Novel 2-alkyl sulfonyl ethyl-1,4-diaminobenzenes of formula 1 ##STR1## wherein R denotes CH.sub.3 or C.sub.2 H.sub.5 and the salts thereof, a process for making the compositions of formula I as well as compositions for the oxidative dyeing of human hair upon the basis of a developing substance-coupler substance-combination with a content of a composition of formula I as developing substance. The well water soluble developing substances of the formula I result in very natural appearing blond to brown color shades in combination with the coupler substances resorcinol, 4-chororesorcinol,4,6-dichlororesorcinol, 4-hydroxy-1,2-methylenedioxybenzene and 4-amino-1,2-methylenedioxybenzene.