title: Crystal structure of 2-acetyl-5-(3,4-di-meth-oxy-phen-yl)-6-eth-oxy-carbonyl-3,7-dimethyl-5H-thia-zolo[3,2-a]pyrimidin-8-ium chloride.
abstract: The title mol-ecular 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-dimeth-oxy-substituted phenyl ring subtends a dihedral angle of 88.38 (7)° with the pyrimidine ring and 6.79 (8)° with the thia-zole 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 inter-actions, generating a three-dimensional network. In addition, a weak C-H⋯π inter-action is observed.
authors.affiliation: Department of Studies in Chemistry, Central College Campus, Bangalore University, Bangalore 560 001, Karnataka, India.
authors.forename: N L
authors.initials: NL
authors.lastname: Prasad
authors.affiliation: Department of Studies in Chemistry, Central College Campus, Bangalore University, Bangalore 560 001, Karnataka, India.
authors.forename: M S
authors.initials: MS
authors.lastname: Krishnamurthy
authors.affiliation: Department of Studies in Chemistry, Central College Campus, Bangalore University, Bangalore 560 001, Karnataka, India.
authors.forename: Noor Shahina
authors.initials: NS
authors.lastname: Begum
keywords: C—H⋯π inter­actions; biological activity; chloride; crystal structure; hydrogen bonding; pharmacological properties; pyrimidine derivatives; pyrimidinium; salt