反应详情

To a well stirred solution of (+)-5-(benzyloxycarbonyl)-1,6-dihydro-2-methoxy-4-ethyl-6-(3,4-diflurophenyl)pyrimidine (17.0 g, 44.04 mmol) and 4-dimethylaminopyridine (6.99 g, 57.25 mmol) in CH2Cl2 (200 mL) was added a powder of 4-nitrophenyl chloroformate 11.54 g, 57.25 mmol) at room temperature. The reaction mixture was stirred for 12 hours and then the solvent was removed in vacuo. The residue was purified by chromatography (SiO2, EtOAc/Hexane 10-30%) to get (+)-5-(benzyloxycarbonyl) -4-ethyl-1,6-dihydro-2-methoxy-6-(3,4-diflurophenyl)-1-[(4-nitrophenyloxy)carbonyl]pyrimidine as a colorless viscous oil(19.3 g, 76%).

1. customthe solvent was removed in vacuo
2. customThe residue was purified by chromatography (SiO2, EtOAc/Hexane 10-30%)