Stereochemistry of anticholinergic agents. Part III. Crystal and molecular structure of piperidolate (N-ethyl-3-piperidyl diphenylacetate) hydrochloride

Abstract

Crystals of the title compound are monoclinic, space group P2₁/c, with Z= 4 in a cell of dimensions a= 9·60, b= 15·46, c= 13·49 Å(all ±0·01 Å), β= 98·6°± 0·05°. The structure was determined by Fourier and least squares methods from three-dimensional X-ray counter-data and refined by least squares to R 6·4% for 1339 structure amplitudes. The piperidine ring is in the chair conformation with the ester group oriented axially. The acetylcholine-like portion adopts a conformation similar to, but somewhat more compact than, that of acetylcholine in crystals of the bromide salt.