反应详情

10 g of the formate solvate of the syn isomer of 3-acetoxymethyl-7-[2-(2-amino-4-thiazolyl)-2-methoxyimino-acetamido]-ceph-3-eme-4-carboxylic acid (described in Belgium Pat. No. 850,662) were added at room temperature to a solution of 3.5 g of sodium acetate in 5 ml of water and 300 ml of ethanol and when dissolution was complete, the mixture was filtered. The filtrate was added dropwise over one hour with stirring at room temperature to 160 ml of absolute ethanol and the resulting mixture was stirred at room temperature for 3 hours and at 0° C. for 16 hours. The mixture was vacuum filtered and the crystals were washed with ethanol and dried under reduced pressure to obtain 7.75 g of the crystalline D form of the syn isomer of sodium 3-acetoxymethyl-7-[2-(2-amino-4-thiazolyl)-2-methoxyimino-acetamido]-ceph-3-eme-4-carboxylate containing 0.95% of water.

1. filtrationthe mixture was filtered
2. additionThe filtrate was added dropwise over one hour
3. stirringthe resulting mixture was stirred at room temperature for 3 hours and at 0° C. for 16 hours
4. filtrationfiltered
5. washthe crystals were washed with ethanol
6. customdried under reduced pressure