Hair dyes

摘要

1,2-Nitroaniline derivatives of formula (I) are new. A = 1-4C (hydroxy)alkylene or phenyl; R<1> = carboxyl or 2-4C hydroxyalkyl ; R<2> = H, 1-4C alkyl, allyl, 2-4C hydroxyalkyl or -(A)-R<1> ; R<3>-R<5> = H, F or 1-4C perfluoroalkyl, with the provision that at least one of R<3>-R<5> is H. Also claimed are (i) hair dyes comprising dyestuffs and dye precursors in a carrier, containing 0.001-5 wt.% (I) as a powder, cream, emulsion, gel, surfactant solution or aerosol foam in the carrier and (ii) a method for dyeing human hair by applying this dye onto the hair and then rinsing it out after it has been left in for a certain length of time.