2-methylsulfonylethenylbenzene

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 130 mg of zinc chloride, 3.2 g (20 mmoles) of methanesulfonic acid bromide and 0.15 ml of 50% strength hydrogen peroxide are successively added to a solution of 2.1 g (20 mmoles) of styrene in 5 ml of nitromethane. After 50 hours at room temperature, the mixture is taken up in methylene chloride and the solution is washed with water. The crude 1-methylsulfonyl-2-bromo-2-phenylethane which remains after stripping off the methylene chloride is dissolved in 10 ml of benzene and dehydrobrominated by adding 25 mmoles of triethylamine. Distillation at from 121° to 124° C. at 0.01 mm Hg gives β-methylsulfonylstyrene, of melting point 77° - 79° C. (after recrystallization from ether). According to the NMR spectrum (J = 15.5 Hz), the product is in the trans-configuration. the solution is washed with water is dissolved in 10 ml of benzene Distillation at from 121° to 124° C. at 0.01 mm Hg