反应详情

Next, a solution of NaOH (41.3 mL of 35% NaOH in 375 mL H2O) was slowly added to a solution of 2,6-dimethyl-3-carbomethoxy-4-(3-nitrophenyl)-5-(2-cyano)ethoxycarbonyl-1,4-dihydropyridine (80 g, 0.21 mol) in acetone (240 mL). Then, CH2Cl2 (500 mL) was added and 12N HCl (41.3 mL) slowly introduced. The resulting precipitate was filtered and recrystallized from dimethylformamide/H2O (175 mL DMF, 72 mL H2O) to yield 2,6-dimethyl-3-carbomethoxy-4-(3-nitrophenyl)-5-carboxy-1,4-dihydropyridine (mp=242° C.).

1. filtrationThe resulting precipitate was filtered
2. customrecrystallized from dimethylformamide/H2O (175 mL DMF, 72 mL H2O)