Hydrochloric Acid → Dimethyl 2-methyl-4-(3-nitrophenyl)-6-formyl-1,4-dihydropyridine-3,5-dicarboxylate

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Reaction Steps

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,

Provenance & Evidence