SYNTHESIS AND HERBICIDAL ACTIVITIES OF 2-(5-ISOXAZOLYLOXY)ACETAMIDE DERIVATIVES

A series of 2-(5-isoxazolyloxy)acetamide derivatives was synthesized a nd their herbicidal activities against upland field plants were assess ed. Studies on the structure-activity relationships revealed that pote nt herbicidal activity was associated with the compounds carrying a 4- methyl-3-trifluoromethyl-5-isoxazolyl group on the oxyacetamide oxygen . Among the compounds examined, methyl-3-trifluoromethyl-5-isoxazolylo xy)acetamide (28) showed strong herbicidal activities against upland w eeds (barnyard grass, large crabgrass, pale smartweed and slender amar anth) without affecting cotton at 0.25-0.5 kg a.i./ha.