649736-31-2

121247-16-3

649736-31-2

Step 3b: A mixture of 1-(2,3-difluoro-6-nitrophenyl)propan-2-one (Compound 302, 4.30 g, 0.02 mol), sodium acetate (AcONa, 1.72 g, 0.021 mol) and N,N-dimethylformamide (DMF, 40 mL) was stirred and reacted for 12 hours at 100 °C. After completion of the reaction, the mixture was filtered and the solvent was removed by distillation under reduced pressure. The residue was extracted with ethyl acetate (100 mL) and the organic layer was washed sequentially with water and saturated saline, dried over anhydrous magnesium sulfate (MgSO?) and concentrated. The crude product was purified by silica gel column chromatography (eluent: ethyl acetate/petroleum ether = 1/1) to afford 1-(2-fluoro-3-hydroxy-6-nitrophenyl)propan-2-one (Compound 303, 2.3 g, 54%) as a light yellow solid.LCMS: 214 [M + 1]? ; 1H NMR (DMSO-d6): δ 2.30 (s, 3H), 4.26 (s, 2H), 7.67 (m, 1H), 8.05 (m, 1H).