摘要:
The invention resides in the use of the compounds having the formula given below, or an acid salt thereof, as couplers in dyeing compositions for keratin fibres which contain an oxidation base: ##STR1## in which formula n is equal to 2, 3 or 4 and R.sub.1 and R.sub.2 are identical or different and represent an alkyl group having from 1 to 4 carbon atoms.