Acetone → 2-Chlorobenzylideneacetone

Participants

Reaction Conditions

Reaction Steps

A solution of 200 g (1.4 mole) of 2-chlorobenzaldehyde in 500 ml of acetone is treated with 200 ml of water, cooled in an ice bath, then treated with 40 ml of 10% NaOH by drops. The mixture is kept below 40° C. After the addition is complete the mixture is stirred at 25° C. for 1.5 hours, then acidified with 10% HCl. The mixture is diluted with water and extracted with benzene. 0.5 g of toluene-sulfonic acid is added to the benzene solution and the mixture refluxed under a water separator. A total of 6 ml of water is collected. The mixture is cooled, shaken with bicarbonate, dried (Na2SO4), and evaporated. Distillation gives 150 g (60%) of 4-(2-chlorophenyl)-but-3-ene-2-one, b.p. 106°-120° C. @ 1 mm Hg.

Provenance & Evidence