Thianthrene → Thianthrene-2-sulfonic acid

Participants

Reaction Steps

To a stirred solution of thianthrene (6.0 g, 27.7 mmol) in 160 mL of dichloromethane at 0° C. was added dropwise, 2.03 mL (30.5 mmol) of chlorosulfonic acid. The resulting deep purple mixture was stirred for 4 hours and then hexanes were added, and the reaction was filtered to give thianthrene-2-sulfonic acid. This acid (3.18 g, 10.7 mmol) was mixed with 7.36 g (35.3 mmol) of phosphorous pentachloride, and the neat solids were heated to a melt at 110° C. for 2 hours. The resulting mixture was quenched with ice and extracted with dichloromethane. The organic phase was dried over magnesium sulfate and concentrated to give the title compound as a green oil which was used without further purification.

Provenance & Evidence