An X-ray study of the aromatic ring–dipole interaction in hydantoin crystals

Abstract

The X-ray crystal structures of 5-p-chlorobenzyl-3-(o-tolyl)hydantoin (1a) and 3-ethyl-5-p-hydroxybenzyl-2-thiohydantoin (1b) have been determined in order to explore aromatic ring–dipole interaction. A folded conformation with the aromatic ring over the amide region of the hydantoin was found in (1a) while in (1b) an extended conformation with the aromatic ring over a polar region of hydrogen bonds was found. The paper includes a description of the crystallographic solution of both compounds.