3-Aryloxypropiononitriles Intermediates: Crystal and Molecular Structure of 2- and 4-(2-Bromoethoxy)diphenylmethanes

Abstract

The crystal structure of 2- and 4-(2-bromoethoxy)diphenylmethanes (I and II respectively), intermediates in a novel synthesis of substituted 3-aryloxypropiononitriles, have been determined by single crystal X-ray diffraction at room temperature (r.t.) and at 150K. No significant changes in the crystal structure of I and II have been observed in going from r.t. to 150K. In both compounds the bromoethoxy group presents a gauche conformation and shows a short Br...O intramolecular interaction that allows to explain the very good reaction yields obtained in the novel synthesis. The three-dimensional structure of I is stabilized by two intermolecular hydrogen bonds and that of II by six. This difference in the crystal packing of I and II explains the variation in the m.p. The analysis of 1 H and 13 C NMR spectra suggests that the molecular conformations in solution are similar to those found in solid state.