Conversion of diarylchalcones into 4,5-dihydropyrazole-1-carbothioamides: molecular and supramolecular structures of two precursors and three products
Abstract
Chalcones of type 4-XC6H4C(O)CH=CHC6H4(OCH2CCH)-4, where X = Cl, Br or MeO, have been converted to the corresponding 4,5-dihydropyrazole-1-carbothioamides using a cyclocondensation reaction with thiosemicarbazide. The chalcones 1-(4-chlorophenyl)-3-[4-(prop-2-ynyloxy)phenyl]prop-2-en-1-one, C18H13ClO2, (I), and 1-(4-bromophenyl)-3-[4-(prop-2-ynyloxy)phenyl]prop-2-en-1-one, C18H13BrO2, (II), are isomorphous, and their molecules are linked into sheets by two independent C—Hπ(arene) interactions, both involving the same aryl ring with one C—H donor approaching each face. In each of the products (RS)-3-(4-chlorophenyl)-5-[4-(prop-2-ynyloxy)phenyl]-4,5-dihydropyrazole-1-carbothioamide, C19H16ClN3OS, (IV), (RS)-3-(4-bromophenyl)-5-[4-(prop-2-ynyloxy)phenyl]-4,5-dihydropyrazole-1-carbothioamide, C19H16BrN3OS, (V), and (RS)-3-(4-methoxyphenyl)-5-[4-(prop-2-ynyloxy)phenyl]-4,5-dihydropyrazole-1-carbothioamide, C20H19N3O2S, (VI), the reduced pyrazole ring adopts an envelope conformation with the C atom bearing the 4-prop-2-ynyloxy)phenyl substituent, which occupies the axial site, displaced from the plane of the four ring atoms. Compounds (IV) and (V) are isomorphous and their molecules are linked into chains of edge-fused rings by a combination of N—H···S and C—H···S hydrogen bonds. The molecules 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.
Citation
Shaibah , M A E , Yathirajan , H S , . , A , Manju , N , Kalluraya , B , Rathore , R S & Glidewell , C 2020 , ' Conversion of diarylchalcones into 4,5-dihydropyrazole-1-carbothioamides: molecular and supramolecular structures of two precursors and three products ' , Acta Crystallographica Section E , vol. 76 , no. 3 , pp. 360-365 . https://doi.org/10.1107/S2056989020001735
Publication
Acta Crystallographica Section E
Status
Peer reviewed
ISSN
2056-9890Type
Journal article
Rights
Copyright © 2020 The Author(s). This is an open-access article distributed under the terms of the Creative Commons Attribution (CC-BY) Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.
Description
HSY thanks the University Grants Commission, New Delhi for the award of a BSR Faculty Fellowship for three years.Collections
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