反应详情

Benzhydryl 7-(2-thienylacetamido)-3-cephem-4-carboxylate (2.45 g. 5 mmol) was dissolved in calcium hydride dried benzene (130 ml) containing dry pyridine (0.59 g, 7.4 mmol). The solution was maintained at 0° and PCl5 (1.54 g. 7.4 mmol.) was added with stirring. The reaction mixture was stirred under nitrogen at 0° for 3 hours and then the solvent was removed in vacuo. Anhydrous methanol (260 ml) was added to the residue and the resultant mixture was allowed to stand 2 hours. The methanol was removed in vacuo and the residue was treated with 20% aqueous tetrahydrofuran. After 15 minutes the tetrahydrofuran was removed in vacuo and the aqueous residue was adjusted to pH 7.5 and extracted with ethyl acetate. The extracts were washed with water, dried over MgSO4 and evaporated to give the solid product which was triturated with chloroform-petroleum ether and dried under high vacuum.

1. temperatureThe solution was maintained at 0°
2. stirringThe reaction mixture was stirred under nitrogen at 0° for 3 hours
3. customthe solvent was removed in vacuo
4. additionAnhydrous methanol (260 ml) was added to the residue
5. customThe methanol was removed in vacuo
6. additionthe residue was treated with 20% aqueous tetrahydrofuran
7. customAfter 15 minutes the tetrahydrofuran was removed in vacuo
8. extractionextracted with ethyl acetate
9. washThe extracts were washed with water
10. dry with materialdried over MgSO4
11. customevaporated
12. customto give the solid product which
13. customwas triturated with chloroform-petroleum ether
14. customdried under high vacuum