Sulfur Dioxide → Benzoic acid, 2-[2-(4-bromophenyl)ethyl]-

Participants

Reaction Conditions

Reaction Steps

Sulfur dioxide (625 mL) was condensed into a large flask with a dry ice condenser to this flask was added TFA (10 mL) and bromine (2 equiv). When the solution temperature reached -50°, o-phenethylbenzoic acid was added. The reaction was stirred at -28° C. for 17 hours. The SO2 and excess bromine were evaporated off at room temperature over a 2 hour period leaving slightly yellow solid. A 30 g sample was dissolved in hot toluene-hexane (100 mL of 2:3) with a few mL of Et2O. The solution was cooled slowly to 10° C., and the product was isolated by filtration.

Provenance & Evidence