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Published on: October 19, 2017
Solvates of acotiamide hydrochloride: characterization and phase transformation
Guoshun Zhang1, Na Wang1, Xiaoqing Shang1
1Department of Pharmacy, Shanxi Medical University, Taiyuan, 030001, People's Republic of China.
Abstract:
Five novel crystals of acotiamide hydrochloride (AH) with solvates dimethyl formide (DMF), dimethyl sulfoxide (DMSO), ethyl acetate (EA) and water (W) [1AH-1W-1DMF, 1AH-1DMSO-I, 1AH-1DMSO-II, 1AH-1W-1DMSO and 2AH-2DMSO-1EA] were characterized using single-crystal X-ray diffraction, powder X-ray diffraction, thermal analysis and Fourier transform infrared spectroscopy. The five crystals can be divided into four distinct structural types based on analysis of their similarities; 1AH-1W-1DMF and 1AH-1W-1DMSO are isostructural. The benzene rings in 1AH-1DMSO-I, 1AH-1DMSO-II and 2AH-2DMSO-1EA can rotate 180°, and the intramolecular hydrogen bond changes from an OH...C=O bond to an NH...OH bond relative to what is seen in 1AH-1W-1DMF and 1AH-1W-1DMSO. Phase transformation experiments show that a humidity-induced phase transformation is closely tied to moisture content.
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