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

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Reaction Steps

A solution of 1.3 g of sodium metal in 30 ml of ethanol is treated with 9 g of diethylmalonate and an ethanolic solution of 12.1 g of 3,4-dichlorobenzalacetone, heated under reflux for 15 min, cooled and concentrated to dryness in vacuo. The residue is treated with 400 ml of water containing 7 g of 80% potassium hydroxide pellets and heated under reflux for 2 hr. Insoluble material is removed and the filtrate is acidified with concentrated sulfuric acid, heated under reflux until carbon dioxide evolution ceases, cooled, filtered, washed with water and dried. Recrystallization from 2-propanol gives 5-(3,4-dichlorophenyl)-1,3-cyclohexanedione; mp 198°-200° C.

Provenance & Evidence