反应详情

Methyl 3-oxo-7-phthalimidocepham-4-carboxylate (b) thus prepared by above methods is dissolved in dioxane, mixed with a solution of diazomethane in ether, and stirred for 1 hour at room temperature. The reaction mixture is evaporated under reduced pressure to give methyl 3-methoxy-7-phthalimido-3-cephem-4-carboxylate in nearly quantitative yield. Recrystallization from a mixture of acetone and ether gives pure crystals, m.p. 225°-227° C.

1. customThe reaction mixture is evaporated under reduced pressure