反应详情

20% Aqueous solution of sodium hydroxide was added to a suspension of 7-[2-(2-aminothiazol-4-yl)-2-methoxyiminoacetamido]-3-cephem-4-carboxylic acid (syn isomer, 15 g.) in a mixture of ethanol (8 ml.) and water (8 ml.) at room temperature to make a solution of pH 7.5. After filtration and washing, the filtrate and washings were combined (which contained 18.3 ml. of water) and added dropwise to ethanol (46 ml.) at 20° to 25° C. under stirring and stirred at the same temperature for 30 minutes. Ethanol (28 ml.) was added dropwise to the mixture over 30 minutes, and stirred at the same temperature for 2 hours. The precipitates were collected by filtration, washed with ethanol (20 ml.) and dried in vacuo at room temperature to give plates of sodium 7-[2-(2-aminothiazol-4-yl)-2-methoxyiminoacetamido]-3-cephem-4-carboxylate dihydrate (syn isomer, 13.5 g.), mp 160° C. (dec.).

1. filtrationAfter filtration
2. washwashing
3. additionadded dropwise to ethanol (46 ml.) at 20° to 25° C.
4. stirringstirred at the same temperature for 30 minutes
5. additionEthanol (28 ml.) was added dropwise to the mixture over 30 minutes
6. stirringstirred at the same temperature for 2 hours
7. filtrationThe precipitates were collected by filtration
8. washwashed with ethanol (20 ml.)
9. customdried in vacuo at room temperature