(Diethylamino)sulfur trifluoride → Methyl (3,5-difluorophenyl)fluoroacetate

Participants

Reaction Steps

A solution of diethylaminosulfur trifluoride (DAST) (1.1 eq) in methylene chloride was cooled to 0° C. and a pre-cooled solution of methyl 3,5-difluoromandelate (1 eq) in methylene chloride was added. The transfer flask was rinsed with a small portion of methylene chloride. After 15 minutes, the cooling bath was removed and the reaction mixture was stirred an additional 40 minutes at ambient temperature. The mixture was poured over ice and the layers separated. The organic phase was washed with saturated NaHCO3 and brine. The organic layer was dried over Na2SO4, filtered, and concentrated. The residue was purified via HPLC eluting with 7% ethyl acetate/hexanes providing the title intermediate as a yellow oil.

Provenance & Evidence