AMIFLOXACINE INTERMEDIATE

Abstract: New 6-fluoro-7-chloro-1-methylamino-4-oxo-1,4-dihydro-quinoline-3-carboxylic acid/boric acid anhydrides of general formula (I), (wherein R and R<1> stand for halogen; an aliphatic acyloxy group comprising 2-6 carbon atoms and optionally substituted by halogen; or an aromatic acyloxy group comprising 7-11 carbon atoms). The new compounds of general formula (I) are valuable intermediates useful in the preparation of the antibacterial agent 6-fluoro-1-methylamino-7-(4-methyl-piperazino)-4-oxo-1,4-dihydro-quinoline-3-carboxylic acid. The new compounds of general formula (I) may be prepared by reacting a compound of formula (II), or a compound of general formula (III), (wherein R<2> stands for alkyl comprising 1-4 carbon atoms) with hydrogen fluoro borate of the formula (IV), or a borone trihalide of general formula (V), (wherein X stands for fluorine, chlorine or bromine) or a complex thereof formed with an ether or a borone derivative of general formula (VI), (wherein R<3>, R<4> and R<5> stand for alkyl comprising 1-5 carbon atoms and optionally substituted by halogen or aryl comprising 6-10 carbon atoms).

Description: AMIPLOXACINE INTERMEDIATE This invention relates to new Amifloxacine inter¬ mediates and a process for the preparation thereof. More particularly it is concerned with new anhydrides of 6~f luoro-7-chloiO-l«--αethylamino-4-oxo-l,-4-.ihydro- -quinoline-3-carboxylic acid and boric acids. Ethyl-6-fluoro-7-chloro-l-methylamino-4-oxo-l,4- -dihydro-quinolin e-3-carboxylate is an intermediate useful in the preparation of the antibacterial agent 6-f luoro-l-me hyla__t±-io-7- (4-methyl-piperazino )-4-oxo- -l,4-dihydro-quinoline-3-carboxylic acid (Journal of Medicinal Chemistry, 27, 1103 /1984/) . The latter com¬ pound can be prepared in two steps from ethyl-6-f luoro- --7-chloro-l-meth lamino-4-oxo-l,4-dihydro-quinoline- -3-carboxylate. The said ester is subjected to hydrolysi whereupon the 6-f luoro-7-chloro-l-methylamino-4-oxo-l,4- -dihydro-quinoline-3-carboxylic acid thus obtained is reacted in the presence of a solvent at a temperature above 100 °C with 1-me hyl-piperazine for 15-22 hours to yield the desired 6-fluoro-l-methylamino-7-(4-__.ethyl- -piperazino)-4-oxo-l,4-dihydro-quinoline-3-carboxylic acid (European patent specification Ho. 90,424; Japa¬ nese patent specification No. 84 01,468). It has been found that the 6-f luoro-1-methylamino- -7-(4-methyl-piperazino)-4-oxo-l,4-dihydro-quinoline- -3-carboxylic acid can be prepared under milder reaction conditions during a shorter reaction time by reacting l-methyl-piperazine with a compound of the general For¬ mula I. According to an aspect of the present invention ther are provided new compounds of the general Formula I 58119-77 Y acyl¬ oxy group comprising 2-6 carbon aioms and optionally sub¬ stituted by halogen; or an aromatic acyloxy group comp¬ rising 7-11 carbon atoms). According to a further aspect of the present inven¬ tion there is provided a process for the preparation of the compounds of the general Formula I (wherein R and R stand for halogen; an aliphatic acyloxy group comprising 2-6 carbon atoms and optionally substituted by halogen; or an aromatic acyloxy group comprising 7-11 carbon atoms), which comprises a) reacting the quinoline-3-carbox lic acid derivative of th with fluoro boric acid of the Formula IV y-z- ' H B F In I or a trihalo borate of the general Formula V B X 3 /v (wherein X stands for fluorine, chlorine or bromine) or a triacyloxy borate derivative of the general (wherein R 3, R4 and stand for alkyl comprising 1-4 carbon atoms and optionally substituted by halo¬ gen* or aryl comprising 6-10 carbon atoms); or b) reacting a quinoline derivative of the general (wherein R stands for hydrogen or alkyl comprising 1-4 carbon atoms) with fluoro boric acid of the Formula IV, or a trihalogeno borate of the general Formula V (wherein X has the same meaning as stated above) or a triacyloxy borate of the general Formula VI (wherein R 3, R4 and R^-. are as stated above) . As compound of the general Formula V borone trifluoride, borone tribromide or borone trichloride or a complex or aqueous solution thereof can be used. One may preferably use a complex formed with an ether alcohol (e.g. a complex of borone trifluoride formed with tetrahydrofuran, die hy1 ether, methanol, or pro- panol). One may preferably apply a solution of a borone trihalide formed with an aliphatic hydrocarbon (e.g. dichloro methane) or a carboxylic acid (e.g. acetic acid, trifluoro acetic acid or propionic acid). The boric acid of the Formula IV, the borone tri¬ halide of the general Formula V or the compound of the general Formula VI can be used in a molar ratio of 1-50 - preferably 1-5 - related to 1 mole of the compoun of the Formula II or III. The above molar ratio is how¬ ever but a preferable interval and an other molar ratio may be applied as well. The above reactions may be carried out, if desired, in the presence of a solvent. As solvent e.g. water, ketones (e.g. acetone, methyl-ethyl-ketone), hydrocar¬ bons (e.g. hexane, benzene, toluene), ethers (e.g. diethyl ether, dioxane, tetrahydrofuran), organic acids (e.g. acetic acid, propionic acid, trifluoro acetic acid, etc.) may be used. The reactions can be carried out at room tempera¬ ture, if desired. On raising the reaction temperature, the reaction time can be shortened. Some reactions can be accomplishe at a temperature between room temperatur and 150 °G. The reaction temperature depends on the solvent used as well. The compound of the general Formula I thus obtained I precipitates from the reaction mixture spontaneously or on cooling and can be isolatedby known methods (e.g. filtration). Further details of the present invention are to be found in the following Examples without limiting the scope of protection to the said Examples. Example 1 5 g of ethyl-6-fluoro-l-d.-formyl-lT-methyl-amino)- -7-chloro-4-oxo-l,4-dihydro-quinoline-3-carboxylate are stirred in 25 ml of an 50 weight/vol % aqueous solu¬ tion of hydrogen fluoroboric acid at 90-95 °C for 4 hours. After one hour and a half the precipitation of crystals begins. The reaction mixture is cooled to room temperature, then placed into a refrigerator and allowed to crystallize overnight. The precipitated crystals are filtered next morning and washed with some water. Thus 4.55 g of an anhydride of 6-fluoro-7-chloro-l- -(methylamino)-4-oxo-l,4-dihydro-quinoline-3-carboxylic acid and difluoro boric acid are obtained, yield: 93.4 . Mp. : 277 °C (decomposition). Analysis for the Formula calculated C = 41.48 %, N = 8.79 found C = 41.59 % , H = 2.34 %■ H = 8.58 Example 2 5 g of 6-fluoro-7-chlorc-l-methyla__ino-4-oxo-l,4- -dihydro-quinoline-3-carboxylic acid are stirred in 25 m of a 50 weight/vol % aqueous solution of hydrogen fluoro boric acid at 80-90 °C for 2 hours. After 45 minutes the precipitation of crystals begins. The reaction mixture is first cooled to room temperature and then allowed to crystallize for 2 hours at 0 °C. The preci¬ pitated crystals are filtered, and washed with some water. Thus 4.95 g of an anhydride of 6-fluoro-7-chloro- -l-methylamino-4-oxo-1,4-dihydro-quinoline-3-carboxylic acid and difluoro boric acid are obtained, yield 84.5 %. Mp. : 277 C (decomposition). A mixture of the product thus obtained with any amount of the compound prepared accordin to Example 1 shows no melting point depression Example 3 A mixture of 1.42 g of boric acid and 10.7 g of propionic anhydride is stirred at 100 °C for 15 minutes whereupon the reaction mixture is heated to boiling point. After 30 minutes the temperature of the reaction mixture is lowered to 110 °C and 4.2 g of 6-fluoro-7- -chloro-1-methyla ino-4-oxo-1,4-dihydro-quinoline-3- -carboxylic acid are added. After some minutes the pre¬ cipitation of crystals begins. The reaction mixture is stirred at 110 °C for 2 hours, cooled to 10 °C, where¬ upon 20 ml of water and 20 ml of ethanol are added to the crystalline suspension. The reaction mixture is allowed to crystallize in a refrigerator overnight. The precipitated crystals are filtered, washed with water and dried. Thus 6.12 g of /6-fluoro-7-chloro-l-methyl- amino-4-oxo-1,4-dihydro-quinoline-3-carboxylie acid- -borone-dipropionyloxy/-anhydride are obtained. Yield: 93.5 %, Mp.: 215 °C (decomposition). Analysis for the Formula C^H T -BFClϊ-gOγ calculated C = 47.86 %, H = 4.01 %, IT = 6.56 found C = 48.07 , H = 3.87 , N = 6.48 Example 4 0.568 g of boric acid and 3.28 g of acetic acid anhydride are reacted in the presence of 1 mg zinc chloride, while the temperature of the reaction raises to 40 °C. The white suspension is slowly heated to 100 °C and 2 g ethyl /_ " 7-chloro-6-fluoro-1 ,4- dihydro-l-(formylmethyl-amino)-4-oxo-3-quinoline- -carboxylate_7 are added which had previously been dis¬ solved in 10 ml of 96 % by W/V acetic acid. The reaction mixture is further heated at 110 C for 2 hours. The solution is cooled to room temperature and diluted with 40 ml of cold water. The precipitated crystals are filtered and washed with water and cold abs. ethanol, and dried. Off-white crystalline /_~6-ϊluoro-7-chloro- -l,4-dihydro-l-(methyl-amino)-4-oxo-3-quinolinecarboxylate- -fj ,_ _7-bis(acetate-0_)-boroπ is obtained (1.75 g). Decomposition: 272 C. Upon standing further 0.45 g product is precipitated from the mother-liquor. Analysis for the formula C, ,-H, ,BC1FN 2 0-, calculated: 0=45.55% H=3.31% N=3.54 Tl found: C=45.2 % H=3.2% N=3.6

Claims: WHAT WE CLAIM IS : 1. Compounds of the general Formula I (wherein R and R stand for halogen; an aliphatic acyloxy group comprising 2-6 carbon atoms and optio¬ nally substituted by halogen; or an aromatic acyloxy group comprising 7-11 carbon atoms).- 2. Process for the preparation of compounds of the general Formula I (wherein R and R stand for halogen; an aliphatic acyloxy group comprising 2-6 carbon atoms and optionally substituted by halogen; or an aromatic acyloxy group comprising 7-11 carbon atoms), which comprises reacting a compound of the /II/ or a compound of the general Formula III (wherein R stands for alkyl comprising 1-4 carbon atoms with hydrogen fluoro borate of the Formula IV or a borone trihalide of the general Formula V B X 3 πι (wherein X stands for fluorine, chlorine or bromine) or a complex thereof formed with an ether, or a borone derivative of the general Formula VI (wherein R 3, and stand for alkyl comprising 1-5 carbon atoms and optionally substituted by halogen or aryl comprising 6-10 carbon atoms). 3. Process according to Claim 2 which comprises carrying out the reaction of the compound of the For¬ mula II or III with the compound of the Formula IV in aqueous medium. 4. Process according to Claim 2 which comprises reacting the compound of the Formula II or III with the compound of the general Formula V in the presence of a solvent. 5. Process according to Claim 2 which comprises reacting the compound of the Formula II or III with the compound of the general Formula VI in the presence of a solvent. 6. Compounds of the general Formula I whenever prepared by the process according to any of Claims -5. 7. A process as substantially described herein with particular reference to the Examples.

Inventors: BALOGH MARIA, HERMECZ ISTVAN, HORVATH AGNES, KERESZTURI GEZA, KOVACS GABOR, MESZAROS ZOLTAN, PAJOR ANIKO, RITLI PETER, SIPOS JUDIT, VASVARI LELLE, BALOGH, MARIA, HERMECZ, ISTVAN, HORVATH, AGNES, KERESZTURI, GEZA, KOVACS, GABOR, MESZAROS, ZOLTAN (DECEASED), PAJOR, ANIKO, RITLI, PETER, SIPOS, JUDIT, VASVARI, LELLE
Applicants: CHINOIN GYOGYSZERRES VEGYESZET, MESZAROS MARTA LEGAL HEIR AND, MESZAROS ZOLTANNE LEGAL HEIR A, CHINOIN GYOGYSZERRES VEGYESZETI TERMEKEK GYARA RT., MESZAROS, MARTA (LEGAL HEIR AND REPRESENTATIVE OF, MESZAROS, ZOLTANNE (LEGAL HEIR AND REPRESENTATIVE
Application year: 1986
Main classification: C07F5
IPC codes: C07D215, C07F5