反应详情

Triethylamine (2.37 g.), dimethylaniline (7.12 g.) and trimethylsilyl chloride (3.93 g.) were added to a stirred suspension of 4-nitrobenzyl 7-(2-phenylacetamido)-3-hydroxy-3-cephem-4-carboxylate (10 g.) in methylene chloride (200 ml.) in turn, and the solution was stirred at room temperature for an hour. Phosphorus pentachloride (4.88 g.) was added to the solution at -30° to -25° C. and stirred at -25° to -20° C. for 3 hours. Methanol (42 ml.) was added to the solution at -25° to -20° C., and stirred for an hour. To the solution was added water (35 ml.) at -25° to -20° C., and the solution was stirred at room temperature. The precipitates were collected by filtration, washed with methylene chloride and diethyl ether in turn, and dried to give 4-nitrobenzyl 7-amino-3-hydroxy-3-cephem-4-carboxylate (5.2 g.), mp 148° C. (dec.).

1. stirringstirred at -25° to -20° C. for 3 hours
2. stirringstirred for an hour
3. stirringthe solution was stirred at room temperature
4. filtrationThe precipitates were collected by filtration
5. washwashed with methylene chloride and diethyl ether in turn
6. customdried