Disclosed are nitro-sulfide dyes of formula (1) , their salts, isomers, hydrates and other solvates, wherein R1, R2, R3, independently from each other are hydrogen C1-C20alkyl or C1-C20alkoxy, which may be substituted by one or more C1-C5alkoxy, halogen, -NH2, mono-C1-C5alkylamino, di-C1-C5alkylamino, -NO2 or hydroxy C3-C6cycloalkyl -C(O)H -C(O)-C1-C5alkyl -C(O)OH -C(O)O-C1-C5alkyl halogen NO2 OH SH phenyl, which may be substituted by one or more C1-C5alkyl, C1-C5alkoxy, halogen, -NH2, mono-C1-C5alkylamino, di-C1- C5alkylamino, -NO2 or hydroxy or a radical of formula (1a) -NR4R5, wherein R4 and R5 independently from each other are hydrogen C1-C12alkyl, which may be substituted by one or more C1-C5alkyl, C1-C5-alkoxy, hydroxy or -(CO)-H -(CO)-C1- C5alkyl phenyl or phenyl-C1-C4alkyl, wherein the phenyl moiety may be substituted by one or more C1-C5alkyl, C1-C5alkoxy, halogen, -NH2, mono-C1-C5alkylamino, di-C1-C5alkylamino, -NO2, carboxy or hydroxy or a radical of formula (2) wherein at least one of the radicals R1, R2 or R3 is NO2 Y1 is C1-C10alkylene C5-C10cycloalkylene C5-C10arylene or C5-C10arylene-(C1-C10alkylene) Z1 is the direct bond formula (3) or a cationic biradical of a saturated, aromatic or heteroaromatic group Q1 is -C(O)- --C(O)O- -OCO- -N(R6)-X2- -CON(R6)- -(R6)NC(O)- -O- -S- -S(O)- or -S(O)2- X1 and X2 independently from each other are the direct bond C1-C10alkylene C5- C10cycloalkylene C5-C10arylene or C5-C10arylene-(C1-C10alkylene) and R6, R7 and R8 independently from each other are hydrogen C1-C14alkyl C2-C14alkenyl C6- C10aryl C6-C10aryl-C1-C10alkyl or C1-C10alkyl(C5-C10aryl) m is 1 or 2 U is hydrogen, if m is 1 or the direct bond, if m is 2 with the proviso that the method does not comprise contacting hair with an enzyme of the type of a protein disulfidisomerase (EC 5.3.4.1). Further, the present invention relates to novel sulfide compounds, compositions thereof, especially comprising other dyes, and to processes for their preparation.Linvention
