反应详情

To a mixture of 7-aminocephalosporanic acid (23.1 g., purity 86.4%) and 2-mercaptobenzothiazole (14.7 g.) in water (800 ml.), sodium bicarbonate (13.5 g.) was added portionwise with stirring, and acetone (250 ml.) was added thereto. The mixture was stirred at 73° C. for 4.5 hours, cooled below 20° C. and adjusted to pH 3.4 with 6 N hydrochloric acid. The precipitating crystals were collected by filtration, washed with water and acetone in turn and dried under reduced pressure to give 7-amino-3-(benzothiazol-2-yl)thiomethyl-3-cephem-4-carboxylic acid (18.7 g.).

1. additionwas added portionwise
2. stirringThe mixture was stirred at 73° C. for 4.5 hours
3. temperaturecooled below 20° C.
4. filtrationThe precipitating crystals were collected by filtration
5. washwashed with water and acetone in turn
6. customdried under reduced pressure