Acetone → 7-Chloro-2,2-dimethyl-benzo[1,3]dioxin-4-one

Participants

Reaction Steps

10 mL of trifluoroacetic anhydride and 2 mL of acetone were added to a 0° C. slurry of 4-chlorosalicylic acid (2.23 g, 13 mmol) in 16 mL of trifluoroacetic acid. The mixture was allowed to slowly warm to room temperature and stirred for 25 hours under a nitrogen atmosphere. The tan solution was concentrated under vacuum, dissolved and re-concentrated from toluene twice, and dried under vacuum. The crude solid was dissolved in ethyl acetate and washed twice with saturated sodium bicarbonate solution and once with brine. The organic fraction was dried over sodium sulfate, and concentrated to a tan semi-solid, which was partially dissolved in 10 mL of dichloromethane and filtered to remove solids. The mother liquor was concentrated to give 1.28 g of a tan semi-solid. MS: (+) m/z 215.0/213.0 (M+1, 35/37Cl)

Provenance & Evidence