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

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.

1. additionwere added dropwise to the resulting mixture at 10° C
2. additionAfter completion of the addition
3. stirringthe mixture was stirred at room temperature for 4 hours
4. temperatureThe mixture was then heated at 30°- 40° C for 7 hours
5. customand, after the methanol had been evaporated off under reduced pressure
6. extractionthe mixture was extracted with diethyl ether
7. dry with materialThe extract was dried over potassium carbonate
8. customthe ether was removed
9. distillationThe residue was subjected to distillation under reduced pressure

ORD record

ord-d8ddd18719d04e5d8966c78cd45ca532

Source dataset

uspto-grants-1977_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04055536