反应详情

A mixture of 4-nitrobenzyl 7-[2-ethoxyimino-2-(5-amino-1,2,4-thiadiazol-3-yl)acetamido]-3-cephem-4-carboxylate (syn isomer) (5.0 g) and 10% palladium on carbon (2.5 g) in 70% aqueous tetrahydrofuran (75 ml) was stirred under hydrogen atmosphere for 3 hours at ambient temperature. The catalyst was removed by filtration and the filtrate was concentrated to third volume. The residue was extracted with ethyl acetate and transferred into an aqueous solution of sodium bicarbonate. The aqueous layer was acidified to pH 3 with 10% hydrochloric acid and extracted with ethyl acetate. The extract was dried over magnesium sulfate and concentrated to 10 ml under reduced pressure. The resultant precipitates were collected, washed with ethyl acetate and dried to give 7-[2-ethoxyimino-2-(5-amino-1,2,4-thiadiazol-3-yl)acetamido]-3-cephem-4-carboxylic acid (syn isomer) (1.33 g), mp. 190° to 195° C. (dec.).

1. customThe catalyst was removed by filtration
2. concentrationthe filtrate was concentrated to third volume
3. extractionThe residue was extracted with ethyl acetate
4. extractionextracted with ethyl acetate
5. dry with materialThe extract was dried over magnesium sulfate
6. concentrationconcentrated to 10 ml under reduced pressure
7. customThe resultant precipitates
8. customwere collected
9. washwashed with ethyl acetate
10. customdried