Acetone → 3,3-Dimethylphthalide

Participants

Reaction Conditions

Reaction Steps

To a solution of 2-bromobenzoic acid (500 mg, 2.49 mmol) in THF (12.0 ml) cooled at −78° C. was added 2.5M n-BuLi/Hexane (2.0 ml). After stirring for 18 minutes, acetone (0.91 ml, 12.4 mmol) was added. The reaction was allowed to warm to room temperature after 5 minutes at −78° C., and then quenched into 10% HCl aqueous solution (50 ml). The acidic solution was rapidly stirred for 1 hour, and then extracted with EtOAc. The combined organic layers were washed with saturated NaHCO3, brine, dried with anhydrous Na2SO4, and rotary evaporated to give a mixture. Gradient chromatography of the mixture through silica gel column eluted with 20% to 30% EtOAc in hexane afforded 3,3-dimethyl-2-benzofuran-1(3H)-one as a white solid (161 mg, 40%).

Provenance & Evidence