Hydrochloric Acid → 2,6-Dimethyl-4-(3-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylic acid monomethyl ester

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Reaction Steps

The resulting (-)-1-ethoxymethyl-2,6-dimethyl-3-carbomethoxy-4-(3-nitrophenyl)-5-carboxy-1,4-dihydropyridine is then dissolved in acetone (100 mL), and treated with 1N HCl (20 mL) at room temperature for 1 h. The acetone is then removed, the residue taken up in water (20 mL), and the resulting mixture extracted with EtOAc. The ethyl acetate extract is washed with water, dried, and evaporated to yield (-)-2,6-dimethyl-3-carbomethoxy-4-(3-nitrophenyl)-5-carboxy-1,4-dihydropyridine (12-(-), mp=196°-197° C., αD22 =-19.6°). The (+) isomer is similarly prepared (12-(+), mp=194°-195° C., αD22 =+19.1°).

Provenance & Evidence