Dissymmetric azomethine direct dyes and process for their preparation, cosmetic composition comprising at least one such dye and use thereof

Abstract

The present invention relates to dissymmetric azomethine direct dyes of formula (I) and the leuco forms thereof of formula (II), and also to the use thereof for dyeing keratin fibres, in particular human keratin fibres such as the hair: ##STR00001##
in which formula (I) or (II) R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.6, n and n are as defined in the description. The compounds of formula (I) or (II) according to the invention can give powerful, chromatic and sparingly selective colourings with good colour build-up, which are resistant to the various attacking factors to which keratin fibres may be subjected, such as inclement weather, light, washing and perspiration.

Claims

1. A compound chosen from compounds of formulae (I) and/or (II) below, organic or mineral acid or base salts thereof, tautomeric forms thereof, optical isomers thereof, geometrical isomers thereof, or solvates thereof: ##STR00042## wherein formulae (I) and (II): n and n, which may be identical or different, represent an integer equal to 0, 1, 2, 3, 4 or 5; R.sub.1 and R.sub.2, which may be identical or different, represent: a halogen atom; a sulfonic radical SO.sub.3H or sulfonate radical SO.sub.3.sup.; a carboxyl radical CO.sub.2H, a carboxylate radical COO.sup.; an aromatic or non-aromatic, 5- to 10-membered cationic heterocycle, which is optionally substituted with one or more identical or different radicals chosen from C.sub.1-C.sub.4 alkyl and C.sub.1-C.sub.4 hydroxyalkyl; an aromatic or non-aromatic, 5- to 6-membered non-cationic heterocycle, substituted with: an ammonium radical N.sup.+RRR, An.sup. with R, R and R, which may be identical or different, representing a (C.sub.1-C.sub.4)alkyl group optionally substituted with at least one hydroxyl group, and/or an aromatic or non-aromatic, 5- to 10-membered cationic heterocycle, which is optionally substituted with one or more identical or different radicals chosen from C.sub.1-C.sub.4 alkyl and C.sub.1-C.sub.4 hydroxyalkyl; an ammonium radical N.sup.+RRR, An.sup., with R, R and R, which may be identical or different, representing a (C.sub.1-C.sub.4)alkyl group optionally substituted with at least one hydroxyl group; amino; hydroxyl, or thiol; a radical WR.sub.7, in which: W represents: an oxygen or sulfur atom, a divalent group N(R.sub.8) or a linear or branched, saturated or unsaturated, divalent hydrocarbon-based chain, comprising from 1 to 14 carbon atoms, the hydrocarbon-based chain being: optionally substituted with one or more radicals, which may be identical or different, chosen from the following radicals: i) hydroxyl, ii) (di)(C.sub.1-C.sub.6)(alkyl)amino, iii) ammoniums N.sup.+RRR with R, R and R, which may be identical or different, representing a (C.sub.1-C.sub.4)alkyl group optionally substituted with at least one hydroxyl group, iv) aromatic or non-aromatic, optionally substituted, 5- to 10-membered cationic heterocycles, v) aromatic or non-aromatic, 5- or 6-membered non-cationic heterocycles, substituted with one or more radicals, which may be identical or different, chosen from the following radicals: a) ammonium N.sup.+RRR with R, R and R, which may be identical or different, representing a (C.sub.1-C.sub.4)alkyl group optionally substituted with at least one hydroxyl group, or b), aromatic or non-aromatic, 5- to 10-membered cationic heterocycle, optionally substituted with one or more identical or different radicals chosen from C.sub.1-C.sub.4 alkyl; and/or optionally interrupted, optionally starting and/or optionally terminating with one or more divalent heteroatoms or groups, which may be identical or different, chosen from: O, S, N(R.sub.10), S(O), S(O).sub.2, and C(X) with X representing an oxygen or sulfur atom or a group NR.sub.10 wherein R.sub.10 represents a hydrogen atom or a (C.sub.1-C.sub.6)alkyl group, or combinations thereof; R.sub.7 and R.sub.8, which may be identical or different, represent: a hydrogen atom, a linear or branched C.sub.1-C.sub.14 alkyl group, said alkyl group being: optionally interrupted with at least one heteroatom or group, which may be identical or different, chosen from O, S, N(R.sub.8), S(O), S(O).sub.2, or C(X) with X representing an oxygen or sulfur atom or a group NR.sub.10 wherein R.sub.10 represents a hydrogen atom or a (C.sub.1-C.sub.6)alkyl group, or combinations thereof; and/or optionally substituted with one or more radicals, which may be identical or different, chosen from the following radicals: i) hydroxyl, ii) (di)(C.sub.1-C.sub.6)(alkyl)amino, iii) ammoniums N.sup.+RRR with R, R and R, which may be identical or different, representing a (C.sub.1-C.sub.4)alkyl group optionally substituted with at least one hydroxyl group, iv) aromatic or non-aromatic, optionally substituted, 5- to 10-membered cationic heterocycles, optionally substituted with one or more (C.sub.1-C.sub.4)alkyl groups, v) aromatic or non-aromatic, 5- or 6-membered non-cationic heterocycles, substituted with one or more radicals, which may be identical or different, chosen from the following radicals: a) ammonium N.sup.+RRR with R, R and R, which may be identical or different, representing a (C.sub.1-C.sub.4)alkyl group optionally substituted with at least one hydroxyl group, or b), aromatic or non-aromatic, 5- to 10-membered cationic heterocycle, optionally substituted with one or more identical or different radicals chosen from C.sub.1-C.sub.4 alkyl; R.sub.3 and R.sub.4, which may be identical or different, representing: a hydrogen atom, a (C.sub.1-C.sub.6)alkyl radical optionally substituted with at least one radical chosen from i) hydroxyl, ii) (C.sub.1-C.sub.4)alkoxy, iii) amino, iv) (C.sub.1-C.sub.6)alkylamino, or v) di(C.sub.1-C.sub.6)alkylamino; R.sub.5 and R.sub.6, which may be identical or different, represent an atom or group chosen from: a hydrogen atom, a halogen atom, a C.sub.1-C.sub.6 alkyl radical, a (C.sub.1-C.sub.6)alkyl radical substituted with at least one radical chosen from the following radicals: i) hydroxyl, ii) amino NH.sub.2, iii) (C.sub.1-C.sub.6)alkylamino, or iv) di(C.sub.1-C.sub.6)alkylamino, a (C.sub.1-C.sub.6)alkoxy radical, or a (C.sub.1-C.sub.6)alkoxy radical substituted with one or more radicals chosen from the following radicals: i) hydroxyl, ii) amino, iii) (C.sub.1-C.sub.6)alkylamino, or iv) di(C.sub.1-C.sub.6)alkylamino, it being understood that: the compounds of formulae (I) and (II) are dissymmetric, the sum of n+n is greater than or equal to 1, when the compound of formula (I) or (II) is cationic, it optionally comprises one or more anions An.sup. and optionally one or more cations M.sup.+ to ensure the electrical neutrality of the molecule; with: An.sup. denoting an anion chosen from bromide, chloride, methylsulfate, toluenesulfonate ions, or a mixture of these ions; and M.sup.+ representing a cation chosen from sodium, potassium, magnesium, calcium, or ammonium.

2. The compound of formulae (I) or (II) according to claim 1, wherein R.sub.3 and R.sub.4 represent a hydrogen atom.

3. The compound of formulae (I) or (II) according to claim 1, wherein R.sub.5 and R.sub.6 represent a hydrogen atom.

4. The compound of formulae (I) or (II) according to claim 1, wherein n represents an integer equal to 0 or 1.

5. The compound of formulae (I) or (II) according to claim 1, wherein R.sub.1 and R.sub.2, which may be identical or different, represent: a sulfonic radical SO.sub.3H or sulfonate radical SO.sub.3.sup.; a radical WR.sub.7, in which: W represents an oxygen or sulfur atom or a divalent group N(R.sub.8); R.sub.7 and R.sub.8, which may be identical or different, represent a linear or branched, saturated or unsaturated, alkyl group, comprising from 1 to 8 carbon atoms, said hydrocarbon-based chain being: optionally substituted with one or more radicals, which may be identical or different, chosen from the following radicals: i) hydroxyl, ii) (di)(C.sub.1-C.sub.6)(alkyl)amino, iii) ammoniums N.sup.+RRR with R, R and R, which may be identical or different, representing a (C.sub.1-C.sub.4)alkyl group optionally substituted with at least one hydroxyl group, iv) aromatic or non-aromatic, optionally substituted, 5- to 10-membered cationic heterocycles, v) aromatic or non-aromatic, 5- or 6-membered non-cationic heterocycles, substituted with a radical chosen from the following radicals: a) ammonium N.sup.+RRR, An.sup. with R, R and R, which may be identical or different, representing a (C.sub.1-C.sub.4)alkyl group optionally substituted with at least one hydroxyl group, and b) aromatic, 5- to 10-membered cationic heterocycle, optionally substituted with one or more radicals, which may be identical or different, chosen from C.sub.1-C.sub.4 alkyl; and/or optionally interrupted with at least one divalent heteroatom or group, which may be identical or different, chosen from: O, N(R.sub.10), and C(O), with R.sub.10, or combinations thereof; R.sub.7, and R.sub.8, which may be identical or different, represent: a hydrogen atom, a linear or branched C.sub.1-C.sub.14 alkyl group, said alkyl group being: optionally interrupted with at least one heteroatom or group, which may be identical or different, chosen from O, S, N(R.sub.10), S(O), S(O).sub.2, C(X), or combinations thereof; and/or optionally substituted with at least one radical, which may be identical or different, chosen from the following radicals: i) hydroxyl, ii) (di)(C.sub.1-C.sub.6)(alkyl)amino, iii) ammoniums N.sup.+RRR, iv) aromatic or non-aromatic, optionally substituted, 5- to 10-membered cationic heterocycles, v) aromatic or non-aromatic, 5- or 6-membered non-cationic heterocycles, substituted with a radical chosen from the following radicals: a) ammonium N.sup.+RRR, or b), aromatic or non-aromatic, 5- to 10-membered cationic heterocycle, optionally substituted with one or more identical or different radicals chosen from C.sub.1-C.sub.4 alkyl; n and n represent an integer equal to 0 or 1; R.sub.3 and R.sub.4, which may be identical or different, represent a hydrogen atom, a (C.sub.1-C.sub.6)alkyl radical, or a (C.sub.1-C.sub.6)alkyl radical substituted with one or more radicals chosen from hydroxyl or C.sub.1-C.sub.4 alkoxy; R.sub.5 and R.sub.6 represent a hydrogen atom; An.sup. is an anionic counterion chosen from bromide, chloride, methyl sulfate, toluenesulfonate ions, or a mixture of these ions.

6. The compound of formulae (I) or (II) according to claim 1, wherein R.sub.1 and R.sub.2, which may be identical or different, represent a group WR.sub.7 in which: W represents an oxygen atom or a divalent group N(R.sub.8); R.sub.7 and R.sub.8 are chosen from: a hydrogen atom, or a C.sub.1-C.sub.8 alkyl group; optionally interrupted with at least one heteroatom or group, which may be identical or different, chosen from O, S, S(O), S(O).sub.2, and C(X) with X representing an oxygen or sulfur atom or NR.sub.10, or combinations thereof; and/or optionally substituted with one or more radicals, which may be identical or different, chosen from the following radicals: i) hydroxyl, ii) C.sub.1-C.sub.4 alkoxy, iii) amino, iv) C.sub.1-C.sub.4 mono- and/or dialkylamino, v) ammoniums N.sup.+RRR, vi) optionally substituted 5- to 10-membered cationic heteroaryls or heterocycles, optionally substituted with one or more (C.sub.1-C.sub.4)alkyl groups chosen from imidazoliums, piperaziniums, pyrrolidiniums, morpholiniums, or piperidiniums, and vii) 5- or 6-membered non-cationic heteroaryls or heterocycles, optionally substituted with a radical chosen from ammoniums N.sup.+RRR with R, R and R as defined previously, and 5- to 10-membered cationic heteroaryls.

7. The compound of formulae (I) or (II) according to claim 1, wherein R.sub.1 and R.sub.2, which may be identical or different, represent a group chosen from: a radical OR.sub.7; a radical SR.sub.7; a radical NR.sub.7R.sub.8; a linear or branched C.sub.1-C.sub.14 alkyl radical, the alkyl radical being: optionally interrupted with one or more heteroatoms or groups, which may be identical or different, chosen from O, S, N(H), N(R.sub.10) S(O), S(O).sub.2, C(X) with X representing an oxygen or sulfur atom or NR.sub.10, or combinations thereof; and/or optionally substituted with one or more radicals, which may be identical or different, chosen from the following radicals: i) hydroxyl, ii) C.sub.1-C.sub.4 alkoxy, iii) amino NH.sub.2, iv) C.sub.1-C.sub.6 mono- and/or dialkylamino, v) ammoniums N.sup.+RRR with R, R and R, and vi) optionally substituted, aromatic or non-aromatic, 5- to 10-membered cationic heterocycles, optionally substituted with one or more (C.sub.1-C.sub.4)alkyl groups, vii) aromatic or non-aromatic, 5- or 6-membered non-cationic heterocycles, substituted with a radical chosen from the following radicals: ammoniums N.sup.+RRR, or optionally substituted, aromatic or non-aromatic, 5- to 10-membered cationic heterocycle, optionally substituted with one or more (C.sub.1-C.sub.4)alkyl groups; a hydroxyl, amino, C.sub.1-C.sub.4 alkylamino, C.sub.1-C.sub.4 dialkylamino, C.sub.1-C.sub.4 alkoxy, C.sub.1-C.sub.4 alkyl, or C.sub.1-C.sub.4 hydroxyalkyl radical; a linear or branched C.sub.1-C.sub.14 alkoxy radical, said alkoxy radical being: optionally interrupted with at least one heteroatom or group, which may be identical or different, chosen from O, S, S(O), S(O).sub.2, C(X) with X representing an oxygen or sulfur atom or NR, or combinations thereof; and/or optionally substituted with at least one radical, which may be identical or different, chosen from the following radicals: i) hydroxyl, ii) C.sub.1-C.sub.4 alkoxy, iii) amino NH.sub.2, iv) C.sub.1-C.sub.6 mono- and/or dialkylamino, v) ammoniums N.sup.+RRR, and vi) optionally substituted, aromatic or non-aromatic, 5- to 10-membered cationic heterocycles, optionally substituted with one or more (C.sub.1-C.sub.4)alkyl groups vii) aromatic or non-aromatic, 5- or 6-membered non-cationic heterocycles, substituted with a radical chosen from the following radicals: ammoniums N.sup.+RRR, and/or optionally substituted, aromatic or non-aromatic, 5- to 10-membered cationic heterocycle, optionally substituted with one or more (C.sub.1-C.sub.4)alkyl groups; a hydroxyl, amino, C1-C4 alkylamino, C1-C4 dialkylamino, C1-C4 alkoxy, C1-C4 alkyl, or C1-C4 hydroxyalkyl radical.

8. The compound of formulae (I) or (II) according to claim 1, wherein n and n represent an integer equal to 1, and R.sub.1 and R.sub.2 are, respectively, in position 4 and 4.

9. The compound of formulae (I) or (II) according to claim 1, wherein n represents an integer equal to 1, n represents an integer equal to 0, and R1 is in position 4.

10. The compound of formulae (I) or (II) according to claim 1, wherein said cationic heterocycle(s) are chosen from imidazoliums, piperaziniums, pyrrolidiniums, morpholiniums and piperidiniums; optionally substituted with one or more radicals, which may be identical or different, chosen from (hydroxy)(C.sub.1-C.sub.4)alkyl radicals.

11. The compound of formulae (I) or (II) according to claim 1, wherein said non-cationic heterocycle(s) are 5- or 6-membered and are chosen from piperidines, piperazines, pyrrolidines, morpholines, thiazoles, imidazoles, or pyridines, the 5- or 6-membered non-cationic heterocycles optionally substituted with: an ammonium radical N.sup.+RRR, An.sup. with R, R and R, which may be identical or different, representing a (C1-C4)alkyl group optionally substituted with one or more hydroxyl groups, and/or an aromatic or non-aromatic, 5- to 10-membered cationic heterocycle, which is optionally substituted with one or more identical or different radicals chosen from (hydroxy)(C.sub.1-C.sub.4)alkyl radicals.

12. The compound of formulae (I) or (II) according to claim 1, wherein the non-cationic heterocycle(s) are pyrrolidines substituted with: an ammonium radical N.sup.+RRR, An.sup., and/or an aromatic or non-aromatic, 5- to 10-membered cationic heterocycle, which is optionally substituted with one or more (hydroxy)(C.sub.1-C.sub.4)alkyl groups.

13. The compound of formulae (I) or (II) according to claim 1, wherein R.sub.1 and R.sub.2, which may be identical or different, represent a group chosen from: hydroxyl, amino, (di)(hydroxy)(C.sub.1-C.sub.6)alkylamino, (hydroxy)(C.sub.1-C.sub.6)alkoxy, or (di)(alkoxy)alkylamino.

14. The compound of formulae (I) or (II) according to claim 1, wherein the compound is chosen from compounds (1) to (16) and (1) to (16), geometrical or optical isomers thereof, tautomers thereof, organic or mineral acid or base salts thereof, or solvates thereof: ##STR00043## ##STR00044## ##STR00045## ##STR00046## with An.sup. as defined in claim 1, ##STR00047## ##STR00048## ##STR00049## ##STR00050##

15. The compound of formulae (I) or (II) according to claim 1, wherein the compound of formula (II) cannot represent the following compound: ##STR00051##

16. A cosmetic composition comprising at least one compound of formulae (I) and (II) according to claim 1.

17. The composition according to claim 16, wherein the composition does not comprise any chemical oxidizing agent.

18. The composition according to claim 16, wherein the composition further comprises at least one chemical oxidizing agent chosen from hydrogen peroxide, urea peroxide, alkali metal bromates, persalts, perborates, persulfates, peracids, or oxidase enzymes.

19. A method for dyeing keratin fibers, comprising: applying to the keratin fibers of a composition comprising at least one compound chosen from compounds of formulae (I) or (II) below, organic or mineral acid or base salts thereof, tautomeric forms thereof, optical isomers thereof, geometrical isomers thereof, or solvates thereof: ##STR00052## wherein formulae (I) and (II): n and n, which may be identical or different, represent an integer equal to 0, 1, 2, 3, 4 or 5; R.sub.1 and R.sub.2, which may be identical or different, represent: a halogen atom; a sulfonic radical SO.sub.3H or sulfonate radical SO.sub.3; a carboxyl radical CO.sub.2H, a carboxylate radical COO.sup.; an aromatic or non-aromatic, 5- to 10-membered cationic heterocycle, which is optionally substituted, with one or more identical or different radicals chosen from C.sub.1-C.sub.4 alkyl and C.sub.1-C.sub.4 hydroxyalkyl; an aromatic or non-aromatic, 5- to 6-membered non-cationic heterocycle, substituted with: an ammonium radical N.sup.+RRR, An.sup. with R, R and R, which may be identical or different, representing a (C1-C4)alkyl group optionally substituted with at least one hydroxyl group, and/or an aromatic or non-aromatic, 5- to 10-membered cationic heterocycle, which is optionally substituted, with one or more identical or different radicals chosen from C.sub.1-C.sub.4 alkyl and C.sub.1-C.sub.4 hydroxyalkyl; an ammonium radical N.sup.+RRR, An.sup.; amino; hydroxyl, or thiol; a radical WR.sub.7, in which: W represents: an oxygen or sulfur atom, a divalent group N(R.sub.8) or a linear or branched, saturated or unsaturated, divalent hydrocarbon-based chain, comprising from 1 to 14 carbon atoms, the hydrocarbon-based chain being: optionally substituted with one or more radicals, which may be identical or different, chosen from the following radicals: i) hydroxyl, ii) (di)(C.sub.1-C.sub.6)(alkyl)amino, iii) ammoniums N.sup.+RRR, iv) aromatic or non-aromatic, optionally substituted, 5- to 10-membered cationic heterocycles, v) aromatic or non-aromatic, 5- or 6-membered non-cationic heterocycles, substituted with one or more radicals, which may be identical or different, chosen from the following radicals: a) ammonium N.sup.+RRR, or b), aromatic or non-aromatic, 5- to 10-membered cationic heterocycle, optionally substituted with one or more identical or different radicals chosen from C.sub.1-C.sub.4 alkyl; and/or optionally interrupted, optionally starting and/or optionally terminating with one or more divalent heteroatoms or groups, which may be identical or different, chosen from: O, S, N(R.sub.10), S(O), S(O).sub.2, and C(X) with X representing an oxygen or sulfur atom or a group NR.sub.10 wherein R.sub.10 represents a hydrogen atom or a (C.sub.1-C.sub.6)alkyl group, or combinations thereof; R.sub.7 and R.sub.8, which may be identical or different, represent: a hydrogen atom, a linear or branched C.sub.1-C.sub.14 alkyl group, said alkyl group being: optionally interrupted with at least one heteroatom or group, which may be identical or different, chosen from O, S, N(R.sub.8), S(O), S(O).sub.2, or C(X) with X as defined previously, or combinations thereof; and/or optionally substituted with one or more radicals, which may be identical or different, chosen from the following radicals: i) hydroxyl, ii) (di)(C.sub.1-C.sub.6)(alkyl)amino, iii) ammoniums N.sup.+RRR, iv) aromatic or non-aromatic, optionally substituted, 5- to 10-membered cationic heterocycles, optionally substituted with one or more (C.sub.1-C.sub.4)alkyl groups, v) aromatic or non-aromatic, 5- or 6-membered non-cationic heterocycles, substituted with one or more radicals, which may be identical or different, chosen from the following radicals: a) ammonium N.sup.+RRR, or b), aromatic or non-aromatic, 5- to 10-membered cationic heterocycle, optionally substituted with one or more identical or different radicals chosen from C.sub.1-C.sub.4 alkyl; R.sub.3 and R.sub.4, which may be identical or different, representing: a hydrogen atom, a (C.sub.1-C.sub.6)alkyl radical optionally substituted with at least one radical chosen from i) hydroxyl, ii) (C.sub.1-C.sub.4)alkoxy, iii) amino, iv) (C.sub.1-C.sub.6)alkylamino, or v) di(C.sub.1-C.sub.6)alkylamino; R.sub.5 and R.sub.6, which may be identical or different, represent an atom or group chosen from: a hydrogen atom, a halogen atom, a C.sub.1-C.sub.6 alkyl radical, a (C.sub.1-C.sub.6)alkyl radical substituted with at least one radical chosen from the following radicals: i) hydroxyl, ii) amino NH.sub.2, iii) (C.sub.1-C.sub.6)alkylamino, or iv) di(C.sub.1-C.sub.6)alkylamino, a (C.sub.1-C.sub.6)alkoxy radical, or a (C.sub.1-C.sub.6)alkoxy radical substituted with one or more radicals chosen from the following radicals: i) hydroxyl, ii) amino, iii) (C.sub.1-C.sub.6)alkylamino, or iv) di(C.sub.1-C.sub.6)alkylamino, it being understood that: the compounds of formulae (I) and (II) are dissymmetric, the sum of n+n is greater than or equal to 1, when the compound of formula (I) or (II) is cationic, it optionally comprises one or more anions An.sup. and optionally one or more cations M.sup.+ to ensure the electrical neutrality of the molecule; with: An.sup. denoting an anion chosen from bromide, chloride, methylsulfate, toluenesulfonate ions, or a mixture of these ions; M.sup.+ representing a cation chosen from sodium, potassium, magnesium, calcium, or ammonium; applying to the keratin fibers, in a first step a) a composition comprising at least one compound of formula (II), and then, in a second step b) applying an oxidizing composition comprising a chemical oxidizing agent chosen from hydrogen peroxide, urea peroxide, alkali metal bromates, persalts, perborates, persulfates, peracids, or oxidase enzymes; wherein between step a) and step b), the fibers are optionally rinsed, and/or washed and then optionally dried.

20. The method according to claim 19, wherein the composition comprising at least one compound chosen from compounds of formulae (I) or (II) is applied to the fibers, and the fibers are then optionally rinsed, and/or washed, and the fibers are dried or left to dry.

21. The method according to claim 19, wherein the cosmetic composition comprising at least one compound of formula (II) is applied to the fibers, and the fibers are then optionally rinsed, and/or washed, and said fibers are dried or left to dry.

22. A method of preparing a compound of formulae (I) or (II) as defined in claim 15, according to the following scheme: access to the compounds (I): ##STR00053## access to the compounds (IL ##STR00054## which comprises the compounds (I): a) in a first stage, in reacting one molar equivalent of 1,5-dinitrobenzene compound (i) comprising in positions 2 and 4 a nucleofugal group Nu with one molar equivalent of aniline compound (ii); Nu representing a nucleofugal group; wherein this reaction is performed i) in a polar protic solvent chosen from water or a mixture of water/C.sub.1-C.sub.10 alcohol ii) and/or in the presence of one or more mineral or organic basifying agents chosen from diisopropylethylamine, trimethylamine, sodium hydroxide, potassium hydroxide, a mineral carbonate, or an acetate, iii) and/or at a temperature of between 0 C. and 75 C.; and then b) in a second stage, in maintaining the reaction medium under stirring for a time of between 5 minutes and 48 hours; and then c) the reaction product (iii) is optionally purified via recrystallization, filtration, or chromatography; d) in a third stage, in reacting compound (iii) with one molar equivalent of aniline compound (iv); wherein this reaction is performed i) in a polar protic solvent chosen from water, a mixture of water/C.sub.1-C.sub.10 alcohol, 1-methyl-2-pyrrolidinone, acetone, acetonitrile, pyridine, or N,N-dimethylformamide; ii) and/or in the presence of one or more mineral or organic basifying agents, chosen from diisopropylethylamine, trimethylamine, sodium hydroxide, potassium hydroxide, a mineral carbonate, or an acetate, iii) and/or at a temperature of between room temperature and the reflux temperature the solvent; and then e) in a fourth stage, in maintaining the reaction medium under stirring for a time of between 5 minutes and 48 hours; and then f) the reaction product (v) is optionally purified via recrystallization, filtration, or chromatography; g) according to another variant, compound (iii) is not purified, and reacts with one molar equivalent of aniline compound (iv) under the same conditions as steps d) and e), to give the product (v), which is optionally purified via recrystallization, filtration, or chromatography; h) in a fifth stage, in performing a reduction reaction on compound (v), wherein the reaction is performed in a solvent chosen from esters, (C.sub.1-C.sub.6)alkyl acetates, ethyl acetate, (C.sub.1-C.sub.6)alkanols I, or mixtures thereof; to give compound (I); and then i) compound (I) optionally being N-substituted with halogenated reagents R.sub.3-Hal and R.sub.4-Hal, wherein Hal is a halogen atom, after filtration, removal of the precipitate and optionally purification by chromatography or recrystallization; j) said process comprising the compounds (II) in performing a reduction reaction on the compounds (I).

23. A multi-compartment device comprising: (1) a first compartment comprising at least one compound chosen from compounds of formulae (I) and/or (II) below, organic or mineral acid or base salts thereof, tautomeric forms thereof, optical isomers thereof, geometrical isomers thereof, or solvates thereof: ##STR00055## in which formulae (I) and (II): n and n, which may be identical or different, represent an integer equal to 0, 1, 2, 3, 4 or 5; R.sub.1 and R.sub.2, which may be identical or different, represent: a halogen atom; a sulfonic radical SO.sub.3H or sulfonate radical SO.sub.3.sup.; a carboxyl radical CO.sub.2H, a carboxylate radical COO.sup.; an aromatic or non-aromatic, 5- to 10-membered cationic heterocycle, which is optionally substituted, with one or more identical or different radicals chosen from C.sub.1-C.sub.4 alkyl and C.sub.1-C.sub.4 hydroxyalkyl; an aromatic or non-aromatic, 5- to 6-membered non-cationic heterocycle, substituted with: an ammonium radical N.sup.+RRR, An.sup. with R, R and R, which may be identical or different, representing a (C.sub.1-C.sub.4)alkyl group optionally substituted with at least one hydroxyl group, and/or an aromatic or non-aromatic, 5- to 10-membered cationic heterocycle, which is optionally substituted, with one or more identical or different radicals chosen from C.sub.1-C.sub.4 alkyl and C.sub.1-C.sub.4 hydroxyalkyl; an ammonium radical N.sup.+RRR, An.sup.; amino; hydroxyl, or thiol; a radical WR.sub.7, in which: W represents: an oxygen or sulfur atom, a divalent group N(R.sub.8) or a linear or branched, saturated or unsaturated, divalent hydrocarbon-based chain, comprising from 1 to 14 carbon atoms, the hydrocarbon-based chain being: optionally substituted with one or more radicals, which may be identical or different, chosen from the following radicals: i) hydroxyl, ii) (di)(C.sub.1-C.sub.6)(alkyl)amino, iii) ammoniums N.sup.+RRR, iv) aromatic or non-aromatic, optionally substituted, 5- to 10-membered cationic heterocycles, v) aromatic or non-aromatic, 5- or 6-membered non-cationic heterocycles, substituted with one or more radicals, which may be identical or different, chosen from the following radicals: a) ammonium N.sup.+RRR, or b), aromatic or non-aromatic, 5- to 10-membered cationic heterocycle, optionally substituted with one or more identical or different radicals chosen from C.sub.1-C.sub.4 alkyl; and/or optionally interrupted, optionally starting and/or optionally terminating with one or more divalent heteroatoms or groups, which may be identical or different, chosen from: O, S, N(R.sub.10), S(O), S(O).sub.2, and C(X) with X representing an oxygen or sulfur atom or a group NR.sub.10 wherein R.sub.10 represents a hydrogen atom or a (C.sub.1-C.sub.6)alkyl group, or combinations thereof; R.sub.7 and R.sub.8, which may be identical or different, represent: a hydrogen atom, a linear or branched C.sub.1-C.sub.14 alkyl group, said alkyl group being: optionally interrupted with at least one heteroatom or group, which may be identical or different, chosen from O, S, N(R.sub.8), S(O), S(O).sub.2, or C(X), or combinations thereof; and/or optionally substituted with one or more radicals, which may be identical or different, chosen from the following radicals: i) hydroxyl, ii) (di)(C.sub.1-C.sub.6)(alkyl)amino, iii) ammoniums N.sup.+RRR, iv) aromatic or non-aromatic, optionally substituted, 5- to 10-membered cationic heterocycles, optionally substituted with one or more (C.sub.1-C.sub.4)alkyl groups, v) aromatic or non-aromatic, 5- or 6-membered non-cationic heterocycles, substituted with one or more radicals, which may be identical or different, chosen from the following radicals: a) ammonium N.sup.+RRR, or b), aromatic or non-aromatic, 5- to 10-membered cationic heterocycle, optionally substituted with one or more identical or different radicals chosen from C.sub.1-C.sub.4 alkyl; R.sub.3 and R.sub.4, which may be identical or different, representing: a hydrogen atom, a (C.sub.1-C.sub.6)alkyl radical optionally substituted with at least one radical chosen from i) hydroxyl, ii) (C.sub.1-C.sub.4)alkoxy, iii) amino, iv) (C.sub.1-C.sub.6)alkylamino, or v) di(C.sub.1-C.sub.6)alkylamino; R.sub.5 and R.sub.6, which may be identical or different, represent an atom or group chosen from: a hydrogen atom, a halogen atom, a C.sub.1-C.sub.6 alkyl radical, a (C.sub.1-C.sub.6)alkyl radical substituted with at least one radical chosen from the following radicals: i) hydroxyl, ii) amino NH.sub.2, iii) (C.sub.1-C.sub.6)alkylamino, or iv) di(C.sub.1-C.sub.6)alkylamino, a (C.sub.1-C.sub.6)alkoxy radical, or a (C.sub.1-C.sub.6)alkoxy radical substituted with one or more radicals chosen from the following radicals: i) hydroxyl, ii) amino, iii) (C.sub.1-C.sub.6)alkylamino, or iv) di(C.sub.1-C.sub.6)alkylamino, it being understood that: the compounds of formulae (I) and (II) are dissymmetric, the sum of n+n is greater than or equal to 1, when the compound of formula (I) or (II) is cationic, it optionally comprises one or more anions An.sup. and optionally one or more cations M.sup.+ to ensure the electrical neutrality of the molecule; with: An.sup. denoting an anion chosen from bromide, chloride, methylsulfate, toluenesulfonate ions, or a mixture of these ions; M.sup.+ representing a cation chosen from sodium, potassium, magnesium, calcium, or ammonium; and (2) a second compartment comprising at least one chemical oxidizing agent chosen from hydrogen peroxide, urea peroxide, alkali metal bromates, persalts, perborates, persulfates, peracids, or oxidase enzymes.

Description

SYNTHESIS EXAMPLES

Synthesis of 4-{4-amino-3-[4-aminophenylimino]-6-iminocyclohexa-1,4-dien-1-ylamino}phenol Hydrate (a)

(1) ##STR00022##

i) Synthesis of N-(5-chloro-2,4-dinitrophenyl)benzene-1,4-diamine (1a)

(2) ##STR00023##

(3) 8.44 mmol of 1,5-dichloro-2,4-dinitrobenzene (2.0 g, 1 equivalent) and 27.85 mmol of diisopropylethylamine (4.85 ml, 3.3 equivalents) are placed in a 250 ml three-necked flask under an inert atmosphere containing 40 ml of ethanol. 9.28 mmol of benzene-1,4-diamine dihydrochloride (1.68 g, 1.1 equivalents) are added portionwise while maintaining the temperature of the reaction medium below 25 C. with a bath constituted of an ice/water mixture, and the reaction is monitored by TLC with dichloromethane as eluent. After 1 hour at room temperature, the insoluble dark red matter formed is filtered off on a sinter, washed with 220 ml of ethanol, suction-filtered and dried in a desiccator (P.sub.2O.sub.5, vacuum, 40 C.) to give compound (1a) in the form of a dark red solid.

(4) The NMR and mass spectrometry analyses are in accordance with the expected structure (1a).

ii) Synthesis of 4-({5-[4-aminophenyl)amino]-2,4-dinitrophenyl}amino)phenol

(5) ##STR00024##

(6) 6.47 mmol of compound (1a) (2.0 g, 1 equivalent), 6.80 mmol of 4-aminophenol (742 mg, 1.05 equivalents), 6.80 mmol of diisopropylethylamine (1.18 ml, 1.05 equivalents) and 15 ml of 1-methyl-2-pyrrolidinone are placed in a 100 ml three-necked flask under an inert atmosphere. The reaction medium is heated to 70 C. and the reaction is monitored by TLC with an eluent constituted of a dichloromethane/methanol mixture (95/5). After 1 hour at 70 C., the heating is stopped and the reaction medium is then poured onto ice. The insoluble brown matter formed is filtered off on a sinter, washed with 350 ml of water, suction-filtered and then dried in a desiccator (P.sub.2O.sub.5, vacuum, 40 C.) to give compound (2a) in the form of a dark brown solid.

(7) The NMR and mass spectrometry analyses are in accordance with the expected structure (2a).

iii) Synthesis of 4-{4-amino-3-[4-aminophenylimino]-6-iminocyclohexa-1,4-dien-1-ylamino}phenol Hydrate (a)

(8) ##STR00025##

(9) 5.24 mmol of compound (2a) (2.0 g) are dissolved in 500 ml of methanol and are then reduced by catalytic hydrogenation with 5% palladium on charcoal in the presence of hydrogen at 70 C. under a pressure of 50 bar using an H-Cube midi hydrogenator sold by the company Thales Nanotechnologies, with a flow rate of 5 ml/minute. The resulting solution is evaporated and the black solid obtained is then purified by chromatography on normal-phase silica with an eluent constituted of dichloromethane and methanol. Compound (a) is obtained in the form of a light brown solid.

Synthesis of 2-[{4-[2-amino-4-imino-5-phenylaminocyclohexa-2,5-dienylideneamino]phenyl}-(2-hydroxyethyl)amino]ethanol (b)

(10) ##STR00026##

i) Synthesis of 2,2-({4-[(5-chloro-2,4-dinitrophenyl)amino]phenyl}imino)diethanol (1b)

(11) ##STR00027##

(12) 63.29 mmol of 1,5-dichloro-2,4-dinitrobenzene (15.0 g, 1 equivalent) and 202.52 mmol of diisopropylethylamine (35.3 ml, 3.2 equivalents) are placed in a 500 ml three-necked flask under an inert atmosphere containing 150 ml of ethanol. 66.45 mmol of 2,2-[(4-aminophenyl)imino]diethanol sulfate hydrate (salt) (20.75 g, 1.05 equivalents) are added portionwise while maintaining the temperature of the reaction medium below 25 C. with a bath constituted of an ice/water mixture, and the reaction is monitored by TLC with dichloromethane as eluent. After 2 hours at room temperature, the insoluble dark brown matter formed is filtered off on a sinter, washed with 2250 ml of water, suction-filtered and dried in a desiccator (P.sub.2O.sub.5, vacuum, 40 C.) to give compound (1b) in the form of a dark brown solid.

(13) The NMR and mass spectrometry analyses are in accordance with the expected structure (1 b).

ii) Synthesis of 2,2-[(4-({[2,4-dinitro-5-(phenylamino)phenyl]amino}phenyl)imino]diethanol (2b)

(14) ##STR00028##

(15) 12.60 mmol of compound (1 b) (5.0 g, 1 equivalent), 12.60 mmol of aniline (1.15 ml, 1 equivalent), 13.86 mmol of diisopropylethylamine (2.41 ml, 1.1 equivalents) and 20 ml of 1-methyl-2-pyrrolidinone are placed in a 250 ml three-necked flask under an inert atmosphere. The reaction medium is heated to 100 C. and the reaction is monitored by HPLC. After 6 hours at 100 C., the heating is stopped and the reaction medium is then poured onto ice. The insoluble brown matter formed is filtered off on a sinter, washed with 3200 ml of water, suction-filtered and then dried in a desiccator (P.sub.2O.sub.5, vacuum, 40 C.) to give compound (2b) in the form of a dark brown solid.

(16) The NMR and mass spectrometry analyses are in accordance with the expected structure (2b).

iii) Synthesis of 2-[{4-[2-amino-4-imino-5-phenylaminocyclohexa-2,5-dienylideneamino]phenyl}-(2-hydroxyethyl)amino]ethanol (b)

(17) ##STR00029##

(18) 12.13 mmol of compound (2b) (5.5 g, 1 equivalent) and 2.7 g of 5% palladium on charcoal are placed in a 250 ml three-necked flask under an inert atmosphere containing 60 ml of methanol. The reaction medium is heated to 65 C., 121.29 mmol of ammonium formate (7.65 g, 10 equivalents) are then added portionwise to the reaction medium and the reaction is monitored by TLC (dichloromethane/methanol: 95/5). After 2 hours at 65 C., the reaction medium is filtered through a sinter packed with Celite and the filtrate is then evaporated. The black solid obtained is then purified by chromatography on neutral alumina using an eluent constituted of a mixture of dichloromethane and methanol. Compound (b) is obtained in the form of a black solid.

(19) The NMR and mass spectrometry analyses are in accordance with the expected structure (b).

Synthesis of 2-[{4-[2-amino-5-(4-ethoxyphenylamino)-4-iminocyclohexa-2,5-dienylideneamino]phenyl}(2-hydroxyethyl)amino]ethanol (c)

(20) ##STR00030##

i) Synthesis of 2,2-{[4-({5-[(4-ethoxyphenyl)amino]-2,4-dinitrophenyl}amino)phenyl]imino}diethanol (1c)

(21) ##STR00031##

(22) 12.60 mmol of compound (1b) (5.0 g, 1 equivalent), 12.60 mmol of 4-ethoxyaniline (1.63 ml, 1 equivalent), 13.86 mmol of diisopropylethylamine (2.41 ml, 1.1 equivalents) and 20 ml of 1-methyl-2-pyrrolidinone are placed in a 250 ml three-necked flask under an inert atmosphere. The reaction medium is heated to 100 C. and the reaction is monitored by HPLC. After 3 hours at 100 C., the heating is stopped and the reaction medium is then poured onto ice. The insoluble dark red matter formed is filtered off on a sinter, washed with 3200 ml of water, suction-filtered and then dried in a desiccator (P.sub.2O.sub.5, vacuum, 40 C.) to give compound (1c) in the form of a dark brown solid.

(23) The NMR and mass spectrometry analyses are in accordance with the expected structure (1c).

ii) Synthesis of 2-[{4-[2-amino-5-(4-ethoxyphenylamino)-4-iminocyclohexa-2,5-dienylideneamino]phenyl}(2-hydroxyethyl)amino]ethanol (c)

(24) ##STR00032##

(25) 12.46 mmol of compound (1c) (6.2 g, 1 equivalent) and 3.0 g of 5% palladium on charcoal are placed in a 250 ml three-necked flask under an inert atmosphere containing 65 ml of methanol. The reaction medium is heated to 65 C., 124.62 mmol of ammonium formate (7.86 g, 10 equivalents) are then added portionwise to the reaction medium and the reaction is monitored by TLC (dichloromethane/methanol: 95/5). After 2 hours at 65 C., the reaction medium is filtered through a sinter packed with Celite and the filtrate is then evaporated. The black solid obtained is then purified by chromatography on neutral alumina using an eluent constituted of a mixture of dichloromethane and methanol. Compound (c) is obtained in the form of a black solid.

(26) The NMR and mass spectrometry analyses are in accordance with the expected structure (c).

Synthesis of 3-(4-amino-3-{4-[bis(2-hydroxyethyl)amino]phenylimino}-6-iminocyclohexa-1,4-dienylamino)phenol (d)

(27) ##STR00033##

i) Synthesis of 3-{[5-({4-bis(2-hydroxyethyl)amino]phenyl}amino)-2,4-dinitrophenyl]amino}phenol (1d)

(28) ##STR00034##

(29) 7.62 mmol of compound (1b) (3.0 g, 1 equivalent), 7.62 mmol of 3-aminophenol (832 mg, 1 equivalent), 8.38 mmol of diisopropylethylamine (1.46 ml, 1.1 equivalents) and 20 ml of 1-methyl-2-pyrrolidinone are placed in a 250 ml three-necked flask under an inert atmosphere. The reaction medium is heated to 100 C. and the reaction is monitored by TLC with an eluent constituted of a dichloromethane/methanol mixture (95/5). After 3 hours at 100 C., the heating is stopped and the reaction medium is then poured onto ice. The insoluble dark red matter formed is filtered off on a sinter, washed with 3200 ml of water, suction-filtered and then dried in a desiccator (P.sub.2O.sub.5, vacuum, 40 C.) to give compound (1d) in the form of a dark red solid.

(30) The NMR and mass spectrometry analyses are in accordance with the expected structure (1d).

ii) Synthesis of 3-(4-amino-3-{4-[bis(2-hydroxyethyl)amino]phenylimino}-6-iminocyclohexa-1,4-dienylamino)phenol (d)

(31) ##STR00035##

(32) 7.45 mmol of compound (1d) (3.5 g, 1 equivalent) and 1.70 g of 5% palladium on charcoal are placed in a 250 ml three-necked flask under an inert atmosphere containing 40 ml of methanol. The reaction medium is heated to 65 C., 74.55 mmol of ammonium formate (4.70 g, 10 equivalents) are then added portionwise to the reaction medium and the reaction is monitored by TLC (dichloromethane/methanol: 95/5). After 2 hours at 65 C., the reaction medium is filtered through a sinter packed with Celite and the filtrate is then evaporated. The black solid obtained is then purified by chromatography on neutral alumina using an eluent constituted of a mixture of dichloromethane and methanol. Compound (d) is obtained in the form of a black solid.

(33) The NMR and mass spectrometry analyses are in accordance with the expected structure (d).

Synthesis of 4-(4-amino-3-{4-[bis(2-hydroxyethyl)amino]phenylimino}-6-iminocyclohexa-1,4-dienylamino)phenol (e)

(34) ##STR00036##

i) Synthesis of 4-{[5-({4-[bis(2-hydroxyethyl)amino]phenyl}amino)-2,4-dinitrophenyl]amino}phenol (1e)

(35) ##STR00037##

(36) 12.69 mmol of compound (1b) (5.0 g, 1 equivalent), 12.69 mmol of 4-aminophenol (1.39 g, 1 equivalent), 13.97 mmol of diisopropylethylamine (2.43 ml, 1.1 equivalents) and 20 ml of 1-methyl-2-pyrrolidinone are placed in a 100 ml three-necked flask under an inert atmosphere. The medium is heated to 100 C. and the reaction is monitored by TLC with an eluent constituted of a dichloromethane/methanol mixture (95/5). After 3 hours at 100 C., the heating is stopped and the reaction medium is then poured onto ice. The insoluble dark red matter formed is filtered off on a sinter, washed with 3200 ml of water, suction-filtered and then dried in a desiccator (P.sub.2O.sub.5, vacuum, 40 C.) to give compound (1e) in the form of a dark red solid.

(37) The NMR and mass spectrometry analyses are in accordance with the expected structure (1e).

ii) Synthesis of 4-(4-amino-3-{4-[bis(2-hydroxyethyl)amino]phenylimino}-6-iminocyclohexa-1,4-dienylamino)phenol (e)

(38) ##STR00038##

(39) 11.71 mmol of compound (1b) (5.5 g, 1 equivalent) and 2.25 g of 5% palladium on charcoal are placed in a 250 ml three-necked flask under an inert atmosphere containing 60 ml of methanol. The reaction medium is heated to 65 C., 117.15 mmol of ammonium formate (7.39 g, 10 equivalents) are then added portionwise to the reaction medium and the reaction is monitored by TLC (dichloromethane/methanol: 95/5). After 2 hours at 65 C., the reaction medium is filtered through a sinter packed with Celite and the filtrate is then evaporated. The black solid obtained is then purified by chromatography on neutral alumina using an eluent constituted of a mixture of dichloromethane and methanol. Compound (e) is obtained in the form of a black solid.

(40) The NMR and mass spectrometry analyses are in accordance with the expected structure (e).

(41) Examples of Dyeing Evaluation:

(42) Cosmetic compositions 1 to 6 below were prepared:

(43) TABLE-US-00001 Composition Composition Composition Composition Composition 1 2 3 4 5 Compound 500 mg (a) Compound 500 mg (b) Compound 500 mg (c) Compound 500 mg (d) Compound 500 mg (e) Water 79.5 g 79.5 g 79.5 g 79.5 g 79.5 g Ethanol 15 g 15 g 15 g 15 g 15 g Benzyl 5 g 5 g 5 g 5 g 5 g alcohol

(44) 2.0 g of compositions 1 to 6 are applied to a lock of 1.0 g of grey hair containing 90% white hairs. After a leave-on time of 30 minutes at room temperature, the lock is rinsed, washed with a standard shampoo and then dried.

(45) Spectrocolorimetric Evaluation:

(46) The colour of the locks was evaluated in the CIE L* a* b* system using a Minolta Spectrophotometer CM3610D colorimeter. In this L* a* b* system, the three parameters respectively denote the intensity of the colour (L*), the green/red colour axis (a*) and the blue/yellow colour axis (b*).

(47) Colour Build-Up:

(48) The variation in colouration between the non-dyed and dyed locks of hair is defined by (E*) according to the following equation:
E*={square root over ((L*L.sub.o*).sup.2+(a*a.sub.o*).sup.2+(b*b.sub.o*).sup.2)}

(49) In this equation, L*, a* and b* represent the values measured on locks of hair after dyeing and L.sub.0*, a.sub.0* and b.sub.0* represent the values measured on locks of hair before dyeing. The higher the value of E*, the greater the colour build-up.

(50) Results:

(51) The colours obtained on the lock thus treated are collated in the attached table:

(52) TABLE-US-00002 Composition 1 Composition 2 Composition 3 Composition 4 Composition 5 L* = 28.79 L* = 24.22 L* = 23.41 L* = 23.52 L* = 22.68 a* = 3 a* = 4.74 a* = 1.22 a* = 4.01 a* = 1.1 b* = 4.69 b* = 0.97 b* = 0.34 b* = 0.89 b* = 0.1 E* = 35.13 E* = 41.32 E* = 41.63 E* = 41.88 E* = 42.24 Brown Dark green Blueish-black Dark green Blueish-black

(53) It is seen through these results that the compositions according to the invention give intense, chromatic hair colourings and good colour build-up.

COMPARATIVE EXAMPLES

(54) The following dye compositions A, B (comparative) and C (invention) were prepared from the ingredients mentioned in the table below. The contents are expressed as percentages of active material (in g) relative to the total weight of the composition.

(55) TABLE-US-00003 Compound 1 0 Compound 2 Compound 3 Composition Composition A Composition B C (comparative) (comparative) (invention) Compound 1 0.5 Compound 2 0.5 Compound 3 0.5 Pure ethyl alcohol 15 15 15 Benzyl alcohol 5 5 5 Water 79.5 79.5 79.5

(56) Process

(57) 2 g of each of the compositions are applied to 1 g locks of natural Caucasian hair containing 90% white hairs. After 30 minutes, the locks are rinsed, shampooed and then dried. The colorimetric data of each of the locks are then measured with a Minolta CM-3610d spectrophotometer.

(58) Results

(59) The results are given in the table below.

(60) TABLE-US-00004 L* a* b* E colour Composition A 50.24 2.94 16.52 9.66 Very very (comparative) light brown Composition B 47.34 1.58 12.22 13.15 Very very (comparative) light grey Composition C 28.79 3.00 4.69 35.13 Brown (invention)

(61) It is seen from the above table that the colour obtained with the comparative compositions A and B is significantly lighter than that obtained with composition C according to the invention. It should also be noted that the colour build-up is significantly greater for the composition according to the invention than for that obtained with the comparative compositions. Finally, it was not possible to obtain a brown shade with the comparative compositions A and B, whereas composition C according to the invention makes it possible to obtain a very intense grey-black colour.