反应详情

To a suspension of phosphorus pentachloride (13.74 g) in dichloromethane (150 ml) was dropwise added pyridine (5.34 ml) at -15° to -10° C. under stirring which was continued at the same temperature for 30 minutes. To the above mixture was added benzhydryl 7-phenylacetoamido-3-(2,2-dibromovinyl)-2-cephem-4-carboxylate (29.4 g) at -5° C. After the reaction mixture was stirred at -5° for 1.5 hours, methanol (26.62 ml) was dropwise added to the reaction mixture under cooling at -20° and the mixture was stirred at -20° C. to -5° C. for 1.5 hours. Then water (30 ml) was added to the reaction mixture under ice-cooling. After the reaction mixture was stirred for an hour at the same temperature, diisopropylether (100 ml) was added to the reaction mixture at 0° C. The resultant precipitates were collected by filtration and washed in turn with water and diisopropyl ether to give benzhydryl 7-amino-3-(2,2-dibromovinyl)-2-cephem-4-carboxylate hydrochloride (25.23 g).

1. customat -15° to -10° C.
2. stirringAfter the reaction mixture was stirred at -5° for 1.5 hours
3. temperatureunder cooling at -20°
4. stirringthe mixture was stirred at -20° C. to -5° C. for 1.5 hours
5. temperaturecooling
6. additionwas added to the reaction mixture at 0° C
7. customThe resultant precipitates
8. filtrationwere collected by filtration
9. washwashed in turn with water and diisopropyl ether