Hydrochloric Acid → 2-Cyclohexen-1-one, 4,4-dimethyl-

HRID 893420Notes

Reaction equation

[C:1](Cl)(=[O:3])[CH3:2].[Cl-].[Al+3].[Cl-].[Cl-].[CH2:9]=[CH2:10].Cl.[CH3:12][CH:13]([CH3:16])[CH:14]=O>ClCCCl.C1(C)C=CC(S(O)(=O)=O)=CC=1.O>[CH3:12][C:13]1([CH3:16])[CH2:10][CH2:9][C:1](=[O:3])[CH:2]=[CH:14]1

Participants

Conditions

Temperature: 60 °C

Procedure

Ethanoyl chloride (78.5 g, 1 mole) was added over a period of 30 minutes to a suspension of aluminium chloride (140 g, 1.05 moles) in 1,2-dichloroethane (390 ml) whilst maintaining the temperature below 20° C. by cooling. Ethene (35 g, 1.25 moles) was then passed into the solution at 5°-10° C. over a period of 2 hours and the subsequent mixture worked up by slowly pouring into 2M hydrochloric acid (900 ml). The organic phase was separated and 2-methylpropanal (50.4 g, 0.7 moles) and para-toluenesulphonic acid (0.4 g, 21 mmoles) were added. The mixture was then refluxed with azeotropic water removal until no more water separated. The organic phase was then washed with 10% (w/v) sodium hydroxide (250 ml) by stirring at 60° C. for 15 minutes to destroy any traces of 4-chlorobutan-2-one and the solvent flashed. Fractionation gave 70 g 4,4-dimethylcyclohex-2-en-1-one, b.pt. 70°-72° C. at 20 mm Hg. (Yield: 80%)

Workup

temperaturewhilst maintaining the temperature below 20° C.
temperatureby cooling
customThe organic phase was separated
customseparated
washThe organic phase was then washed with 10% (w/v) sodium hydroxide (250 ml)
customto destroy any traces of 4-chlorobutan-2-one

Sources & evidence

ORD record: ord-2dba326a8b9445d1881bba42a70550fd
Source dataset: uspto-grants-1992_06
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US05124486

Reaction notes

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