Dimethylformamide → 6-bromo-2,2-dimethyl-1-benzothiophen-3(2H)-one 1,1-dioxide

Participants

Reaction Steps

A solution of 6-bromo-1-benzothiophen-3(2H)-one 1,1-dioxide (Intermediate 240; 1.00 g; 3.83 mmol) in anhydrous DMF (4 mL) was treated with sodium hydride (337 mg; 8.43 mmol) and stirred for 1 h. The resulting mixture was treated with iodomethane (715 μl; 11.5 mmol) and stirred for 15 min. The reaction was quenched with water, then partitioned between AcOEt and brine. The organic phase was washed with brine, dried on MgSO4, filtered and concentrated to give a residue which was purified by flash column chromatography (silica), eluting with cyclohexane containing increasing amounts of EtOAc. The title compound was obtained as an orange oil. Methyl 4-bromo-2-(isopropylsulfonyl)benzoate was also isolated and denominated as Intermediate 242.

Provenance & Evidence