反应详情

温度

-30 °C

To a solution of 3-p-toluenesulfonyloxy-7beta-phenylacetylaminocepham-4-carboxylic acid diphenylmethyl ester (3d) in dichloromethane (7 parts) cooling at -25° to -20° C. under nitrogen are added pyridine (2 equivalents) and phosphorus pentachloride (1.7 equivalents). After stirring at -15° to -10° C. for 4 hours, the mixture is diluted with methanol (12 parts) cooled at -30° C., stirred at -30° to -25° C. for 30 minutes and at 0° to 5° C. for 2 hours. The reaction mixture is diluted with dichloromethane and ice-water and stirred at 0° to 5° C. for 20 minutes. The formed organic layer is taken, washed with water, dried, and concentrated. The residue is crystallized from dichloromethane-ether mixture to give 3-p-toluenesulfonyloxy-7beta-aminocepham-4-carboxylic acid diphenylmethyl ester (4d) p-toluenesulfonate salt. mp. 190°-194° C. (decomposition).

1. stirringstirred at -30° to -25° C. for 30 minutes and at 0° to 5° C. for 2 hours
2. stirringstirred at 0° to 5° C. for 20 minutes
3. washwashed with water
4. customdried
5. concentrationconcentrated
6. customThe residue is crystallized from dichloromethane-ether mixture