反应详情

To a solution of benzhydryl 7-amino-3-vinyl-3-cephem-4-carboxylate hydrochloride (1.9 g) and trimethylsilylacetamide (4.6 g) in ethyl acetate (30 ml) was added at -30° C. a solution of the activated acid, which was prepared by stirring a mixture of 2-(2-formamidothiazol-4-yl)-2-methoxyiminoacetic acid (syn isomer) (1.1 g), phosphorus oxychloride (0.81 g), N,N-dimethylformamide (0.39 g) and ethyl acetate (20 ml) for half an hour under ice-cooling, and the mixture was stirred at -30° to -10° C. for an hour. After addition of ethyl acetate (100 ml) and water (50 ml), the organic layer was separated out, washed with a saturated aqueous solution of sodium bicarbonate and an aqueous solution of sodium chloride, dried over anhydrous magnesium sulfate and then evaporated to dryness to give benzhydryl 7-[2-(2-formamidothiazol-4-yl)-2-methoxyiminoacetamido]-3-vinyl-3-cephem-4-carboxylate (syn isomer) (2.4 g).

1. customwas prepared
2. temperaturecooling
3. stirringthe mixture was stirred at -30° to -10° C. for an hour
4. customthe organic layer was separated out
5. washwashed with a saturated aqueous solution of sodium bicarbonate
6. dry with materialan aqueous solution of sodium chloride, dried over anhydrous magnesium sulfate
7. customevaporated to dryness