Stereochemical studies. Part 29. Crystal structure of 2-benzyl-1,2,3,4-tetrahydro-6,7-dimethoxy-2-methyl-1-phenylisoquinolinium iodide

Abstract

The structure of the title compound has been established by X-ray crystallography from diffractometer data. Crystals are orthorhombic, space group Pbca, cell dimensions a= 33.443(10), b= 9.654(4), c= 13.991(5)Å, Z= 8. The structure was solved by Patterson and Fourier techniques and refined by least-squares calculation to R 0.036 for 1 875 observed reflections. Ring A is in the half-chair conformation. The 1-phenyl and 2-benzyl substituents are trans diaxial, which has only partly corroborated the conclusion (trans diequatorial) inferred from ¹H n.m.r. studies. The nitrogen atom maintains an almost regular tetrahedron formed by four polarized C(sp³)-N+(sp³) single bonds (mean 1.532 Å). Geometry of the molecule resembles that of 1,2,3,4-tetrahydro-6,7-dimethoxy-2-methyl-1-(3,4-methylenedioxyphenyl)isoquinoline (cryptostyline I) methiodide.