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

Participants

Reaction Conditions

Reaction Steps

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%)

Provenance & Evidence