Chlorobenzene-2,4-disulphonates (II), -disulphones (IV), and -disulphonamides (V) have been prepared from chlorobenzene-2,4-disulphonyl chloride (I). The properties and reactions of I–V have been compared with those of related derivatives of p-chlorobenzenesulphonic acid and phenoxybenzene-4,4′-disulphonic acid.