反应详情

To a solution of 2,6-dimethyl-3-carbomethoxy-4-(3-nitrophenyl)-5-(2-[4-(2-hydroxyethyl)phenoxy]ethoxycarbonyl)-1,4-dihydropyridine (1.25 g, 2.52 mmoles) in CH2Cl2 (15 mL) cooled to 0° C., were added pyridine (0.25 mL, 3.10 mmoles) and acetic anhydride (0.85 mL, 9.0 mmoles). The reaction mixture was left at room temperature for 24 hours. Water (20 mL) was then added to extract the pyridine. The organic layer was dried over anhydrous Na2SO4. After evaporation of the solvent, the crude product (1.5 g) was purified by flash chromatography (solvent=93:7 CH2Cl2 :acetone) to yield 2,6-dimethyl-3-methoxycarbonyl-4-(3-nitrophenyl)-5-(2-[4-(2-acetoxyethyl)phenoxy]ethoxycarbonyl)-1,4-dihydropyridine, mp=110° C. NMR (CDCl3) δppm: 8.2(m, 9H); 5.15(s, 1H); 4.5-3.9(m, 6H); 3.63(s, 3H); 2.87(t, 2H); 2.37(s, 6H); 2.07(s, 3H).

1. extractionto extract the pyridine
2. dry with materialThe organic layer was dried over anhydrous Na2SO4
3. customAfter evaporation of the solvent
4. customthe crude product (1.5 g) was purified by flash chromatography (solvent=93:7 CH2Cl2 :acetone)