Acetyl chloride → 7-Acetyl-3-methylimidazo[5,1-b]thiazole

Participants

Reaction Steps

Aluminum chloride (16.0 g) was added to a solution of 10.0 ml of acetyl chloride in 100 ml of carbon disulfide at room temperature. The mixture was stirred for 30 min. A solution of 2.76 g of 3-methylimidazo[5,1-b]thiazole in 40 ml of dichloromethane was added dropwise thereto over a period of 15 min with stirring. The mixture was further stirred for 6 hr. The reaction solution was added to a mixture of 200 ml of dichloromethane with 100 g of ice with thorough stirring. After dissolution of the ice, 40 g of sodium carbonate and 50 g of sodium sulfate were added in that order with thorough stirring. The mixture was stirred under ice cooling for 30 min. After standing, the organic layer was separated by decantation. The gum residue was extracted with dichloromethane (100 ml, five times), and then combined with the organic layer. The combined organic layer was dried over anhydrous magnesium sulfate, and concentrated to dryness under the reduced pressure. Ethyl acetate (10 ml) was added to the concentrate. The resultant solid was triturated with 10 ml of ethyl acetate, collected by filtration, and washed with a minor amount of ethyl acetate. The washed product was dried under the reduced pressure to give 2.92 g of 7-acetyl-3-methylimidazo[5,1-b]thiazole.

Provenance & Evidence