Conversion of di-aryl-chalcones into 4,5-di-hydro-pyrazole-1-carbo-thio-amides: mol-ecular and supra-molecular structures of two precursors and three products

• Published in: Acta crystallographica. Section E, Crystallographic communications Vol. 76; no. Pt 3; pp. 360 - 365
• Main Authors: Shaibah, Mohammed A E, Yathirajan, Hemmige S, Asma, Manju, Nagaraja, Kalluraya, Balakrishna, Rathore, Ravindranath S, Glidewell, Christopher
• Format: Journal Article
• Language: English
• Published: England International Union of Crystallography 01.03.2020
• Subjects: Research Communications; chalcones; synthesis; hydrogen bonding; cyclo­condensation; supra­molecular assembly; mol­ecular conformation; reduced pyrazoles; heterocyclic compounds; crystal structures
• ISSN: 2056-9890; 2056-9890
• DOI: 10.1107/S2056989020001735

Chalcones of type 4- C H C(O)CH=CHC H (OCH CCH)-4, where = Cl, Br or MeO, have been converted to the corresponding 4,5-di-hydro-pyrazole-1-carbo-thio-amides using a cyclo-condensation reaction with thio-semicarbazide. The chalcones 1-(4-chloro-phen-yl)-3-[4-(prop-2-yn-yloxy)phen-yl]prop-2-en-1-one, C H ClO , (I), and 1-(4-bromo-phen-yl)-3-[4-(prop-2-yn-yloxy)phen-yl]prop-2-en-1-one, C H BrO , (II), are isomorphous, and their mol-ecules are linked into sheets by two independent C-H⋯π(arene) inter-actions, both involving the same aryl ring with one C-H donor approaching each face. In each of the products ( )-3-(4-chloro-phen-yl)-5-[4-(prop-2-yn-yloxy)phen-yl]-4,5-di-hydro-pyrazole-1-carbo-thio-amide, C H ClN OS, (IV), ( )-3-(4-bromo-phen-yl)-5-[4-(prop-2-yn-yloxy)phen-yl]-4,5-di-hydro-pyrazole-1-carbo-thio-amide, C H BrN OS, (V), and ( )-3-(4-meth-oxy-phen-yl)-5-[4-(prop-2-yn-yloxy)phen-yl]-4,5-di-hydro-pyrazole-1-carbo-thio-amide, C H N O S, (VI), the reduced pyrazole ring adopts an envelope conformation with the C atom bearing the 4-prop-2-yn-yloxy)phenyl substituent, which occupies the axial site, displaced from the plane of the four ring atoms. Compounds (IV) and (V) are isomorphous and their mol-ecules are linked into chains of edge-fused rings by a combination of N-H⋯S and C-H⋯S hydrogen bonds. The mol-ecules of (VI) are linked into sheets by a combination of N-H⋯S, N-H⋯N and C-H⋯π(arene) hydrogen bonds. Comparisons are made with the structures of some related compounds.