FR2983857A1 - New azomethine compounds, useful as direct dyes for coloring or lightening keratinous fibers, preferably human keratinous fibers such as hair - Google Patents

Abstract

Azomethine compounds (I) are new. Azomethine compounds of formula (I) and their organic or inorganic acid or base salts, their tautomers, optical isomers or geometrical isomers and/or their solvates, are new. R : linear or branched 1-4C-alkyl (optionally substituted by one or more hydroxy or imidazolium radicals, An ->), halo or 1-4C-alkoxy; An ->anion or its mixture; R1 : H or linear or branched 1-4C-alkyl; X : OH or N(R2)(R3); R2, R3 : H or linear or branched 1-6C-alkyl (optionally substituted with one or more OH or 1-4C-alkoxy); and n : 0-4. (1) substituted 3-amino-5,6-bis-phenylamino-pyridin-2-ol compounds of formula (II) and their organic or inorganic acid or base salts, their tautomers, optical isomers or geometrical isomers and/or their solvates; (2) a composition comprising (I) in a medium, or (II) and optionally comprising one or more oxidizing agents in a medium; (3) a method for dyeing keratin fibers, preferably human keratin fibers such as the hair, comprising either applying a dye composition comprising (I) in a medium to the fibers to obtain desired coloration, rising the fibers, optionally washing with shampoo and rinsed again, and drying or leaving the fibers to dry, or simultaneously or sequentially applying a dye composition comprising (II) and an oxidizing composition comprising the oxidizing agents to the wet or dry fibers; (4) a method for lightening the keratin fibers, comprising applying a dye composition comprising (I) in a suitable medium, where the composition is free of oxidizing agents, a cosmetic composition comprising one or more oxidizing agents to the fibers, and the compositions are sequentially or simultaneously applied to the fibers, rising the fibers, optionally washing with shampoo and rinsed again, and drying or leaving to dry the fibers; and (5) a multicompartment device comprising a first compartment containing a composition comprising (I) or (II) and a second compartment comprising the oxidizing agents. [Image] [Image].

Description

The present invention relates to specific triatomic azomethine direct dyes comprising at least one derived unit. 3-amino-2-hydroxypyridine as well as their use for coloring keratinous fibers, in particular human keratin fibers such as the hair The invention also relates to a keratinous fiber dyeing composition comprising, in a medium suitable for dyeing such azomethine direct dyes as well as a dyeing process using said composition. Finally, the subject of the invention is the precursors of these direct dyes, their use for dyeing keratinous fibers and a multi-compartment device containing them. The present invention relates to the field of dyeing keratin fibers and more particularly to that of hair dyeing.

It is known to dye keratinous fibers, and in particular the hair, with dyeing compositions containing one or more direct dyes, according to a process known as "direct dyeing". The method conventionally used in direct dyeing consists in applying to the keratinous fibers one or more direct dyes, or coloring molecules, having an affinity for said fibers, allowing them to be paused and then rinsing the fibers. The direct dyes heretofore used are generally nitrobenzene dyes, anthraquinone dyes, nitropyridine dyes, azo, xanthene, acridine, azine dyes or triarylmethane dyes.

These direct dyes may also be applied to the keratinous fibers in the presence of an oxidizing agent if it is desired to obtain a simultaneous effect of lightening the fibers. However, the resulting colorations are temporary or semi-permanent colorings, because the nature of the interactions that bind the direct dyes to the keratinous fiber, and their desorption of the surface and / or the core of the fiber are responsible for their weak dye power and their poor resistance to washing, weathering or perspiration.

Moreover, such direct dyes are generally sensitive to the action of oxidizing agents, which makes them particularly difficult to use in direct lightening dyeing compositions which are formulated from oxygenated water and an alkalizing agent, which are close to the compositions used for the oxidation dyeing. In other words, the direct dyes are generally not very compatible with the dyeing compositions intended to lighten the fibers and, consequently, their use in a lightening dyeing process, as an alternative to oxidation dyeing, is not still entirely satisfactory.

These dyes also have the disadvantage of lack of stability vis-à-vis the light, because of the low resistance of the chromophore to photochemical attacks, which tends to lead to a fading time of the color of the keratinous fibers.

There is therefore a real need for direct dyes that not only dye keratin fibers satisfactorily but are also stable in light, capable of leading to stain resistant to the various attacks that can suffer fibers such as bad weather, washing and transpiration, and furthermore, which are sufficiently stable in the presence of oxidizing agents such as hydrogen peroxide to be able to obtain a simultaneous lightening of the fiber with the advantages described above.

These objects are attained with the present invention which has particular subject azométhinique direct dyes of formula (I) below, their acid or base salts, organic or mineral, their tautomeric forms, optical isomers, geometric isomers and / or or their solvates: Formula (I) in which: n represents an integer equal to 0, 1, 2, 3 or 4; R represents: a linear or branched C1-C4 alkyl radical optionally substituted with one or more identical or different radicals chosen from hydroxyl or imidazolium radicals, An-; An-designating an anion or a mixture of cosmetically acceptable anions; a C1-C4 alkoxy radical; a halogen atom; - R1 represents: - a hydrogen atom, - a linear or branched C1-C4 alkyl radical, - X represents: - a hydroxyl radical, - a radical -NR2R3 in which R2 and R3 independently represent one of the other: a hydrogen atom, a linear or branched C 1 -C 6 alkyl radical, (R) n X R 1 N NH 2 (I), a linear or branched C 1 -C 6 alkyl radical substituted with one or several hydroxyl or C1-C4 alkoxy radicals. Another subject of the present invention relates to the use of one or more direct dyes of the azomethine type of formula (I) as defined above for the dyeing of keratinous fibers, in particular human keratinous fibers such as the hair. The present invention also relates to a composition for dyeing keratinous fibers, in particular human keratinous fibers such as the hair, comprising, in a medium suitable for dyeing, one or more azomethine-type direct dyes of formula (I) as defined previously. In particular, the invention also relates to the use of said dye composition for dyeing keratinous fibers, especially human keratin fibers such as the hair. The invention furthermore relates to a process for dyeing keratinous fibers, in particular human keratinous fibers such as the hair, in which said dyeing composition according to the invention is applied to said fibers for a time sufficient to obtain the desired coloration, after which it is rinsed, the fibers are optionally washed with shampoo, rinsed again and the resulting fibers are dried or allowed to dry. Similarly, the invention relates more particularly to a process for lightening keratinous fibers, especially human keratinous fibers such as the hair, in which said fiber (i) is applied to said dyeing composition that is free of oxidizing agent and (ii) a cosmetic composition comprising one or more oxidizing agents; the compositions (i) and (ii) being applied to said keratinous fibers sequentially or simultaneously for a time sufficient to obtain the desired lightening, after which the fibers are rinsed, washed optionally with shampoo, rinsed again and dried or the resulting fibers are allowed to dry.

The direct dyes of the azomethine type of formula (I) according to the invention thus make it possible to lead to colorings that are resistant to the various attacks that keratin fibers such as weather, light, washing and transpiration can undergo. In addition, the direct dyes according to the invention make it possible to dye the keratin fibers satisfactorily, in particular by leading to powerful, chromatic and low-selective colorations.

The direct dyes according to the invention have the advantage of being light-stable and can be used in the presence of an oxidizing agent, which facilitates their use in direct lightening dyeing compositions based on oxidizing agents. In other words, the direct dyes according to the present invention lead to stubborn colorations and are compatible with dye compositions which are intended to lighten the keratinous fibers. Furthermore, the subject of the invention is leuco-type colorless or weakly colored compounds, which correspond to the reduced form of the azomethine-type direct dyes according to the invention, of formula (II) below, their salts of acid or of organic or inorganic bases, their tautomeric forms, optical isomers, geometrical isomers and / or their solvates: ## STR5 ## Formula (II) in which n, R, R1 and X have the same meanings as those indicated in formula (I). The compounds of the leuco type according to the invention lead in the presence of one or more oxidizing agents to the direct dyes of the azomethine type of formula (I). Thus, the invention also relates to the use of one or more leuco-type compounds of formula (II) as precursors of direct dyes of formula (I). In particular, the invention relates to the use of one or more leuco-type compounds of formula (II) in the presence of one or more oxidizing agents for dyeing keratin fibers, in particular human keratin fibers such as hair. The invention also relates to a multi-compartment device or kit containing a first compartment comprising one or more leuco type compounds of formula (II) as defined above and a second compartment comprising one or more oxidizing agents. The leuco-type compounds of formula (II) used under oxidizing conditions thus have the advantage of leading to colorings that are resistant to the various attacks that keratinous fibers, such as weather, washing, light or sweat. Other features, aspects, objects and advantages of the present invention will become more apparent upon reading the following description and examples. I. Direct Azomethine Dyes The direct dyes according to the present invention comprise in their structure three or more aromatic rings and at least one unit derived from 3-amino-2-hydroxypyridine and an azomethine bond.

Preferably, in formula (I), direct dyes of the azomethine type according to the invention are as taken together or separately: n represents an integer equal to 0, 1 or 2; - R represents: - a C1-C2 alkyl radical, preferably methyl; a C2-C3 alkyl radical, linear or branched, substituted with one or more hydroxyl or imidazolium radicals, An-, preferably a 2-hydroxyethyl radical; a C1-C2 alkoxy radical, preferably a methoxy radical; a halogen atom, preferably chlorine; - R1 represents: - a hydrogen atom, - a C1-C2 alkyl radical, preferably a methyl radical; and / or - X represents: - a hydroxyl radical; - a radical -NR 2 R 3 in which R 2 and R 3 represent, independently of one another, a hydrogen atom or a linear or branched C 1 -C 4 alkyl radical; branched, preferably an ethyl or isopropyl radical, a linear or branched C2-C6 alkyl radical substituted with one or more hydroxyl or C1-C4 alkoxy radicals, preferably an ethyl or hexyl radical substituted by a hydroxyl radical, in particular a 2-hydroxyethyl radical or a 6-hydroxyethyl radical. An- denotes an anion or a mixture of cosmetically acceptable anions such as, for example, halides, such as chloride, methosulphates, nitrates; alkylsulfonates: Alk-S (O) 20- such as methylsulfonate or mesylate and ethylsulfonate; arylsulfonates: Ar-S (O) 20- such as benzenesulphonate and toluenesulphonate or tosylate; citrate; succinate; tartrate; lactate; alkyl sulphates: Alk-O-S (O) O- such as methylsulfate; aryl sulphates such as benzenesulphate and toluenesulphate; phosphate; acetate; triflate; and borates such as tetrafluoroborate. Preferably, An- is an anionic counterion selected from bromide, chloride, methylsulfate, toluenesulfonate or a mixture of these ions. Preferably, n represents an integer equal to 0, 1 or 2, in particular 0 or 2. Preferably, R represents a C1-C2 alkyl radical or a halogen atom. More preferably, R represents a C1-C2 alkyl radical, in particular a methyl radical. Preferably, R1 represents a hydrogen atom or a C1-C2 alkyl radical. More preferably, R 1 represents a hydrogen atom.

Preferably, X represents a radical -NR2R3 in which R2 and R3 represent, independently of one another, a hydrogen atom or a linear or branched C1-C6 alkyl radical optionally substituted with one or more hydroxyl radicals. . Preferably, R 2 and R 3 represent, independently of one another, a hydrogen atom, an ethyl radical, an isopropyl radical, an ethyl radical substituted with a hydroxyl radical, in particular a 2-hydroxyethyl radical, a hexyl radical substituted by a hydroxy radical, in particular a 6-hydroxyethyl radical. More preferably, R2 and R3 represent, independently of one another, a hydrogen atom, an ethyl radical or an isopropyl radical. Alternatively, X represents a hydroxy radical. According to one embodiment, n is equal to 0 or 2, R1 represents a hydrogen atom and X represents a radical -NR2R3 in which R2 and R3 represent, independently of one another, a hydrogen atom or a linear or branched C1-C6 alkyl radical optionally substituted by one or more hydroxyl radicals. According to this embodiment, n is preferably equal to 0 and X represents a radical -NR2R3 in which R2 and R3 represent, independently of one another, a linear or branched C1-C6 alkyl radical. According to this embodiment, n is preferably equal to 2, R represents a C1-C2 alkyl radical and X represents a radical -NR2R3 in which R2 and R3 represent a hydrogen atom. Preferably, the direct dyes of the azomethine type of formula (I) according to the invention are chosen from the following compounds as well as their geometric or optical isomeric forms, their tautomers, their acid or base salts, organic or inorganic or their solvates such as the hydrates: ## STR1 ## ({4- [ethyl (propan-2-yl) amino] phenylimino) pyridin Compound 1-2 (5H) -one H 2 N "NNH 2 3-amino-6 - [(4-amino-2,3-dimethylphenyl) amino] [(4-amino-2,3-dimethylphenyl] pyridine [5H] -one] HN N 0 lei NH 2 Compound 2 N H NNH 2 3-Amino-6- {4- [ethyl- (2-OH-gel, N-O-hydroxy-ethyl) -amino] - IN OH phenylamino} -5 - {4- [ethyl-2- (3-hydroxyethyl) -amino] -phenyl imino} -5H-pyridin-2-one H 2 N goi Compound NN H 2 3-Amino-6- (4-amino-HN) Phenylamino) -5- [4-amino-NH 2 N-phenylimino] -5H-pyridin-2-one 4H 2 N HN 3 N 2 H 2 NNH 2 N-O 3 -Amino-6- (4-amino-3 (or 2) -, ... Zz.,. methyl-phenylamino) -5- [4-amino-3 (or 2) -methylphenylimino] -5H-pyridin-2-one HO ® Compound NN ---., H2 0 3-Amino-6- (4- 5-hydroxy-phenylimino] -5H-lei OH 6 pyridin-2-one HON NNH 2 3-amino-5-hydroxy-phenylamino) 6- {4- [bis- (2-hydroxy-N, N-ethyl) -1,4,8-triazolamino] -phenylamino} -5- {OH 1-hydroxy-ethyl) -amino] -N, phenylimino} -5H-pyridin-2-C-one Compound 7 Cl- NNI-12 3-Amino-6- (3-chloro-4- HO) hydroxy-phenylamino) -5- [3-NH-N-chloro-4-hydroxy-1-chlorophenylimino] -5H-pyridin-2-one Compound 8 HO CI 3 -Amino-6- (2-chloro-4- [NNH] hydroxy-phenylamino) -5- [2- .., .. _-. '... <k .... chloro-4-hydroxy-NN o phenylimino] -5H-pyridin-2-one CI I-OH Compound 9 HON g NNH 2 cpyridin-2-one - ,, .. 3-Amino-6- {4- [bis- (2-hydroxy-HN) N-ethyl ) 1-amino] -2-methylphenylamino} -5- {4- [bis- (2-hydroxy-ethyl) -amino] -2-methylphenylimino} -5H-OH N OH Compound 10 / OH / HN NNI 3-Amino-6- [4- (6-hydroxy-hexylamino) ino) ... [phenylamino] -544- (6-NH-N-hydroxy-hexylamino) -phenylimino] -5H-pyridin-NH 2-one / Compound 11 NNH 2 3-Amino-6- [4- (ethyl-isopropyl) -2- [amino] phenylamino] - 5- [4- HN N 0 (ethyl-isopropyl-amino) -phenylimino] -4-methyl-5H-pyridin-2-one Compound 12 H 2 N ill N. .., ... - ..,. NH 2 3-Amino-6- (4-amino-2,3- '....... ...... es. dimethyl-phe HN N 0 nylamino) -5- [4-amino-2,3-dimethyl-phenylimino] -4-methyl-5-methyl-5-pyridin-2-one OH [ethyl- (2-hydroxy-ethyl) -. 3-Amino-6- {4- [ethyl- (2-hydroxy-N-methyl-1-hydroxy-ethyl-1-amino) -phenylamino} -5- {4- N amino] -phenyl imino} -4-methyl-5H-pyridin-2- Compound 14 one H 2 N,..., -. NH 3-Amino-6- (4-amino-N, -phenylamino) -5- [4-amino-N, phenylimino] -4-methyl-5H-lei NH 2 pyridin-2-one Compound H2N gib NNI-1, 3-Amino-6- (4-amino-3 (or 2) -NH-methyl-phenylaliphenyl) -5- [4-amino-3 (or 2) -methyl-phenylimino] 4-methyl-5H-pyridin-2-one NH 2 Compound 16 HO,.......... NH 3-Amino-6- (4-hydroxy-N-) - 2-phenylamino) -5 HN N 0 - [(4-hydroxy-phenylimino] -4-lei -OH-methyl-5H-pyridin-2-one Compound 17 HON ii NNH 2 3-Amino-6- {4- [bis- (2-Hydroxyethyl) HN ''....... E.zz., 0-amino] -phenylamino} -5- {4- OH OH OH [bis - O1-1 (2-hydroxy-ethyl) -amino] - compound 18 phenylimino} -4-methyl-5H-pyridin-2-one CI low Compound N NNH2O3-Amino-6- (3-chloro-4- 1H-hydroxy-phenylamino) -5- [3-chloro-4-hydroxy-OH phenylimino] -4-methyl-5H- pyridin-2-one HO CI Compound `, .. .., 3-Amino-6- (2-chloro-4- is N ....... HN N 2 hydroxy-phenylamino) -5- [2- ## STR5 ## NH 4 -Hydro-phenylimino] -4-methyl-5H-pyridin-2-one HO N NH 2 3 -Amino-6- 4- [bis- (2-hydroxy-1-ethyl) NHNN-amino] -2-methyl-phenylamino} -5- {4- [bis (2-hydroxy-ethyl) -amino] -2 N-methyl-phenylimino} -4-OH-methyl-5H-pyridin-2-one Compound 21 Preferably, the direct dyes of formula (I) according to the present invention are chosen from compounds of azomethine type 1 and 2. The dyes The compounds of formula (I) can be obtained according to the procedure below: ## STR1 ## The compounds corresponding to formula (I) are obtained in a controlled manner. generally by reacting the compounds 1 with 3-amino-2-hydroxypyridine derivatives 2 in a basic medium in the presence of an oxidizing agent. The base used is preferably an aqueous solution of ammonia and the oxidizing agent is preferably hydrogen peroxide. Synthetic methods approaching that described above are described in patent applications FR2234277, FR2047932, FR2106661 and FR2121101. The invention also relates to the use of one or more direct dyes of the azomethine type of formula (I) as described above for the dyeing of keratinous fibers, in particular human keratinous fibers such as the hair. II. Dyeing composition As indicated above, the present invention also relates to a dye composition of keratinous fibers, in particular human keratinous fibers such as the hair comprising, in a medium suitable for dyeing, one or more direct dyes of formula (I) such that previously defined. Preferably, the dyeing composition comprises one or more direct dyes of formula (I) chosen from compounds of azomethine type 1 and 2 and their mixture. The direct dye (s) as defined above may be present in the dye composition according to the invention in a content ranging from 0.001% to 10% by weight, preferably in a content ranging from 0.005% to 6% by weight, relative to to the total weight of the dye composition The dye composition according to the invention may further comprise one or more oxidation dyes. The oxidation dyes are generally chosen from oxidation bases optionally combined with one or more couplers. By way of example, the oxidation bases are chosen from para-phenylenediamines, bis-phenylalkylenediamines, para-aminophenols, ortho-aminophenols, heterocyclic bases and their addition salts. Among the para-phenylenediamines, there may be mentioned, for example, para-phenylenediamine, para-toluenediamine, 2-chloro-para-phenylenediamine, 2,3-dimethyl-para-phenylenediamine, 2,6-dimethyl-para-phenylenediamine, 2,6-diethyl-para-phenylenediamine, 2,5-dimethyl-para-phenylenediamine, N, N-dimethyl-para-phenylenediamine, N, N-diethyl-para-phenylenediamine, N, N-dipropyl-para-phenylenediamine, 4-amino-N, N-diethyl-3-methylaniline, N, N- bis - ((3-hydroxyethyl) paraphenylenediamine, 4-N, N-bis - ((3-hydroxyethyl) amino-2-methylaniline, 4-N, N-bis - ((3-hydroxyethyl) amino 2-chloro aniline, 2-13-hydroxyethyl paraphenylenediamine, 2-fluoro-para-phenylenediamine, 2-isopropyl-para-phenylenediamine, N - ((3-hydroxypropyl) paraphenylenediamine, 2-hydroxymethyl-para-phenylenediamine, N, N-dimethyl-3-methyl-para-phenylenediamine, N, N- (ethyl, (3-hydroxyethyl) paraphenylenediamine, N - ((3,7-dihydroxypropyl) paraphenylenediamine, N- (4'-aminophenyl) paraphenylenediamine, N-phenyl paraphenylenediamine, 2-P-hydroxyethyloxy para-phenylenediamine, 2-P-acetylaminoethyloxy para-phenylenediamine, N - ((3-methoxyethyl) para-phenylene diamine, 4-aminophenylpyrrolidine, 2-thienyl paraphenylenediamine, 2-hydroxyethylamino 5-amino toluene, 3-hydroxy-1- (4'-aminophenyl) pyrrolidine and their addition salts with an acid. Of the paraphenylenediamines mentioned above, paraphenylenediamine, para-toluenediamine, 2-isopropyl paraphenylenediamine, 2-13-hydroxyethyl paraphenylenediamine, 2-P-hydroxyethyloxy paraphenylenediamine, 2,6-dimethyl paraphenylenediamine, 2,6 ethyl paraphenylenediamine, 2,3-dimethyl paraphenylenediamine, N, N-bis - ((3-hydroxyethyl) paraphenylenediamine, 2-chloro-para-phenylenediamine, 2-P-acetylaminoethyloxy-para-phenylenediamine, and their addition salts with an acid Particularly preferred bis-phenylalkylenediamines include, for example, N, N-bis (3-hydroxyethyl) N, N'-bis (4'-aminophenyl) -1,3-diamino. propanol, N, N-bis ((3-hydroxyethyl) N, N'-bis- (4'-aminophenyl) ethylenediamine, N, N'-bis- (4-aminophenyl) tetramethylenediamine, N, N- bis - ((3-hydroxyethyl) N, N'-bis (4-aminophenyl) tetramethylenediamine, N, N'-bis- (4-methylaminophenyl) tetramethyl L-diamine, N, N'-bis (ethyl) N, N'-bis (4'-amino, 3'-methylphenyl) ethylenediamine, 1,8-bis (2,5-diamino phenoxy) -3 , 6-dioxaoctane, and their addition salts. Among para-aminophenols, para-aminophenol, 4-amino-3-methylphenol, 4-amino-3-fluoro phenol, 4-amino-3-chlorophenol, 4- amino 3-hydroxymethyl phenol, 4-amino-2-methylphenol, 4-amino-2-hydroxymethylphenol, 4-amino-2-methoxymethylphenol, 4-amino-2-aminomethylphenol, 4-amino-2 - ( 3-hydroxyethylaminomethyl) phenol, 4-amino-2-fluoro phenol, and their addition salts with an acid Among the ortho-aminophenols, there may be mentioned, by way of example, 2-amino phenol, 2- amino-5-methyl phenol, 2-amino-6-methylphenol, 5-acetamido-2-amino phenol, and their addition salts Amongst the heterocyclic bases, mention may be made by way of example, pyridine derivatives, pyrimidine derivatives and pyrazole derivatives.

Among the pyridine derivatives, mention may be made of the compounds described for example in patents GB 1 026 978 and GB 1 153 196, such as 2,5-diamino pyridine, 2- (4-methoxyphenyl) amino-3-amino pyridine, 3,4-diamino pyridine, and their addition salts.

Other pyridinic oxidation bases useful in the present invention are the 3-amino pyrazolo [1,5-4-pyridines oxidation bases or their addition salts described for example in the patent application FR 2801308. A by way of example, mention may be made of pyrazolo [1,5-a] pyridin-3-ylamine; 2-acetylamino pyrazolo [1,5-a] pyridin-3-ylamine; 2-morpholin-4-yl-pyrazolo [1,5-a] pyridin-3-ylamine; 3-amino-pyrazolo [1,5-a] pyridin-2-carboxylic acid; 2-methoxy-pyrazolo [1,5-a] pyridin-3-ylamino; (3-Amino-pyrazolo [1,5-a] pyridin-7-yl) -methanol; 2- (3-Amino-pyrazolo [1,5-a] pyridin-5-yl) -ethanol; 2- (3-Amino-pyrazolo [1,5-a] pyridin-7-yl) -ethanol; (3-Amino-pyrazolo [1,5-a] pyridin-2-yl) -methanol; 3,6-diamino-pyrazolo [1,5-a] pyridine; 3,4-diamino-pyrazolo [1,5-a] pyridine; pyrazolo [1,5-a] pyridine-3,7-diamine; 7-morpholin-4-yl-pyrazolo [1,5-a] pyridin-3-ylamine; pyrazolo [1,5-a] pyridine 3,5-diamine; 5-morpholin-4-yl-pyrazolo [1,5-a] pyridin-3-ylamine; 2 - [(3-amino-pyrazolo [1,5-a] pyridin-5-yl) - (2-hydroxyethyl) -amino] ethanol 2 - [(3-Amino-pyrazolo [1,5-a]) pyridin-7-yl) - (2-hydroxyethyl) amino] ethanol; 3-amino-pyrazolo [1,5-a] pyridine-5-ol; 3-amino-pyrazolo [1,5-a] pyridin-4-ol; 3-amino-pyrazolo [1,5-a] pyridin-6-ol; 3-amino-pyrazolo [1,5-a] pyridin-7-ol; as well as their addition salts. Among the pyrimidine derivatives, mention may be made of the compounds described, for example, in DE 2359399; JP 88-169571; JP 05-63124; EP 0770375 or patent application WO 96/15765 such as 2,4,5,6-tetraaminopyrimidine, 4-hydroxy 2,5,6-triaminopyrimidine, 2-hydroxy 4,5,6-triaminopyrimidine, 2 , 4-dihydroxy-5,6-diaminopyrimidine, 2,5,6-triaminopyrimidine and their addition salts and tautomeric forms, when tautomeric equilibrium exists.

Among the pyrazole derivatives, mention may be made of the compounds described in DE 3843892, DE 4133957 and patent applications WO 94/08969, WO 94/08970, FR-A-2 733 749 and DE 195 43 988 as the 4.5 1-methyl pyrazole, 4,5-diamino-1 - ((3-hydroxyethyl) pyrazole, 3,4-diamino pyrazole, 4,5-diamino-1- (4'-chlorobenzyl) pyrazole, 4, 5-diamino 1,3-dimethyl pyrazole, 4,5-diamino-3-methyl-1-phenylpyrazole, 4,5-diamino-1-methyl-3-phenylpyrazole, 4-amino-1,3-dimethyl-5-hydrazino pyrazole, 1-benzyl-4,5-diamino-3-methyl-pyrazole, 4,5-diamino-3-tert-butyl-methyl-pyrazole, 4,5-diamino-1-tert-butyl-3-methyl-pyrazole, 4 5-diamino-1 - ((3-hydroxyethyl) 3-methylpyrazole, 4,5-diamino-1-ethyl-3-methyl-pyrazole, 4,5-diamino-1-ethyl-3- (4'-methoxyphenyl) pyrazole, 4,5-diamino-1-ethyl-3-hydroxymethyl pyrazole, 4,5-diamino-3-hydroxymethyl-1-methyl pyrazole, 4,5-diamino-3-hydroxymethyl-1-isopropyl pyrazole, 4,5-diamino-3-m 1-isopropyl pyrazole, 4-amino 5- (2'-aminoethyl) amino 1,3-dimethyl pyrazole, 3,4,5-triamino pyrazole, 1-methyl 3,4,5-triamino pyrazole, 3,5-diamino-1-methyl-4-methylamino pyrazole, 3,5-diamino 4- (13-hydroxyethypamino-1-methyl pyrazole, and their addition salts. 4-5-Diaminol- (13-methoxyethyl) pyrazole may also be used, preferably a 4,5-diaminopyrazole and even more preferably 4,5-diamino-1 - ((3-hydroxyethyl) pyrazole and / or one of its salts.

As pyrazole derivatives, mention may also be made of diamino N, N-dihydropyrazolopyrazolones and especially those described in application FR-A-2 886 136 such as the following compounds and their addition salts: 2,3-diamino-6 7-Dihydro-1H, 5H-pyrazolo [1,2-a] pyrazol-1-one, 2-amino-3-ethylamino-6,7-dihydro-1H, 5H-pyrazolo [1,2-a] pyrazol -1-one, 2-amino-3-isopropylamino-6,7-dihydro-1H, 5H-pyrazolo [1,2-a] pyrazol-1-one, 2-amino-3- (pyrrolidin-1-yl) 6,6-dihydro-1H, 5H-pyrazolo [1,2-a] pyrazol-1-one, 4,5-diamino-1,2-dimethyl-1,2-dihydro-pyrazol-3-one, 4 5-Diamino-1,2-diethyl-1,2-dihydro-pyrazol-3-one, 4,5-diamino-1,2-di- (2-hydroxyethyl) -1,2-dihydro-pyrazol-3 -one, 2-amino-3- (2-hydroxyethyl) amino-6,7-dihydro-1H, 5H-pyrazolo [1,2-a] pyrazol-1-one, 2-amino-3-dimethylamino-6, 7-Dihydro-1H, 5H-pyrazolo [1,2-a] pyrazol-1-one, 2,3-diamino-5,6,7,8-tetrahydro-1H, 6H-pyridazino [1,2-a] pyrazol-1-one, 4-amino-1,2-diethyl-5- (pyrrolidin-1-yl) -1,2-dihydro-pyrazol-3-one, 4-amino-5- (3- dimethylamino-pyrrolidin-1-yl) -1,2-diethyl-1,2-dihydro-pyrazol-3-one, 2,3-diamino-6-hydroxy-6,7-dihydro-1H, 5H-pyrazolo [1 , 2-a] pyrazol-1-one. It will be preferred to use 2,3-diamino-6,7-dihydro-1H, 5H-pyrazolo [1,2-a] pyrazol-1-one and / or a salt thereof. As heterocyclic bases, 4,5-diamino-1- (13-hydroxyethyl) pyrazole and / or 2,3-diamino-6,7-dihydro-1H, 5H-pyrazolo [1,2-a] will be used preferentially. pyrazol-1-one and / or a salt thereof The dyeing composition may optionally comprise one or more couplers advantageously chosen from those conventionally used for dyeing keratin fibers, among these couplers, mention may in particular be made of meta-phenylenediamines, meta- aminophenols, meta-diphenols, naphthalenic couplers, heterocyclic couplers and their addition salts, for example 1,3-dihydroxybenzene or 1,3-dihydroxy-2-methyl. benzene, 4-chloro-1,3-dihydroxybenzene, 2,4-diamino-1- (4-hydroxyethyloxy) benzene, 2-amino-4- (B-hydroxyethylamino) -1-methoxybenzene, 1,3-diamino benzene, 1,3-bis- (2,4-diaminophenoxy) propane, 3-ureido aniline, 3-ureido 1-dimethylamino benzene, sesame ol, 1-β-hydroxyethylamino-3,4-methylenedioxybenzene, α-naphthol, 2-methyl-1-naphthol, 6-hydroxyindole, 4-hydroxyindole, 4-hydroxy-N-methylindole, amino-3-hydroxy-pyridine, 6-hydroxybenzomorpholine, 3,5-diamino-2,6-dimethoxypyridine, 1-N- (B-hydroxyethyl) amino-3,4-methylene dioxybenzene, 2,6 -bis- (β-hydroxyethylamino) toluene, 6-hydroxyindoline, 2,6-dihydroxy-4-methylpyridine, 1-H-methylpyrazole-5-one, 1-phenyl-3-methylpyrazole-5-one , 2,6-dimethyl pyrazolo [1,5-b] -1,2,4-triazole, 2,6-dimethyl [3,2-c] -1,2,4-triazole, 6-methyl pyrazolo [1,5-a] benzimidazole, their addition salts with an acid, and mixtures thereof. In general, the addition salts of the oxidation bases and couplers that can be used in the context of the invention are chosen especially from the addition salts with an acid such as hydrochlorides, hydrobromides, sulphates, citrates, succinates, tartrates, lactates, tosylates, benzenesulfonates, phosphates and acetates. The oxidation base (s) each advantageously represent from 0.001% to 10% by weight, and preferably from 0.005% to 6% by weight, relative to the total weight of the composition. The content of the coupler (s), if they are (are) present (s), are each advantageously from 0.001% to 10% by weight relative to the total weight of the composition, and preferably from 0.005% to 6% by weight relative to the total weight of the dye composition The dye composition according to the invention may also comprise one or more additional direct dyes different from the direct dyes of the azomethine type defined above. The additional direct dye (s) according to the invention are chosen from nitro dyes of the benzene series, which are neutral, acidic or cationic, acid or cationic neutral azo direct dyes, direct quinone dyes, and in particular neutral, acidic or cationic anthraquinone dyes, azine direct dyes, triarylmethane direct dyes, azomethine direct dyes and natural direct dyes. Among the benzene direct dyes that may be used according to the invention, the following compounds may be mentioned in a nonlimiting manner: -1,4-diamino-2-nitrobenzene, -1-amino-2-nitro-4-B-hydroxyethylaminobenzene -1-amino -2-nitro-4-bis ((3-hydroxyethyl) -aminobenzene -1,4-bis (13-hydroxyethylamino) -2-nitrobenzene -1-B-hydroxyethylamino-2-nitro-4-bis- ((3- hydroxyethylamino) -benzene -1-B-hydroxyethylamino-2-nitro-4-aminobenzene -1-13-hydroxyethylamino-2-nitro-4- (ethyl) (13-hydroxyethyl) aminobenzene -1-amino-3-methyl 4-13-hydroxyethylamino-6-nitrobenzene -1-amino-2-nitro-4-P-hydroxyethylamino-5-chlorobenzene -1,2-Diamino-4-nitrobenzene -1-amino-2-P-hydroxyethylamino-5- 1,2-Bis - ((3-hydroxyethylamino) -4-nitrobenzene -1-amino-2-tris (hydroxymethyl) methylamino-5-nitrobenzene -1-hydroxy-2-amino-5-nitrobenzene -1-nitrobenzene -1 2-Hydroxy-2-amino-4-nitrobenzene -1-Hydroxy-3-nitro-4-aminobenzene -1-Hydroxy-2-amino-4,6-dinitrobenzene -1-13-hydroxyethyloxy-2-13-hydro xyethylamino-5-nitrobenzene -1-methoxy-2-β-hydroxyethylamino-5-nitrobenzene -1-β-hydroxyethyloxy-3-methylamino-4-nitrobenzene -1-13,7-dihydroxypropyloxy-3-methylamino-4-nitrobenzene 1-13-hydroxyethylamino-4-13,7-dihydroxypropyloxy-2-nitrobenzene -1-13,7-dihydroxypropylamino-4-trifluoromethyl-2-nitrobenzene -1-13-hydroxyethylamino-4-trifluoromethyl-2-nitrobenzene -1- 13-hydroxyethylamino-3-methyl-2-nitrobenzene -1-P-aminoethylamino-5-methoxy-2-nitrobenzene -1-hydroxy-2-chloro-6-ethylamino-4-nitrobenzene -1-hydroxy-2-chloro 6-amino-4-nitrobenzene -1-Hydroxy-6-bis - ((3-hydroxyethyl) -amino-3-nitrobenzene -1-P-hydroxyethylamino-2-nitrobenzene -1-hydroxy-4-p-hydroxyethylamino-3 nitrobenzene. Among the azo direct dyes that may be used according to the invention, mention may be made of the cationic azo dyes described in the patent applications WO 95/15144, WO-95/01772 and EP714954, the content of which forms an integral part of the invention. Among these compounds, mention may be made of the following dyes: 1,3-dimethyl-24 [4- (dimethylamino) phenyl] azo] -1H-imidazolium chloride, 1,3-dimethyl-2-chloro [- (- 4-Aminophenyl) azo] -1H-imidazolium, 1-methyl-4 - [(methylphenylhydrazono) methyl] -pyridinium methylsulphate. Mention may also be made, among the azo direct dyes, of the following dyes, described in the COLOR INDEX INTERNATIONAL 3rd edition: Disperse Red 17, Acid Yellow 9, Acid Black 1, Basic Red 22, Basic Red 76, Basic Red 51, Basic Yellow 57, Basic Brown 16, Acid Yellow 36, Acid Orange 7, Acid Red 33, Acid Red 35, Basic Brown 17, Acid Yellow 23, Acid Orange 24, Disperse Black 9. Mention may also be made of 1- (4'-aminodiphenylazo) - 2-methyl-4bis- ((3-hydroxyethyl) aminobenzene and 4-hydroxy-3- (2-methoxyphenylazo) -1-naphthalenesulfonic acid Among the quinone direct dyes, the following dyes may be mentioned: Disperse Red 15 , Solvent Purple 13, Purple Acid 43, Disperse Purple 1, Disperse Purple 4, Disperse Blue 1, Disperse Purple 8, Disperse Blue 3, Disperse Red 11, Acid Blue 62, Disperse Blue 7, Purple 22, Disperse Purple 15, Basic Blue 99 and the following compounds: -1-N-methylmorpholiniumpropylamino-4-hydroxyanthraquinone -1-Aminopropylamino-4-met hylaminoanthraquinone -1-Aminopropylaminoanthraquinone -5-13-hydroxyethyl-1,4-diaminoanthraquinone -2-aminoethylaminoanthraquinone -1,4-bis - ((3,7-dihydroxypropylamino) anthraquinone.

Among the azine dyes, mention may be made of the following compounds: Basic Blue 17 and Basic Red 2. Among the triarylmethane dyes that can be used according to the invention, mention may be made of the following compounds: Basic Green 1, Acid Blue 9, Basic Violet 3, Basic Violet 14, Basic Blue 7, Acid Violet 49, Basic Blue 26 and Acid Blue 7. Among the azomethine dyes that may be used according to the invention, there may be mentioned the following compounds: -2-13-hydroxyethylamino-5- [bis - (( 3-4'-hydroxyethyl) amino] anilino-1,4-benzoquinone -2-13-hydroxyethylamino-5- (2'-methoxy-4'-amino) anilino-1,4-benzoquinone-3-N (2 ') -Chloro-4'-hydroxy) phenyl-acetylamino-6-methoxy-1,4-benzoquinone imine-3-N (3'-chloro-4'-methylamino) phenyl-ureido-6-methyl-1,4-benzoquinone imine-344 '-N- (ethyl, carbamylmethyl) -amino] -phenyl-ureido-6-methyl-1,4-benzoquinone imine Among the natural direct dyes that can be used according to the invention, let us mention the lawsone, the juglone, alizarin, purpurin, acid c arminic acid, keretic acid, purpurogalline, protocatechaldehyde, indigo, isatin, curcumin, spinulosin, apigenidine. It is also possible to use the extracts or decoctions containing these natural dyes, and in particular poultices or extracts made from henna. The additional direct dye (s) may be present in the dyeing composition in a content ranging from 0.001% to 10% by weight, preferably in a content ranging from 0.005% to 6% by weight, relative to the total weight of the composition. Preferably, the dyeing composition comprises one or more direct dyes of formula (I) as defined above and one or more azomethine direct dyes different from those of the present invention.

The medium suitable for dyeing, also called dyeing medium, is a cosmetic medium generally consisting of water or a mixture of water and at least one organic solvent. As organic solvent, there may be mentioned for example lower alkanols C1-C4, such as ethanol and isopropanol; polyols and polyol ethers such as 2-butoxyethanol, propylene glycol, propylene glycol monomethyl ether, diethylene glycol monoethyl ether and monomethyl ether, as well as aromatic alcohols such as benzyl alcohol or phenoxyethanol, and mixtures thereof. The solvents when present are present in proportions preferably of between 1 and 99% by weight approximately relative to the total weight of the dye composition, and even more preferably between 5 and 95% by weight approximately.

The dyeing composition may also contain various adjuvants conventionally used in compositions for dyeing hair, such as anionic, cationic, nonionic or amphoteric surfactants, or mixtures thereof, anionic, cationic, nonionic or amphoteric polymers, or mixtures thereof, inorganic or organic thickeners, and in particular anionic, cationic, nonionic and amphoteric polymeric associative thickeners, antioxidants, penetrating agents, sequestering agents, perfumes, buffers, dispersing agents, conditioning agents such as, for example, volatile or nonvolatile silicones, modified or otherwise, such as aminosilicones, film-forming agents, ceramides, preserving agents, opacifying agents. The adjuvants above are generally present in an amount for each of them between 0.01 and 20% by weight relative to the weight of the composition. Of course, one skilled in the art will take care to choose this or these optional additional compounds in such a way that the advantageous properties intrinsically attached to the dyeing composition according to the invention are not, or not substantially, impaired by the or the additions envisaged. The pH of the dye composition in accordance with the invention is generally between 3 and 12, preferably between 5 and 11, and even more preferably between 6 and 8.5. It can be adjusted to the desired value by means of acidifying or alkalizing agents usually used for coloring keratinous fibers or else using conventional buffer systems. Among the acidifying agents, mention may be made, by way of example, of mineral or organic acids such as hydrochloric acid, orthophosphoric acid, sulfuric acid, carboxylic acids such as acetic acid, tartaric acid, citric acid, lactic acid, sulphonic acids. Among the alkalinizing agents that may be mentioned, by way of example, are ammonia, alkaline carbonates, alkanolamines such as mono-, di- and triethanolamines and their derivatives, sodium or potassium hydroxides and following formula (III): Ra, Rb NWN 'Re Rd (III) wherein W is a propylene residue optionally substituted by a hydroxyl group or a C1-C4 alkyl radical; Ra, Rb, R, and Rd, which may be identical or different, represent a hydrogen atom, a C1-C4 alkyl radical or a C1-C4 hydroxyalkyl radical. The dye composition according to the invention may be in various forms, such as in the form of liquids, creams, gels, or in any other form suitable for dyeing keratinous fibers, and in particular human hair. As indicated above, the invention also relates to the use of the dye composition as defined above for the dyeing of keratinous fibers, in particular human keratinous fibers such as the hair. III. Dyeing process The dyeing process according to the present invention consists in applying to the keratin fibers, dry or wet, a dyeing composition as defined above for a time sufficient to obtain the desired coloration, after which the fibers are rinsed, optionally washed. with the shampoo, rinsed again and dried or allowed to dry the resulting fibers. Preferably, the exposure time of the dyeing composition is between 1 and 60 minutes, preferably between 5 and 40 minutes, and even more preferably between 10 and 30 minutes. The dyeing composition is generally applied to the keratinous fibers at room temperature, preferably between 25 and 55 ° C.

According to one embodiment, the dye composition according to the invention is applied to the keratinous fibers in the presence of one or more oxidizing agents for a time sufficient to obtain the desired lightening. The oxidizing agent may be present in the dye composition or may be used separately in a cosmetic composition. Preferably, the oxidizing agent is used separately in a cosmetic composition. Thus, the present invention also relates to a process for lightening keratinous fibers, in particular human keratinous fibers such as the hair, in which said dye composition as defined previously free of oxidizing agent is applied to said fibers (i) and ( ii) a cosmetic composition comprising one or more oxidizing agents; the compositions (i) and (ii) being applied to said keratinous fibers sequentially or simultaneously for a time sufficient to obtain the desired lightening, after which the fibers are rinsed, washed optionally with shampoo, rinsed again and dried or the resulting fibers are allowed to dry.

By "sequentially" is meant in the sense of the present invention that the oxidizing composition is applied before or after the dye composition, that is to say in pre- or post-treatment. The oxidizing agents used are chosen from hydrogen peroxide, urea peroxide, alkali metal bromates, persalts such as perborates and persulfates, peracids and oxidase enzymes (with their possible cofactors), among which mention peroxidases, 2-electron oxidoreductases such as uricases and 4-electron oxygenases such as laccases.

Preferably, the oxidizing agent is hydrogen peroxide. The oxidizing composition may also contain various adjuvants conventionally used in hair dye compositions and as defined above. The pH of the oxidizing composition containing the oxidizing agent is such that, after mixing with the dyeing composition, the pH of the resulting composition applied to the keratin fibers preferably varies between 3 and 12, more preferably between 5 and 11, and even more particularly between 6 and 9.5. It can be adjusted to the desired value by means of acidifying or basifying agents usually used for coloring keratinous fibers and as defined above. IV. The present invention also relates to compounds of the following leuco type of formula (II), their organic or inorganic acid salts, their tautomeric forms, optical isomers, geometric isomers and / or their solvates: X R1 HNN H2N NOH H25 Formula (II) wherein n, R, R1, and X have the same meanings as those indicated in formula (I). In particular, the preferred variants of n, R, R1 and X in the formula (II) of the leuco compounds correspond to those indicated in the formula (I) of the direct dyes. The leuco compounds of formula (II) are obtained generally by reacting the azomethine compounds of formula (I) with a reducing agent according to the following reaction scheme: Reducing agent Fe (I) Synthesis approximating this reaction scheme are described in patent applications FR2056799, FR2047932, FR2165965 and FR2262023. The leuco compounds of formula (II) are used as precursors of direct dyes of formula (I). Preferably, the leuco type compounds of formula (II) are chosen from the compounds corresponding to the reduced form of the azomethine direct dyes 1 to 22 mentioned above. In other words, the leuco type compounds of formula (II) are chosen from the precursors of direct dyes of azomethine type 1 to 22.

Even more preferably, the leuco type compounds of formula (II) are chosen from the precursors of direct dyes of azomethine type 1 and 2.

In particular, the invention relates to a cosmetic composition comprising one or more leuco type compounds of formula (II) as defined above. The present invention also relates to a dyeing process in which a cosmetic composition comprising one or more leuco-type compounds of formula (II) above, in the presence of one or more oxidizing agents, is applied to the keratin fibers for a time sufficient to develop the desired coloring, after which the fibers are rinsed, washed optionally with shampoo, rinsed again and dried or allowed to dry the resulting fibers. The oxidizing agent can be oxygen of the air or be chosen from the oxidizing agents mentioned above. In particular, when the oxidizing agent is oxygen in the air, the simple exposure to air of the keratinous fibers treated with the composition comprising the leuco-type compound (s) makes it possible to generate the dyeing species and, for example, therefore, color the keratin fibers. According to one variant, the oxidizing agent (s) may be applied simultaneously or sequentially to the cosmetic composition comprising the leuco type compounds. Thus, the cosmetic composition comprising the oxidizing agent (s) may be applied to the keratin fibers before, simultaneously with or after the cosmetic composition comprising the leuco type compounds of formula (II) according to the invention. According to another variant, a ready-to-use composition is applied to the keratinous fibers which results from the mixing of a cosmetic composition comprising one or more leuco-type compounds of formula (II) above and of a cosmetic composition comprising one or more several oxidizing agents. The ready-to-use composition which is thus applied to the keratinous fibers may be in various forms, such as in the form of liquids, creams, gels or in any other form suitable for dyeing keratinous fibers, and including human hair. The exposure time of the composition (s) varies from 1 to 60 minutes, preferably from 5 to 40 minutes, and even more preferably from 10 to 30 minutes. The cosmetic composition comprising such leuco type compounds is generally applied to the keratin fibers at room temperature, preferably between 25 and 55 ° C. Thus, the invention relates to a cosmetic composition, in particular for dyeing keratinous fibers such as the hair, comprising, in a cosmetically acceptable medium, one or more leuco type compounds of formula (II) and optionally one or more oxidizing agents.

V. Dyeing Device The present invention further relates to a multi-compartment device or dyeing kit comprising a first compartment containing a cosmetic composition comprising one or more direct dyes of formula (I) above or one or more leuco type compounds of formula (II) above, and optionally a second compartment containing a cosmetic composition comprising one or more oxidizing agents. The device is suitable for dyeing keratin fibers. In particular, the invention relates to a multi-compartment device or dyeing kit comprising a first compartment containing a cosmetic composition comprising one or more direct dyes of formula (I) above or one or more leuco type compounds of formula (II) above and a second compartment containing a cosmetic composition comprising one or more oxidizing agents.

Thus, the invention relates to a multi-compartment device or dyeing kit comprising a first compartment containing a cosmetic composition comprising one or more direct dyes of formula (I) above free of oxidizing agent, and a second compartment containing a cosmetic composition comprising one or more oxidizing agents. Furthermore, the invention relates to a multi-compartment device or dyeing kit comprising a first compartment containing a cosmetic composition comprising one or more leuco type compounds of formula (II) above, and a second compartment containing a cosmetic composition comprising a or several oxidizing agents. According to a particular embodiment, the device comprises a compartment containing a cosmetic composition comprising one or more leuco type compounds of formula (II) above. In this case, the composition comprising the leuco type compound (s) as defined above is applied to the keratinous fibers which are colored by virtue of their exposure to air.

The examples which follow serve to illustrate the invention without, however, being limiting in nature. Synthesis Examples Example 1: Synthesis of 3-amino-6 - ({4- [ethyl (propan-2-yl) amino] phenylamino) -5 - ({4- [ethyl (propan-2-yl)} amino] phenyl} imino) pyridin-2 (5H) -one (compound 1) yCH, CH3 CH3 Compound 1 To a solution of 0.002 mole (0.42 g) of N-ethyl-N-isopropylbenzene hydrochloride 1,4-diamine and 0.001 moles (0.11 g) of 3-amino-2-hydroxypyridine in 1 ml of water and 1 ml of acetone brought to pH 9.5 with a 20% ammonia solution, add 3.5 ml of hydrogen peroxide at 6% 20V; After stirring for 5 hours at room temperature, the black gum formed containing 3-amino-6 - ({4- [ethyl (propan-2-yl) amino] phenylamino) -5 - is washed with water. 4- [ethyl (propan-2-yl) amino] phenyl} imino) pyridin-2 (5H) -one (compound 1). Liquid chromatography and mass spectrometry of the obtained gum show that molecular ion 461 (ES +) is detected in bulk. Example 2 Synthesis of 3-amino-6 - [(4-amino-2,3-dimethylphenyl) amino] -5 - [(4-amino-2,3-dimethylphenyl) imino] pyridin-2 (5H) - one (compound 2) 2 NH 2 HN NH 2 H 2 O 2 Acetone / H 2 O H, CLCH 2, H 2, C 25 NH 2 H 2 O 2 Acetone / H 2 O 2 NH 2 2HCl NH 2 Compound 2 To a solution of 0.002 mol (0.41 g) of dihydrochloride of 2 dimethyl-benzene-1,4-diamine and 0.001 mol (0.11 g) of 3-amino-2-hydroxypyridine in 1 ml of water and 1 ml of acetone brought to pH 9.5 with an ammonia solution at 20%, 3.5 ml of 6% hydrogen peroxide at 20 volumes; after stirring for 5 hours at ambient temperature, the precipitate formed is filtered off. After drying, 60 mg of the compound 3-amino-6 - [(4-amino-2,3-dimethylphenyl) amino] -5 - [(4-amino-2,3-dimethylphenyl) imino] pyridin-2 ( 5H) -one 2 as a black powder. The 376 molecular ion (ES +) is detected in bulk.

II - Dyeing Evaluation The following coloring aid is prepared: - 78.5 grams of water, - 15 grams of ethanol, - 5 grams of benzyl alcohol, - 1.5 grams of oleocetyl dimethyl hydroxyethyl ammonium chloride. adjusts the pH of the staining medium to a value of 9.5 with ammonia at 20% by weight. 6.25 mg of the dye of Example 2 and 1.25 mg of support as described above are mixed.

The composition obtained is applied to a lock of 0.25 gram of gray hair at 90% white. After 30 minutes of installation, rinse the wick, wash with a standard shampoo, then rinse again and dry. We get a brown color.20

Claims (16)

REVENDICATIONS1. Azomethine direct dye of the following formula (I), their acid or base salts, organic or inorganic, their tautomeric forms, optical isomers, geometrical isomers and / or their solvates: Formula (I) in which: n represents an integer equal to 0, 1, 2, 3 or 4; R represents: a linear or branched C1-C4 alkyl radical optionally substituted with one or more identical or different radicals chosen from hydroxyl or imidazolium radicals, An-; An-designating an anion or a mixture of cosmetically acceptable anions; a C1-C4 alkoxy radical; a halogen atom; R1 represents: - a hydrogen atom, - a linear or branched C1-C4 alkyl radical, - X represents: which R2 and R3 represent - a hydroxyl radical, - a radical -NR2R3 in independently one of the other: (R) n R 1 N NH 2 (I), a hydrogen atom, a linear or branched C 1 -C 6 alkyl radical, a linear or branched C 1 -C 6 alkyl radical substituted with one or more hydroxy or C 1 -C 4 alkoxy radicals. 2. Direct dye of azomethine type of formula (I) according to claim 1, characterized in that, taken together or separately: n represents an integer equal to 0, 1 or 2; - R represents: - a C1-C2 alkyl radical, preferably methyl; a C2-C3 alkyl radical, linear or branched, substituted with one or more hydroxyl or imidazolium radicals, An-, preferably a 2-hydroxyethyl radical; a C1-C2 alkoxy radical, preferably a methoxy radical; a halogen atom, preferably chlorine; - R1 represents: - a hydrogen atom, - a C1-C2 alkyl radical, preferably a methyl radical; and / or - X represents: - a hydroxyl radical; - a radical -NR 2 R 3 in which R 2 and R 3 represent, independently of one another, a hydrogen atom or a linear or branched C 1 -C 4 alkyl radical; branched, preferably an ethyl or isopropyl radical, a linear or branched C 2 -C 6 alkyl radical substituted by one or more hydroxyl or C 1 -C 4 alkoxy radicals, preferably an ethyl or hexyl radical substituted by a hydroxyl radical, in particular a 2-hydroxyethyl radical or a 6-hydroxyethyl radical. 3. Direct dye of azomethine type of formula (I) according to claim 1 or 2, characterized in that R represents a C1-C2 alkyl radical, in particular a methyl radical. 4. Direct dye of azomethine type of formula (I) according to any one of claims 1 to 3, characterized in that R1 represents a hydrogen atom. 5. Direct dye of azomethine type of formula (I) according to any one of claims 1 to 4, characterized in that X represents a radical -NR2R3 in which R2 and R3 represent, independently of one another, a hydrogen atom or a linear or branched C1-C6 alkyl radical, optionally substituted by one or more hydroxyl radicals. 6. Direct dye of azomethine type of formula (I) according to any one of the preceding claims, characterized in that it is selected from the following compounds and their geometric or optical isomeric forms, their tautomers, their acid salts. or organic or inorganic base or their solvates such as hydrates: 3-amino-6 - ({4- [ethyl (propan-2-yl) amino] phenylamino) -5- ({4- [ethyl (propanol)} 2-yl) amino] phenylimino) -2-pyridin (5H) -one compound 125H2N "Compound, ..... s ... HN lei NH2 NNI-1, 3-amino-6 - [(4-amino) 2,3-dimethylphenyl) amino] -5 - [(4-amino-2,3-diol) dimethylphenyl] pyridin] (5H) -one N 2 O N HN '. NNH 2 3-Amino-6- {4- [ethyl- (2-hydroxy-ethyl) -amino] -phenylamino} -5- {4- [ethyl- (2-hydroxy-ethyl) -amino] -phenyl] OH gel, ..... k .... N -O imino} -5H-pyridin-2-one IN OH Compound 3 H2N goi Compound NNI-12 0 3-Amino-6- (4-amino-HN) N-phenylamino) -5- [el NH 2 4 4-amino-phenylimino] -5H-pyridin-2-one H 2 N Composite ## STR2 ## 4-N-amino-3 (or 2-methylphenylimino) -5H-pyridin-2-one HO 1, NNH 2 3-Amino-6- (4-hydroxy-N, phenylamino) -5-lei [(4-Hydroxy-phenylimino) -5H-OH-pyridin-2-one Compound 6 HON NNH 2 3-Amino-6- {4- [bis (2-hydroxy)} - [...] ethyl) n-amino-phenylamino} -5- {4- OH [bis-OH (2-hydroxy-ethyl) -amino] -N-phenylimino} -5H-pyridin-2-C-one Compound 7 CI "NH 2 3-Amino-6- (3-chloro-4- HO)". ......,. hydroxy-phenylamino) -5- [3-NH-N-chloro-4-hydroxy-chloro-phenylimino] -5H-pyridin-2-one Compound 8 HO CI 3-Amino-6- (2-chloro-4-yl) NH 2 hydroxy-phenylamino) -5- [2- '... -. ## STR1 ## ## STR2 ## ## STR2 ## 6- [4- [bis- (2-hydroxy-N, N-ethyl) OH -amino] -2-methylphenylamino} -5- {4- [bis (2-hydroxy-ethyl) -amino] -2 -methyl-phenylimino} -5H-OH N OH Compound 10 / OH / HN NNI-12 3-Amino-6- [4- (6-hydroxy-hexylamino)] 5'-Phenylamino] -544- (6-hydroxy-hexylamino) -phenylimino] -5H-pyridin-NH 2-one / Compound 11 N NNH 2 3-Amino-6- [4- (ethyl-isopropyl-amino) -phenylamino] -5- [4- ---. (1-ethylsopropylamino) HN N 0 '......... phenylimino] -4-methyl-5H-pyridin-2-one compound Compound 12H2N Compound N Hne. H 3-Amino-6- (4-amino-2,3-NH 2, N 2 -dimethyl-phenylamino) -5- [4 - ', N-amino-2,3-dimethyl-phenylimino] -4-methyl- 5H-pyridin-2-one go N., -. ,, NH2 3-Amino-6- {4- [ethyl- (2- N HN ...... - .., -... N- OH 1) amino-phenylamino} -5- {4-methyl-2- (2-hydroxy-ethyl) -1-amino] -phenyl imino} -4-methyl-1-hydroxy-ethyl-OH 1 5H-pyridin-2-one H 2 N igo Compound NNH 2 O 3-Amino-6- (4-amino-N, N-phenylamino) -5- [lei NH 2 N 4 -amino-phenylimino] - 4 Methyl-5H-pyridin-2-one-3-amino-6- (4-amino-3 (or 2-methyl-phenylamino) -5- [4-amino-3 (or 2) -methyl-phenylimino] - 4-Methyl-1H-pyridin-2-one NH 2 Compound 16 OH Compound 17 3-Amino-6- (4-hydroxyphenylamino) -5 - [(4-hydroxy-phenylimino] -4-methyl-5H-pyridin] 2-one HON OH 01-1 Compound 18 3-Amino-6- {4- [bis (2-hydroxyethyl) amino] phenylamino} -5- {4- [bis (2-hydroxyethyl) ) -amino] -phenylimino} -4-methyl-5H-pyridin-2-one NNH2 -., .., ...:, -, .... 'H2N HN N OCI low Compound N NNH2 0 Cl HO HN 19 3-Amino-6- (3-chloro) o-4-hydroxy-phenylamino) -5- [3-chloro-4-hydroxyphenylimino] -4-methyl-5H-pyridin-2-one 1H-OH-3-amino-6- ( 2-chloro-4-butyloxy-4-hydroxy-phenylamino) -5- [2-chloro-4-hydroxy- Phenylimino] -4-methyl-5H-pyridin-2-one HON OH compound. NN 3-Amino-6- {4- [bis- (2-hydroxy-NH) CN 2 -Hyl) -OH- [α] -amino] -2-methyl-N-phenylamino} -5 - {4- [bis- (2-OH-hydroxy-ethyl) -amino] -2-methyl-phenylimino} -4-methyl-5H-pyridin-2-one 7. Use of one or more azomethine direct dyes of formula (I) as defined according to any one of claims 1 to 6 for dyeing keratinous fibers, in particular human keratinous fibers such as the hair. 8. Composition, in particular dyeing for keratinous fibers such as the hair, characterized in that it comprises, in a medium suitable for dyeing, one or more direct dyes of the azomethine type of formula (I) as defined according to any of claims 1 to 6. 9. A process for dyeing keratinous fibers, in particular human keratinous fibers such as the hair, in which a dyeing composition comprising, on a medium which is suitable for dyeing, one or more direct dyes of the azomethine type of dye, is applied to said fibers. formula (I) as defined in any one of claims 1 to 6 for a time sufficient to obtain the desired color, after which it is rinsed, the fibers are optionally washed with shampoo, rinsed again and dried or allowed to dry dry the resulting fibers. 10. Process for lightening keratinous fibers, in particular human keratin fibers such as the hair, 3-Amino-6- [4- (6-hydroxyhexylamino) phenylamino] -544- (6-hydroxy-hexylamino) phenylimino] -4-methyl-5H-pyridin-2-one HN OH / NI-1 HO Compound 22in which is applied to said fibers, a dye composition comprising, in a medium suitable for dyeing, (i) one or more direct dyes of azomethine type of formula (I) as defined according to any one of claims 1 to 6 free of oxidizing agent and (ii) a cosmetic composition comprising one or more oxidizing agents; the compositions (i) and (ii) being applied to said keratinous fibers sequentially or simultaneously for a time sufficient to obtain the desired lightening, after which the fibers are rinsed, washed optionally with shampoo, rinsed again and dried or the resulting fibers are allowed to dry. 11. Leuco-type compound of formula (II) below, their acid or base salts, organic or inorganic, their tautomeric forms, optical isomers, geometric isomers and / or their solvates: X (II) Formula (II) in which n, R, R1 and X have the same meanings as those indicated in any one of claims 1 to 5. 12. Composition, in particular for dyeing keratinous fibers such as the hair, comprising one or more compounds of formula (II) as defined according to the preceding claim and optionally comprising one or more oxidizing agents. 13. A method of dyeing keratinous fibers, characterized in that one applies, simultaneously or sequentially, on said fibers, dry or wet, a dyeing composition (R) R1 HNN H2 NN OH) 1,1 Hcomprenant one or more compounds of formula (II) as defined according to claim 11 and an oxidizing composition comprising one or more oxidizing agents. 14. Use of one or more compounds of leuco type of formula (II) as defined according to claim 11 as precursors of direct dyes of azomethine type of formula (I) as defined according to any one of claims 1 to 6. 15. Use of one or more leuco type compounds of formula (II) as defined according to claim 11 in the presence of one or more oxidizing agents for dyeing keratinous fibers, in particular human keratinous fibers such as hair . 16. A multi-compartment device or "kit" comprising a first compartment containing a composition comprising one or more dyes of formula (I) as defined in any one of claims 1 to 6 or containing one or more leuco-type compounds of formula ( II) as defined in claim 11, and a second compartment comprising one or more oxidizing agents.