Acetone → (E)-4-(3-Chloro-4-cyclohexyl-phenyl)-3-butene-2-one

Participants

Reaction Steps

222.72 Gm (1.0 mol) of 3-chloro-4-cyclohexyl-benzaldehyde, 3,500 gm (60.3 mols) of acetone and 200 ml of methanol were charged into a 6-liter three-necked flask equipped with a stirrer, dropping funnel and internal thermometer. While thoroughly stirring the contents of the flask, a solution of 2.805 gm (0.05 mol) of potassium hydroxide in 16 ml of water was added dropwise thereto, while an internal temperature of 20° to 25°C was maintained. The mixture was then stirred for 3 hours more. The precipitate solid by-product was filtered off, and the filtrate was neutralized by dropwise addition of glacial acetic acid, and concentrated by evaporation in vacuo. The residue was shaken with a mixture of water and ether. The ether phase separated, dried over sodium sulfate, clarified with charcoal, and evaporated. The residual oil was distilled in a high vacuum (b.p. 162°-175°C at 0.2 mm Hg), crystallized by trituration with a small quantity methanol, and finally recrystallized once from methanol. The colorless crystals melted at 48°-49°C. Yield: 40 % of theory.

Provenance & Evidence