反应详情

Trifluoroacetic acid (3.6 ml) was added to a suspension of 7-[2-tert-butoxycarbonylmethoxyimino-2-(1,2,4-thiadiazol-3-yl)acetamido]-3-cephem-4-carboxylic acid (syn isomer) (1.2 g) in anisole (1.2 ml), and the mixture was stirred for 2 hours at ambient temperature. The resultant solution was added dropwise to diisopropyl ether (100 ml) and the precipitates were collected by filtration. The precipitates were added to a mixture of water (50 ml) and ethyl acetate (50 ml) and adjusted to pH 6.5 with 5% aqueous sodium bicarbonate. The separated aqueous layer was adjusted to pH 2.5 with 10% hydrochloric acid and extracted with ethyl acetate. The extract was washed with water, dried over magnesium sulfate and then evaporated to give 7-[2-carboxymethoxyimino-2-(1,2,4-thiadiazol-3-yl)acetamido]-3-cephem-4-carboxylic acid (syn isomer) (0.5 g).

1. filtrationthe precipitates were collected by filtration
2. additionThe precipitates were added to a mixture of water (50 ml) and ethyl acetate (50 ml)
3. extractionextracted with ethyl acetate
4. washThe extract was washed with water
5. dry with materialdried over magnesium sulfate
6. customevaporated