NL192574C - Antibacterial preparation, and a 1-substituted 7- (3-substituted-1-pyrrolidinyl) -6-fluoro-4-oxo-1,4-dihydro-1,8-naphthyridine-3-carboxylic acid derivative. - Google Patents

Description

1 192574

Antibacterial preparation and a 1-substituted 7- (3-substituted-1-pyrrofidinyl) -6-fluoro-4-oxo-1,4-dihydro-1,8-naphthyridine-3-carboxylic acid derivative

The invention relates to an antibacterial composition comprising a 1-substituted 7- (3-5 substituted-1-pyrrolidinyl) -6-fluoro-4-oxo-1,4-dihydro-1,8-naphthyridine-3-carboxylic acid derivative as an active substance.

Such a preparation is known from European patent application 0.027.752, which concerns, inter alia, the use of 7- (3-methylamino-1-pyrrolidinyl) -1-ethyl-6-fluoro-4-oxo-1.4 as active substance. dihydro-1,8-naphthyridine-3-carboxylic acid or pharmaceutically acceptable salts thereof. As a pharmaceutically acceptable salt, a salt with hydrogen chloride or with methanesulfonic acid is preferably used.

The preparation shows strong antibacterial activity against both Gram positive and Gram negative bacteria, including Pseudomonas aeruginosa.

Such a preparation is also known from French patent application 2,500,833, which inter alia refers to 7- (3-methylamino-1-15 pyrrolidinyl) -6-fluoro-4 substituted in position 1 with a vinyl or 2-fluoroethyl group. -oxo-1,4-dihydro-1,8-naphthyridine-3-carboxylic acids or pharmaceutically acceptable salts thereof. The pharmaceutically acceptable salt can be an acid addition salt, but also a salt with a base. The preparation shows a strong antibacterial action, especially against Gram-negative bacteria, including Pseudomonas strains.

It has now been found that new compounds of the formula I of the formula sheet 20 in which R4 and R5 have the combinations of meanings to be described hereinafter, have a strong antibacterial activity against Gram-positive and Gram-negative bacteria, in particular against bacteria which have become resistant to antibiotics.

The invention therefore provides the antibacterial preparation described in the preamble, characterized in that the active substance is a compound of the formula 1, in which R4 is a fluorine atom and R5 is a hydroxyl group, or in which R4 is a fluorine atom and R5 is a methylamino group or wherein R4 is a hydrogen atom and R5 is a methylamino group, or is a pharmaceutically acceptable salt thereof.

The salt formation with the compounds of the formula I can occur both on basic groups, such as methylamino groups, and on the acidic carboxyl group. The former include salts with inorganic and organic acids such as hydrogen chloride, sulfuric acid, oxalic acid, formic acid, trichloroacetic acid, trifluoroacetic acid, methanesulfonic acid, p-toluenesulfonic acid and naphthalenesulfonic acid. For example, salts with the carboxyl group are suitable for sodium, potassium, calcium, magnesium and ammonium salts, as well as salts with organic nitrogen bases such as procaine, dibenzylamine, N-benzyl-p-phenethylamine, 1-phenphenamine, Ν , Ν-dibenzylethylenediamine, triethylamine, trimethylamine, tributylamine, pyridine, Ν, Ν-dimethylaniline, N-methylpiperidine, N-methylmorpholine, diethylamine and dicyclohexylamine.

The optical antipodes of the compounds of the formula I as well as all crystal forms and hydrates of those compounds are within the scope of this invention.

It should also be noted that in a publication by J. Matsumoto et. al. in J. Medicinal Chem 27, 292-301 (March 1984) the results of a study of the antibacterial activity of various 40 1,6,7-trisubstituted 4-oxo-1,4-dibydro-1,8 have been described -naphthyridine-3-carboxylic acid derivatives. As substituents in position 1 are mentioned the ethyl, 2-fluoroethyl, difluoromethyl and vinyl group. This publication does not indicate to a person skilled in the art that in a position 1 substituted 7- (3-methylamino-1-pyrrolidinyl) -6-fluoro-4-oxo-1,4-dihydro-1,8-naphthyridine-3-carboxylic acid derivative is known from the aforementioned prior art, replacing an ethyl, 2-fluoroethyl or vinyl group as substituents in position 1 with a 4-fluorophenyt or 2,4-difluorophenyl group leads to compounds - compounds of the present formula 1 - which show a strong antibacterial effect against both Gram-positive and Gram-negative bacteria.

It should also be noted that in the non-prepublished European patent application 0,153,580; in which the Netherlands is one of the designated States and for which a priority right has been invoked from 26 January 1984; the antibacterial activity of 1,7-disubstituted 6-fluoro-4-oxo-lr4-50 dihydro-1,8-naphthyridine-3-carboxylic acid derivatives is represented by the present formula 1a, wherein R, a hydrogen atom or a carboxyl group is a protecting group, R2 represents an unsubstituted or substituted phenyl group or an aromatic heterocyclic group, and R3 represents an unsubstituted or substituted amino group or an aliphatic heterocyclic group. However, the compounds of the present formula 1 are not mentioned as such in the older part of this European patent application and appear to exhibit a considerably stronger action compared to strains of Staphylococcus aureus and Staphylococcus epidermidis than for the contents of these European patent applications. patent application to deem representative 1- (optionally substituted phenyl) -6-fluoro-4-oxo-1,4-dihydro-1,8-naphthyridine-192574 2 3-carboxylic acids substituted at position 7 with a piperazino or 4- methylpiperazino group.

Listed below are the antibacterial effects of the compounds of formula I, which were determined as follows: 1. In vitro activity

According to the standard method of the Japanese Chemotherapy Association [Chemotherapy 29 (1), 76-79 (1981)], a plate of cardiac infusion agar containing the substance to be tested was bone with a bacterial suspension, obtained by cultivation at 37 ° for 20 hours C in a heart infusion broth (from Eiken Kagaku).

After incubating the inoculated plate at 37 ° C for 20 hours, it was checked whether bacteria were growing on it. The minimum concentration of the test substance which inhibited the growth of bacteria was determined; this is the MIC value (in / µg / ml). The seed was 104 cells per plate (106 cells / ml). The MIC values found are shown in Table A. In this table, penicillinase-forming bacteria are indicated by * 1 and cell alosporinase-forming bacteria by * 2; * 3 indicates inoculation with 108 cells / ml.

15 2. Acute toxicity

The test compound was always dissolved in 1 equivalent 0.1N NaOH solution in water, and 10 ml of this solution was slowly injected into the tail vein of male mice of the ICR strain (of 20 ± 2 g; 5 kg). mice per group).

The LD50 value of the compound 1 in Table A is greater than 200 mg / kg.

TABLE A

MIC values, in / µg / ml 25 Compound of the formula 1 R4 fluorine fluorine hydrogen

Microorganism investigated Rs hydroxy methylamino methylamino 30 - 1 2 3

St. aureus FDA209P £ 0.05 0.2 0.2

St. epidermidis IID866 0.Γ3 0.2 0.2

St. aureus F-137 * 1 £ 0.05 0.1 0.2 35 E. COli NIHJ s 0.05 £ 0.05 £ 0.05 E. coli TK-111 s 0.05 £ 0.05 £ 0.05 E. coli GN5482'2 s 0.05 £ 0.05 £ 0.05

Ps. aeruginosa S-68 1.56 0.78 1.56

Aci. anitratus A-6 0.1 0.1 0.1 40 Ps. aeruginosa IFQ3445 3.13 1.56 1.56

Ps. aeruginosa GN918 * 2 0.78 0.39 0.39

The invention further relates to a position 1 substituted 7- (3-substituted-1-45 pyrrolidinyl) -6-fluoro-4-oxo-1,4-dihydro-1,8-naphthyridine-3-carboxylic acid derivative of the formula 1 as defined above or a pharmaceutically acceptable salt thereof, suitable for use as an active substance in the antibacterial preparation described in the opening paragraph.

The compounds of the invention are prepared in a manner known per se for analogous compounds. In particular, this can be done according to the reaction scheme given herein, in which R. 50 represents a hydrogen atom or a carboxyl protecting group, R 1a represents the same protecting group as in R 1, R 2 represents a 4-fluorophenyl or 2,4-difluorophenyl group, R3 represents a 3-hydroxy-1-pyrrolidinyl or 3-methylamino-1-pyrrolidinyl group, with the proviso that R3 does not represent a 3-hydroxy-1-pyrrolidinyl group when R2 represents a 4-fluorophenyl group, and R3a represents a halogen atom, such as fluorine , chlorine and bromine. Depending on the outcome, the corresponding 55 salts can also be used and the resulting products can be recovered as salts.

Compounds of general formula 3 or general formula 6 can be obtained by reacting an appropriate acetal, such as Ν, Ν-diethylformamide dimethyl acetal or N, N-dimethylformamide diethyl acetal, with a compound of formula 2 or according to the formula 5 and then with an amine of the formula R2-NH2.

The solvent to be used in these reactions can be any solvent which is inert under the reaction conditions, such as benzene, toluene, xylene, dioxane, tetrahydrofuran, anisole, dimethoxy-5 ethane, methylene chloride, chloroform, dichloroethane, Ν, Ν-dimethylformamide, N, N-dimethylacetamide, and dimethyl sulfoxide; these solvents can be used alone or in combination. The amount of acetal used is preferably 1 mol or more, in particular 1.0-1.3 mol per mol of the compound of the formula 2 or 5. The reaction is generally carried out at a temperature between 0 and 100 ° C, preferably between 50 and 80 ° C, and generally requires between 20 minutes and 50 hours, usually between 1 and 10 3 hours. Of the amine of the formula R2-NH2, 1 mole or more per mole of the compound of the formula 2 or 5 is used. The reaction is carried out at a temperature between 0 and 100 ° C, preferably between 10 and 60 ° C, and requires between 20 minutes and 30 hours, usually between 1 and 5 hours.

Alternatively, it is also possible to react a compound of the formula 2 or of the formula 5 in the presence of acetic anhydride with ethyl chloroformate or methyl orthoformate, and then with an amine of the formula R2-NH2 or a salt thereof. Then, too, a compound of the formula 3 or 6 or a salt thereof is obtained.

The compound of general formula 4 or 1a or a salt thereof is obtained by causing ring closure in a compound of formula 3 or formula 6 under the influence of a base (preferably under heating).

The solvent to be used in this cyclization reaction can be any solvent which is inert in the reaction, such as Ν, Ν-dimethylformamide, N.N-dimethylacetamide, dioxane, anisole, dimethoxyethane and dimethyl sulfoxide. These solvents can be used alone or in combination. The base can be, for example, NaHCO3, K2CO3, potassium tertiary butoxide or NaH. The amount of base to be used is between 0.5 and 5 moles per mole of the compound of formula 3 or 6. The reaction is carried out at a temperature between 20 and 160 ° C, preferably between 100 and 150 ° C, and required in generally between 5 minutes and 30 hours, usually between 5 minutes and 1 hour.

A compound of the general formula 5, 6 or 1a can also be obtained by reacting a compound of the general formula 2, 3 or 4 respectively with a pyrrolidine of the general formula R 3 -H or a salt thereof.

The solvent to be used in that reaction can be any inert liquid, such as benzene, toluene, xylene, dioxane, dimethoxyethane, methylene chloride, chloroform, dichloroethane, Ν, Ν-dimethylformamide, Ν, Ν-dimethylacetamide and dimethyl sulfoxide; these solvents can be used alone or in combination. The pyrrolidine compound used is preferably an excess, most preferably between 2 and 5 moles per mole of the compound of formula 2, 3 or 4. It is also possible to suffice with 1 to 1.3 moles of a pyrrolidine compound of the formula R3-H. if per mole of the compound of formula 2, 3 or 4 there is also 1 mole of an acid binding agent present. Acid-binding agents include organic and inorganic bases such as triethylamine, 1,8-diazabicyclo [5.4.0] undec-7-ene, potassium tertiary butoxide, K2CO3, NajCO2 and NaH.

The cyclic amine of the formula R3-H can also be used as a salt. The reaction is generally conducted between 0 and 150 ° C, preferably between 50 and 100 ° C, and generally lasts between 5 minutes and 30 hours, usually between 30 minutes and 3 hours.

A compound of the general formula 1a or 4, wherein R 1 represents a carboxyl protecting group, and the salts thereof can be converted to the corresponding free acids by hydrolysing them conventionally with acid or base, generally at a temperature between 0 and 45 100 ° C, preferably between 20 and 100 ° C. This hydrolysis takes between 5 minutes and 50 hours, usually between 5 minutes and 4 hours. Furthermore, a compound of the formula 1a can be converted into a salt in a known manner. When the compound of formula 1a or a salt thereof contains an R 3 protecting group, the protecting group is removed in the usual manner.

The compounds obtained can be isolated and purified in a conventional manner, using methods such as column chromatography, recrystallization, or extraction.

When the compounds of the invention are used as a medicament, they are conveniently combined with carriers customary in pharmaceutical preparations. The compositions may be in the form of tablets, capsules, powders, syrups, granules, suppositories, ointments, injection fluids and the like.

The mode of administration, the doses used and the number of doses can be varied as needed depending on the symptoms of the patients; usually they will be administered orally or parenterally (for example, by injection, by instillation or through the rectum) at a dose between 0.1 and 100 mg / kg per day, optionally in multiple portions.

192574 4

The invention is now further illustrated by the following examples.

Example I

a) A solution of 21 g of 2,6-dichloro-5-fluoro-nicotinic acid, 23.8 g of thionyl chloride and 0.1 g of N, N-5 dimethylformamide in 210 ml of chloroform was reacted at 70 ° C for 2 hours. Solvent and excess thionyl chloride were then removed by distillation under reduced pressure and the residue (2,6-dichloro-5-fluoro-nicotinoyl chloride) was taken up in 21 ml of tetrahydrofuran.

A solution of 25.1 g of diethyl ethoxymagnesium malonate in 110 ml of tetrahydrofuran was cooled to between -40 and -30 ° C and the solution of 2,6-dichloro-5-fluoromicotinoyl chloride just mentioned was added dropwise for 30 minutes at the same temperature. This mixture was stirred at the same temperature for an additional 1 hour and then the mixture was allowed to warm gradually to room temperature. The solvent was removed by distillation under reduced pressure and 200 ml of chloroform and 100 ml of water were added to the residue. The pH value was adjusted to 1 with hydrochloric acid. The organic layer was separated, washed successively with 50 ml of water, 50 ml of 5% aqueous NaHCO3 solution and 50 ml of saturated aqueous NaCl solution, and finally dried over anhydrous MgSO4. The solvent was then distilled off under reduced pressure and 50 ml of water and 0.15 g of p-toluenesulfonic acid were added to the residual oily liquid and the mixture was allowed to react at 100 ° C with vigorous stirring for 2 hours. The reaction mixture was then extracted with 100 ml of chloroform. The organic layer was washed with 50 ml of saturated aqueous NaCl solution and dried over anhydrous MgSO 4, then the solvent was distilled off under reduced pressure. The residue thus obtained was purified by column chromatography with toluene on Wako silica gel C-200, adding 23.5 g of ethyl (2,6-dichloro-5-fluoro-nicotinoyl) acetate with mp. 64-65 ° C.

IR (in KBr): maxima at 1650, 1630, 1620 cm -1, NMR (CDCIg): maxima at δ values (in ppm), 1.25 (1.29H, t, J = 7Hz), 1.33 (1.71H, t, J = 7Hz), 4.07 (1.14H, 25s), 4.28 (2H, q, J = 7Hz), 5.82 (0.43H, s), 7.80 (1H, d, J = 7Hz), 12.62 (0.43H, s).

b) A solution of 8.8 g of ethyl (2,6-dichloro-5-fluoro-nicotinoyl) acetate and 4.5 g of N, N-dimethylformamide dimethyl acetal in 40 ml of benzene was reacted at 70 ° C for IV2 hours. Then 4.1 g of 2,4-difluoroaniline was added and that mixture was allowed to stand at room temperature for 4 hours. The solvent was then removed by distillation under reduced pressure. The resulting residue was purified by column-30 chromatography with chloroform (Wako silica gel C-200), yielding 9.0 g of ethyl 2- (2,6-dichloro-5-fluoro-nicotinoyl) -3- (2,4-difluorophenylamino) acrylic with mp. 138-139 ° C.

IR (in KBr): maximum at 1690 cm -1, NMR (CDCIg): maximums at δ values (in ppm) 1.08 (3H, t, J = 7Hz), 4.10 (2H, q, J = 7Hz), 6.77-7.40 (4H, m), 8.50 (1H, d, J = 13Hz), 12.70 (1H, d, J = 13Hz).

C) To a solution of 9.0 g of ethyl 2- (2,6-dichloro-5-fluoro-nicotinoyl) -3- (2,4-difluorophenylamino) acrylate in 90 ml of Ν, Ν-dimethylformamide, 3.6 g NaHCO 3 was added and that mixture was kept at 120 ° C for 20 minutes. The solvent was then distilled off under reduced pressure and the residue was taken up in 50 ml of chloroform. This solution was washed successively with 30 ml of water and 30 ml of saturated aqueous NaCl solution and then dried over anhydrous MgSO 4. The solvent was distilled off under reduced pressure 40 and the crystalline residue was washed with 30 ml of diethyl ether to give 7.0 g of ethyl 7-chloro-6-fluoro-1- (2,4-difluorophenyl) -4-oxo-1, 4-dihydro-1,8-naphthyridine-3-carboxylate with m.p. 200-222 ° C.

IR (in KBr): maxima at 1730, 1690 cm -1, NMR (CDCI3): maxima at δ values (in ppm), 1.36 (3H, t, J = 7Hz), 4.30 (2H, q , J = 7Hz), 6.80-7.60 (3H, m), 8.27 (1H, d, J = 7Hz), 8.42 (1H, S).

45 d) To a solution of 0.50 g of ethyl 7-chloro-6-fluoro-1- (2,4-difluorophenyl) -4-oxo-1,4-dihydro-1,8-naphthyridine-3-carboxylate , 0.20 g of 3- (N-acetyl-N-methylamino) pyrrolidine and 0.15 g of triethylamine were added in 5 ml of chloroform. The mixture was kept at 60 ° C for one hour. The solvent was then distilled off under reduced pressure and the residue was purified by column chromatography (with 3% ethanol in chloroform (Wako silica gel C-200) some ethyl 7- [3- (N-acetyl-N-methylamino) -1-pyrrolidinyl 6-fluoro-1-50 (2,4-difluorophenyl) -4-oxo-1,4-dihydro-1,8-naphthyridine-3-carboxylate, mp 196-197 ° C.

IR (in KBr): maxima at 1730, 1695 cm -1.

e) A solution of 0.25 g of ethyl-7- [3- (N-acetyl-N-methylamino) -1-pyrrolidinyl] -6-fluoro-1- (2,4-difluorophenyl) -4-OXO-1 4-dihydro-1,8-naphthyridine-3-carboxylate in 2.5 ml of 6N hydrochloric acid was refluxed for 2 hours. After cooling to room temperature, the pH of the mixture was adjusted to 12 with 1N aqueous 55 NaOH solution and then to 6.5 with acetic acid. The crystals that were deposited therein were collected by filtration, washed with 2 ml of water and then dried. This gave 7- [3-methylamino-1-pyrrolidinyl] -6-fluoro-1- (2,4-difluorophenyl) -4-oxo-1,4-dihydro-1,8-naphthyridine-3-carboxylic acid

Claims (2)

192574 mp 275-278 ° C. IR (in KBr): sch. at 1720 cm -1. Example II 5 a) In the manner of Example Ib, ethyl (2- (2,6-dichloro-5-fluoromicotinyl) acetate (see example 1a) and 4-fluoroaniline ethyl-2- (2,6-dichloro-5-fluoromicotinyl) ) -3- (4-fluorophenylamino) acrylate prepared; m.p. 110-114 ° C. IR (in KBr); maxima at 1710 and 1680 cm'1. This compound was converted to ethyl 7-chloro-6-fluoro-1- (4-fluorophenyl) -4-oxo-1,4-dihydro-1,8-naphthyridine-3-carboxylate with melting point in the manner of Example 1c 231-232 ° C. 10 IR (in KBr): maxima at 1730, 1705 cm -1. In the manner of Example 1d, ethyl 7-chloro-6-fluoro-1- (4-fluorophenyl) -4-oxo-1,4-dihydro-1,8-naphthyridine-3-carboxylate with 3- (N- acetyl-N-methylamino) pyrrolidine converted to ethyl 7- [3- (N-acetyl-N-methylamino) -1-pyrrolidinyl] -6-fluoro-1 - (4-fluorophenyl) -4-oxo-1,4 dihydro-1,8-naphthyridine-3-carboxylate, mp 201-202 ° C. IR (in KBr): maxima at 1725, 1695 cm -1. B) The compound prepared in a) was converted as in Example 1e to 7- [3-methylamino-1-pyrrolidinyl] -6-fluoro-1- (4-fluorophenyl) -4-oxo-1,4- dihydro-1,8-naphthyridine-3-carboxylic acid, mp 259-261 ° C. IR (in KBr): sch. at 1720 cm -1. 20 Conclusions An antibacterial preparation containing a 1-substituted 7- (3-substituted-1-pyrrolidinyl) -6-fluoro-4-oxo-1,4-dihydro-1,8-naphthyridine-3-carboxylic acid derivative as active substance, characterized in that the active ingredient is a compound of formula 1, wherein R4 is a fluorine atom and R5 is a hydroxyl group, or wherein R4 is a fluorine atom and R5 is a methylamino group, or wherein R4 is a hydrogen atom and R5 is a methylamino group or is a pharmaceutically acceptable salt thereof. 2. Position 1-substituted 7- (3-substituted-1-pyrrolidinyl) -6-fluoro-4-oxo-1,4-dihydro-1,8-naphthyridine-3-carboxylic acid derivative, characterized in that it is a compound of the formula 1 wherein R4 is a fluorine atom and Rs is a hydroxyl group, or wherein R4 is a fluorine atom and Rs is a methylamino group, or wherein R4 is a hydrogen atom and R5 is a methylamino group, or a pharmaceutically acceptable salt thereof for use as active substance in the preparation according to claim 1. 1 sheet of drawing