[2-amino-3,5-dichloro-benzoic acid and 3-amino-2,5-dichloro-benzoic acid derivatives with phytotoxic action].

Derivatives of 2-amino-3,5-dichloro- and 3-amino-2,5-dichlorobenzoic acids have been prepared in order to extend previous research regarding the phytotoxicity of these two acids and of the corresponding N,N-di,sec.butylamides. The methyl esters of the two acids, the corresponding acids acetylated on the amino group and their respective methyl esters, and the N,N-di,sec.butylamides acetylated or formylated on the amino group were prepared. All these compounds were subjected to pre- and post-emergence tests using seven representative weeds, using doses of 6 kg/ha and, where substances proved active, at lower doses also. The results showed the importance of the N,N-di,sec.butylamide of 2-amino-3,5-dichlorobenzoic acid which, in contrast to the other derivatives tested, shows selective activity. For 3-amino-2,5-dichlorobenzoic acids and the amides tested, it was confirmed that only the acid shows marked generic phytotoxic activity in both pre- and post-emergence tests. It should be noted that the methyl ester of 3-acetylamino-2,5-dichlorobenzoic acid shows selective phytotoxicity activity.