[Asymmetric N,N-dialkyl-3,5-dichlorobenzamides having phytotoxic activity].

Asymmetric N,N-dialkyl-3,5-dichlorobenzamides bearing on the amide N a sec.butyl group or a 1-methylbutyl or 1-ethylpropyl and a second C3 or C4 alkyl group which may be branched or linear, saturated or unsaturated, were prepared and tested for phytotoxicity in pre- and post-emergence experiments. As reference compounds were prepared and tested 3,5-dichlorobenzamides, isomers of the first series, characterized by the presence on the amide N of a n.butyl or ter.butyl in place of the sec.butyl, of a 1-ethylpropyl or other branched alkyl in place of the 1-methylbutyl and a second alkyl group (C2 leads to C4) of varying weight and nature. The results show that all the 3,5-dichlorobenzamides studied have high phytotoxic activity and good selectivity in respect of the two graminaceous weeds tested. The amides proving most active against the weeds were tested against some species of agricultural interest. The substances proving active against the weeds and atoxic for the agrarian species were characterized by the presence on the amide N of a branched C4 or C5 group and a second C3 or C4 group.