反应详情

To a solution of benzhydryl 7-(4-bromo-3,3-diethoxy-2-methoxyiminobutyramido)-3-vinyl-3-cephem-4-carboxylate (syn isomer) (3.36 g) and anisole (2.1 g) in methylene chloride (20 ml) was added trifluoroacetic acid (8.0 g) under ice-cooling with stirring, and the stirring was continued at ambient temperature for an hour. After removal of the solvent, the residue was dissolved in a mixture of ethyl acetate and water. To the separated ethyl acetate solution was added water, followed by adjusting to pH 7 with a saturated aqueous sodium bicarbonate. To the separated aqueous solution was added ethyl acetate, followed by adjusting to pH 2 with 10% hydrochloric acid. The ethyl acetate layer was separated out, washed with an aqueous sodium chloride and then dried over anhydrous magnesium sulfate. Removal of the solvent gave 7-(4-bromo-2-methoxyiminoacetoacetamido)-3-vinyl-3-cephem-4-carboxylic acid (syn isomer) (1.6 g).

1. temperaturecooling
2. waitthe stirring was continued at ambient temperature for an hour
3. customAfter removal of the solvent
4. dissolutionthe residue was dissolved in a mixture of ethyl acetate and water
5. additionTo the separated ethyl acetate solution was added water
6. additionTo the separated aqueous solution was added ethyl acetate
7. customThe ethyl acetate layer was separated out
8. washwashed with an aqueous sodium chloride
9. dry with materialdried over anhydrous magnesium sulfate
10. customRemoval of the solvent