Abstract: The invention relates to a process for preparing sulphonyl-ureas of the general formula (I) ##STR1## wherein Ar.sub.1 represents a phenyl, naphthyl or thienyl group, the derivatives thereof substituted by C.sub.1-4 alkyl, C.sub.1-4 haloalkyl, (halo)alkoxycarbonyl, (halo)alkyloxy, nitro, cyano groups as well as by halogen atoms,Ar.sub.2 represents a phenyl, pyridyl, pirimidinyl or triazinyl group and the derivatives thereof substituted by C.sub.1-4 (halo)alkyl, C.sub.1-4 (halo)alkyloxy, amino, O-acyl, O-arylsulphonyl, O-(substituted carbamoyl) groups as well as by halogen atoms.