反应详情

2-(2-Chloro-4,5-difluorobenzoyl)-3-ethoxy-2-propenoic acid ethyl ester (material from preceding preparation) was mixed with isopropyl alcohol (250 ml) and cooled to 0°. 4-Fluoroaniline (9.33 g, 84.0 mmol) was added, and the reaction mixture was allowed to warm to room temperature and stir for 18 hours. The precipitate was filtered and washed with isopropyl ether, yielding the title product (11.0 g, 28.7 mmol). Additional product (10.2 g, 26.6 mmol, 73% overall yield for two steps) was obtained from the filtrate, which was concentrated in vacuo and subjected to column chromatography (eluting with chloroform), providing material was was further purified by recrystallization from ether/hexanes.

1. temperaturecooled to 0°
2. filtrationThe precipitate was filtered
3. washwashed with isopropyl ether