3-ARYLOXYPROPIONONITRILES INTERMEDIATES - CRYSTAL AND MOLECULAR-STRUCTURE OF 2-(2-BROMOETHOXY)DIPHENYLMETHANE AND 4-(2-BROMOETHOXY)DIPHENYLMETHANE

The crystal structure of 2- and 4-(2-bromoethoxy) diphenylmethanes (I and II respectively), inter-mediates in a novel synthesis of substitut ed 5-aryloxypropiononitriles, have been det ermined by single crystal X-ray diffraction at room temperature (r.t.) and at 150K. No significa nt 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 prese nts a gauche conformation and shows a short Br...O intramolecular inte raction that allows to explain the very good reaction yields obtained in the novel synthesis. The three-dimensional structure of I is stabil ized by two intermolecular hydrogen bonds and that of II by six. This difference in the crystal packing of I and II explains the variation i n the m.p. The analysis of H-1 and C-13 NMR spectra suggests that the molecular conformations in solution are similar to those found in soli d state.