A mixture of ethyl 2-(2,6-dimethoxyphenyl)-4,5-dioxo-1-(4-(trifluoromethoxy)-benzyl)pyrrolidine-3-carboxylate (11.400 g; 23.68 mmol) and NaCl (2.767 g; 47.36 mmol) in DMSO (111 ml) and water (37 ml) was refluxed, under nitrogen, for 3 h. After cooling to rt, water (150 ml) was added, and the mixture was extracted with AcOEt (3×150 ml). The mixed organic layers were washed with brine (50 ml), dried over anh. MgSO4, filtered, and concentrated to dryness under reduced pressure. Addition of Et2O and trituration allowed the precipitation of the product. Subsequent filtration, and drying of the obtained solid under HV afforded 5-(2,6-dimethoxyphenyl)-1-(4-(trifluoromethoxy)benzyl)pyrrolidine-2,3-dione as a pink solid. LC-MS (conditions A): tR=0.85 min.; [M+H]+: 410.15 g/mol.
