反应详情

温度

70 °C

A mixture of methyl 2-{(3,4-difluorophenyl)methylene}-3-oxobutyrate (8.8 g, 36.6 mmol), O-methylisourea hydrogen sulfate (9.4 g, 55 mmol), and NaHCO3 (12.3 g, 0.146 mol) in DMF (30 mL) was stirred and heated at 70° C. for 16 hours. The mixture was cooled, diluted with EtOAc (300 mL) and washed with water (5×300 mL), brine (300 mL), and dried (MgSO4). Solvent was evaporated and the crude product was purified by flash column chromatography on silica gel using 10% through 20% EtOAc in hexane as the gradient eluent, to leave the product as an oil (3.82 g, 30.2%); 1H-NMR (CDCl3): δ2.32,2.39 (2 s, 3 H), 3.58, 3.64 (2 s, 3 H), 3.72, 3.85 (2 s, 3 H), 5.55 (s, 1H), 6.13-7.8 (m, 4 H).

1. temperatureThe mixture was cooled
2. washwashed with water (5×300 mL), brine (300 mL)
3. dry with materialdried (MgSO4)
4. customSolvent was evaporated
5. customthe crude product was purified by flash column chromatography on silica gel using 10% through 20% EtOAc in hexane as the gradient eluent