Chlorosulfonic acid → 5-bromo-3-methyl-1-benzothiophene-2-sulfonyl chloride

Participants

Reaction Conditions

Reaction Steps

Chlorosulfonic acid (2.20 ml, 0.033 mmol) was added dropwise at −5° C. to a solution of 5-bromo-3-methylbenzothiophene (Intermediate 9) (3.0 g, 13.2 mmol) in CHCl3 (30 mL). The reaction mixture was stirred at 0° C. for 3 h, and then poured into a mixture of ice/NaHCO3 and stirred vigorously for 5 min. The organic phase was immediately separated, dried and concentrated to give the title compound (1.70 g, 39%).

Provenance & Evidence