4-(2,4-dichlorophenyl)but-3-en-2-one → 5-(2,4-Dichlorophenyl)cyclohexane-1,3-dione

Participants

Reaction Conditions

Reaction Steps

To a solution of 2.3 g of sodium in 200 ml of ethanol is added 15.7 g of diethylmalonate followed by a suspension of 20 g of 1-(2,4-dichlorophenyl)-1-butene-3-one in 100 ml ethanol. The mixture is heated under reflux for 2 hrs and then concentrated to dryness in vacuo. The solid is partitioned between 200 ml water and 200 ml ether. The ether layer is discarded and 20 ml 50% NaOH is added to the aqueous layer which is heated under reflux for 2 hrs. The mixture is filtered and the filtrate is made strongly acidic pH <2 with concentrated sulfuric acid. The mixture is heated on a steam bath for 2 hrs. The resulting solid is collected, pulverized and suspended in 500 ml of 10N sulfuric acid and heated on a steam bath for 2 hrs and cooled to 0° C. The solid is collected, washed with water and recrystallized from a mixture of dimethylformamide and ethyl acetate. Drying in vacuo at 80° C. for 6 hrs gives 5-(2,4-dichlorophenyl)cyclohexane-1,3dione; mp 192°-196° C.

Provenance & Evidence