反应详情

A solution of ethyl 2-benzyloxyimino-4-chloro-3-oxobutyrate (syn isomer, 51.4 g.), thiourea (17.5 g.) and sodium acetate (31.3 g.) in a mixture of water (130 ml.) and ethanol (130 ml.) was stirred at 40° to 45° C. for 2.5 hours. The resultant solution was adjusted to pH 6.5 with aqueous sodium bicarbonate and the precipitates were collected by filtration and washed with diisopropyl ether to give ethyl 2-(2-aminothiazol-4-yl)-2-benzyloxyiminoacetate (syn isomer, 39.78 g.).

1. filtrationthe precipitates were collected by filtration
2. washwashed with diisopropyl ether