反应详情

A mixture comprising ethyl 2-(4,6-dibromo-3-fluoro-2-methylbenzoyl)-3-cyclopropylaminoacrylate (45.0 g), potassium carbonate (16.7 g) and dimethylformamide (450 ml) is reacted at 140° C. for 30 minutes. After cooling, the reaction mixture is poured into ice-water and the precipitated crystals are filtered, which are recrystallized from ethanol to give ethyl 1-cyclopropyl-6-fluoro-7-bromo-5-methyl-1,4-dihydro-4-oxoquinoline-3-carboxylate (33.6 g), as white crystals, m.p. 195°-197° C.

1. temperatureAfter cooling
2. filtrationthe precipitated crystals are filtered
3. customwhich are recrystallized from ethanol