The crystal structures and Hirshfeld surface analyses of four 3,5-diacetyl-2-methyl-2,3-di-hydro-1,3,4-thia-diazol-2-yl derivatives.

ABSTRACT: The title compounds, 4-(5-acetamido-3-acetyl-2-methyl-2,3-di-hydro-1,3,4-thia-diazol-2-yl)phenyl benzoate, C20H19N3O4S (I), 4-(5-acetamido-3-acetyl-2-methyl-2,3-di-hydro-1,3,4-thia-diazol-2-yl)phenyl isobutyrate 0.25-hydrate, C17H21N3O4S·0.25H2O (II), 4-(5-acetamido-3-acetyl-2-methyl-2,3-di-hydro-1,3,4-thia-diazol-2-yl)phenyl propionate, C16H19N3O4S (III) and 4-(5-acetamido-3-acetyl-2-methyl-2,3-di-hydro-1,3,4-thia-diazol-2-yl)phenyl cinnamate chloro-form hemisolvate, C22H21N3O4S·0.5CHCl3 (IV), all crystallize with two independent mol-ecules (A and B) in the asymmetric unit in the triclinic P space group. Compound II crystallizes as a quaterhydrate, while compound IV crystallizes as a chloro-form hemisolvate. In compounds I, II, III (mol-ecules A and B) and IV (mol-ecule A) the five-membered thia-diazole ring adopts an envelope conformation, with the tetra-substituted C atom as the flap. In mol-ecule B of IV this ring is flat (r.m.s. deviation 0.044?Å). The central benzene ring is in general almost normal to the mean plane of the thia-diazole ring in each mol-ecule, with dihedral angles ranging from 75.8?(1) to 85.5?(2)°. In the crystals of all four compounds, the A and B mol-ecules are linked via strong N-H?O hydrogen bonds and generate centrosymmetric four-membered R 4 4(28) ring motifs. There are C-H?O hydrogen bonds present in the crystals of all four compounds, and in I and II there are also C-H?? inter-actions present. The inter-molecular contacts in the crystals of all four compounds were analysed using Hirshfeld surface analysis and two-dimensional fingerprint plots.

SUBMITTER: NizamMohideen M 

PROVIDER: S-EPMC6775747 | biostudies-literature | 2019 Oct

REPOSITORIES: biostudies-literature