反应详情

In 2 ml of dichloromethane was dissolved 476 mg of (S)-1,4-dihydro-2,6-dimethyl -1-methoxymethyl-4-(3-nitrophenyl) -5-pivaloyloxymethoxycarbonyl-3-pyridinecarboxylic acid obtained in Example 3 ro 4, and 6 ml of a 0.5M solution of diazomethane in diethyl ether was added to the solution under cooling with ice, followed by stirring for 1 hour. Acetic acid was added to the reaction mixture until the yellow color disappeared, and the reaction mixture was concentrated. The residue was purified by short silica gel column chromatogrpahy (ether acetate/hexane=1/3) to give 460 mg (yield: 94%) of (S)-methyl pivaloyloxymethyl 1,4-dihydro -2,6-dimethyl-1-methoxymethyl-4-(3-nitrophenyl) -3,5-pyridinedicarboxylate as a pale yellow crystal.

1. additionwas added to the solution
2. temperatureunder cooling with ice
3. concentrationthe reaction mixture was concentrated
4. customThe residue was purified by short silica gel column chromatogrpahy (ether acetate/hexane=1/3)