Unexpected diastereotopic behaviour in the ¹H NMR spectrum of 1,4-dihydropyridine derivatives triggered by chiral and prochiral centres

1,4-dihydropyridine derivatives constitute an important pharmacological group for the treatment of cardiovascular diseases. We have synthesised a series 4-(5'-nitro-2'-furyl)-1,4-dihydropyridine derivatives, which were characterised by ¹H-NMR. We have found that carboethoxy groups at the C-3 and C-5 on the 1,4-dihydropyridine ring show a much more complex signal in the ¹H NMR spectra, either when C-4 is a pseudo-prochiral or a chiral centre.

NMR; 1H NMR; 1,4-dihydropyridines; carboethoxy group; enantiotopic methylene hydrogens