3-Nitrobenzaldehyde → HCID 20230121, compound

Participants

Reaction Steps

In 300 ml of isopropanol are dissolved 28.9 g of 1-phenyl-2-piperidinoethyl acetoacetate, 15.1 g of m-nitrobenzaldehyde and 11.5 g of methyl β-aminocrotonate, and the mixture is refluxed under heating for 17 hours. The reaction mixture is concentrated under reduced pressure and the residue is purified by column chromatography on silica gel (eluent:chloroform:methanol=10:1 (by volume)). The eluate containing the object compound is concentrated and recrystallized from isopropanol to give 2,6-dimethyl-4-(m-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylic acid-3-methylester-5-(1-phenyl-2-piperidinoethyl)ester as crystals melting at 183°-185° C. (decomposition). This is α-diastereoisomer. The hydrochloride thereof melts at 238°-240° C. (decomposition). The β-diastereoisomer which can be obtained in similar manner melts at 127°-130° C. (from isopropanol), and the hydrochloride thereof melts at 222°-223° C. (decomposition) (from ethanol).

Provenance & Evidence