Hydrochloric Acid → 2,6-Diethyl-2,3,6-trimethylpiperidin-4-one

Participants

Reaction Steps

19.6 g of 2,4,6-triethyl-2,6-dimethyl-1,2,5,6-tetrahydropyrimidine and 0.4 g of ammonium bromide were added to 200 ml of methanol, and 10 g of 37% hydrochloric acid were added dropwise to the resulting mixture at 10° C, under stirring. After completion of the addition, the mixture was stirred at room temperature for 4 hours, and then 20 ml of 18% hydrochloric acid were added dropwise to it. The mixture was then heated at 30°- 40° C for 7 hours and allowed to stand overnight at room temperature. The mixture was made alkaline with 40% aqueous potassium carbonate solution; and, after the methanol had been evaporated off under reduced pressure, the mixture was extracted with diethyl ether. The extract was dried over potassium carbonate and the ether was removed. The residue was subjected to distillation under reduced pressure, to give 15.1 g of the desired compound as an oil boiling at 91°- 93° C/2.0 mmHg.

Provenance & Evidence