ES395191A1 - N-substituted indamines - Google Patents

Abstract

A method of preparing a dye composition for keratin fibers, characterized in that: a) New endamines of formula are prepared **(See formula)** where R and R'each represent a hydrogen atom, an alkyl or lower alkoxy radical or an amino, acylamino or hydroxyl radical and one of them, but only one, is obligatorily an amino, acylammon or hydroxyl radical; R1 and R2 each representing a lower alkyl radical optionally substituted with a hydroxyl, amino, acylamino, carbamyl, alkylsulfonylamino or arylsulfonylamino radical; R3, R4, R5, R6, R7 and R8 represent a hydrogen atom or an alkyl or lower alkoxy radical; as well as their acid addition salts and their double zinc salts, it being understood that these compounds can be presented in a tautomeric form of that represented by formula (I); and for this purpose a paraphenylenediamine of the formula is counted **(See formula)** where Z1 and Z2 both represent a hydrogen atom or both a lower alkyl radical optionally substituted with a hydroxyl, amino, acylamino, carbamyl, alkylsulfonylamino to arylsulfonylamino moiety and Z3, Z4, Z5 and Z6 represent a hydrogen atom or an alkyl radical or lower alkoxy, with a compound of the general formula: **(See formula)** where Y represents an amino, acylamino or hydroxyl radical Y1 and Y2 both represent a hydrogen atom, in case the radicals Z1 and Z2 of formula (II) are different from hydrogen atoms, or both represent an alkyl radical lower optionally substituted with a hydroxyl, amino, acylamino, carbamyl, alkyl sulfonylamino or arylsulfonylamino residue, in the case that the radicals Z1 and Z2 are both hydrogen atoms; Y3, Y4, and Y5 each represent a hydrogen atom or a lower alkyl or alkoxy radical, this condensation being carried out in aqueous alkaline or hydroacetonic medium or in an alkaline mixture of water and isopropanol, in the presence of an oxidant, the compounds being able to be used (II) and (III) in the form of one of its salts and subsequently transformed, if necessary, the indamine or the indamine salt thus obtained into the desired indamine salt b) The product obtained in a) is separated, washed in a solvent and dried; c) The product obtained in b) is dissolved in an aqueous or hydro-alcoholic solution in an amount of 0.002 to 1% by weight of indamine or indamine salts; d) Other ingredients for dyeing compositions such as wetting agents, dispersing agents, penetrating agents, thickeners and cosmetic resins are introduced into the solution prepared in c) in an amount of 1 to 3% by weight relative to the total weight of the composition ; and everything adjusts to a PH of 3 to 10 and preferably of 6 to 9. (Machine-translation by Google Translate, not legally binding)