反应详情

A solution of the hydrochloride (80 g) of methyl 2-(p-methoxybenzyl)-4-oxo-1,3,3-trimethyl-5-piperidinecarboxylate in 450 ml of 1 N hydrochloric acid is refluxed for 12 hours. After cooling, some resinous material is removed by extraction with ether. Alkalinization of the aqueus solution with the aid of ammonia causes the separation of the piperidone which is extracted with ether. Concentration in vacuo of the extent gives a residue which is dissolved in ethanolic hydrogen chloride. Evaporation of the ethanol leaves a syrupy residue which is dissolved in acetone, whereafter the crystalline hydrochloride separates. Yield 87%. Melting point 168° - 170° C, with decomposition.

1. temperatureAfter cooling
2. customsome resinous material is removed by extraction with ether
3. customthe separation of the piperidone which
4. extractionis extracted with ether
5. concentrationConcentration in vacuo of the extent
6. customgives a residue which
7. customEvaporation of the ethanol
8. customleaves a syrupy residue which