Target 4-cyclopropyl-7-fluoro-6-(4-methylpiperazin-1-yl)-1,2,4,9-tetrahydrothiazolo[5,4-b]quinoline-2,9-dione (5a) was obtained from 3-amino-1-cyclopropyl-6-fluoro-7-(4-methylpiperazin-1-yl)-2-mercaptoquinolin-4(1H)-one (9b). This intermediate was obtained from 3-amino-1-cyclopropyl- 6,7-difluoro-2-(methylsulfinyl)quinolin-4(1H)-one (9f) via 3-amino-1-cyclopropyl-6-fluoro-7-(4-methylpiperazin-1-yl)-2-(methylsulfinyl)quinolin-4(1H)-one (9c). Compound 9f was prepared from 2,4,5-trifluoroacetophenone (6a) in several steps. 4-Cyclopropyl-6,7-difluoro-2,3,4,9-tetrahydrothiazolo[5,4-b]quinoline-3,4-dione (5b) was prepared similarly as the target compound. Treatment of 5b with N-methylpiperazine did not afford 5a but 1-cyclopropyl-6,7-difluoro-2-mercapto-3-[(4-methylpiperazin-1-yl)carbonylamino]quinolin-4(1H)-one (11). Several unsuccessful attempts to prepare compound 5a and/or some useful intermediates of its synthesis are also described.
目标化合物4-环丙基-7-氟-6-(4-甲基哌嗪-1-基)-1,2,4,9-四氢噻唑并[5,4-b]喹啉-2,9-二酮(5a)是从3-氨基-1-环丙基-6-氟-7-(4-甲基哌嗪-1-基)-2-巯基喹啉-4(1H)-酮(9b)得到的。该中间体是从3-氨基-1-环丙基-6,7-二氟-2-(甲磺酰氧基)喹啉-4(1H)-酮(9f)通过3-氨基-1-环丙基-6-氟-7-(4-甲基哌嗪-1-基)-2-(甲磺酰氧基)喹啉-4(1H)-酮(9c)制备而来。化合物9f是从2,4,5-三氟乙酮(6a)经过多步反应制备而成。类似地合成了目标化合物4-环丙基-6,7-二氟-2,3,4,9-四氢噻唑并[5,4-b]喹啉-3,4-二酮(5b)。用N-甲基哌嗪处理5b未能得到5a,而是得到了1-环丙基-6,7-二氟-2-巯基-3-[(4-甲基哌嗪-1-基)甲酰氨基]喹啉-4(1H)-酮(11)。还描述了几次未能成功制备化合物5a和/或其合成中有用的中间体的尝试。