CC([O:4][CH2:5][C:6]1[CH2:15][S:14][C@@H:9]2[C@H:10]([NH2:13])[C:11](=[O:12])[N:8]2[C:7]=1[C:16]([OH:18])=[O:17])=O.[OH-].[Na+].Cl>O>[NH2:13][C@@H:10]1[C:11](=[O:12])[N:8]2[C:7]([C:16]([OH:18])=[O:17])=[C:6]([CH2:5][OH:4])[CH2:15][S:14][C@H:9]12In 100 ml of water was suspended 10 g of 7-aminocephalosporanic acid (hereinafter abbreviated as "7-ACA"). The pH of the suspension was maintained at 12.5 to 13.4 by gradual addition of 2N-sodium hydroxide solution under ice-cooling and stirring. The mixture was further stirred for 2 hours, and adjusted to pH 3.4 with 4N-hydrochloric acid after confirming the disappearance of the starting material (7-ACA) by TLC. The precipitating crystals were collected by filtration, washed with water and acetone and dried over phosphorus pentoxide under reduced pressure to give 5.4 g of 7β-amino-3-hydroxymethyl -3-cephem-4-carboxylic acid as pale yellow crystals.
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