TY - JOUR
T1 - Conversion of diarylchalcones into 4,5-dihydropyrazole-1-carbothioamides: molecular and supramolecular structures of two precursors and three products
AU - Shaibah, Mohammed A. E.
AU - Yathirajan, Hemmige S.
AU - ., Asma
AU - Manju, Nagaraja
AU - Kalluraya, Balakrishna
AU - Rathore, Ravindranath S.
AU - Glidewell, Christopher
N1 - HSY thanks the University Grants Commission, New Delhi for the award of a BSR Faculty Fellowship for three years.
PY - 2020/3
Y1 - 2020/3
N2 - 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.
AB - 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.
KW - Synthesis
KW - Cyclocondensation
KW - Chalcones
KW - Heterocyclic compounds
KW - Reduced pyrazoles
KW - Crystal structures
KW - Molecular conformation
KW - Hydrogen bonding
KW - Supramolecular assembly
U2 - 10.1107/S2056989020001735
DO - 10.1107/S2056989020001735
M3 - Article
SN - 2056-9890
VL - 76
SP - 360
EP - 365
JO - Acta Crystallographica Section E
JF - Acta Crystallographica Section E
IS - 3
ER -