反应详情

A solution of 2-dichloroacetoxyimino-(thien-2-yl)acetyl chloride (syn-isomer) in ethyl acetate (300 ml.) was added to a stirred solution of t-butyl 3-acetoxymethyl-7β-aminoceph-3-em-4-carboxylate (43 g) and propylene oxide (34 ml.) in ethyl acetate (400 ml.) at 20°. Initially a solid precipitated out but it gradually redissolved. The temperature was maintained between 20° and 30° by alternately cooling and warming the solution. After 4 hours the solution was washed with 2 N-hydrochloric acid, saturated sodium bicarbonate solution, water and brine, and was dried and concentrated under reduced pressure to give the title ester as an oil that was used directly in the next stage.

1. customInitially a solid precipitated out
2. dissolutionit gradually redissolved
3. temperatureThe temperature was maintained between 20° and 30°
4. temperatureby alternately cooling
5. temperaturewarming the solution
6. washAfter 4 hours the solution was washed with 2 N-hydrochloric acid, saturated sodium bicarbonate solution, water and brine
7. customwas dried
8. concentrationconcentrated under reduced pressure