Synthesis and bioefficacy evaluation of 2-[4-(3-arylprop-2-enoyl)phenoxy]N-substituted acetamides and 2-[4-(5-aryl-4,5-dihydro-1H-pyrazol-3-yl)phenoxy]acetic acid hydrazides as potential pesticides

Base catalyzed condensation of 4-hydroxyacetophenone 1 with araldehydes 2-8 yields 3-aryl-1-(4-hydroxyphenyl)prop-2-en-1-ones 9-15. The compounds 9-15 are alkylated with ethyl chloroacetate to furnish ethyl [4-(3-arylprop-2-e noyl)phenoxy]acetates 16-22. The esters 16-22 are subjected to nucleophilic displacement reactions with isopropylamine and morpholine to give the titl e compounds, 2-[4(-3-arylprop-2-enoyl)phenoxyl-N-isopropylacetamides 23-29 and 4-[{4-(3-arylprop-2-enoyl)phenoxylacetyl]morpholine 30-36, respectively . The esters 16-22 are cyclized with excess of hydrazine hydrate in ethanol to give the title compounds, 2-[4-(5aryl-4,5-dihydro-1H-pyrazol-3-yl)pheno xy]acetic acid hydrazides 37-43. All the compounds are tested for their tox icity against five phytopathogenic fungi, Rhizoctonia solani, Rhizoctonia b ataticola, Sclerotinia sclerotiorum, Alternaria brassicae, and Fusarium sol ani, two saprophytic fungi Penicillium digitatum, and Aspergillus niger and one phytopathogenic bacterium Xanthomonas campestris pv. citrii. Some of t he compounds inhibit the growth of S. sclerotiorum, A. niger and X. campest ris pv. citrii at a concentration of 200 ppm.