1,8-Diazabicyclo(5.4.0)undec-7-ene → 3-(3,4-Difluorophenoxy)-5,5-dimethyl-4-(4-(methylsulfonyl)phenyl)-5H-furan-2-one

Participants

Reaction Steps

A solution of 3,4-difluorophenoxyacetic acid (0.51 g, 2.73 mmol), 2-hydroxy-4'-(methylsulfonyl)isobutyrophenone (Ex. 1, Step 1, 0.5 g, 2.1 mmol), CMC (1.13 g, 2.73 mmol) and DMAP (15 mg, 0.10 mmol) in dichloromethane (12 mL) was stirred at r.t. for 18 hrs. DBU (0.63 ml, 4.2 mmol) was then added and the reaction mixture was heated to reflux for 3 hrs. After cooling to r.t., the mixture was extracted with ethyl acetate and washed successively with water, 1N HCl and brine. The organic layer was dried over MgSO4, filtered and concentrated. The residue was triturated with a mixture of ethyl acetate and hexane to afford the title compound as a solid. m.p.: 93°-95° C.

Provenance & Evidence