PCT No. PCT/EP80/00103 Sec. 371 Date Apr. 8, 1981 Sec. 102(e) Date Apr. 8, 1981 PCT Filed Sep. 25, 1980 PCT Pub. No. WO81/00810 PCT Pub. Date Apr. 2, 1981.Use is made in the oxidative dyeing of hair of a preliminary coloring stage of the general formula <IMAGE> (I) wherein R signifies COOR', CONH2, CONHR', CONR'2, CONH-NH2, CONH-OH, CN, CH2OH, CHO, CH(OH)(OR'), CH(OR')2 and R' represents an alkyl group with 1 to 5 carbon atoms. The preliminary coloring stages as per formula (I) may be contained in the hair dyeing agents singly or in a mixture with known preliminary coloring stages and/or direct-acting hair dyeing agents. The hair dyeing agents may, in particular, additionally contain amino acids present in nature, their esters and/or their amides. The hair dyeing agents as described, are well compatible physiologically and it will particularly be brown to reddish-brown colorings having a natural effect, that may be obtained by their use.
Agent for oxidative dyeing of hair