反应详情

A mixture of 7-[2-(2-formamidothiazol-4-yl)-2-(2-tert-butoxycarbonylaminoethoxyimino)acetamido]3-cephem-4-carboxylic acid (syn isomer, 0.70 g.), conc. hydrochloric acid (0.48 g.) and methanol (7 ml.) was stirred at room temperature for 4 hours. After concentrating the resultant solution in vacuo, the residue was dissolved in methanol (10 ml.) and crystallized by adding diisopropyl ether (20 ml.). The precipitates were collected by filtration, washed with a mixture of methanol and diisopropyl ether (1:1) and dried to give 7-[2-(2-aminothiazol-4-yl)-2-(2-aminoethoxyimino)acetamido]-3-cephem-4-carboxylic acid dihydrochloride (syn isomer, 0.58 g.).

1. concentrationAfter concentrating the resultant solution in vacuo
2. dissolutionthe residue was dissolved in methanol (10 ml.)
3. customcrystallized
4. additionby adding diisopropyl ether (20 ml.)
5. filtrationThe precipitates were collected by filtration
6. washwashed with a mixture of methanol and diisopropyl ether (1:1)
7. customdried