Acetyl chloride → 1-(4,4-Dimethylthiochroman-6-yl)ethanone

Participants

Reaction Steps

37 g of aluminum chloride were suspended at 0° C. in 200 ml of methylene chloride and the suspension was treated slowly with 22 g of acetyl chloride while stirring vigorously. After 30 minutes, a solution of 49.4 g of 3,4-dihydro-4,4-dimethyl 2H-1-benzothiopyran in 150 ml of methylene chloride was added dropwise thereto. After stirring at 0° C. for 1 hour, the mixture was poured into ice/water and extracted with methylene chloride. The organic phase was washed neutral with 1N sodium hydroxide solution and water, dried and evaporated. The oily crude product was filtered over a short column of silica gel [eluting agent: hexane/ether (9:1)]. There were obtained 51.5 g of 3,4-dihydro-4,4-dimethyl-2H-1-benzothiopyran-6-yl methyl ketone in the form of a colorless oil which solidifies upon standing in a refrigerator.

Provenance & Evidence