反应详情

A mixture of ethyl 6-(5-chloro-2-thienyl)-6-oxo-5-phenoxycarbonyloxyhexanoate (30.5 g), ammonium acetate (28.6 g) and acetic acid (100 ml) was stirred with heating under reflux for 2 hours. The reaction mixture was poured into 500 ml of water, and the resulting solid precipitate was collected, washed with water and isopropyl ether and air-dried to give crystals of ethyl 4-[4-(5-chloro-2-thienyl)-2-oxo-4-oxazolin-5-yl]butanoate (13.6 g, 58%). Recrystallization from acetone-isopropyl ether gave pale yellow prisms. Melting point 95-96° C.

1. temperaturewith heating
2. temperatureunder reflux for 2 hours
3. customthe resulting solid precipitate was collected
4. washwashed with water and isopropyl ether
5. customair-dried