title: Two polymorphs of afobazole from powder diffraction data.
abstract: Afobazole {systematic name: 2-[2-(morpholin-4-yl)ethylsulfanyl]-1H-benzimidazole} is a new anxiolytic drug and Actins, Auzins & Petkune [(2012). Eur. Patent EP10163962] described four polymorphic modifications. In the present study, the crystal structures of two monoclinic polymorphs, 5-ethoxy-2-[2-(morpholin-4-ium-4-yl)ethylsulfanyl]-1H-benzimidazol-3-ium dichloride, C15H23N3O2S(2+)·2Cl(-), (II) and (IV), have been established from laboratory powder diffraction data. The crystal packing and conformation of the dications in (II) and (IV) are different. In (II), there are channels in the [001] direction, which offer atmospheric water molecules an easy way of penetrating into the crystal structure, thus explaining the higher hygroscopicity of (II) compared with (IV).
authors: Department of Chemistry, M. V. Lomonosov Moscow State University, Moscow 119991, Russian Federation. vladimir@struct.chem.msu.ru
authors: Vladimir V
authors: VV
authors: Chernyshev
authors: Sanita
authors: S
authors: Petkune
authors: Andris
authors: A
authors: Actins
authors: Raimonds
authors: R
authors: Auzins
authors: Dmitry I
authors: DI
authors: Davlyatshin
authors: Pavel V
authors: PV
authors: Nosyrev
authors: Yurii A
authors: YA
authors: Velikodny
mesh_terms: D001562:Benzimidazoles / Q000737:chemistry*; D003460:Crystallization; D008958:Models, Molecular; D009025:Morpholines / Q000737:chemistry*; D033362:Powder Diffraction; D014961:X-Ray Diffraction
chemical_list: C410924:2-((2-morpholino)ethylthio)-5-ethoxybenzimidazole; C580905:2-(2-(morpholin-4-yl)ethylsulfanyl)-1H-benzimidazole; C580906:5-ethoxy-2-(2-(morpholin-4-ium-4-yl)ethylsulfanyl)-1H-benzimidazol-3-ium dichloride; D001562:Benzimidazoles; D009025:Morpholines