Crystal structure of oxotremorine sesquioxalate, 1-[4-(2-oxopyrrolidin-1-yl)but-2-ynyl]pyrrolidinium sesquioxalate

Abstract

The crystal structure of the title compound (I) has been determined from X-ray diffraction data. Crystals are triclinic, a= 8·183(4), b= 14·449(6), c= 8·879(4)Å, α= 125·00(3), β= 89·32(3), γ= 98·30(3)°, Z= 2, space group P. The structure was solved by direct methods and refined by full-matrix least-squares to R 0·104 for 1895 three-dimensional diffractometer data. There is considerable disorder in the positions of the oxalic acid and oxalate anion. The pyrrolidine ring adopts the envelope conformation with the nitrogen 0·54 Å out of the plane of the carbon atoms, and the nitrogen substituent in the pseudo-equatorial position. The pyrrolidone ring is almost planar. The structure is linked by a series of hydrogen bonds between the oxotremorine cation and the oxalic acid and oxalate moieties.