Synthesis and Herbicidal Activity of <i>N</i>-Aryl-2-methyl-2-aryipropanamides and <i>N</i>-Aryl-2-methyl-2-arylbutanamides

Abstract

One hundred and twelve N-aryl-2-methyl-2-arylpropanamides and N-aryl-2-methyl-2arylbutanamides were synthesized and their herbicidal activities were measured. Most of the compounds exhibited strong herbicidal activity against Echinochloa oryzicola VASING., Scirpus juncoides ROXB. subsp. juncoides ROXB. and Cyperus serotinus RoTTB. in pot tests. Introduction of substituents into the two benzene rings varied the activity to different extents. Both a meta alkyl substituent in the amine moiety and an ortho substituent in the acid moiety contributed to high activity, whereas introduction of strong electron-withdrawing substituents at the para position in the amine moiety or bulky substituents at the para position in the acid moiety was unfavorable to the activity. Among the compounds, N-(3-propylphenyl)-2methyl-2-(2-methoxyphenyl)butanamide showed the strongest activity against the test plants, completely killing Echinochloa oryzicola VASING. at a dose of 0.625 g a. i. /a in pot tests.