DETERMINATION OF α OR β SUBSTITUTION OF THE INDOLE NUCLEUS BY NUCLEAR MAGNETIC RESONANCE

Abstract

Marked differences in chemical shift of the signal for the α proton in indole and substituted indoles occur when spectra are obtained in non-polar and polar solvents. In contrast, using polar and non-polar solvents, only small differences are observed in the chemical shift of the signal for the β proton in indoles. The utility of the solvent effect on the chemical shift to distinguish between α and β substitution of the indole nucleus is pointed out.