Crystal structure of 2-acetyl-5-(3,4-dimethoxyphenyl)-6-ethoxycarbonyl-3,7-dimethyl-5H-thiazolo[3,2-a]pyrimidin-8-ium chloride

• Main Authors: N. L. Prasad, M. S. Krishnamurthy, Noor Shahina Begum
• Format: Article
• Language: English
• Published: International Union of Crystallography 2015-10-01
• Series: Acta Crystallographica Section E: Crystallographic Communications
• Subjects: crystal structure; salt; pyrimidinium; chloride; pyrimidine derivatives; pharmacological properties; biological activity; hydrogen bonding; C—H...π interactions
• Online Access: http://scripts.iucr.org/cgi-bin/paper?S2056989015016229

The title molecular salt, C21H25N2O5S+·Cl−, crystallizes with two ion pairs in the asymmetric unit. The cations have similar conformations (r.m.s. overlay fit = 0.40 Å), with one of them showing disorder of the terminal methyl group of the ester in a 0.72 (2):0.28 (2) ratio. In the first cation, the 3,4-dimethoxy-substituted phenyl ring subtends a dihedral angle of 88.38 (7)° with the pyrimidine ring and 6.79 (8)° with the thiazole ring. The equivalent data for the second cation are 89.97 (3) and 6.42 (7)°, respectively. The pyrimidine ring adopts a sofa conformation in each cation. In the crystal, the components are linked by N—H...Cl hydrogen bonds, generating isolated ion pairs. The ion pairs are are linked by C—H...O interactions, generating a three-dimensional network. In addition, a weak C—H...π interaction is observed.