[Selective phytotoxic activity of N,N-di,sec.butylamides of aminobenzoic acids mono-, di- and tri-substituted on the nucleus].

N,N-di,sec.butylaminobenzamides, mono-, di- or trisubstituted on the nucleus with methyl and/or halogen groups were prepared and tested for phytotoxicity. The corresponding benzoic acids and series of N-alkyl- and N,N-dialkylamides of 2-amino-3-bromo-5-methyl-, 2-amino-3,5-dibromo, 2-amino-3,5-dichloro- and 3-amino-2,5-dichlorobenzoic acids were studied in parallel. Both pre- and post-emergence phytotoxicity tests were carried out with doses of 6 kg/ha or less on seven representative weeds and some plants of agricultural interest. The series of N,N-di,sec.butylamides studied proved to be effectively phytotoxic on absorption through either the roots or the foliage. As regards the effect of substitution in the nucleus on the phytotoxicity of these amides, 3,5-dihalogenation proved important. The results also showed: 1) the importance of two sec.butyl groups on the amide nitrogen for the appearance of selective phytotoxicity against two grass weeds; 2) the different behaviour of the two acids (XXIa) and (XXIIa) in comparison with the corresponding di,sec.butylamides (XXI) and (XXII); 3) the importance of derivative (IL) which was highly active against graminaceous weeds but showed low phytotoxicity against crop plants, graminaceous ones included.