Thiophenol → Benzo(b)thiophene-2,3-dione

Participants

Reaction Conditions

Reaction Steps

To a solution of thiophenol (100 g, 0.907 mol) in ether is added dropwise a solution of oxalyl chloride (175 g, 1.38 mol) in ether. The mixture is stirred two hours at reflux and concentrated in vacuo. The residue is taken up in methylene chloride and cooled to 0° C. Aluminum chloride (145 g, 1.09 mol) is added in portions such that the temperature does not exceed 25° C. The resultant mixture is stirred 30 minutes at reflux, cooled to room temperature and poured into ice water with stirring. The organic layer is washed with saturated sodium bicarbonate, water and brine, dried over anhydrous magnesium sulfate, filtered and concentrated in vacuo to an orange solid which is recrystallized from methylene chloride:hexanes to afford the title compound (102 g, 69.0%) which is identified by NMR spectral analysis.

Provenance & Evidence