title: Synthesis of 2-(2-hydroxyethyl)-1-(2-hydroxyphenyl)-6,7-dimethoxy-1,2,3,4-tetrahydroisoquinoline and pseudosymmetry in its crystal structure.
abstract: Natural and synthetic isoquinoline alkaloids display a wide variety of potent biological activities. The title 1-aryl-2-hydroxyethyl-1,2,3,4-tetrahydroisoquinoline, C19H23NO4, crystallizes with two molecules in the asymmetric unit related by pseudo-translation but differing only slightly in conformation. The pseudosymmetry is also reflected in the diffraction pattern. The subset of reflections corresponding to the smaller cell and average structure are on average twice as intense as those subtending the larger cell. Tentative refinement in the subcell leads to a disordered structural model with satisfactory agreement factors and, after appropriate use of restraints, acceptable molecular geometry but significantly larger and more anisotropic displacement parameters. In the correct unit cell, the independent molecules differ with respect to the orientation of the hydroxyethyl group. Intramolecular hydrogen bonding occurs between the hydroxyphenyl group and the N atom.
authors.affiliation: S. Yunusov Institute of Chemistry of Plant Substances, Academy of Science of Uzbekistan, Mirzo Ulugbek Str. 77, Tashkent 100170, Uzbekistan.
authors.forename: Kambarali K
authors.initials: KK
authors.lastname: Turgunov
authors.affiliation: S. Yunusov Institute of Chemistry of Plant Substances, Academy of Science of Uzbekistan, Mirzo Ulugbek Str. 77, Tashkent 100170, Uzbekistan.
authors.forename: Sherzod N
authors.initials: SN
authors.lastname: Zhurakulov
authors.affiliation: Institute of Inorganic Chemistry, RWTH Aachen University, Landoltweg 1, 52056 Aachen, Germany.
authors.forename: Ulli
authors.initials: U
authors.lastname: Englert
authors.affiliation: S. Yunusov Institute of Chemistry of Plant Substances, Academy of Science of Uzbekistan, Mirzo Ulugbek Str. 77, Tashkent 100170, Uzbekistan.
authors.forename: Valentina I
authors.initials: VI
authors.lastname: Vinogradova
authors.affiliation: S. Yunusov Institute of Chemistry of Plant Substances, Academy of Science of Uzbekistan, Mirzo Ulugbek Str. 77, Tashkent 100170, Uzbekistan.
authors.forename: Bakhodir
authors.initials: B
authors.lastname: Tashkhodjaev
mesh_terms: D000470:Alkaloids / Q000138:chemical synthesis / Q000737:chemistry*; D003460:Crystallization; D018360:Crystallography, X-Ray; D006860:Hydrogen Bonding; D008958:Models, Molecular; D008968:Molecular Conformation; D044005:Tetrahydroisoquinolines / Q000138:chemical synthesis / Q000737:chemistry*
chemical_list: D000470:Alkaloids; D044005:Tetrahydroisoquinolines; C024133:heliamine
keywords: NMR analysis; O—H...N hydrogen bonds; crystal structure; isoquinoline; medicinally active compounds; pseudosymmetry