Intramolecular C-H···O Hydrogen Bonding in 1,4-Dihydropyridine Derivatives

Abstract

The diastereotopy of the methylene protons at positions 2 and 6 in 1,4-dihydropiridine derivatives with various substituents has been investigated. NMR spectroscopy and quantum chemistry calculations show that the CH···O intramolecular hydrogen bond is one of the factors amplifying the chemical shift differences in the 1H-NMR spectra.

Keywords

• 1,4-dihydropyridines
• bromination
• nucleophilic substitution
• hydrogen bond
• NMR spectra
• quantum chemical calculations