反应详情

温度

70 °C

5-(Benzyloxycarbonyl)-1,6-dihydro-2-methoxy-4-ethyl-6-(3,4-difluorophenyl)pyrimidine. A suspension of benzyl 3-[(3,4-difluorophenyl)methylene]-4-oxopentancate (16.0 g, 48.0 mmol), O-methylisourea hydrogen sulfate (16.65 g, 97.02 mmol), NaHCO3 (16.3 g, 130.2 mmol) in DMF (190 mL) was stirred at 70° C. for 20 h. After cooling to room temperature, the mixture was filtered and the filtrate was diluted with EtOAc (300 mL) and then washed with water (4×100 mL), brine (200 mL) and dried over Na2SO4. After removal of solvent, the residue was purified by column chromatography (SiO2, EtOAc/Hexane, 10%-30%) to get 5-(benzyloxycarbonyl)-1,6-dihydro-2-methoxy-4-methyl-6-(3,4-difluorophenyl)pyrimidine as a colorless oil (10.6 g, 58%). The NMR analysis showed it to be a mixture of amine/imine tautomers and was used as is in the next step.

1. temperatureAfter cooling to room temperature
2. filtrationthe mixture was filtered
3. additionthe filtrate was diluted with EtOAc (300 mL)
4. washwashed with water (4×100 mL), brine (200 mL)
5. dry with materialdried over Na2SO4
6. customAfter removal of solvent
7. customthe residue was purified by column chromatography (SiO2, EtOAc/Hexane, 10%-30%)