The title compound 1-ethyl-6-fluoro-7-(1-pyrrol-1-yl)-1,4-dihydro-4-oxoquinoline-3-carboxylic acid is a quinolone carboxylic acid derivative of "oxacin" family bearing a fluorine atom and a pyrrol-1-yl moiety at 6 and 7 position respectively. It is represented by the following formula:
and has been prepared by alkaline hydrolysis of the corresponding ethyl ester. The latter compound has been synthesized starting from 2-fluoro-5-nitroaniline. Treatment of this amine with diethoxytetrahydrofuran in glacial acetic acid afforded 4-fluoro-3-(1-H-pyrrol-1-yl)-nitrobenzene, which was then reduced by catalytic hydrogenation to 4-fluoro-3-(1 H-pyrrol-1-yl)aniline.
Reaction of this compound with diethyl ethoxymethylene malonate and cyclization of the malonate obtained by heating in diphenyl ether at 120°C resulted in formation of ethyl ester of 6-fluoro-7-(1H-pyrrol-1-yl)quinoline-3-carboxylic acid. Ethylation of this ester with ethyl iodide in the presence of sodium carbonate gave the required 1-ethyl-6-fluoro-7-(1H-pyrrol-1-yl)-1,4-dihydro-4-oxoquinoline-3-carboxylic acid ethyl ester.
The title acid exhibits high activity against Gram-positive bacteria, Enterobacteriaceae, Proteus and Pseudomonas, superior to those of nalidixic acid, piromidic acid and pipemidic acid; again, its antimicrobial spectrum is somewhat superior also to that of enoxacin.
1-Ethyl-6-fluoro-7-(1H-pyrrol-1-yl)-1,4-dihydro-4-oxo- quinoline-3-carboxylic acid is a new potent fluorinated quinolone antibacterial agent useful in the management of urinary tract and systemic infections.
The present invention also relates to a process for the preparation of such compound.
标题化合物 1-乙基-6-
氟-7-(1-
吡咯-1-基)-1,4-二氢-4-氧代
喹啉-3-羧酸是一种 "氧杂
喹啉 "家族的
喹啉酮羧酸衍
生物,其 6 位和 7 位分别含有一个
氟原子和一个
吡咯-1-基分子。其分子式如下
并通过碱
水解相应的
乙酯制备而成。后一种化合物是从
2-氟-5-硝基苯胺开始合成的。用
冰醋酸中的二乙氧基
四氢呋喃处理这种胺,可得到 4-
氟-3-(1-H-
吡咯-1-基)-
硝基苯,然后通过催化氢化还原成 4-
氟-3-(1-H-
吡咯-1-基)
苯胺。
将这种化合物与
乙氧基亚甲基丙二酸二乙酯反应,并在 120°C 的
二苯醚中加热使
丙二酸二乙酯环化,生成 6-
氟-7-(1H-
吡咯-1-基)
喹啉-3-羧酸乙酯。在
碳酸钠存在下,用
碘化
乙酯对该酯进行
乙酯化反应,得到了所需的 1-乙基-6-
氟-7-(1H-
吡咯-1-基)-1,4-二氢-4-氧代
喹啉-3-羧酸乙酯。
标题酸对革兰氏阳性菌、肠杆菌科、变形杆菌和假单胞菌具有较高的活性,优于
萘啶酸、
吡咯咪啶酸和
哌啶咪啶酸;其抗菌谱也略优于
恩诺沙星。
1-乙基-6-
氟-7-(1H-
吡咯-1-基)-1,4-二氢-4-氧代-
喹啉-3-羧酸是一种新型强效
氟化喹诺
酮类抗菌剂,可用于治疗尿路感染和全身感染。
本发明还涉及一种制备这种化合物的工艺。