Robert K. Howe

SYNTHESIS AND APPLICATION OF NOVEL THIAZOLES AS HERBICIDE ANTIDOTES

Abstract Alachlor, 2-chloro-2′,6′-diethyl-N-(methoxymethyl) acetanilide, has gained wide acceptance for its effective control of grasses and certain broadleaf weeds in corn, soybeans, peanuts and other crops. However, the inherent phytotoxicity of alachlor against grain sorghum has precluded its use for weed control in this crop. Monsanto has recently discovered a series of chemical safeners which permit the use of alachlor in grain sorghum. Noteworthy are the 2,4-disubstituted-thiazoles which possess excellent crop safety and are highly effective in countering injury of alachlor and other acetanilides such as acetochlor, butachlor and propachlor. The experiments reported describe the synthetic routes for preparation of these chemical safeners, as well as the biological data on spectrum of activity, application methods, genotypic response, seed storage features, yield performance and toxicology for Screen® (5-thiazolecarboxylic acid, benzylester,2-chloro-,4-(trifluoromethyl)-,).