Hydrogen Bromide → Triphenylsulfonium Bromide

Participants

Reaction Steps

A 3.0 M solution of phenylmagnesium bromide in diethyl ether (42 ml, 0.126 mole) was distilled under vacuum with slow heating from 20° to 80° C. Toluene (40 ml) was added, followed by n-heptane (200 ml). The resulting mixture was stirred and a solution of diphenylsulfoxide 10.1 g, (0.050 mol), in benzene (60 ml) was added during 1 hour at 80° C. The mixture was stirred for 3 hours and cooled to room temperature. An 25% aqueous hydrobromic acid solution (180 ml) was slowly added to the reaction mixture (exotherm-). The layers were separated and the organic layer was extracted twice with 5% aqueous hydrobromic acid (2×30 ml). The combined aqueous extracts were extracted three times with dichloromethane (3×250 ml). The dichloromethane extracts were dried over magnesium sulfate, filtered and the organic solvent evaporated to leave a residue which was crystallized from dichloromethane/diethyl ether to give triphenylsulfonium bromide (7.7 g, 44%).

Provenance & Evidence