反应详情

To a solution of benzhydryl 7-amino-3-vinyl-3-cephem-4-carboxylate hydrochloride (6.4 g) and timethylsilylacetamide (9.8 g) in ethyl acetate (80 ml) was added 4-bromo-3,3-diethoxy-2-methoxyiminobutyryl chloride (syn isomer) (5.0 g) at -20° C. with stirring, and the stirring was continued at -20° to 5° C. for an hour. To the reaction mixture were added ethyl acetate and water, and the separated ethyl acetate solution was washed with a saturated aqueous sodium bicarbonate and an aqueous sodium chloride, followed by drying over anhydrous magnesium sulfate. Removal of the solvent gave benzhydryl 7-(4-bromo-3,3-diethoxy-2-methoxyiminobutyramido)-3-vinyl-3-cephem-4-carboxylate (syn isomer) (10.1 g).

1. waitthe stirring was continued at -20° to 5° C. for an hour
2. washthe separated ethyl acetate solution was washed with a saturated aqueous sodium bicarbonate
3. dry with materialby drying over anhydrous magnesium sulfate
4. customRemoval of the solvent