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Synthesis and fungitoxic activity of 5‐aryl‐1‐formyl‐4,5‐dihydro‐3‐(2‐hydroxyphenyl)‐1 H ‐pyrazoles and their complexes
Author(s) -
Singh Nisha,
Sangwan Naresh K,
Dhindsa Kuldip S
Publication year - 2000
Publication title -
pest management science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.296
H-Index - 125
eISSN - 1526-4998
pISSN - 1526-498X
DOI - 10.1002/(sici)1526-4998(200003)56:3<284::aid-ps128>3.0.co;2-m
Subject(s) - deprotonation , chemistry , aryl , medicinal chemistry , ligand (biochemistry) , fusarium oxysporum , pyrazole , formic acid , stereochemistry , organic chemistry , alkyl , ion , receptor , biochemistry , botany , biology
Cyclization of 3‐aryl‐1‐(2‐hydroxyphenyl)prop‐2‐en‐1‐ones with hydrazine hydrate in refluxing formic acid afforded the title ligands, 5‐aryl‐1‐formyl‐4,5‐dihydro‐3‐(2‐hydroxyphenyl)‐1 H ‐pyrazoles (HL 1 –HL 4 , Ar = Ph, 4‐CH 3 O‐C 6 H 4 ‐, 2‐furyl, 2‐thienyl). Reaction of HL 1 –HL 4 with the divalent metal ions, Mn 2+ , Co 2+ , Ni 2+ , Cu 2+ , and Zn 2+ , afforded novel complexes of the type [ML 2 ] (M = metal ion; L = deprotonated ligand) which were characterized by elemental analyses, molecular weight determinations, molar conductances, magnetic moments and electronic and infrared spectral data. The ligands behaved as tridentate, coordinating through the phenolic oxygen after deprotonation, N‐2 of the pyrazole ring and oxygen of the 1‐formyl group. The ligands and their complexes were evaluated for growth‐inhibiting activity against four phytopathogenic fungi. Macrophomina phaseoli was generally most sensitive followed by Alternaria alternata and Colletotrichum falcatum while Fusarium oxysporum was least sensitive to the tested compounds. The ligand HL 1 and its complexes showed the best activity against the fungi tested. © 2000 Society of Chemical Industry