反应详情

To a solution of benzhydryl 7-[2-tert-butoxycarbonylmethoxyimino-2-(2-formamidothiazol-4-yl)acetamido]-3-vinyl-3-cephem-4-carboxylate (syn isomer) (2.5 g) in anisole (2.5 ml) and methylene chloride (5.0 ml) was added trifluoroacetic acid (10.0 ml) under ice-cooling, and the mixture was stirred at ambient temperature for 2 hours. To the reaction mixture was added dropwise diisopropyl ether, and the precipitated crystals were collected by filtration, washed with diisopropyl ether to obtain 7-[2-carboxymethoxyimino-2-(2-formamidothiazol-4-yl)acetamido]-3-vinyl-3-cephem-4-carboxylic acid (syn isomer) (1.57 g).

1. temperaturecooling
2. filtrationthe precipitated crystals were collected by filtration
3. washwashed with diisopropyl ether