反应详情

A solution of 1,3-dicarbomethoxy-3-methyl-4-piperidone (51.45 g, 225 mmol) in hydrobromic acid (48%, 250 mL) is heated under reflux for 4 h and then cooled to room temperature. The resultant solution is concentrated in vacuo to give an orange colored solid. The solid is suspended in methanol (50 mL) and concentrated in vacuo again to give 3-methyl-4-piperidone hydrobromide salt: 42.9 g; 98%; mp 203°-205° C.

1. temperatureunder reflux for 4 h
2. concentrationThe resultant solution is concentrated in vacuo
3. customto give an orange colored solid
4. concentrationconcentrated in vacuo again