be protected prior to carrying out the processes, or some phases of the processes, described above. This is the case, in particular, when the radical R contains primary or secondary amino groups or hydroxyl groups which are capable of giving rise to side reactions. In this case, the said groups must be protected by any method known to those versed In the art, and then unblocked after reaction.
The new products of general formula (I) may be purified by the usual known methods, e.g. by crystallization, chromatography or successive extractions in acidic and basic medium.
The new products of general formula (I) may be converted to an addition salt with acids, by the action of an acid in an organic solvent such as an alcohol, a ketone, an ether or a chlorinated solvent. The salt formed precipitates, where appropriate after concentration of its solution; it is separated by filtration or decantation.
The products of general formula (I) possess especially advantageous pharmacological properties, which reveal an anxiolytic, hypnotic, anticonvulsant, antiepileptic and muscle relaxant activity. Thus, they show appreciable affinity in vitro for benzodiazepine receptor sites at concentrations whose values are between 0.4 and 200 nM according to the technique described by J.C. BLANCHARD and L. JULOU, J. of Neurochemistry, 40, SOI (1983) modelled on the work of SQUIRES and BRAESTRUP, Nature, 266, 732 (1977).
In animals (mice), they have been shown to be active, at doses which are generally of between 0.3 and 200 mg/kg orally, with respect to pentetrazole-induced convulsions according to a technique closely allied to that of EVERETT and RICHARDS, J. Pharmacol., 81? 402 (1944).
The new products of general formula (I) and their salts possess, in addition, low toxicity. Their oral LD50 is generally between 300 and 900 mg/kg in mice.
For medicinal use, the new products of general formula (I) may be employed as they are or in the state of pharmaceutically acceptable salts, i.e. salts which are non-toxic at the doses at which they are used.
As examples of pharmaceutically acceptable salts, there may be mentioned the addition salts with inorganic acids, such as hydrochlorides, sulphates, nitrates and phosphates, or with organic acids, such as acetates, propionates, succinates, benzoates, fumarates, maleates, methanesulphonates, isethionates, theophyllineacetates, salicylates, phenolphthalinates and methylenebis(β~ oxynaphthoates), or substitution derivatives of these compounds.
Of special value are the products of general formula (I) in which A forms with the pyrrole ring an isoindoline ring-system, Het denotes a 1,8-naphthyridin2- yl radical substituted with a halogen atom or a (1 to 4 C) alkyloxy radical and R denotes a straight- or branched-chain alkyl radical containing 1 to 5 carbon atoms which is unsubstituted or substituted with an alkyloxy, dialkylamino, alkylcarbonylamino or piperidino radical, or alternatively R denotes a 3-piperidyl (sic) radical, on the understanding that th® alkyl radicals are straight- or branched-chain radicals and contain, except where specifically stated, 1 to 10 carbon atoms, and that the piperidino and piperidyl radicals can be unsubstituted or substituted at any position with one or more alkyl radicals.
The following products are of very special value: (RS) -2-(7-Chloro-1,8-naphthyridin-2-yl)-3-oxo-lisoindolinyl 4-acetamidobutyrate (RS)-2- (7-Chloro-1,8-naphthyridin-2-yl)-3-oxo-lisoindolinyl l-propionyl-4-piperidinecarboxylate (RS)-2-(7-Methoxy-1,8-naphthyridin-2-yl)-3-oxo-lisoindolinyl 5-methylhexanoate (RS)-2-(7-Chloro-1,8-naphthyridin-2-yl)-3-oxo-lisoindolinyl 3-diisopropylaxttinopropionate.
The examples which follow show how the invention may be put into practice.
EXAMPLE 1 3-Dimethylaminopropionic acid hydrochloride (9.2 g) and l,8-diazabicyclo[5.4.0]undec-7~ene (16.7 g) are added at a temperature in the region of 20 °C to a solution, maintained under an argon atmosphere, of 3- chloro-2-(7-chloro-1,8-naphthyridin-2-yl)-1isoindolinone (16.5 g) in anhydrous dimethylformamide (100 cc), and the suspension obtained is stirred for 24 hours at a temperature in the region of 20°C. Distilled water (200 cc) and dichloromethane (200 cc) are then added. The aqueous phase ia separated after settling has occurred and then re-extracted with dichloromethane (3 x 50 cc). The organic phases are combined, washed with distilled water (2 x 50 cc), dried over magnesium sulphate, filtered and then concentrated to dryness under reduced pressure (2.7 kPa) at 80°C. The residue obtained is dissolved in dichloromethane (100 cc) and the solution extracted with 1 N aqueous hydrochloric acid solution (2 x 100 cc). The aqueous phases are combined# washed with dichloromethane (50 cc)# alkalinized with 10 N sodium hydroxide solution to a pH in the region of 11 and extracted with dichloromethane (2 x 150 cc). The organic phases are combined# washed with distilled water (2 x 30 cc)# dried over magnesium sulphate# filtered and then concentrated to dryness under reduced pressure (2.7 kPa) at 60 eC. After the product thereby obtained has been recrystallized twice successively in ethanol# 2- (7-chloro-l# 8-naphthyridin~2-yl)-3-oxo-l-isoindolinyl 3- dimethylaminopropionate (2.9 g)# m.p. 150°C# is obtained. 3-Dimethylaminopropionic acid hydrochloride may be obtained by the method described by CLARKE H.T.# GILLESPIE H.b. and WEISSHAUS S.Z.# J. Am. Chem. Soc.# 55# 4571 (1933). 3-Chloro-2~(7-chloro-l#8-naphthyridin-2-yl)-1=isoindolinone may be prepared in the following manner: sulphinyl chloride (200 cc) Is added dropwise with stirring to 3-hydroxy-2-(7-m®thoxy-l#8=naphthyridin~2yl)-1-isoindolinone (15.5 g). The reaction mixture is heated to reflux with stirring for 1 hour# then treated with dimethylf ormamide (10.5 ec) and heated, again to reflux for 3 hours# then cooled to a temperature in the region of SO’C and concentrated to dryness under reduced pressure (2.7 kPa) at 60eC. Dichloromethane (100 cc) Is added to the residue obtained# and the mixture is concentrated to dryness under reduced pressure (2.7 kPa) at 60°C. Dichloromethane (100 cc) Is added to the residual solid obtained and th© mixture is stirred for 10 minutes. The insoluble product is separated by filtration and washed with dichloromethane (15 cc) and then with diisopropyl ether (2 x 25 cc) and dried in the air. 3-Chloro2- ( 7-chloro-l, 8-naphthyridin-2-yl)-1-isoindolinone (12.4 g) # which has not melted at 300°C» is thereby obtained. 3- Hydroxy-2-(7-methoxy-l, 8-naphthyridin-2-yl)-1isoindolinone may be prepared by the method described in Belgian Patent 815,019.
EXAMPLE 2 Working in a manner similar to that described in Example 1, but starting with 3-chloro-2-(7-chloro-l,8naphthyridin-2-yl)-1-isoindolinone (8.25 g), 4-dimethylaminobutanoic acid hydrochloride (4.25 g) and 1,8-diazabicyclo[5.4.0]undec-7-ene (7.6 g), 2-(7-chloro-l,8naphthyridin-2-yl)-3-oxo-l-isoindolinyl 4-dimethylaminobutanoate (4.1 g), m.p. 148°C, is obtained. 4- Dimethylaminobutanoic acid may be prepared by the method described by C. HARRIES and F. DUVSL, Liebigs Ann. Chem., (1915) 110, 54.
EXAMPLE 3 4-Methylpentanoic acid (2.4 g) and 1,8-diazabicyclo[5.4.0]undee-/-ene (3.05 g) are added at a temperature in the region of 20°C to a solution, maintained under an argon atmosphere, of 3-chloro-2-(7-chloro-l,8naphthyridin-2-yl)-1-isoindolinone (6.6 g) in anhydrous dimethyl formamide (60 cc), and the suspension obtained is stirred for 24 hours at a temperature in the region of 20°C. Distilled water (500 cc) and dichloromethane (150 cc) are then added. The aqueous phase is separated after settling has occurred and then re-extracted with dichloromethane (2 x 150 cc). The organic phases are combined, washed with distilled water (3 x 50 cc), dried over magnesium sulphate, filtered and then concentrated to dryness under reduced pressure (2.7 kPa) at 60°C. The oily residue Is purified by chromatography on silica gel (150 g) contained in a column 3.5 cm in diameter [eluants dichloromethane/methanol (98s2 by volume)]. Elution Is first performed with 200 cc of solvents the corresponding eluate is discarded; elution is then performed with 900 cc of solvents the corresponding eluate is concentrated to dryness under reduced pressure (2.7 kPa) at 40 C- After recrystallization in ethanol, 2-(7-chloro1,8-naphthyridin-2-yl)-3-oxo-l-isoindolinyl 4-methylpentanoate (4 g), m.p. 147eC, is obtained.
EXAMPLE 4 Working as in Example 1, but starting with 3 - chloro-2 - (7 -c hloro-1,8 -n a p h t hyr i d i n-2-y1)~1 isoindolinone (9.9 g) in anhydrous dimethylformamide (100 cc), l-methyl-3-piperidinecarhoxylic acid hydrochloride (5.4 g) and l,8-diasabicyelo[5.4»0)undec-7-ene (10.7 g), a product (11.3 g), m.p. about 70°C, is obtained after precipitation in water (1000 cc), filtration and drying in the air. The solid obtained is dissolved in ethanol (40 cc). A solution of fumaric acid (3 g) in ethanol (30 cc) is added to the hot solution obtained. The crystallized product obtained is separated by filtration, washed with ethanol (15 cc) and dried under reduced pressure (0.07 kPa) at 45°C. 2-(7~Chlorol, 8-naphthyridin-2-yl)-3-oxo-l-isoindolinyl 1-methyl-3piperidineearboxylate acid fumarate (9.8 g), m.p. 211°C, is thereby obtained. l-Methyl-3-piperidinecarboxylic acid hydrochloride may be prepared in the following manners ethyl l-methyl-3-piperxdinecarhoxylate (17.1 g) is dissolved in N aqueous hydrochloric acid solution (67 cc). After hours under reflux,, the solution is concentrated to dryness and the residue recrystallised in acetone. l-Methyl-3-piperidinecarboxylic acid hydrochloride (15.7 g), m.p. 186°C, is thereby obtained.
EXAMPLE 5 Working as in Example 1, but starting with 3-chlorO-2-(7-chloro-1,8-naphthyridin-2-yl)-1isoindolinone (9.9 g) in anhydrous dimethylformamide (100 cc), l-methyl-4-piperidinecarboxylic acid hydrochloride (5.4 g) and 1,8~diasabicyclo[5.4.Ojundec-7-ene (10.7 g),, and after the residue obtained has been recrystallised twice successively in ethanol and then in acetonitrile, 2-(7-chloro-1,8-naphthyridin-2-yl)-3-oxol-isoindolinyl l-methyl-4-piperidinecarboxylate (5.6 g), m. p. 13a°C and then 157eC, is obtained. 1-Methyl—4-~piperidinee&rhoxylic acid hydrochloride may be prepared according to the method described in Example 4 for the preparation of 1- methyl-3-piperidinecarhoxylic acid hydrochloride, but starting with ethyl l-methyl-4-piperidinecarboxylate (8.6 g) and 6 N aqueous hydrochloric acid solution (33 cc). After recrystallization. in acetone, 1-methyl5 4-piperidinecarboxylic acid hydrochloride (6.5 g), m.p. 231°C, is obtained.
Ethyl l-methyl-4-piperidinecarboxylate may be prepared in the following manners to a solution, maintained at a temperature in the region of 5 °C, of ethyl 4-piperidinecarbosiylate (15.7 g) in water (8 cc), a 37% strength (weight/volume) solution (20.3 cc) of formaldehyde is added in the course of 15 minutes at the seme temperature, followed, again in the course of 15 minutes, by formic acid (11.5 g). The mixture is heated for 4 hours under reflux, then cooled, and brought to a pH in the region of 10 using 10 N aqueous sodium hydroxide solution. After extraction with methylene chloride (3 x 150 cc), washing the organic extracts with water, drying and concentration to dryness under reduced pres20 sure (2.7 kPa) at 70"C, ethyl l-methyl-4-piperidinecarboxylate (13.5 g) is obtained in the form of an oil, which is employed in the crude state in the subsequent syntheses.
EXAMPLE 6 'Working as in Example 1, but starting with 3-ehloro-2»(7-chloro-1,8-naphthyridin-2-yl)-1isoindolinone (6.9 g) in anhydrous dimethylformamide (70 cc), 3-diisopropylsminopropionIc acid hydrochloride (4.4 g) and l»8-diazabicyclo[5.4.0]undec-7-ene (7.45 g), and after the residue obtained has been recrystallized successively, first In acetonitrile and then In ethanol, 2- ( 7-ehloro-l»8-n&phthyridin-2~yl) -3-oxo-l-isoindolinyl 3- diisopropylaminopropionate (2.7 g)» m.p. 135‘C, is obtained. 3-Diisopropylaminopropionic acid hydrochloride may be obtained by working according to the method described In Example 4 for the preparation of 1-methyl3-piperidinecarboxylic acid, but starting with ethyl 3-diisopropylaminopropionate (5 g) and 6 N aqueous # i hydrochloric acid solution (35 cc) . After the product obtained has been recrystallized in acetone, 3-diisopropylaminopropionic acid hydrochloride (2.3 g), m.p. 170°C, is obtained.
Ethyl 3-diisopropylaminopropionate may be obtained in the following manners ethyl 3-bromopropionate (18.1 g) is introduced dropwise in the course of 30 minutes into a solution of diisopropylamine (28.5 cc) and ethanol (40 cc) maintained at a temperature of 25°C. The suspension obtained is heated to reflux for 4 hours. After being cooled, the reaction mixture is taken up with water (100 cc) and 4 N aqueous hydrochloric acid solution (70 cc). After the mixture is washed with ethyl ether (100 cc), it is alkalinized to a pH in the region of 9 with 4 N aqueous sodium hydroxide solution. The oil formed is extracted with methylene chloride (3 x 150 cc). After being washed with water (2 x 100 cc) and dried, the methylene chloride solution obtained is concentrated to dxymess under reduced pressure (2.7 kPa) at 40eC. Ethyl S-diisopropylaminopropionate (11.6 g) is thereby obtained in the form of an oil, which is employed in the crude state in the subsequent syntheses.
EXAMPLE 7 Triethylamine (27 cc) is added to a solution, maintained at a temperature in the region of 20eC, of 2- ( 7-methoxy-1,8-naphthyridin-2-yl)-3-hydroxy-1-isoindolinone (12.3 g) in methylene chloride (200 ce). 4-Methylpentanoyl chloride (10.8 g) and 4-dimethylaminopyridine (50 mg) are then introduced dropwise in the course of 20 minutes, and the reaction mixture is then heated for 19 hours under reflux. The suspension obtained is poured Into water (800 cc) and the solid obtained is separated by filtration and removed. The organic phase is separated after settling has occurred, washed with water, dried and concentrated to dryness under reduced pressure (2.7 kPa). The oily residue obtained is purified by chromatography on silica gel (0.063-0.2 mm; 150 g) contained in a column 2.7 cm In diameter (eluant: methylene chloride), eluting 50-cc fractions. Fractions m S to 18 are combined and concentrated to dryness under reduced pressure (2.7 kPa) at 40°C. After the solid obtained has been recrystallised in acetonitrile, 2- (7-methoxy-1,8-naphfchyridin-2-yl) - 3-oxo-l-isoindolinyl 4-methylpentanoate (4.9 g), m.p. 133°C, is obtained. 4-Methylpentanoyl chloride may be prepared according to F. KOGL and C.A. SALEMINK, Rec. Trav. Chim. 71, 779-97 (1952), EXAMPLE 8 Working as in Example 1, but starting with 3- chloro-2-(7-chloro-1,8-naphthyridin-2~yl)-1-isoindolinone (9.9 g) in anhydrous dimethylformamide (100 cc), 5-methylhexanoie acid (3.9 g) and 1,8-diasabicyclo[5.4.0]undec-7-ene (4.6 g), and after recrystallization in ethanol, 2-(7-chloro-l,8-naphthyridin-2-yl)3-oxo-l-isoindolinyl 5-methylhexanoate (8 g), m.p. 132"C, is obtained.
EXAMPLE 9 The procedure is as' in Example 7, but starting with 2-(7-methoxy-I,8-naphthyridin-2-yl)-3-hydroxy-lisoindolinone (5.8 g) in methylene chloride (100 cc), triethylamine (10.1 g), 5-methylhexanoyl chloride (6.4 g) and 4-dimethylaminopyridine (50 mg). The residue obtained after treatment is purified by chromatography on silica gel (0.063-0.2 mm; 100 g) contained in a column 2.8 cm in diameter (eluants methylene chloride), collecting 30-cc fractions. Fractions 19 to 94 are combined and concentrated to dryness under reduced pressure (2.7 kPa). After the residue obtained has been recrystallized in heptane (75 cc), 2-(7-methoxy-l,8-naphthyridin-2-yl)-3-oxo-lisoindolinyl 5-methylhexanoate (5.6 g), m.p. 105°C, is obtained» EZAJgLS^lO Working as in Example 1, but starting with 3-chloro-2-(7-chloro-l,8-naphthyridin-2-yl)-1-isoindolinone (29.7 g) in anhydrous dimethylformamide (300 cc), 4-acetamidobutyric acid (13.1 g) and 1.8- diasabicyclo[5.4.0]undec-7-ene (13.7 g), 2-(7-chloro1.8- naphthyr idIn = 2-yl)-3-oxo-l-isoindolinyl ) 4 4-acetoamidobutyrate (18 g), m.p. 186°C# is obtained after recrystallization in acetonitrile.
EXAMPLE 11 The procedure is as in Example 1» but starting 5 with 3-chloro-2~(7-chloro-l#8-naphthyridin-2-yl)-1= isoindolinone (4.95 g) in anhydrous dimethylformamide (60 cc), phenylacetic acid (2.05 g) and l#8-diazabicycloE5.4.0]undec-7-ene (2.25 g). After recrystallisation in ethyl acetate# 2-(7-chloro-l#8-naphthyridin-2-yl)-3-oxo10 1-isoindolinyl phenylacetate (4.4 g)# m.p. 222-224’C# is obtained.
EXAMPLE 12 Working as in Example 1# but starting with 3-chloro-2- ( 7-chloro-l, 8-naphthyrldin-2~yl) -l-iso15 indolinone (9.9 g) in anhydrous dimethyl formamide (100 cc) # 3- (2 #6-dimethylpiperidino)propionic acid hydrochloride (6.7 g) and 1#8-diazabicyclo[5.4.0]undec7-ene (10.7 g)» 2-(7-chloro-l#8-naphthyridin-2-yl)-3-oxol-isoindolinyl 3-(2 e6-dimethylpiperidino) propionate (6 g), m.p. 159°C# Is obtained after recrystallisation in ethanol. 3-(2 e6-Dimethylpiperidino)propionic acid hydrochloride may be obtained by working according to the method described in Example 4 for the preparation of l-methyl-3-piperidinecarboxylic acid hydrochloride# but starting with ethyl 3-(2#6-dimethylpiperidino)propionate hydrochloride (12 ,,5 g) and 6 N aqueous hydrochloric acid solution (35 cc) . 3-(2,,6-Dimethylpiperidino)propionic acid hydrochloride# m.p. 215°C# is thereby obtained.
Ethyl 3-(2#6-dimethylpiperidino)propionate hydrochloride may be obtained by working according to the method described in Example 6 for the preparation of ethyl 3-dIIsopropylaminopropionate» but starting with ethyl 3-bromopropxonate (18.1 g)# 2#6-dimethylpxperidine (27 cc) and ethanol (30 cc). The reaction mixture is concentrated to dryness under reduced pressure (2.7 kPa) and the residue obtained is taken up with water (50 cc) and 4 N aqueous hydrochloric acid solution (30 cc). The aqueous phase is washed with ethyl ether (2 x 80 cc) and neutralized with 4 N aqueous sodium hydroxide solution (40 cc). The insoluble oil is extracted with ethyl ether (3 x 120 cc); the organic extracts are then washed with water (2 x 80 cc) and concentrated to dryness under reduced pressure (2.7 kPa) at 40"C. The residue is dissolved in ethyl ether (100 cc) . A 4.5 ft solution (13.4 cc) of gaseous hydrochloric acid in ethyl ether is added to the solution obtained. A product precipitates. It is separated by filtration, washed and dried in the air. Ethyl 3-(2,6-dimethylpiperidino)propionate hydrochloride (14.4 g), m.p. 146°C, is thereby obtained. EXAMPLE 13 Working as in Example 1, but starting with 3- chloro-2-(7-chloro-l,8-naphthyridin-2-yl)-1-iso15 indolinone (9-9 g) in anhydrous dimethylformamide (100 cc), 4-piperidinobutyric acid hydrochloride (6.2 g) and l,8-diazabicyclo[5.4.0]undec~7-ene (10.7 g), 2-(7chloro-1,S-naphthyridin-2-yl)-3-oxo-l-isoindolinyl 4- piperidinobutyrate (9.4 g), m.p. 16SeC,, is obtained after recrystallization in ethanol. 4-Piperidinobutyric acid hydrochloride may be obtained by working according to the method described in Example 4 for the preparation of l-methyX-3-piperidinecarboxylic acid hydrochloride, but starting with ethyl 4-piperidinobutyrate (19.9 g) and 6 H aqueous hydrochloric acid solution (66.5 cc), and by heating for 24 hours under reflux. 4-Piperidinobutyric acid hydrochloride (16.3 g), m.p. 190°C, is thereby obtained.
Ethyl 4-piperidinobutyrate may be prepared by working according to the method described in Example 6 for the preparation of ethyl 3-diisopropylaminopropionate, but starting with ethyl 4-bromobutyrate (48.8 g), piperidine (42.5 g) and ethanol (75 cc). The reaction mixture is taken up with water (200 cc) and 4 N aqueous hydrochloric acid solution (120 cc). After being washed with ethyl ether (150 cc), the aqueous phase is alkalinized to a pH in the region of 9 with 4 N aqueous sodium hydroxide solution. Th© oil formed is extracted with methylene chloride (3 x 150 cc). The organic ί 6 extracts are combined, washed with water, dried and concentrated to dryness under reduced pressure (2.7 kPa) at 70°C. Ethyl 4-piperidinobutyrate (47 g) is thereby obtained in the form of an oil, which is employed in the crude state in the subsequent syntheses.
EXAMPLE 14 Working as in Example 1, but starting with 3-chloro~2-{ 7-chloro-l, 8-napht hyr idin-2-yl) -1-isoindolinone (9.9 g) In anhydrous dimethyl formamide (100 cc), 4-propionamidobutanoic acid (4.8 g) and 1.8- diasabicyclo[5.4.0jlundec-7-ene (4.6 g), 2-(7~chloro~ 1.8- naphthyridin-2-yl)-3-oxo-l-isoindolinyl 4-propionamidobutyrate (6.6 g), m.p. 179eC, is obtained after recrystallization is acetonitrile. 4-Propionamidobutanoic acid may be prepared in the following manner: 4-aminobutyric acid (10.3 g) is added in the course of 15 minutes to propionic anhydride (10 cc) at a temperature in the region of 200C, followed by 5 drops of concentrated sulphuric acid (0=1.83), and the mixture is heated to a temperature In the region of 100°C for 2 hours. After the mixture is cooled, the crystallised solid is separated off by filtration, washed with ethyl ether (5 κ 100 ec) and dried. 4-Propionamidobutanoic acid (9.8 g), m.p. 85-90’C, Is thereby obtained. EXAMPLE, 15 To a solution, maintained at a temperature In the region of 20’C, of 2-(7-methoxy-l,8-naphthyridin-2-yl)3-hydroxy-l-isoindolinone (9.2 g) and triethylamine (20 cc) in 1,2-dichloroethane (150 cc), there is added. In the course of 20 minutes, a solution of 2-methylpropoxyacetyl chloride (9 g) in 1,2-dichloroethane (20 cc) followed by 4-dimethylaminopyridine (50 mg), and the mixture Is heated to reflux for IS hours. The reaction mixture Is poured into water (250 cc) and then extracted with methylene chloride (100 cc). After the extract is washed with water, dried and concentrated to dryness under reduced pressure (3 kPa), the residue obtained is purified by two successive recrystallizations in ethanol. 2-(7-Methoxy-l,8-naphthyridin-2-yl)~ 7 3-oxo-l-isoindolinyl 2-methylpropoxyacetate (7.9 g), m.p. 114 °C, is thereby obtained. 2-Methylpropoxyacetyl chloride may be obtained in the following manner: thionyl chloride (5 cc) is added in the course of 15 minutes to a solution of 2-methylpropoxyacetic acid (8.3 g) in chloroform (50 cc). The mixture is heated for 5 hours under reflux and then evaporated to dryness ’Under reduced pressure (2.7 kPa). 2~Methylpropoxyacetyl chloride (7.5 g) is thereby obtained in the form of an oil, which is employed in the crude state in the subsequent syntheses. 2-Methvlpropoxyacetic acid may be obtained in the following manners sodium (12.7 g) is added to isobutyl alcohol (200 cc) maintained at a temperature in the region of 100°C, and the mixture is heated until the sodium has disappeared. Chloroaeetic acid (23.6 g) is then added in the course of 1 hour, and heating is continued for 2 hours. After being cooled, the reaction mixture is poured into water (250 cc). The aqueous phase is washed with ethyl ether (200 cc), concentrated to half the volume under reduced pressure (3 kPa) and then acidified to a pH in the region of 1 with 1 N aqueous hydrochloric acid solution. The oil formed is extracted with ethyl ether (3 x 150 cc), The organic phase is washed with water, dried and concentrated to dryness under reduced pressure (3 kPa). After the residue obtained has been distilled under reduced pressure, 2-methylpropoxyacefcic acid (21.8 g)y b.p. 92-96°C (0.93 kPa), Is obtained.
EXAMPLE 16 The procedure is as in Example 1, but starting with 3-chloro-2-(7-chloro-l,8-naphthyridin-2-yl)-1isoindolinone (6.6 g) in anhydrous dimethylformamide (60 cc), l-isopropyl-4-piperidinecarboxylic acid hydrochloride (4.3 g) and li8-diazabicyclo[5.4.0]undec-7-en® (7.1 g). After recrystallization in acetonitrile, a solid (4.1 g) is obtained, which is dissolved in ethanol (120 cc) under reflux; fumaric acid (1.03 g) dissolved In ethanol (20 cc) is added. After crystallization in 8 acetonitrile, 2-(7-chloro-l»8-naphthyridin-2-yl) -3-oxo1-isoindolinyl 1-isopropyl-4-piperidinecarboxylate acid fumarate (4.9 g), m.p. 184°Cf, is obtained. l-Isopropyl-4-piperidineearboxylic acid hydrochloride may be prepared according to the method described in Example 4 for the preparation of l-methyl-3piperidinecarboxvlie acid hydrochloride, but starting with ethyl l-isopropyl-4-piperidinecarboxylate hydrochloride (6.5 g) and ο N aqueous hydrochloric acid solution (18.6 cc). l-Isopropyl-4-piperidinecarboxylic acid hydrochloride (4.5 g), m.p. 260-265°C, is thereby obtained.
Ethyl l-isopropyl-4-piperidinecarboxylate hydrochloride may be prepared in the following manners ethyl 4-piperidinecarboxylate (15.7 g) Is added in the course of 10 minutes at a temperature in the region of 25C to a solution of 2-bromopropane (6.15 g) in propanol (50 cc). The reaction mixture Is heated for 48 hours under reflux and then concentrated to dryness under reduced pressure (2.7 kPa). The residue Is taken up with 1.5 N aqueous hydrochloric acid solution (150 cc) and the solution obtained is washed with ethyl ether (2 κ 100 cc). The aqueous phase is alkalinised to a pH In the region of 9 with 4 N aqueous sodium hydroxide solution, and extracted with methylene chloride (3 x 100 cc). The organic phase is washed with water, dried and concentrated to dryness under reduced pressure (2.7 kPa) at 40 cC. Th® residue obtained is dissolved in ethanol (30 cc). A 4.5 H solution (12 cc) of gaseous hydrochloric acid in ethyl ether Is added to th® solution obtained. The precipitate formed Is separated by filtration, washed and dried. Ethyl l-isopropyl-4-piperxdinecarboxylate hydrochloride (6.9 g), m.p. 195-200"C, is thereby obtained.
EXAMPLE. 17 3-Chloro-2-(7-chloro-l,8-naphthyrIdin-2-yl)-lisoindolinone (6.6 g) is added to a solution of N-acetyl^-alanine (3.9 g) in dimethyl formamide (66 cc). l»8-Diazabicyclo[5.4.0]undec-7-ene (3.8 g) Is added ί 9 dropwise to the beige suspension obtained, and the mixture is stirred at a temperature in the region of 20°C for 18 hours. N-acetyl-^-alanine (1 g) is added again, followed by 1,8-diasabicyclo[5.4.0]undec-7~ene (1 g), and the mixture is stirred at a temperature in the region of 20"C for 24 hours. The reaction mixture is then poured into water (130 cc). The solid obtained is separated by filtration, washed with water (3 κ 25 cc) and purified by chromatography under pressure (50 kPa) on silica (500 g) contained in a column 5 cm in diameter [eluants dichloromethane/methanol (95:5 by volume)], collecting 75-cc fractions. Fractions 7 to 9 are combined and concentrated to dryness under reduced pressure (2.7 kPa). After the solid obtained has been recrystallized in acetonitrile, 2- ( 7~chloro~l, 8-naphthyridin-2-yl) -3-oxo-l-isoindolinyl 3- acetamidopropanoate (3.9 g), m.p. 220°C, is obtained.
N-Acetyl-^-alanine may be prepared according to the method described in Example 14 for the preparation of 4- propionamidobutanoic acid, but starting with ^-alanine (8.9 g) and acetic anhydride (9.S g). N-Acetyl-0-alanine (12.9 g) is thereby obtained in the form of an oil, with is employed in the crude state in the subsequent syntheses.
EXAMPLE 18 The procedure is as in Example 17, but starting with 5-ecetamidopentanoic acid (5 g) in dimethyl formamide (66 cc), 3~chXorO"2~(7-chloro-1,8-naphthyridin-2-yl)-1-isoindolinone (6.6 g) and 1,8-diasabicyclo [5.4.0 ]undec-7-ene (4.7 cc). After recrystallization in acetonitrile, 2-(7-chloro~l,8-naphthyridin-2-yl)-3~ oxo-l-isoindolinyl 5-acetoamidopentanoate (3.3 g), m.p. 185°C, is obtained.
-Acetamidopentanoic acid may be prepared according to the method described in Example 14 for the preparation of 4-propionamidobutanoic acid, but starting with 5-aminopentanoic acid (11.7 g) and acetic anhydride (12.6 g). The reaction mixture is concentrated to dryness under reduced pressure (0.05 kPa) and 5-acetamidopentanoie acid (6 g) is thereby obtained in the form of 0 an oil, which is employed in the crude state in the subsequent syntheses.
EXAMPLE 19 The procedure is as in Example 1, but starting with 3-chloro-2-(7-chloro-l,8-naphthyridin-2-yl)-1isoindolinone (9.9 g) in anhydrous dimethyl formamide (100 cc), 4-isobutyrylaminobutyric acid (5.2 g) and 1.8- diasabicyclo[5.4.0]undec-7-ene (4.6 g) . The residue obtained is recrystallised in acetonitrile and then purified by chromatography on silica (0.063-0.2 mm; 130 g) contained in a column 3 cm in diameter [eluants methylene chloride/methanol (98s2 by volume) mixture] collecting 25~cc fractions. Fractions 79 to 85 are combined and concentrated to dryness under reduced pressure (2.7 kPa). The residue obtained is crystallized by stirring in isopropyl ether. 2-(7-Chloro-1,8-naphthyr idin-2-yl)-3-oxo-l-isoindolinyl 4-isobutyrylaminobutyrate (5.5 g), m.p. 208eC, is thereby obtained. 4-Isobutyrylarainohutyric acid may be prepared according to the method described in Example 14 for the preparation of 4-propionamidobutanoic acid, but starting with 4-asainobutyric acid (10.3 g) and isobutyric anhydride (15.8 g). 4-Isobutyrylaminobutyric acid (15.5 g) is thereby obtained in the form of an oil, which is employed in the crude state in the subsequent syntheses.
EXAMPLE 20 l,8-Diazabicyclo[5.4.0]undec-7-ene (10.7 g) is added dropwise to a suspension of 3-chloro-2-(7-chloro1.8- naphthyridin~2-yl)-1-isoindolinone (9.9 g) and 4-diisopropylaminobutyric acid hydrochloride (6.7 g) in dimethylformamide (100 cc), and the mixture is stirred at a temperature in the region of 20°C for 20 hours. The reaction mixture is then poured into water (130 cc). The solid obtained is separated by filtration and then dissolved in methylene chloride (200 cc). The organic extracts are washed with 0.1 ft aqueous hydrochloric acid solution (2 x 35 cc), 0.5 ft aqueous hydrochloric acid solution (35 cc), and then with water (2 κ 35 cc). The 1 organic phase is dried over magnesium sulphate, filtered and concentrated to dryness under reduced pressure (2.7 kPa). The residue obtained is taken up with methylene chloride (200 cc). The organic phase is washed with saturated aqueous sodium hydrogen carbonate solution (2 x 50 cc). The organic phase is dried over magnesium sulphate, filtered and concentrated to dryness under reduced pressure (2.7 kPa). The residue is reerystallized in isopropyl ether. 2~(7-Chloro-l,S-naphthyridin-2-yl)~ 3-OKo-l-isoindolinyl 4-diisopropylaminobutyrate (7.1 g), m.p. 118eC, is thereby obtained. 4-Diisopropylaminobutyric acid hydrochloride may be obtained by working according to the method described in Example 4 for the preparation of l-methyl-3-piperi15 dinecarboxylie acid hydrochloride, but starting with ethyl 4-diisopropylaminobutyrate (9.2 g) and 6 N aqueous hydrochloric acid solution (28.5 cc) and by heating for β hours under reflux. 4-Diisopropylaminobutyric acid hydrochloride (8 g), m.p. 136°C, is thereby obtained.
Ethyl 4-diisopropylaminobutyrate may be obtained in the following manner: diisopropylamine (40.4 g) is added dropwise to a solution of ethyl 4-bromobutyrate (39 g) in ethanol (80 cc). The solution obtained is heated to reflux for 6 hours. After the insoluble material formed has been filtered off, the filtrate is concentrated to dryness under reduced pressure (2.7 kPa). The residue is taken up with distilled water (15 cc) and 4 N aqueous hydrochloric acid solution (100 cc). The aqueous phase is washed with ethyl ether (3 x 75 cc) and then alkalinized with 10 N aqueous sodium hydroxide solution. The oil formed is extracted with ethyl ether (3 x 75 cc). The organic phase obtained is concentrated to dryness under reduced pressure (2.7 kPa). Ethyl 4-diisopropylaminobutyrate (9.2 g) is thereby obtained in the form of an oil, which is employed in the crude state in the subsequent syntheses.
EXAMPLE .21.
Triethylamine (12.2 g), pyridine (90 cc) and then 3-methylhutyryl chloride (9.7 g) is added to a suspension of 2- (7-chloro-l# 8-naphthyridin-2-yl) -3-hydroxy-1-isoindolinone (12.5 g) in methylene chloride (600 cc)# while the temperature is maintained in the region of 25°C. After 4 hours' stirring at a temperature in the region of 25 "C# 3-methylbutyryl chloride (9.7 g) is added again and the mixture is stirred for a further 16 hours at this temperature. The reaction mixture is then concentrated to dryness under reduced pressure (3 kPa) and the residue is taken up with water (500 cc). The insoluble product formed is separated by filtration# washed# dried and then recrystallized in a mixture of isopropyl ether and ethyl acetate (50:50 by volume). 2-(7-Chloro-l»8-naphthyridin~ 2-yl)-3-oxo-l-isoindolinyl 3-methylbutyrate (7.9 g)# m.p. 154°C, is thereby obtained.
EXM14PLE 22 Pyridine (24 cc) followed# In the course of 30 minutes# by propionyl chloride (5.5 g) are added successively to a solution of 2-(7-chloro-l,8naphthyridin-2-yl)-3-hydroxy-1-isoindolinone (3.2 g) in methylene chloride (ISO cc)# while the temperature is maintained In the region of 25°C. The mixture is stirred for 3 hours at this temperature and then treated with water (100 cc). The organic phase is separated after settling has occurred# washed with water# dried and concentrated to dryness under reduced pressure (2.7 kPa). The residue obtained is crystallised in isopropyl ether and then recrystallised in a mixture of isopropyl ether and ethyl acetate (25:75 by volume). 2-(7-Chloro-l#8naphthyridin-2-yl) -3-oxo-l-isoindolinyl propionate (1 g) # m.p. 160 °C» is thereby obtained.
EXAMPLE 23 The procedure Is as in Example 22» but starting with 2-(7-chloro-l#8-naphthyridin-2-yl)-3-hydroxy-lisoindolinone (6.4 g) in methylene chloride (320 cc)# pyridine (48 cc) and butyryl chloride (12.8 g). After one recrystallisation in isopropyl ©ther followed by two recrystallisations in acetonitrile# 2-(7-chloro-l#8naphthyridin-2-yl)-3-oxo-l-isoindolinvl butyrate (3.4g)» m.p. 140eC# is obtained. 3 EXAMPLE 24 The procedure is as in Example 7, but starting with 2-(7-bromo-l,8-naphthyridin-2-yl)-3-hydroxy-lisoindolinone (8.55 g) in methylene chloride (110 cc), triethylamine (11.1 g), 5-methylhexanoyl chloride (7 g) and 4-dimethylaminopyridine (50 mg). After the residue obtained has been crystallized in hexane and then recrystallized in ethanol, 2-(7-brorao-l,8-naphthyridin~2~yl)~ 3- oxo-l-isoindolinyl 5-methylhexanoate (7.5 g), m.p. 136 °C, is obtained. 2-(7-Bromo-1,8-naphthyridin-2-yl)-3-hydroxy-1isoindolinone may be prepared as described in Belgian Patent 815,019.
EXAMPLE 25 An oily suspension (50% by weight; 0.96 g) of sodium hydride is added in the course of 15 minutes to a suspension of 3-hydroxy-2-(7-methoxy-1,8-naphthyridin-2yl)-1-isoindolinone (6.15 g) of anhydrous dimethylformamide (50 ec) while the temperature is maintained in the region of 0eC, the mixture then being stirred again for 30 minutes at 0eC. Diethyl chlorophosphate (2.9 ec) is then added dropwise in the course of 30 minutes while the temperature is maintained in the region of 0°C. A solution of sodium 4-acetylaminobutanoate, prepared from 4- acetamidobutyric acid (2.9 g) in anhydrous dimethylformamide (30 cc) and an oily suspension (50% by weight; 0.96 g) of sodium hydride, is added at a temperature in the region of 0C to the solution obtained. The mixture is stirred for 1 hour at 0°C, then 20 hours at a temperature in the region of 20*C, and finally 4 hours at 80°C. The reaction mixture is poured into water (400 ce) and extracted with methylene chloride (3 κ 200 cc). The organic extracts are combined and washed with water, dried and concentrated to dryness under reduced pressure (2.7 kPa). Th© residue obtained is purified by chromatography on silica (0.063-0.2 mm; 350 g) contained in a column 5 ea in diameter [eluant: methylene chloride/methanol (99si by volume)], collecting 100-cc fractions. Fractions 23 to 39 are combined and concentrated to dryness under reduced pressure (2.7 kPa) at 40°C; the residue is recrystallized in acetonitrile. 2-(7-Methoxy1.8- naphthyridin-2-yl)-3-oxo-l-isoindolinyl 4-acetylaminobutyrate (2 g), m.p. 190°C, is thereby obtained. EXAMPLE 2S The procedure is as in Example 7, but starting with 2-(7-methyl-1,8-naphthyridin-2-yl)-3-hydroxy-1isoindolinone (3.7 g), 5-methylhexanoyl chloride (7.8 g), triethylamine (12 cc) and 4-dimethylaminopyridine (50 mg). After the solid obtained after treatment has been recrystallized in methylcyclohexane, 2-(7-methyl1f8-naphthyridin-2-yl)-3-oxo-l-isoindolinyl 5-methylhexanoate (3.8 g), m.p. 144 °C, is obtained. 3- Hydroxy-2- (/ -methyl-1,8-naphthyridin-2-yl )-1isoindolinone may be prepared by the method described in German Patent 2,423,650.
-Methylhexanoyl chloride may be prepared by the method described by GOERNER G.L. et al., J. Org. Chem., 24, 1551 (1959).
EXAMPLE 27 The procedure is as In Example 1, but starting with 3-ehloro-2-(7-chloro-l,8-naphthyridin-2-yl)-1isoindolinone (9.9 g) in anhydrous dimethylformamide (100 cc), 4-(N-methylacetamido)butanoic acid (4.8 g) and 1.8- diasabicyclo[5.4.0]undec-7-ene (4.6 g) . The oily residue obtained is purified by chromatography on silica (0.063-0.2 m; 150 g) contained in a column 3 cm in diameter [eluant: methylene chloride/methanol (99:1 by volume)] and collecting 30-cc fractions. Fractions 76 to 175 are concentrated to dryness under reduced pressure (2.7 kPa) at 60°C and, after recrystallization in ethyl ether, 2-(7-chloro-l,8-naphthyridin-2-yl)-3-oxo-l-isoindolinyl 4-(N-methylacetamido)butyrate (3.1 g), m.p. 170°C, is obtained. 4- (N-Methylacetamido)butanoic acid may be prepared in the following manner: acetyl chloride (11.8 g) is added in the course of 1 hour to a solution, maintained at a temperature In the region of 5 °C, of 4-(N-methylemino)butanoic acid hydrochloride (15.4 g) in S 2.5 M aqueous sodium hydroxide solution (200 cc) . The mixture is stirred again for 30 minutes at approximately 5°C and then acidified to a pH in the region of 1 using 12 N aqueous hydrochloric acid solution. The mixture is concentrated to dryness at 80°C under reduced pressure (2.7 kPa) and the residue obtained is taken up with ethanol (150 cc). A solid, is separated by filtration, the filtrate is concentrated to dryness at 60 eC under reduced pressure and the residue is then taken up with methylene chloride (150 cc). The organic phase is dried over magnesium sulphate and concentrated to dryness at 60 °C under reduced pressure (2.7 kPa). 4-(N-Methylacetamido)butanoic acid (19 g) is thereby obtained in the form of an oil, which is employed in the crude state in the subsequent syntheses.
EXAMPLE 28 The procedure is as in Example 7., but starting with 2-(7-fluoro-1,8-naphthyridin-2-yl)-3-hydroxy-1isoindolinone (5 q) In methylene chloride (50 cc), triethylamine (6.5 g)» 4-methylpentanoyl chloride (3.66 g) and 4-dimethylaminopyridine (10 mg). After recrystallisation in ethanol, 2-(7-fluoro-I»3-naphthyridin-2-yl)-3-oxo-l-isoindolinyl 4-methylpentanoate (1.2 g), m.p. 154°C, Is obtained. 2- (7-Fluoro-1,8-naphthyridin-2-yl) -3-hydroxy-lisoindolinone may be prepared in the following manner; potassium borohydride (2.3 g) Is added in small portions at a temperature in the region of 20 'C to a suspension of 2-( 7-fluoro-1,8-naphthyridin-2-yl )-1,3-isoindolinedione (16.6 g) in a mixture of anhydrous methanol (90 cc) and dioxane (90 cc), and the suspension obtained is stirred for 3 hours at a temperature in the region of 20C. The reaction mixture is then poured Into a mixture of ice (120 g) and water (240 cc). Th® insoluble product is separated by filtration, washed with water (3 x 50 cc), dried in the air and recrystallised In acetonitrile. 2-(7-Fluoro-1,8-naphthyridin-2-yl)-3-hydroxy-l-isoindolinone (10.3 g), m.p. 246°C, Is thereby obtained. -(7-Fluoro-lt8-naphthyridin-2-yl ) 3 6 1,3-isoindolinedione may be prepared in the following manner; potassium fluoride (15 g) is added to a suspension, maintained under an argon atmosphere, of 2-(/-chloro-1,8-naphthyridin-2-yl )-1,3-isoindolinedione (20.S g) in anhydrous nitrobenzene (270 cc), and the reaction mixture is heated to reflux with stirring for 22 hours. After being cooled to a temperature in the region of 80°C, the reaction mixture is concentrated to dryness under reduced pressure (0.13 kPa) at 80°C. The residue obtained is taken up with ethyl acetate (170 cc). The insoluble product is separated by filtration, washed successively with ethyl acetate (30 cc) and water (6 x 30 cc) and dried in the air. 2-(7-Fluoro-1,8-naphthyridin-2-yl)-1,3-isoindolinedione (IS.9 g), m.p. 264’C, is thereby obtained. 2-(7-Chloro-l,8-naphfhyridin-2-yl)-1,3-isoindolinedione may be prepared by the method described in Belgian Patent 835,325.
The present invention also relates to the medicinal products which contain the products of formula (I) in the pure state or In the form of compositions in which they are combined with an adjuvant, a diluent and/or a coating which is compatible and pharmaceutically acceptable. These medicinal products may be used orally, rectally, parenterally or percutaneously.
As solid compositions for oral administration, tablets, pills, powders (generally In gelatin capsules) or granules may be used. In these compositions, the active product according to the invention Is mixed with one or more inert diluents such as sucrose, lactose or starch. These compositions can also contain substances other than diluents, e.g. a lubricant such as magnesium stearate.
As liquid compositions for oral administration, emulsions that are pharmaceutically acceptable, solutions, suspensions, syrups and elixirs containing inert diluents, such as water or liquid paraffin, may be used. These compositions can also contain substances other than diluents, e.g. wetting, sweetening or flavouring products.
The compositions according to the invention for parenteral administration can be suspensions, emulsions or aqueous or non-aqueous sterile solutions. As a solvent or vehicle, it is possible to use propylene glycol, a polyethylene glycol, vegetable oils, especially olive oil, or injectable organic esters, e.g. ethyl oleate. These compositions can also contain adjuvants, especially wetting agents, emulsifiers and dispersants. The sterilisation may be carried out in several ways, e.g. using a bacteriological filter, by incorporating sterilizing agents in the composition, by irradiation or by heating. They can also be prepared in th® form of sterile solid compositions which can be dissolved at the time of use in sterile water or any other injectable sterile medium.
The compositions for rectal administration are suppositories which can contain, in addition to the active product, excipients such as cocoa butter or suppowax.
The compositions for percutaneous administration are creams, ointments, lotions and liniments, in which the active product Is combined with liquid or pasty excipients, preferably in combination with a vehicle which promotes percutaneous migration.
The medicinal products and compositions according to the invention are especially useful in human therapy on account of their anxiolytic, hypnotic, anticonvulsant, antiepileptic and muscle relaxant action.
In human therapy, the doses depend on the effect sought and the period of treatment; they are generally between 10 and 500 mg per day orally for an adult.
In general, the doctor will determine the dosage which he considers most suitable in relation to the age and weight and all other factors particular to th© subject to be treated.
The examples which follow illustrate a composition according to the invention.
Example A Tablets containing lO-mg doses of active product and having the following composition are prepared according to the usual technique; 2-(7-chloro-l,8-naphthyridin-2~yl)-1-oxo1-isoindolinyl 3-dimethylaminopropionate ... 0.010 g starch ..................................... 0.200 g precipitated silica ........................ 0.036 g magnesium stearate ......................... 0.004 g Working in the same manner, tablets may be prepared in which the active principle consists of the following products; (RS)-2-(7-Chloro-1,8-naphthyridin-2-yl)-3-oxo-lisoindolinyl 4-acetamidobutyrate (RS)-2-(7-Chloro-l,8-naphthyridin-2-yl)-3-oxo-lisoindolinyl l-propionyl-4-piperidinecarboxylate 15 (RS)-2-(7-Methoxy-1,8-naphthyridin-2-yl)-3-oxo-li s o indo1iny1 5-methyIhexanoate (RS)-2-(7-Chloro-l,8-naphthyridin-2-yl)-3-oxo-lisoindolinyl 3-diisopropylaminopropionate.

Claims (9)

1. A new pyrrole derivative which is of the general formula: in which A forms with the pyrrole ring an isoindoline ring-system, Het denotes a naphthvridinyl radical substituted with a halogen atom or a (1 to 4 C) alkyl or (1 to 4 C) alkyloxy radical and R denotes an alkyl radical which is unsubstituted or substituted with an alkyloxy or dialkylamino radical, with an alkylcarbonylamino radical (in which the amino portion can optionally be substituted with an alkyl radical), or with a piperidyl or piperidino radical, or alternatively R denotes a 4-piperidyl radical, on the understanding that the alkyl radicals are straight- or branched-chain radicals and contain, except where specifically stated, 1 to 10 carbon atoms, and that the piperidino and piperidyl radicals can be unsubstituted or substituted at any position with an alkyl radical, as well as, where they exist, its pharmaceutically acceptable salts and the optical isomers of the products of formula (I).
2. O A process for preparing a product according to claim 1, in which Het is defined as in claim 1 with the exception of denoting a 1,8-naphthyridin-2-yl radical substituted at the 7-position with an alkyloxy radical, wherein an acid of general formula: R-COOH (II) or an alkali metal salt of this acid, in which R is defined as in claim 1, is reacted with a product of general formula: (ill) exception of denoting a 1, 8-naphthyridin-2-yl radical substituted at the 7-position with an alkyloxy radical, and A is as defined as in claim 1, and the product obtained is then isolated and optionally converted, where appropriate, to a pharmaceutically acceptable salt.
3. A process for preparing a product according to claim 1, wherein a product of general formula: R-CO-X (V) in which R is defined as in claim 1 and X denotes a halogen atom or a reactive ester residue, is reacted with a product of general formula: in which A and Het are defined as in claim 1, and the product obtained is then isolated and optionally converted, where appropriate, to a pharmaceutically 5 acceptable salt.
4. A process for preparing a product according to claim 1, wherein an alkali metal salt of an acid of general formula: R-COOH (ΪΙ) 10 in which R is defined as in claim 1, is reacted with a product of general formula: in which R4 denotes a straight- or branched-chain alkyl radical containing 1 to 4 carbon atoms or a phenyl 15 radical and A and Het are defined as in claim 1, and the product obtained is then isolated and converted, if so desired and where appropriate, to a pharmaceutically acceptable salt. ί·ν Κ3
5. A pharmaceutical composition which contains at least one product according to claim 1, in combination with one or more diluents which are compatible and pharmaceutically acceptable. 5
6. A compound according to claim 1, substantially as hereinbefore described and exemplified.
7. A process for preparing a compound according to claim 1, substantially as hereinbefore described and exemplified. 10
8. A compound according to claim 1, whenever prepared by a process claimed in a preceding claim.
9. A pharmaceutical composition according to claim 5, substantially as hereinbefore described and exemplified.
IE325287A 1986-12-02 1987-11-30 New pyrrole derivatives, their preparation and pharmaceutical compositions which contain them IE61089B1 (en)

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