Sulphonylurea-type herbicides, their preparation, the compositions containing them and their use

摘要

Herbicides of formula I: <IMAGE> R is a hydrogen atom or a lower alkyl, lower alkenyl, lower alkynyl, lower alkoxy, lower alkoxyalkyl or lower haloalkyl radical; R1, R2 and R3 represent a hydrogen or halogen atom or a lower alkyl, lower alkoxy, lower haloalkyl or lower alkoxycarbonyl radical; R4 and R5 represent a lower alkyl, lower alkoxy or lower haloalkyl radical (preferably methyl or methoxy); X is a trivalent radical: -CH= or -N=.