Acrolein → 2,6-dimethyl-2-cyclohexen-1-one

26.1 g (0.168 mole) of N-(3-pent-2-enyl)-morpholine is slowly added dropwise to a solution, cooled to 0°, of 16.8 g (0.3 mole) of freshly distilled acrolein in 150 ml of dioxane, with the temperature rising to 5° C. After completion of the addition, stirring is maintained for half an hour with ice-cooling, and the mixture is then allowed to stand overnight. The solvent is afterwards evaporated off and the oil obtained as residue is dissolved in 120 ml of 20% aqueous hydrochloric acid. On stirring of the acidified solution at room temperature, there precipitates an oil which, after one to two days' stirring, is taken up in ether. The aqueous phase is extracted a further five times with ether. The combined ether phases are dried over magnesium sulphate and the ether is distilled off. There is obtained 18.5 g of crude 2,6-dimethyl-cyclohex-2-en-1-one in the form of oil, which yields, after distillation in a water-jet vacuum, 15.0 g of 2,6-dimethyl-cyclohex-2-en-1-one (72% of theory); b.p. 62°-63° C./ 10 Torr.

1. customrising to 5° C
2. additionAfter completion of the addition
3. temperatureis maintained for half an hour with ice-
4. temperaturecooling
5. customThe solvent is afterwards evaporated off
6. customthe oil obtained as residue
7. stirringOn stirring of the acidified solution at room temperature
8. customthere precipitates an oil which
9. stirringafter one to two days' stirring
10. extractionThe aqueous phase is extracted a further five times with ether
11. dry with materialThe combined ether phases are dried over magnesium sulphate
12. distillationthe ether is distilled off

ORD record

ord-7d29b098f7de44609908dee574a2fd1a

Source dataset

uspto-grants-1980_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04188341