title: Crystal structure of ethyl 4-(2,4-di-chloro-phen-yl)-2-methyl-4H-benzo[4,5]thia-zolo[3,2-a]pyrimidine-3-carboxyl-ate.
abstract: In the title compound, C20H16Cl2N2O2S, the pyrimidine ring has a screw-boat conformation. The attached di-chloro-phenyl ring is twisted at an angle of 89.29 (13)° with respect to the pyrimidine ring mean plane. The benzo-thia-zole group is approximately planar (r.m.s. deviation = 0.008 Å) and inclined to the pyrimidine ring mean plane by 3.04 (10)°. The carboxyl-ate group assumes an extended conformation with respect to the pyrimidine ring, which can be seen from the O=C-O-C torsion angle of 3.2 (4) °. In the crystal, mol-ecules are linked via C-H⋯O and C-H⋯N hydrogen bonds, forming slabs lying parallel to (100).
authors.affiliation: Centre of Advanced Study in Crystallography and Biophysics, University of Madras, Guindy Campus, Chennai 600 025, India.
authors.forename: T
authors.initials: T
authors.lastname: Sankar
authors.affiliation: Institution of Excellence, University of Mysore, Manasagangotri, Mysore 570 006, India.
authors.forename: S
authors.initials: S
authors.lastname: Naveen
authors.affiliation: Department of Studies in Physics, University of Mysore, Manasagangotri, Mysore 570 006, India.
authors.forename: N K
authors.initials: NK
authors.lastname: Lokanath
authors.affiliation: Centre of Advanced Study in Crystallography and Biophysics, University of Madras, Guindy Campus, Chennai 600 025, India.
authors.forename: K
authors.initials: K
authors.lastname: Gunasekaran
keywords: C—H⋯N hydrogen bonds; C—H⋯O hydrogen bonds; benzo­thia­zole; crystal structure; pyrimidine