6-bromo-2,2-dimethyl-1-benzothiophen-3(2H)-one 1,1-dioxide → 6-Bromo-2,2,3-trimethyl-2,3-dihydro-1-benzothiophene-3-ol 1,1-dioxide

Participants

Reaction Steps

A cooled (0° C.) solution of 6-bromo-2,2-dimethyl-1-benzothiophen-3(2H)-one 1,1-dioxide (Intermediate 241; 750 mg; 2.59 mmol) in anhydrous Et2O (22.5 ml) was treated carefully with a 3 M solution of methylmagnesium bromide in Et2O (2.6 ml; 7.8 mmol). The white solution was stirred at RT for 1.5 before being quenched with a saturated solution of NH4Cl in water. The phases were separated and the aqueous phase was extracted with Et2O. The combined organic phases were washed with water and brine, dried over anhydrous magnesium sulfate and concentrated to dryness to afford the title compound as a white solid (767 mg, 97%).

Provenance & Evidence