反应详情

To a solution of benzhydryl 7-[2-methoxyimino-2-(2-formamidothiazol-4-yl)acetamido]-3-(2,2-dibromovinyl)-3-cephem-4-carboxylate (syn isomer) (1 g) in methanol (5 ml) was added conc. hydrochloric acid (0.5 ml) and the resulting mixture was stirred at ambient temperature for 2 hours. Then, the reaction mixture was poured into ice-water and adJusted to pH 3.5 with a saturated aqueous solution of sodium bicarbonate. The precipitate was collected by filtration, dried and dissolved in a mixture of trifluoroacetic acid (5 ml) and anisole (0.5 ml) at ambient temperature. After trifluoroacetic acid was evaporated in vacuo, the residue was added to a mixture of ethyl acetate and water and adJusted to pH 3.0 with a saturated aqueous solution of sodium bicarbonate. The separated organic layer was evaporated to give 7-[2-methoxyimino-2-(2-aminothiazol-4-yl)acetamido]-3-(2,2-dibromovinyl)-3-cephem-4-carboxylic acid (syn isomer) (0.35 g).

1. filtrationThe precipitate was collected by filtration
2. customdried
3. dissolutiondissolved in a mixture of trifluoroacetic acid (5 ml) and anisole (0.5 ml) at ambient temperature
4. customAfter trifluoroacetic acid was evaporated in vacuo
5. additionthe residue was added to a mixture of ethyl acetate and water
6. customThe separated organic layer was evaporated