反应详情

Employing ethyl 2-(2-methyl-3,4,5,6-tetrafluorobenzoyl)-3-ethoxyacrylate (10.0 g) and ethylamine gas, the procedure of Reference Example 21 is repeated to give ethyl 2-(2-methyl-3,4,5,6-tetrafluorobenzoyl)-3-ethylaminoacrylate (9.0 g, white crystals), which is then treated with 60% sodium hydride (1.30 g) as in Reference Example 22 to give ethyl 1-ethyl-5-methyl-6,7,8-trifluoro-1,4-dihydro-4-oxoquinoline-3-carboxylate (6.76 g), as pale yellow needles (recrystallized from dichloromethane - n-hexane), m.p. 197°-198° C.