1-ETHYL-6- NITRO-7- (4-METHYLPIPERAZINYL)- 4-OXO- 1,4-DIHYDROQUINOLINE -3-CARBOXYLIC ACID OR ITS HYDROCHLORIDE SHOWING ANTIBACTERIAL ACTIVITY Russian patent published in 1995 - IPC

FIELD: organic chemistry. SUBSTANCE: synthesis is carried out by boiling of 1-ethyl- 6-nitro-7 -chloro-4-oxo-1,4 -dihydroquinoline-3-carboxylic acid ethyl ester in HCl medium in the presence of CH₃COOH following by isolation of corresponding acid and treatment with N-methylpiperazine at boiling in dimethylformamide medium. Yield is 72%, m. p. is 242-243 C, empirical formula is C₁₇H₂₀N₄O₅. Prepared product is conversed to hydrochloride by treatment with HCl spirituous solution. Yield is 96%, m. p. is 261-262 C, empirical formula is C₁₇H₂₀N₄O₅·HCl. Synthesized product shows antibacterial action against gram-positive, gram-negative bacteria, pathogenic fungi, pathogens of microsporia, trichophytosis, candidosis. Maximal tolerant dose is 0.5-1.25 mcg/ml, toxicity LD₅₀ = 2000 mg/kg (for С₁₇H₂₀N₄O₅) and 1000 mg/kg (for C₁₇H₂N₄O₈·HCl). EFFECT: increased effectiveness of products, improved method of synthesis. 1 dwg, 7 tbl