Syntheses and Selective Herbicidal Activities of Ethyl 2-[4-(6-Chloro-2-quinoxalinyloxy) phenoxy] propanoate and Its Related Compounds

Abstract

Several derivatives of heterocyclicoxy phenoxy propanoic acid derivatives have been known as selective herbicide. During extensive investigations on the series with various condensed heterocyclic moieties, the quinoxalinyloxy phenoxy propanoic acid derivatives were found to show an excellent herbicidal activity against grass weeds. Data of herbicidal activities of 22 derivatives of 2-[4-(2-quinoxalinyloxy) phenoxy] propanoic acid against annual and perennial weeds were described. Among them, the title compound, (code No. NCI-96683), especially showed potent herbicidal activity against both annual and perennial grasses, i. e., Echinochloa crus-galli, Digitaria sanguinalis, Eleusine indica, Setaria viridis, Panicum dichotomiflorum, Avena fatua and Sorghum halepence with no significant phytotoxicity to broadleaf crops such as Glysine max (soybean), Gossypium spp. (cotton), Beta vulgaris (sugarbeet) and Brassica napus L. (rapeseed). In the field trials, this herbicide effectively controlled annual grasses at the rate of 0.05-0.15kg a. i./ha and perennial grasses at the rate of 0.11-0.22kg a. i./ha. It is proposed as a potent novel post emergence herbicide.