Couplers for hair coloring compositions for oxidative dyeing of hair are compounds of formula (1) wherein R is selected from the group consisting of C1 to C2 alkyl and hydroxyethyl; R1 is selected from the group consisting of a hydrogen, hydroxy, nitro, halogen, C¿1? to C5 alkyl or haloalkyl, C1 to C5 alkoxy or cycloalkoxy, C1 to C5 hydroxyalkyl and C1 to C5 hydroxyalkoxy; Ar is an aromatic group, preferably an aromatic group selected from the group consisting of a furyl, thienyl, pyridyl, phenyl, 2,3-dihydro-benzo[1,4]dioxin-5 or -6-yl or benzo[1,3]dioxol-4 or 5-yl group; and y = 1 to 3.