Tritium nuclear magnetic resonance spectroscopy of [Pyrrolidine-3H]bepridil

Abstract

Bepridil [N-benzyl-3-isobutoxy-N-phenyl-2-(pyrrolidin-1-yl)propylamine] tritiated in the pyrrolidine ring by reduction of the 2,5-dihydropyrrol-1-yl analogue with tritium shows a complicated ¹H-decoupled ³H n.m.r. spectrum. With the aid of isotopic fractionation by h.p.l.c. this spectrum could be interpreted as a sum of the spectra of various mono-, di-, and tri-tritiated diastereoisomers. In the case of the (+)-(R)-isomer of bepridil the optical purity could be determined by ³H n.m.r. in the presence of Pirkle's alcohol.