反应详情

An excess of an ethereal diazomethane solution was added to an ice-cooled suspension of 5 gm of 7-benzamido-3-methyl-3-cephem-4-carboxylic acid-1-oxide in 150 ml of dichloromethane and the mixture was stirred for half an hour. Then, excess diazomethane was destroyed with acetic acid and methanol was added. The mixture was evaporated to dryness in vacuo and the residue was crystallized from methanol to obtain 4.5 gm (86.6% yield) of methyl 7-benzamido-3-methyl-3-cephem-4-carboxylate-1-oxide.

1. temperaturecooled
2. customThen, excess diazomethane was destroyed with acetic acid and methanol
3. additionwas added
4. customThe mixture was evaporated to dryness in vacuo
5. customthe residue was crystallized from methanol