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

HRID 1448920Notes

Reaction equation

HRID 1448920 reaction equation
[CH:1]([CH:3]=[CH2:4])=[O:2].[CH3:5][CH:6]=[C:7](N1CCCC1)[CH2:8][CH3:9]>C1C=CC=CC=1>[CH3:4][C:3]1[C:1](=[O:2])[CH:6]([CH3:5])[CH2:7][CH2:8][CH:9]=1

Participants

4

Reactant 2

HCID 7847AcroleinHCID 1395741-(1-Ethylpropenyl)pyrrolidine

Product 1

HCID 110946032,6-dimethyl-2-cyclohexen-1-oneYield 60%

Reagents, catalysts & solvents 1

HCID 241BenzeneSolvent

Procedure

19.6 g (0.35 mole) of freshly distilled acrolein is added dropwise at a maximum of 50° C., with ice-cooling, to a solution of 27.8 g (0.2 mole) of N-(3-pent-2-enyl)-pyrrolidine in 50 ml of benzene. After completion of the addition, the mixture is stirred overnight at room temperature; it is subsequently heated for 2 hours at 50°-55° C. and then concentrated by evaporation. The oil remaining is dissolved in 250 ml of 20% hydrochloric acid and the solution is stirred overnight. Extraction is then performed five times with ether; the combined extracts are dried over magnesium sulphate and the ether is distilled off. The crude 2,6-dimethyl-cyclohex-2-en-1-one remaining is purified by vacuum distillation. There is obtained 14.8 g (60% of theory) of 2,6-dimethyl-cyclohex-2-en-1-one, b.p. 62°-64° C./ 10 Torr.

Workup

  1. additionAfter completion of the addition
  2. temperatureit is subsequently heated for 2 hours at 50°-55° C.
  3. concentrationconcentrated by evaporation
  4. dissolutionThe oil remaining is dissolved in 250 ml of 20% hydrochloric acid
  5. stirringthe solution is stirred overnight
  6. extractionExtraction
  7. dry with materialthe combined extracts are dried over magnesium sulphate
  8. distillationthe ether is distilled off
  9. distillationThe crude 2,6-dimethyl-cyclohex-2-en-1-one remaining is purified by vacuum distillation

Sources & evidence

ORD record
ord-6bb880d2b62a460fa3b30e76cf8cbed9
Source dataset
uspto-grants-1980_02
Patent number
US04188341

Reaction notes

Loading…