Synthesis and Crystallographic Study of '-(1-benzylpiperidin-4-yl)acetohydrazide.

As part of a study into new Fentanyl-derived opioid compounds with potent analgesic activity and reduced side effects the starting material title compound, CHNO (), was synthesized and characterized by NMR spectroscopy and single-crystal X-ray diffraction. The crystal structure is monoclinic with unit cell parameters = 14.1480(3) Å, = 14.1720(4) Å, = 27.6701(7) Å, = 96.956(1)°, = = 90°. The compound has crystallized with four crystallographically unique molecules in the asymmetric unit; each molecule has a very similar conformation and an analysis of the structure shows that although all four unique molecules overlay very well there is no evidence of -symmetry which would relate the molecules in the higher symmetry space group 2/. The crystal packing consists of two separate hydrogen bonded chains which are linked together to form a thick 2D structure in the plane.