反应详情

温度

80 °C

To a stirred mixture of (4R)-1,4-dihydro-2,6-dimethyl-4-(2',3'-dichorophenyl)-5-carboxymethyl-3-pyridinecarboxylic acid (2.93 g, 8.23 mmol) and sodium bicarbonate (1.38 g, 16.5 mmol) in DMF (150 ml) under nitrogen atmosphere was added chloromethyl butyrate (1.72 g, 12.6 mmol). The reaction mixture was heated at 80° C. for 17 h. Workup by filtration followed by evaporation of solvent. The crude residue was chromatographed on silica gel with 5% ethyl acetate in dichloromethane. Recrystallization from diisopropylether gave colorless crystals (2.62 g, 70%), mp. 128°-129° C. NMR spectral data are identical with the data of the racemate as shown in Example 3. [α]D20 =+17.5° (1% in methanol).

1. filtrationWorkup by filtration
2. customfollowed by evaporation of solvent
3. customThe crude residue was chromatographed on silica gel with 5% ethyl acetate in dichloromethane
4. customRecrystallization from diisopropylether