WO2010142777A1

WO2010142777A1 - Azomethine direct dyes or reduced precursors of these dyes obtained from secondary, n-alkylaminated para-phenylenediamines, method of hair dyeing using these dyes

Info

Publication number: WO2010142777A1
Application number: PCT/EP2010/058189
Authority: WO
Inventors: Stéphane SABELLE; Madeleine Leduc; Eric Metais
Original assignee: L'oreal
Priority date: 2009-06-11
Filing date: 2010-06-10
Publication date: 2010-12-16
Also published as: FR2946647B1; FR2946647A1

Abstract

The invention relates to the dyeing of keratin fibres using azomethine direct dyes or reduced precursors of azomethine direct dyes obtained from secondary, N-alkylaminated para-phenylenediamines. The subject of the present application is direct dyes derived from 2-[{2-[(4-aminophenyl) amino] ethyl}(2-hydroxyethyl) amino]ethanol, a dye composition comprising the direct dyes, a method for dyeing keratin fibres using the direct dyes and the use of these dyes for dyeing keratin fibres. This composition makes it possible to obtain a particularly stable and persistent colouring.

Description

AZOMETHINE DIRECT DYES OR REDUCED PRECURSORS OF THESE

DYES OBTAINED FROM SECONDARY, N-ALKYLAMINATED PARA-

PHENYLENEDIAMINES, METHOD OF HAIR DYEING USING THESE

DYES

The invention relates to the dyeing of keratin fibres using azomethine direct dyes or reduced precursors of azomethine direct dyes obtained from secondary, N-alkylaminated para-phenylenediamines . The subject of the present application is direct dyes derived from 2- [ { 2- [ (4-aminophenyl) amino] ethyl } (2- hydroxyethyl) amino] ethanol, a dye composition comprising direct dyes, a method for dyeing keratin fibres using the direct dyes and the use of these dyes for dyeing keratin fibres.

It is known practice to dye keratin fibres, and in particular the hair, with dye compositions containing direct dyes, according to a "direct dyeing" method.

The method conventionally used in direct dyeing comprises applying, to the keratin fibres, direct dyes, or colouring molecules, having an affinity for said fibres, leaving them on, and then rinsing the fibres. The direct dyes used up until now are nitrobenzene dyes, anthraquinones, nitropyridines or dyes of azo, xanthene, acridine, azine or triarylmethane benzene derivative type.

Other dyes result from oxidation bases and oxidation couplers which, once condensed, are applied to the hair. For example, in documents FR 233036, FR 2262022, FR 2262024, US 4,221,729 and FR 2261750, diphenylamines, such as leuco derivatives of indophenols, of indamine and of indoaniline, are used, either alone or in combination with other dyes, in dye compositions. Other compounds corresponding to oxidized derivatives of leuco derivatives, such as those described in documents FR 2254557 and FR 2234277, are also known to dye keratin fibres.

The colourings which result from direct dyeings are temporary or semi-permanent colourings, since the nature of the interactions which bind direct dyes to the keratin fibre and their desorption from the surface and/or from the core of the fibre are responsible for their low dyeing power and for their poor hold with regard to washing operations or perspiration. In addition, these direct dyes are generally sensitive to the action of oxidizing agents such as aqueous hydrogen peroxide, which makes them generally unusable in lightening direct dye compositions based on aqueous hydrogen peroxide and on a basifying agent, which would be similar to oxidation dyeings.

Direct dyes also exhibit a certain lack of stability towards light related to the low resistance of the chromophore with respect to photochemical attacks. In addition, their sensitivity to light is dependent on the distribution of their molecules, uniform or aggregated, in the substrate.

Consequently, there exists a real need to search for direct dyes which make it possible to dye keratin fibres, which are stable towards light, which are also resistant to bad weather, to washing operations and to perspiration, and which are sufficiently stable in the presence of oxidizing agents such as aqueous hydrogen peroxide, so as to be able to obtain simultaneous lightening of the fibre with the advantages set out above, while at the same time exhibiting an improved toxicological profile compatible with cosmetic use on keratin fibres.

These aims are achieved with the present invention, a subject of which is direct dyes of formula (I), (II) or (III) :

the organic or inorganic acid salts thereof, the geometric or optical isomers thereof, the tautomers thereof and the solvates thereof, such as the hydrates; in which formula (I) , (II) or (III) :

• n represents an integer equal to 0, 1 or 2 ;

• m represents an integer equal to 1 or 2 ;

• R represents:

- a C1-C2 alkyl radical or - an -OR⁵ radical; preferably, R is a methyl or ethyl group;

• R¹ represents:

- a hydrogen atom,

- a halogen atom such as chlorine, or - a linear or branched Ci-C₅, preferably C1-C2, alkyl radical;

• R² represents:

- a hydrogen atom,

- a linear or branched Ci-C₅, preferably C1-C2, alkyl radical,

- a linear or branched Ci-C₅ alkyloxy radical which may be functionalized with a hydroxyl radical -OH, preferably a hydroxyalkyloxy radical -O-(CH₂)χ-OH with x = 2, 3, 4 or 5, preferably x = 2; or

- a radical R⁶; R represents:

- a hydrogen atom, or

-- aa rraaddiicc,al R⁶; in particular, R³ represents a radical R⁶;

R⁴ and R⁵, which may be identical or different, represent a linear or branched Ci-C₅ alkyl radical which may be functionalized with a hydroxyl radical; in particular, the alkyl radical is a linear C1-C5 alkyl radical optionally functionalized with a hydroxyl radical; preferably, the alkyl radical is a linear Ci-C₄ alkyl radical or a linear C₂ hydroxyalkyl radical; or else

• R⁴ and R⁵ form, together with the nitrogen atom which bears them, a heterocycloalkyl group optionally substituted with one or more hydroxyl or (Ci-C₄) alkyl radicals, comprising from 5 to 7 ring members, and from 1 to 3 heteroatoms such as oxygen, sulphur or a nitrogen atom; in particular, R⁴ and R⁵ together form a pyrrolidino, piperidino, morpholino or piperazino ring, more particularly a pyrrolidino or piperidino ring; preferably, R⁴ and R⁵ represent a Ci-C₅ alkyl radical which may be functionalized with a hydroxyl radical; more particularly, the alkyl radical is a linear Ci-C₅ alkyl radical optionally functionalized with a hydroxyl radical; preferably, the alkyl radical is a linear Ci-C₄, in particular C2, alkyl radical or is a linear Ci-C₄, in particular C₂, hydroxyalkyl radical; • R⁶ represents the radical corresponding to formula (a), (b) or (C) :

(a) (b) (C) in which (a), (b) or (C) radical , R, R⁴, R⁵, n ar have the same meaning as previously and Z represents a hydroxyl, amino -NH2 or dihydroxyethylamino -N (CH2CH2OH) 2 radical;

• X represents an oxygen atom 0 or an NH radical; • Y represents:

- a hydroxyl radical,

- an -OR7 radical, or

- an -NRgRg radical, in which R₇ represents: o a linear or branched C1-C5 alkyl radical which may be functionalized with a hydroxyl radical, and Rs and Rg, which may be identical or different, represent: o a hydrogen atom, o a linear or branched C1-C5 alkyl radical, or o a linear or branched C1-C5 alkyl radical functionalized with a hydroxyl radical, preferably a linear C1-C3 hydroxyalkyl radical .

Another subject of the invention relates to reduced precursors of azomethine dyes which are colourless, which, once oxidized, generate the compounds of formula (I) , (II) or (III) as defined above. These precursors correspond to the compounds of formulae (IV) , (V) and (VI) :

the organic or inorganic acid salts thereof, the geometric or optical isomers thereof, the tautomers thereof and the solvates thereof, such as the hydrates; in which formula (IV) , (V) or (VI) R¹, R², R³, R⁴, R⁵, X, Y, n and m are as defined previously.

Another subject of the invention is a dye composition for dyeing keratin fibres, comprising, in a cosmetic medium, at least one compound of formula (I) , (II), (HI), (IV), (V) or (VI) as defined previously.

Another subject of the invention is a method for dyeing keratin fibres using a composition comprising at least one compound of formula (I) , (II) , (HI) _t (IV) , (V) or (VI) as defined previously. Another subject of the invention is the use of the compounds of formula (I) , (II) or (HI) as defined previously, as a direct dye for hair dyeing, and the use of the compounds of formula (IV) , (V) or (VI) as defined previously, as a direct dye precursor for hair dyeing.

The direct dyes of formula (I) , (II) or (III) as defined previously make it possible to remedy the drawbacks of the direct dyes conventionally used previously, and result in dyeings by direct dyeing, which exhibit very good resistance to light, to bad weather, to washing operations, to perspiration and to rubbing. Their good stability with regard to oxidizing agents, such as aqueous hydrogen peroxide, also makes it possible to use them for lightening direct dyeing. Furthermore, it has been discovered that the reduced form of the azomethine derivatives of formulae (IV) , (V) and (VI) , used under oxidizing conditions, can also result in colourings which have very good resistance to light, to bad weather, to washing operations, to perspiration and to rubbing.

For the purpose of the present invention, and unless otherwise indicated: - an "organic or inorganic acid salt" is, for example, chosen from a salt derived i) from hydrochloric acid HCl, ii) from hydrobromic acid HBr, iii) from sulphuric acid H2SO4, iv) from alkylsulphonic acids: AIk-S (0) 2OH, such as methylsulphonic acid and ethylsulphonic acid; v) from arylsulphonic acids: Ar-S(O)2θH, such as benzenesulphonic acid and toluenesulphonic acid; vi) from citric acid; vii) from succinic acid; viii) from tartaric acid; ix) from lactic acid; x) from alkoxysulphinic acids: AIk-O-S(O)OH, such as methoxysulphinic acid and ethoxysulphinic acid; xi) from aryloxysulphinic acids, such as tolyloxysulphinic acid and phenoxysulphinic acid; xii) from phosphoric acid H₃PO₄; xiii) from acetic acid CH₃C(O)OH; xiv) from triflic acid CF₃SO₃H and xv) from tetrafluoroboric acid HBF₄;

- an "alkyl" radical is a saturated, linear or branched, hydrocarbon-based radical containing from 1 to 6 carbon atoms, particularly from 1 to 3 carbon atoms, such as the methyl or ethyl radical;

- an "alkoxy" radical is an "alkyl-oxy" alkyl-O- radical in which the alkyl part is as defined previously;

- the alkyl, alkoxy or heterocycloalkyl radicals followed by "optionally substituted with ..." means that said radicals can have one or more hydrogen atoms replaced with one or more substituents in question, particularly one or two substituents in question.

A subject of the invention relates to direct dyes of formula (I) , (II) or (III) or dye precursors of formula (IV) , (V) or (VI) . One particular embodiment of the invention relates to compounds of formula (I), (II), (III), (IV), (V) or

(VI) for which n is zero.

According to another particular embodiment of the invention, m is 1 in formula (I) , (II) , (HI) , (IV) ,

(V) or (VI) .

More particularly, the compound (s) of formula (I), (II), (III), (IV), (V) or (VI) is (are) such that n is zero and m is 1. According to one particular embodiment of the invention, the compound (s) of formula (I), (H), (III), (IV), (V) or (VI) is (are) such that R¹ is in the 3'- position .

According to another preferred embodiment of the invention, the compound (s) of formula (I), (H), (III),

(IV), (V) or (VI) are such that R² represents i) a Ci-C₂ alkyl radical, ii) an -O- (CH₂) _X-OH radical with x = 2,

3, 4 or 5 and preferably x = 2, or iii) a radical R⁶.

According to one embodiment of the invention, the compound (s) of formula (I), (II), (HI), (IV), (V) or

(VI) is (are) such that R⁴ and R⁵, which may be identical or different, represent a linear Ci-C₅ alkyl radical optionally functionalized with a hydroxyl radical; preferably, the alkyl radical is a linear Ci-C₄ alkyl radical or a linear C₂ hydroxyalkyl radical.

According to another particular embodiment of the invention, the compound (s) of formula (I), (H), (HI), (IV), (V) or (VI) is (are) such that R⁴ and R⁵ form, together with the nitrogen atom which bears them, a heterocycloalkyl group optionally substituted with one or more hydroxyl or (Ci-C₄) alkyl radicals, comprising from 5 to 7 ring members, and from 1 to 3 heteroatoms such as oxygen, sulphur or a nitrogen atom; in particular, R⁴ and R⁵ together form a pyrrolidino, piperidino, morpholino or piperazino ring, more particularly a pyrrolidino or piperidino ring.

Preferably, the compound (s) of the invention, of formula (I), (H), (HI), (IV), (V) or (VI), is (are) such that R⁴ and R⁵ represent a Ci-C₅ alkyl radical which may be functionalized with a hydroxyl radical; more particularly, the alkyl radical is a linear C1-C5 radical optionally functionalized with a hydroxyl radical; preferably, the alkyl radical is a linear C1-C4, in particular C₂, alkyl radical or a linear Ci-C₄, in particular C2, hydroxyalkyl radical.

According to one preferred embodiment, the compound (s) of the invention, of formula (I), (II), (III), (IV), (V) or (VI), is (are) such that R⁶ represents a radical (a) as defined previously.

According to another particular embodiment, the compound (s) of the invention, of formula (I), (II), (III), (IV), (V) or (VI), is (are) such that Y represents a hydroxyl radical or an -NRgRg radical with Rs and Rg, which may be identical or different, being as defined previously, and more particularly Y is chosen from an -OH, -NH₂ and -NHR₈ radical.

By way of example of the compounds of formulae (I) to (VI) contained in the composition according to the invention, mention may be made of dyes 1 to 36, and also the organic or inorganic acid salts thereof, the geometric isomers and tautomers thereof and the solvates such as the hydrates:

Dyes of formula (I), (II) or (III):

All the dye precursors of formula (IV) , (V) or (VI) can be obtained by conventional reduction of the compounds of formula (I) , (II) or (III) , such as dyes 1 to 36 above. The reduction can, for example, be carried out using sodium hydrosulphite, powdered zinc and ascorbic acid.

The compounds of formula (I) , (II) , (III) , (IV) , (V) or (VI) of the invention are prepared according to the following general synthesis pathways:

1- Access to the compounds corresponding to formulae (I) to (III) : The compounds of formulae (I) , (II) and (III) are obtained, in general, by reacting the derivatives \_, 2_ or Z_ with the substituted para-phenylenediamine A, preferably in a basic medium in the presence of an oxidizing agent. The base used is preferably an aqueous solution of ammonia or of sodium hydroxide and the oxidizing agent is preferably chosen from aqueous hydrogen peroxide, potassium ferricyanide, air, ammonium persulphate and manganese oxide.

This type of synthesis is described in documents FR2234277, FR2047932, FR2106661 and FR2121101.

2- Access to the compounds corresponding to formulae (IV) , (V) and (VI) :

The compounds corresponding to formulae (IV) , (V) and (VI) are obtained, in general, by reacting the compounds of formula (I) , (II) or (III) with a reducing agent. This reducing agent can be chosen preferably from sodium hydrosulphite, powdered zinc and ascorbic acid. This reducing agent is preferably sodium hydrosulphite .

This type of synthesis is described in documents FR2056799, FR2047932, FR2165965 and FR2262023.

Another subject of the invention relates to a dye composition for dyeing keratin fibres, in particular human keratin fibres such as the hair, in a cosmetic medium, comprising one or more direct dyes of formula (I) , (II) or (III) , or one or more dye precursors of formula (IV) , (V) or (VI) .

The dye composition of use in the invention generally contains an amount of dye of formula (I) , (II) or (III) , or of precursor of formula (IV) , (V) or

(VI), of between 0.001% and 30% relative to the total weight of the composition. Preferably, this amount is between 0.005% and 10% by weight, and even more preferably between 0.01% and 6% by weight, relative to the total weight of the composition.

The dye composition containing the dye(s) of formula (I) , (II) or (III) , or preferably the precursor (s) of formula (IV), (V) or (VI), can also contain one or more oxidizing agents such as hydrogen peroxide, urea peroxide, alkali metal bromates, persalts, peracids and oxidase enzymes. The dye composition may also contain additional direct dyes other than those of formula (I) , (II) , (III), (IV), (V) or (VI). These direct dyes are, for example, chosen from neutral, acidic or cationic nitrobenzene direct dyes, neutral, acidic or cationic azo direct dyes, tetraazapentamethine dyes, neutral, acidic or cationic quinone and in particular anthraquinone dyes, azine direct dyes, triarylmethane direct dyes, indoamine direct dyes and natural direct dyes . Mention may be made, among nitrobenzene direct dyes, without implying limitation, of the following compounds :

1, 4-diamino-2-nitrobenzene, l-amino-2-nitro-4- (β- hydroxyethylamino) benzene, l-amino-2-nitro-4- [bis (β- hydroxyethyl) amino] benzene, 1, 4-bis (β-hydroxyethyl- amino) -2-nitrobenzene, 1- (β-hydroxyethylamino) -2-nitro- 4- [bis (β-hydroxyethyl) amino] benzene, 1- (β-hydroxyethylamino) -2-nitro-4-aminobenzene, 1- (β-hydroxyethylamino) - 2-nitro-4- [ (ethyl) (β-hydroxyethyl) amino] benzene, 1- amino-3-methyl-4- (β-hydroxyethylamino) -6-nitrobenzene, l-amino-2-nitro-4- (β-hydroxyethylamino) -5-chloro- benzene, 1, 2-diamino-4-nitrobenzene, l-amino-2- (β- hydroxyethylamino) -5-nitrobenzene, 1, 2-bis (β-hydroxyethylamino) -4-nitrobenzene, l-amino-2- [tris- (hydroxymethyl) methylamino] -5-nitrobenzene, 1-hydroxy- 2-amino-5-nitrobenzene, 1-hydroxy-2-amino-4-nitrobenzene, l-hydroxy-3-nitro-4-aminobenzene, l-hydroxy-2- amino-4, 6-dinitrobenzene, 1- (β-hydroxyethyloxy) -2- (β- hydroxyethylamino) -5-nitrobenzene, l-methoxy-2- (β- hydroxyethylamino) -5-nitrobenzene, 1- (β-hydroxyethyl- oxy-3-methylamino) -4-nitrobenzene, 1- (β,γ-dihydroxy- propyloxy) -3-methylamino-4-nitrobenzene, 1- (β-hydroxyethylamino) -4- (β, γ-dihydroxypropyloxy) -2-nitrobenzene, 1- (β,γ-dihydroxypropylamino) -4-trifluoromethyl-2-nitro- benzene, 1- (β-hydroxyethylamino) -4-trifluoromethyl-2- nitrobenzene, 1- (β-hydroxyethylamino) -3-methyl-2-nitro- benzene, 1- (β-aminoethylamino) -5-methoxy-2-nitro- benzene, l-hydroxy-2-chloro-6-ethylamino-4-nitro- benzene, l-hydroxy-2-chloro-6-amino-4-nitrobenzene, 1- hydroxy-6- [bis (β-hydroxyethyl) amino] -3-nitrobenzene, 1-

(β-hydroxyethylamino) -2-nitrobenzene or l-hydroxy-4- (β- hydroxyethylamino) -3-nitrobenzene .

Mention may be made, among azo direct dyes, of the cationic azo dyes described in Patent Applications WO 95/15144, WO-95/01772 and EP-714 954, the contents of which form an integral part of the invention.

Mention may very particularly be made, among these compounds, of the following dyes: 1, 3-dimethyl-2- [ [4- (dimethylamino) phenyl] azo] -lH-imidazolium chloride, 1, 3-dimethyl-2- [ (4-aminophenyl) azo] -lH-imidazolium chloride or l-methyl-4- [ (methylphenylhydrazono) methyl] - pyridinium methyl sulphate.

Mention may also be made, among azo direct dyes, of the following dyes, described in the Colour Index International, 3rd edition:

Disperse Red 17, Acid Yellow 9, Acid Black 1,

Basic Red 22, Basic Red 76, 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 and Disperse Black 9.

Mention may also be made of l-(4'- aminodiphenylazo) -2-methyl-4- [bis (β- hydroxyethyl) amino] benzene and 4-hydroxy-3- (2- methoxyphenylazo) -1-naphthalenesulphonic acid.

Mention may be made, among quinone direct dyes, of the following dyes:

Disperse Red 15, Solvent Violet 13, Acid Violet 43, Disperse Violet 1, Disperse Violet 4, Disperse Blue 1, Disperse Violet 8, Disperse Blue 3, Disperse Red 11, Acid Blue 62, Disperse Blue 7, Basic Blue 22, Disperse Violet 15 and Basic Blue 99, and also the following compounds : 1- (N-methylmorpholiniopropylamino) -4- hydroxyanthraquinone, l-aminopropylamino-4-methyl- aminoanthraquinone, 1-aminopropylaminoanthraquinone, 5- (β-hydroxyethyl) -1, 4-diaminoanthraquinone, 2-amino- ethylaminoanthraquinone and 1, 4-bis (β,γ-dihydroxy- propylamino) anthraquinone . Mention may be made, among azine dyes, of the following compounds:

- Basic Blue 17 and Basic Red 2.

Mention may be made, among triarylmethane dyes, 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.

Mention may be made, among indoamine dyes, of the following compounds:

- 2-β-hydroxyethylamino-5- [bis (β-4' -hydroxy- ethyl) amino] anilino-1, 4-benzoquinone;

- 2-β-hydroxyethylamino-5- (2' -methoxy-4' -amino) - anilino-1, 4-benzoquinone;

- 3-N- (2 ' -chloro-4 ' -hydroxy) phenylacetylamino-6- methoxy-1, 4-benzoquinone imine; - 3-N- (3' -chloro-4 ' -methylamino) phenylureido-6- methyl-1, 4-benzoquinone imine;

- 3- [ 4 ' -N- (ethyl, carbamylmethyl) amino] phenyl- ureido-6-methyl-l, 4-benzoquinone imine .

Mention may be made, among natural direct dyes, of lawsone, juglone, alizarin, purpurin, carminic acid, kermesic acid, purpurogallin, protocatechaldehyde, indigo, isatin, curcumin, spinulosin or apigenidine. It is also possible to use extracts or decoctions comprising these natural dyes and in particular cataplasms or henna-based extracts.

The dye composition can comprise one or more oxidation bases and/or one or more couplers conventionally used for the dyeing of keratin fibres.

Mention may be made, among oxidation bases, of para-phenylenediamines, bisphenylalkylenediamines, para-aminophenols, bis-para-aminophenols, ortho- aminophenols, heterocyclic bases and their addition salts .

Mention may in particular be made, among couplers, of meta-phenylenediamines, meta-aminophenols, meta- diphenols, naphthalene couplers, heterocyclic couplers and their addition salts.

The coupler or couplers are each generally present in an amount of between 0.001% and 10% by weight of the total weight of the dye composition, preferably between 0.005% and 6% by weight.

The oxidation base or bases present in the dye composition are generally present each in an amount of between 0.001% and 10% by weight of the total weight of the dye composition, preferably between 0.005% and 6% by weight.

Generally, the addition salts of the oxidation bases and couplers which can be used in the context of the invention are chosen in particular from the addition salts with an acid, such as hydrochlorides, hydrobromides, sulphates, citrates, succinates, tartrates, lactates, tosylates, benzenesulphonates, phosphates and acetates, and the addition salts with a base, such as alkali metal hydroxides, such as sodium hydroxide or potassium hydroxide, aqueous ammonia, amines or alkanolamines .

The medium appropriate for the dyeing, also known as dyeing vehicle, is a cosmetic medium generally comprising water or a mixture of water and of at least one organic solvent. Mention may be made, as organic solvent, for example, of lower Ci-C₄ alkanols, such as ethanol and isopropanol, polyols and polyol ethers, such as 2-butoxyethanol, propylene glycol, propylene glycol monomethyl ether, diethylene glycol monoethyl ether and diethylene glycol monomethyl ether, aromatic alcohols, such as benzyl alcohol or phenoxyethanol, and their mixtures.

The solvents, when they are present, are preferably present in proportions preferably of between 1% and 50% by weight approximately, with respect to the total weight of the dye composition, more preferably still between 5% and 40% by weight approximately.

The dye composition can also include various adjuvants conventionally used in compositions for dyeing hair, such as anionic, cationic, nonionic, amphoteric or zwitterionic surfactants, or mixtures thereof, anionic, cationic, nonionic, amphoteric or zwitterionic polymers, or mixtures thereof, inorganic or organic thickening agents, in particular anionic, cationic, nonionic and amphoteric polymeric associative thickeners, antioxidants, penetrating agents, sequestering agents, fragrances, buffers, dispersing agents, conditioning agents, such as, for example, volatile or non-volatile and modified or unmodified silicones, such as aminated silicones, film-forming agents, ceramides, preservatives, opacifying agents or conducting polymers. The above adjuvants are generally present in an amount of, for each of them, between 0.01% and 20% by weight, with respect to the weight of the composition.

Of course, a person skilled in the art will take care to choose this or these optional additional compounds so that the advantageous properties intrinsically attached to the dye composition in accordance with the invention are not, or not substantially, detrimentally affected by the envisaged addition or additions. The pH of the dye composition is generally between 3 and 14 approximately. It can be adjusted to the desired value using acidifying or basifying agents commonly used in dyeing keratin fibres or else using conventional buffer systems. According to one particular form of the invention, when the dye composition comprises at least one dye of formula (I) , (II) or (III) as defined previously, the composition has a pH of between 6 and 11. According to another particular form of the invention, when the composition comprises at least one dye precursor of formula (IV) , (V) or (VI) as defined previously, the composition has a pH of between 6 and 11.

Mention may be made, among acidifying agents, by way of example, of inorganic or organic acids, such as hydrochloric acid, orthophosphoric acid, sulphuric acid, carboxylic acids, such as acetic acid, tartaric acid, citric acid or lactic acid, or sulphonic acids.

Mention may be made, among basifying agents, by way of example, of aqueous ammonia, alkaline carbonates, alkanolamines, such as mono-, di- and triethanolamines and their derivatives, sodium hydroxide, potassium hydroxide and the compounds of following formula (γ) :

R_a ^₁l / R_α 3₉2

N W -N Ka4 ^Ka3 (Y) in which W_a is a propylene residue optionally substituted with a hydroxyl group or a Ci-C₄ alkyl radical; R_ai, R_a2, R_a3 and R_a4, which may be identical or different, represent a hydrogen atom, a linear or branched Ci-C₄ alkyl radical or a Ci-C₄ hydroxyalkyl radical .

The dye composition may be in various forms, such as in the form of a liquid, a cream or a gel, or in any other form suitable for carrying out dyeing of keratin fibres, and in particular of the hair.

Another subject of the invention is a method for dyeing keratin fibres, in particular the hair, which consists in applying, to the keratin materials, in the presence or absence of an oxidizing agent, a dye composition comprising, in a cosmetic medium, at least one azomethine dye of formula (I) , (II) or (III) as defined previously, or a dye precursor of formula (IV) , (V) or (VI) as defined previously.

After a leave-on time, the keratin fibres are rinsed, leaving coloured fibres to appear. The leave-on time is generally between 3 and 50 minutes approximately, preferably 5 to 40 minutes approximately.

The application of the dye composition according to the invention is generally carried out at ambient temperature. However, it can be carried out at a temperature ranging from 20 to 80⁰C. The examples which follow serve to illustrate the invention without, however, being limiting in nature.

The dyes of the examples hereinafter were fully characterized by conventional spectroscopic and spectrometric methods.

EXAMPLES

SYNTHESIS EXAMPLES

Example 1 : Synthesis of 2- (4-{2- [bis (2- hydroxyethyl) amino] ethylamino } -1-methylhexa-l ,3,5- trienylamino) -5- (2-hydroxyethylamino) [1,4]- benzoquinone 1:

1.8 ml of 9% aqueous hydrogen peroxide are added, at ambient temperature, to a solution of 239 mg (1 mmol) of 2, 2' - ( { 2- [ (4-aminophenyl) amino] ethyl } - imino) diethanol and 151 mg (1 mmol) of 3, 4-dihydro-2H- 1 , 4-benzoxazin-6-ol in a mixture of water (2 ml) and ethanol (1 ml), and this solution is stirred for 1 hour. The precipitate then formed is filtered off, washed with water and dried. After chromatography (eluent: dichloromethane-methanol) , 18 mg of 2-(4-{2- [bis (2-hydroxyethyl) amino] ethylamino } -1-methylhexa- 1, 3, 5-trienylamino) -5- (2-hydroxyethylamino) [1,4]- benzoquinone are obtained in the form of a dark green powder . The ¹H NMR spectrum is in accordance with the expected structure. The molecular ions 405 (ES+) and 403 (ES-) are detected by mass spectrometry.

Example 2 : Synthesis of 5-amino-4- (4-{2-[bis(2- hydroxyethyl) amino] ethylamino }phenylimino) -2- methylcyclohexa-2 , 5-dienone 2:

1.8 ml of 9% aqueous hydrogen peroxide are added, at ambient temperature, to a solution of 119 mg

(0.5 mmol) of 2, 2' - ( { 2- [ (4-aminophenyl) amino] ethyl } - imino) diethanol and 61 mg (0.5 mmol) of 5-amino-2- methylphenol in 2 ml of a 50/50 (vol/vol) water/ethanol mixture. This solution is stirred for 3 hours. After concentration and chromatography on a silica column

(eluent: dichloromethane/methanol) , 5 mg of 5-amino-4-

(4- { 2- [bis (2-hydroxyethyl) amino] ethylamino } - phenylimino) -2-methylcyclohexa-2, 5-dienone are obtained in the form of a dark purple powder.

The ¹H NMR spectrum is in accordance with the expected structure. The molecular ion 359 (ES+) is detected by mass spectrometry.

Example 3 : Synthesis of 3-amino-4- (4-{2-[bis(2- hydroxyethyl) amino] ethylamino }phenylimino) -2-chloro-6- methylcyclohexa-2 , 5-dienone 3:

278 mg (0.8 mmol) of 2, 2' -( [2- [ (4-aminophenyl) - amino] ethyl] imino) diethanol trihydrochloride and 155 mg (0.8 mmol) of 3-amino-2-chloro-6-methylphenol hydrochloride are solubilized in 6 ml of a 50/50

(vol/vol) water/ethanol solution. The pH is adjusted to

9.5 with 20% aqueous ammonia and then 1.053 g (3.2 mmol) of potassium ferricyanide in solution in

5 ml of water are added dropwise, at ambient temperature. After 5 h of stirring, the ethanol is evaporated off and the azomethine formed is extracted with dichloromethane, and purified by chromatography on a silica column (eluent: dichloromethane-methanol) . 17 mg of 3-amino-4- (4- { 2- [bis (2-hydroxyethyl) amino] - ethylamino jphenylimino) -2-chloro-6-methylcyclohexa-2, 5- dienone are obtained in the form of a purplish black powder . The ¹H NMR spectrum is in accordance with the expected structure.

DYEING EXAMPLE

The following dye composition (A) was prepared: o 0.5 mmol of 3-amino-4- (4- { 2- [bis (2- hydroxyethyl) amino] ethylamino }phenylimino) -2- chloro-6-methylcyclohexa-2 , 5-dienone 3 o 79.5 ml of water o 15 ml of ethanol o 5 ml of benzyl alcohol o 0.5 g of benzoic acid.

This composition was applied to natural hair containing 90% white hairs, at ambient temperature for 30 minutes, with a bath ratio of (0.5 g of hair per 10 g of composition (A) ) .

The shades obtained appear in the table below:

Claims

1. Compound of formula (I) , (II) , (III) , (IV) , (V) or (VI) :

the organic or inorganic acid salts thereof, the geometric or optical isomers thereof, the tautomers thereof and the solvates thereof, such as the hydrates; in which formula (I) , (II) , (III) , (IV) , (V) or (VI) :

• n represents an integer equal to 0, 1 or 2 ;

• m represents an integer equal to 1 or 2 ; • R represents: - a C1-C2 alkyl radical or

- an -OR⁵ radical; in particular, R is a methyl or ethyl group;

• R¹ represents: - a hydrogen atom,

- a halogen atom such as chlorine, or

- a linear or branched Ci-C₅, preferably C1-C2, alkyl radical;

• R² represents: - a hydrogen atom,

- a linear or branched Ci-C₅, preferably C1-C2, alkyl radical,

- a radical R⁶;

• R³ represents: - a hydrogen atom, or

- a radical R⁶; in particular, R³ represents a radical R⁶;

• R⁴ and R⁵, which may be identical or different, represent a linear or branched Ci-C₅ alkyl radical which may be functionalized with a hydroxyl radical; in particular, the alkyl radical is a linear Ci-C₅ alkyl radical optionally functionalized with a hydroxyl radical; preferably, the alkyl radical is a linear C1-C4 alkyl radical or a linear C2 hydroxyalkyl radical; or else

• R⁴ and R⁵ form, together with the nitrogen atom which bears them, a heterocycloalkyl group optionally substituted with one or more hydroxyl or (Ci-C₄) alkyl radicals, comprising from 5 to 7 ring members, and from 1 to 3 heteroatoms such as oxygen, sulphur or a nitrogen atom; in particular, R⁴ and R⁵ together form a pyrrolidino, piperidino, morpholino or piperazino ring, more particularly a pyrrolidino or piperidino ring; preferably, R⁴ and R⁵ represent a Ci-C₅ alkyl radical which may be functionalized with a hydroxyl radical; more particularly, the alkyl radical is a linear Ci-C₅ alkyl radical optionally functionalized with a hydroxyl radical; preferably, the alkyl radical is a linear C1-C4, in particular C2, alkyl radical or is a linear Ci-C₄, in particular C₂, hydroxyalkyl radical; • R⁶ represents the radical corresponding to formula

(a), (b) or (C) :

(a) (b) (C) in which (a) , (b) or (c) radical, R, R⁴, R⁵, n and m have the same meaning as previously and Z represents a hydroxyl, amino -NH2 or dihydroxyethylamino -N (CH2CH2OH) 2 radical;

• X represents an oxygen atom O or an NH radical;

• Y represents:

- a hydroxyl radical,

- an -OR7 radical, or

- an -NRgRg radical, in which R₇ represents:

0 a linear or branched Ci-C₅ alkyl radical which may be functionalized with a hydroxyl radical, and Rs and Rg, which may be identical or different, represent: 0 a hydrogen atom, 0 a linear or branched Ci-C₅ alkyl radical, or

0 a linear or branched Ci-C₅ alkyl radical functionalized with a hydroxyl radical, preferably a linear C1-C3 hydroxyalkyl radical .

2. Compound of formula (I), (II), (III), (IV), (V) or

(VI) , according to the preceding claim, which is such that n is zero.

3. Compound of formula (I), (II), (III), (IV), (V) or (VI) , according to either one of the preceding claims, which is such that m is 1.

4. Compound of formula (I), (II), (III), (IV), (V) or

(VI) , according to any one of the preceding claims, which is such that R¹ is in the 3' -position.

5. Compound of formula (I), (II), (III), (IV), (V) or

(VI) , according to any one of the preceding claims, which is such that R² represents: i) a C1-C2 alkyl radical, ii) an -O-(CH₂)_X-OH radical with x = 2, 3, 4 or 5, or iii) a radical R⁶.

6. Compound of formula (I), (II), (III), (IV), (V) or (VI) , according to any one of the preceding claims, which is such that R⁴ and R⁵, which may be identical or different, represent a linear Ci-C₅ alkyl radical optionally functionalized with a hydroxyl radical; preferably, the alkyl radical is a linear Ci-C₄, in particular C₂, alkyl radical or a linear Ci-C₄, in particular C₂, hydroxyalkyl radical.

7. Compound of formula (I), (II), (III), (IV), (V) or (VI), according to any one of Claims 1 to 5, which is such that R⁴ and R⁵ form, together with the nitrogen atom which bears them, a heterocycloalkyl group optionally substituted with one or more hydroxyl or (Ci-C₄) alkyl radicals, comprising from 5 to 7 ring members, and from 1 to 3 heteroatoms such as oxygen, sulphur or a nitrogen atom; in particular, R⁴ and R⁵ together form a pyrrolidino, piperidino, morpholino or piperazino ring, more particularly a pyrrolidino or piperidino ring.

8. Compound of formula (I), (II), (III), (IV), (V) or (VI) , according to any one of the preceding claims, which is such that R⁶ represents a radical (a) .

9. Compound of formula (I), (II), (III), (IV), (V) or (VI) , according to any one of the preceding claims, which is such that Y represents a hydroxyl radical or an -NRgRg radical with Rg and Rg, which may be identical or different, being as defined previously, and more particularly Y is chosen from an -OH, -NH₂ and -NHRg radical .

10. Compound of formula (I), (II) or (III), according to any one of the preceding claims, of formulae 1 to 36 below and also the reduced form of compounds 1 to 36 belonging to the compounds of formula (IV) , (V) or (VI) :

11. Dye composition for dyeing keratin fibres, comprising, in a cosmetic medium, one or more compounds of formula (I) , (II) , (III) , (IV) , (V) or (VI) according to any one of the preceding claims.

12. Composition according to the preceding claim, in which the compound (s) of formula (I), (II), (HI), (IV) , (V) or (VI) is (are) present in an amount of between 0.001% and 30% by weight relative to the total weight of the composition.

13. Composition according to Claim 11 or 12, which also comprises one or more oxidizing agents.

14. Composition according to the preceding claim, in which the oxidizing agent is chosen from hydrogen peroxide, urea peroxide, alkali metal bromates, persalts, peracids, and oxidase enzymes.

15. Composition according to any one of Claims 8 to 14, which also comprises at least one adjuvant chosen from anionic, cationic, nonionic, amphoteric or zwitterionic surfactants, or mixtures thereof, anionic, cationic, nonionic, amphoteric or zwitterionic polymers, or mixtures thereof, inorganic or organic thickening agents, antioxidants, penetrating agents, sequestering agents, fragrances, buffers, dispersing agents, conditioning agents, film-forming agents, ceramides, preservatives, opacifying agents and conducting polymers.

16. Method for dyeing keratin fibres, in which a suitable dye composition according to any one of Claims

11 to 15 is applied to the materials.

17. Use of compounds of formula (I), (II), (III), (IV) , (V) or (VI) , as defined in any one of Claims 1 to 10, for dyeing keratin fibres.