反应详情

To a solution of dimethyl 2-methyl-4-(3-nitrophenyl)-6-dimethoxymethyl-1,4-dihydropyridine-3,5-dicarboxylate (7.5 g) in acetone (75 ml) was added 6 N hydrochloric acid (7.5 ml) and the mixture was stirred at room temperature for 6 hours. The precipitates which were separated out during the reaction course were collected by filtration to give yellowish crystals of dimethyl 2-methyl-4-(3-nitrophenyl)-6-formyl-1,4-dihydropyridine-3,5-dicarboxylate (2.26 g), and the filtrate was adjusted to pH 7.5 to 8 with an aqueous sodium bicarbonate solution, and the acetone was distilled off under reduced pressure to give additional crops of orange-yellow crystals (3.84 g) of the same product, (total yield, 6.1 g). A small portion of the first crop was recrystallized from methanol to give pure crystals,

1. customThe precipitates which
2. customwere separated out during the reaction course
3. filtrationwere collected by filtration