A high‐pressure polymorph of chlorpropamide formed on hydrostatic compression of the α‐form in saturated ethanol solution. (24th January 2013)

• Record Type: Journal Article
• Authors: Seryotkin, Yury V.; Drebushchak, Tatiana N.; Boldyreva, Elena V.
• Is Part Of: Acta crystallographica. Volume 69:Part 1(2013:Feb.)
• Page Start: 77
• Page End: 85
• Publication Date: 2013-01-24
• Subjects: Crystallography -- Periodicals; Crystallization -- Periodicals; Chemical structure -- Periodicals; Solid state physics -- Periodicals; 530.41105
• DOI: 10.1107/S0108768112051142
• Languages: English
• ISSNs: 0108-7681

Abstract

<abstract abstract-type="main" xml:lang="en"> <title> <x xml:space="preserve">Abstract</x> </title> <p>The crystal structure of the high‐pressure polymorph (α′) of an antidiabetic drug, chlorpropamide [4‐chloro‐<italic>N</italic>‐(propylaminocarbonyl)benzenesulfonamide, C₁₀H₁₃ClN₂O₃S], which is formed at ∼ 2.8 GPa from the α‐polymorph (<italic>P</italic>2₁2₁2₁) on hydrostatic compression in saturated ethanol solution, has been determined. As a result of the phase transition, the <italic>a</italic>, <italic>c</italic> and α parameters change jumpwise, whereas the changes in <italic>b</italic> parameter are continuous through the phase transition point. The high‐pressure form is monoclinic (<italic>P</italic>2₁11) and has <italic>Z</italic>′ equal to 2, the two independent molecules differing in their conformations. The hydrogen bonds <italic>expand</italic> slightly in the high‐pressure polymorph after the transition, and this expansion is interrelated with the changes in molecular conformations enabling a denser packing. The transition is reversible, but the crystal quality deteriorates as a result of multiple compression–decompression cycles, and a pseudomerohedral twinning accompanies the transformation.</p> </abstract>