The present invention relates to novel quinolone carboxylic acid derivatives having useful antibacterial activities of formula (I): ##STR1## wherein, R.sub.1, R.sub.2, and R.sub.3, which may be the same or different, are each hydrogen or a halogen atom, or a lower alkyl group optionally substituted with an amino or a hydroxy group; R.sub.4 is hydrogen atom, a lower alkyl, benzyl, t-butoxycarbonyl or ethoxycarbonyl group; R.sub.5 is hydrogen, chlorine atom, methyl or an amino group; R.sub.6 is a lower alkyl group, or a cyclopropyl or a phenyl group optionally substituted with a halogen atom; and X is a methyne group optionally substituted with a lower alkyl or a lower alkoxy group or a halogen atom, and pharmaceutically acceptable salts thereof, and processes for preparing these compounds. The present invention also relates to novel intermediates which are useful for preparing the quinolone compounds of the invention.
本发明涉及具有有用抗菌活性的新型喹诺
酮羧酸衍
生物,其
化学式为(I):其中,R.sub.1、R.sub.2和R.sub.3,可以相同也可以不同,分别是氢原子或卤素原子,或一个辅以
氨基或羟基的较低烷基基团;R.sub.4是氢原子,一个较低烷基、苄基、叔丁氧羰基或乙氧羰基基团;R.sub.5是氢、
氯原子、甲基或
氨基基团;R.sub.6是一个较低烷基基团,或一个环丙基或苯基,可选地辅以卤素原子;X是一个亚甲基基团,可选地辅以一个较低烷基或一个较低烷氧基团或一个卤素原子,以及这些化合物的药用盐,以及制备这些化合物的方法。本发明还涉及用于制备本发明的
喹诺酮化合物的新型中间体。