Thionylchloride (236 mg, 2.0 mmol) was added to a solution of 5-oxopyrrolidine-2-carboxylic acid 120 (170 mg, 1.32 mmol) in THF (5 mL) at 0° C. DMF (1 drop) was added and the solution was allowed to warm to room temperature for 2 h then cooled to 0° C. A solution of 8-amino-2-(2-(trifluoromethyl)phenyl)-4H-chromen-4-one 11 (100 mg, 0.33 mmol) and pyridine (0.5 mL) in THF (1 mL) was added and the reaction mixture was allowed to warm to room temperature and stirred for 2 h. The reaction mixture was concentrated to dryness, dissolved in EtOAc, washed with sat. aq NaHCO3, brine, and dried (Na2SO4). The crude residue was purified by preparative TLC eluting with EtOAc to give Compound 313. MS (ESI) calcd for C21H15F3N2O4: 416.1. found: 417 [M+H].
