Studies on the Relationship between Physico-chemical Properties and Crystalline Forms of Tulobuterol Hydrochloride. II. Crystal Structure Analyses of the Four Crystalline Forms of Tulobuterol Hydrochloride

概要

論文の詳細を見る
The crystal structures of the three forms (I, II, III) and the hydrate of tulobuterol hydrochloride (C-78) have been determined by X-ray analysis by using direct methods and refined by the block-diagonal least-squares method including anisotropic thermal parameters to final R values of 0.048,0.057,0.066 and 0.060 for forms, I, II, III and the hydrate, respectively. The molecular conformations in the four different crystalline forms are almost identical, though slight conformational differences are observed at the tertiary butyl terminal. The molecular packings however, are very different. Hydrogen bonds connecting the tulobuterol cations and the chloride anions form either a closed dimer-like unit in I and III or an open chain in II. In the hydrated crystal, a ribbon-like system of hydrogen bonds is formed by intervention of water molecules. Comparison of the crystal structures among these four forms of C-78 suggests a mechanism for the phase transition in the solid state and explains their thermodynamic properties previously reported.
社団法人日本薬学会の論文
1982-07-25