反应详情

To a suspension of pyridine-phosphorus pentachloride complex prepared from pyridine (48 g) and phosphorus pentachloride (12.7 g) in methylene chloride (120 ml) was added benzhydryl 7-phenylacetamido-3-[2-(2-pyridyl)vinyl]-3-cephem-4-carboxylate (trans isomer) (12 g) under ice-cooling with stirring. The mixture was stirred at the same temperature for 30 minutes and poured into methanol (90 ml) at -25° C. The mixed solution was further stirred at -5° to -15° C. for 10 minutes and then was evaporated under reduced pressure. To the residue was added a mixture of tetrahydrofuran (200 ml), ethyl acetate (200 ml) and water (200 ml) and the mixture was adjusted to pH 6.5 with a saturated aqueous solution of sodium bicarbonate. The separated organic layer was washed with brine, dried over magnesium sulfate and evaporated to give benzhydryl 7-amino-3-[2-(2-pyridyl)vinyl]-3-cephem-4-carboxylate (trans isomer) (6.6 g).

1. additionTo a suspension of pyridine-phosphorus pentachloride complex
2. temperaturecooling
3. stirringThe mixture was stirred at the same temperature for 30 minutes
4. stirringThe mixed solution was further stirred at -5° to -15° C. for 10 minutes
5. customwas evaporated under reduced pressure
6. additionTo the residue was added
7. additiona mixture of tetrahydrofuran (200 ml), ethyl acetate (200 ml) and water (200 ml)
8. washThe separated organic layer was washed with brine
9. dry with materialdried over magnesium sulfate
10. customevaporated