Complexes of derivatives of 4,5-dihydro-1H-pyrazole as potential pesticides

Department of Chemistry, CCS Haryana Agricultural University, Hisar-125 004, India Manuscript received 22 March 2000, revised 4 September 2000, accepted 30 November 2000 Cyclization of 3-aryl-1-(2-hydroxyphenyl)prop-2-en-1-ones with hydrazine hydrate in refluxing acetic acid furnishes 1-acetyl­-5-aryl-4,5-dihydro-3-(2-hydroxypheny1)-1H-pyrazoles HL1-HL4, Ar = Ph, 4-CH3O-C6H4_, 2-furyl, 2-thienyl, respectively). Refluxing of ligands HL1-HL4 with MnII, CoII, NiII, CuII and ZnII ions (M) in basic medium affords complexes of the type [ML2]. The ligands behave as tridentate, coordinating through oxygen of the 1-acetyl group, the phenolic oxygen after deprotonation and N-2 of the pyrazole ring. The ligands HL1, HL2, HL4 and their complexes show promising antifungal activity