WO2009077390A2

WO2009077390A2 - Azomethine direct dyes or reduced precursors of azomethine direct dyes obtained from 4,5 diaminopyrazole, and hair dyeing process using these dyes or precursors

Info

Publication number: WO2009077390A2
Application number: PCT/EP2008/067149
Authority: WO
Inventors: Stéphane SABELLE; Madeleine Leduc; Karine Picolet
Original assignee: L'oreal
Priority date: 2007-12-14
Filing date: 2008-12-09
Publication date: 2009-06-25
Also published as: WO2009077390A3; FR2925052B1; FR2925052A1

Abstract

The invention relates to the dyeing of keratin fibres using azomethine direct dyes obtained from 4, 5-diaminopyrazole derivatives. The invention relates to a dye composition comprising at least one azomethine direct dye or precursor of an azomethine direct dye, to a process for dyeing keratin fibres, using the said composition, and to their uses in the dyeing of keratin fibres. This composition allows a particularly stable and fast coloration to be obtained.

Description

AZOMETHINE DIRECT DYES OR REDUCED PRECURSORS OF

AZOMETHINE DIRECT DYES OBTAINED FROM

4, 5-DIAMINOPYRAZOLE, AND HAIR DYEING PROCESS

USING THESE DYES OR PRECURSORS

The invention relates to the dyeing of keratin fibres using azomethine direct dyes or reduced precursors of azomethine direct dyes obtained from 4, 5-diamino- pyrazole .

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

The process conventionally used in direct dyeing consists in applying to keratin fibres direct dyes, or colouring molecules, which have affinity for the said fibres, leaving them to stand on the fibres, and then rinsing the fibres. The direct dyes used hitherto are nitrobenzene dyes, anthraquinones, nitropyridines, dyes of azo, xanthene, acridine or azine type or triarylmethanebenzene-based dyes .

Other dyes are obtained from oxidation bases and oxidation couplers, which, once condensed, are applied onto the hair. For example, in documents FR 233 036, FR

2 262 022, FR 2 262 024, US 4 221 729 and FR 2 261 750, diphenylamines such as leuco derivatives of indophenols, of indoamine 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 2 254 557 and FR 2 234 277 are also known for dyeing keratin fibres. Moreover, a number of direct dyes obtained from 4, 5-diaminopyrazole derivatives (FR 2 746 392) are known for dyeing the hair .

The colorations that result from direct dyeing are temporary or semi-permanent colorations, since the nature of the interactions that bind the direct dyes to the keratin fibre, and their desorption from the surface and/or the core of the fibre, are responsible for their poor dyeing power and their poor fastness with respect to washing or to perspiration. These direct dyes are also generally sensitive to the action of oxidizing agents such as hydrogen peroxide, which makes them generally unusable in lightening direct dye compositions based on hydrogen peroxide and on a basifying agent, which would be similar to oxidation dyeing.

Direct dyes also have a certain lack of light stability, associated with the poor resistance of the chromophore to photochemical attack. In addition, their sensitivity to light is dependent on the distribution of their molecules, uniformly or in aggregates, in the substrate .

Consequently, there is a real need to find direct dyes for dyeing keratin fibres, which are light-stable, and which are also resistant to bad weather, washing and perspiration and sufficiently stable in the presence of oxidizing agents such as hydrogen peroxide to be able to obtain simultaneous lightening of the fibre with the advantages outlined above, while at the same time having a toxicological profile that is improved and compatible with cosmetic use on keratin fibres.

These aims are achieved with the present invention, one subject of which is a process for dyeing keratin fibres using a direct dye chosen from those of formulae (I) to (IV) below :

(IB) (IV)

salts thereof with an organic or mineral acid, geometrical isomers thereof, tautomers thereof, and solvates thereof such as the hydrates; in which formulae (I) to (IV) :

• Ri represents:

- a hydrogen atom,

- a Ci-C₅ alkyl radical, or - a Ci-C₅ alkyl radical functionalized with a group chosen from: i) hydroxyl, ii) Ci-C₄ alkoxy, iii) amino, iv) amido, v) di (C1-C3) alkylamino, vi) imidazolyl, vii) phenyl optionally substituted with a chlorine atom, a trifluoromethane radical or a methyl radical;

• R₂ represents:

- a hydrogen atom,

- a bromine atom,

- a Ci-C₅ alkyl radical, or - a phenyl radical; - A -

• R₃ and R₄ represent, independently of one another:

- a hydrogen atom,

- a Ci-C₅ alkyl radical, or

- a Ci-C₅ alkyl radical functionalized with a group chosen from: i) hydroxyl, ii) Ci-C₄ alkoxy, iii) amino, iv) amido, v) di (Ci-C₃) alkylamino, and vi) imidazolyl;

• R₅ represents:

- a hydrogen atom or

- a Ci-C₄ alkyl radical; • R₆ represents:

- a hydrogen atom or

- a radical corresponding to formula (V) below:

(V)

in which formula (V) Ri, R₂, R₃ and R₄ have the same meaning as previously.

Another subject of the invention relates to a dyeing process using reduced precursors of colourless azomethine dyes, which, once oxidized, generate the compounds of formulae (I) to (IV) as defined above.

These precursors are of respective formulae (I' ) to

(IV) below:

(IH") (IV)

the salts thereof with an organic or mineral acid, the geometrical isomers thereof, the tautomers thereof, and the solvates thereof such as the hydrates; in which formula (II) Ri to Re are as defined previously.

Another subject of the invention is a dye chosen from those of formulae (I) to (IV) and a reduced dye precursor chosen from those of formulae (I' ) to (IV ) .

Another subject of the invention is a dye composition for dyeing keratin fibres, in a cosmetic medium, comprising at least one compound of formulae (I) to (IV) or (I') to (IV) as defined previously.

The direct dyes of formulae (I) to (IV) make it possible to overcome the drawbacks of the direct dyes conventionally used previously, and lead to dyeing results by direct dyeing that show very good resistance to light, bad weather, perspiration and rubbing. Their good stability with respect to oxidizing agents such as hydrogen peroxide also allows them to be used in a process of lightening direct dyeing. Furthermore, it has been discovered that the reduced form of the azomethine derivatives obtained from 4, 5-diaminopyrazole derivatives of formulae (I') to (IV), used under oxidizing conditions, may also lead to colorations that show very good resistance to light, bad weather, washing, perspiration and rubbing.

For the purposes of the present invention, and unless otherwise indicated: - a "salt of an organic or mineral acid" is chosen, for example, from a solvent derived from i) hydrochloric acid HCl, ii) hydrobromic acid HBr, iii) sulfuric acid H₂SO₄, iv) alkylsulfonic acids: AIk-S(O)₂OH such as methanesulfonic acid and ethanesulfonic acid; v) arylsulfonic acids: Ar-S(O)₂OH such as benzenesulfonic acid and toluenesulfonic acid; vi) citric acid; vii) succinic acid; viii) tartaric acid; ix) lactic acid; x) alkoxysulfinic acids: AIk-O-S(O)OH such as methoxysulfinic acid and ethoxysulfinic acid; xi) aryloxysulfinic acids such as tolueneoxysulfinic acid and phenoxysulfinic acid; xii) phosphoric acid H₃PO₄; xiii) acetic acid CH₃C(O)OH; xiv) triflic acid CF₃SO₃H; and xv) tetrafluoroboric acid HBF₄; - an "alkyl" radical is a saturated, linear or branched hydrocarbon-based radical, containing from 1 to 6 carbon atoms and 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 benzyl or phenyl radicals followed by "optionally substituted with..." means that the said radicals may have one or more hydrogen atoms replaced with one or more substituents in question, particularly one or two substituents in question . One subject of the invention concerns direct dyes of formulae (I) to (IV) or dye precursors of formula (I') to (IV ) .

One particular embodiment of the invention concerns the compounds of formulae (I) to (IV) or (I' ) to (IV ) for which n is equal to zero.

According to a particular embodiment of the invention, the compounds of formulae (I) to (IV) or (I') to (IV) comprise a radical Ri representing a Ci-C₅ alkyl radical, or a Ci-C₅ alkyl radical functionalized with a hydroxyl group.

One variant concerns the compounds of formulae (I) to (IV) or (I') to (IV) for which R₃ and R₄ represent a hydrogen atom.

Another variant of the invention involves dyes of formula (I) and (IV) or (I') and (IV) for which R₆ represents a radical (V) as defined previously in which R₂, R₃ and R₄ represent a hydrogen atom and Ri represents a Ci-C₅ alkyl radical functionalized with a hydroxyl group.

As examples of compounds of formulae (I) to (IV) or

(I' ) to or (IV ) according to the invention, mention may be made of the dyes (Ia) to (Ij) and precursors

(2a) to (2j) below, and also the salts thereof with an organic or mineral acid, geometrical isomers thereof, tautomers thereof and solvates thereof such as the hydrates : Dyes of formulae (I) to (IV)

2- [5-Amino-l- (2-hydroxyethyl) -IH- pyrazol-4-ylamino] -5- (2- hydroxyethylamino) [1,4] benzoquinone

Family of formula (III)

(Ia)

3-Amino-4- [5-amino-l- (2-hydroxyethyl) -liϊ-pyrazol-4-ylimino] -2- chloro-6-methylcyclohexa-2 , 5-dienone Family of formula (II)

(Ib)

4- [5-Amino-l- (2-hydroxyethyl) -IH- pyrazol-4-ylimino] -3-hydroxycyclo- hexa-2 , 5-dienone Family of formula (I)

(Ic)

2- [5-Amino-l- (2-hydroxyethyl) -IH- pyrazol-4-ylamino] -4- [5-amino-l- (2- hydroxyethyl) -liϊ-pyrazol-4-ylimino] ^■

5-hydroxycyclohexa-2, 5-dienone

Family of formula (I)

(Id)

Dye precursors of formulae (I' ) to (TV') :

More particularly, the dyes contained in the composition are chosen from the preceding dyes (Ia), (Ib), (Ic), (Id), (Ie), (If), (Ig), (In) and (2b) and the salts thereof with an organic or mineral acid, geometrical isomers thereof, tautomers thereof and solvates thereof such as hydrates.

The compounds of formulae (I) to (IV) and (I') to (IV) of the invention are prepared according to the following general synthetic routes:

1- Access to the compounds corresponding to formulae (I' ) to (IV⁷ ) :

The compounds corresponding to formulae (I) to (IV) are generally obtained by reacting the derivatives 1, 2, 3 or 4 with a derivative of 4, 5-diaminopyrazole, preferably in basic medium in the presence of an oxidizing agent. The base used is preferentially an aqueous solution of ammonia or of sodium hydroxide and the oxidizing agent is preferentially chosen from hydrogen peroxide, potassium ferricyanide, air, ammonium persulfate and manganese oxide.

Similar synthetic approaches are described in patents FR 2 234 277 , FR 2 047932 , FR 2 106 661 and FR 2 121 101 .

2- Access to the compounds corresponding to formulae (I⁷ ) to (IV⁷ ) :

The compounds corresponding to formulae (I' ) to (IV ) are generally obtained by reacting the compounds of formulae (I) to (IV) with a reducing agent. This reducing agent is preferentially sodium hydrosulfite .

reducing agent

(IV) (IV)

Similar synthetic approaches are described in patents FR 2 056 799, FR 2 047 932, FR 2 165 965 and FR 2 262 023.

Another subject of the invention is a dye composition for dyeing keratin fibres, in a cosmetic medium, comprising at least one compound of formulae (I) to (IV) or of formulae (I') to (IV) .

The dye composition that is useful in the invention generally contains an amount of dye of formulae (I) to (IV) or of precursor of formulae (I' ) to (IV ) 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 preferentially between 0.01% and 6% by weight relative to the total weight of the composition.

The dye composition containing the dye of formulae (I) to (IV) or the precursor of formulae (I' ) to (IV ) , especially the precursor of formulae (I' ) to (IV ) , may also contain an oxidizing agent 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 formulae (I) to (IV) or (I' ) to (IV ) . These direct dyes are chosen, for example, 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.

Among the nitrobenzene direct dyes that may be mentioned, in a non-limiting manner, are the following compounds : 1, 4-diamino-2-nitrobenzene, l-amino-2-nitro-4-β- hydroxyethylaminobenzene, l-amino-2-nitro-4-bis ( β- hydroxyethyl) aminobenzene, 1, 4-bis ( β-hydroxyethyl- amino) -2-nitrobenzene, l-β-hydroxyethylamino-2-nitro-4- bis (β-hydroxyethylamino) benzene, 1-β-hydroxyethylamino- 2 -nitro-4 -aminobenzene, l-β-hydroxyethylamino-2-nitro- 4- (ethyl) (β-hydroxyethyl) aminobenzene, l-amino-3- methyl-4- β-hydroxyethylamino- 6-nitrobenzene, l-amino-2- nitro-4-β-hydroxyethylamino-5-chlorobenzene, 1, 2- diamino-4 -nitrobenzene, l-amino-2-β-hydroxyethylamino- 5-nitrobenzene, 1, 2 -bis ( β-hydroxyethylamino) -4-nitro- benzene, l-amino-2-tris (hydroxymethyl) methylamino-5- nitrobenzene, l-hydroxy-2-amino-5-nitrobenzene, 1- hydroxy-2 -amino-4 -nitrobenzene, 1 -hydroxy-3-nitro-4- aminobenzene, l-hydroxy-2-amino-4, 6-dinitrobenzene, 1- β-hydroxyethyloxy-2- β-hydroxyethylamino-5-nitrobenzene, 1 -methoxy-2-β-hydroxyethylamino-5-nitrobenzene, 1-β- hydroxyethyloxy-3-methylamino-4-nitrobenzene, 1-β, γ~ dihydroxypropyloxy-3-methylamino-4 -nitrobenzene, 1-β- hydroxyethylamino-4-β, γ-dihydroxypropyloxy-2-nitro- benzene, 1-β, γ-dihydroxypropylamino-4-trifluoromethyl- 2 -nitrobenzene, l-β-hydroxyethylamino-4-trifluoro- methyl-2 -nitrobenzene, 1- β-hydroxyethylamino-3-methyl- 2 -nitrobenzene, l-β-aminoethylamino-5-methoxy-2 -nitrobenzene, 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- hydroxyethy1amino-2 -nitrobenzene, l-hydroxy-4-β- hydroxyethy1amino-3-nitrobenzene .

Among the azo direct dyes, mention may be made of the cationic azo dyes described in patent applications WO-95/15144, WO-95/01772 and EP-714 954, the content of which forms an integral part of the invention.

Among these compounds, mention may be made most particularly 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, l-methyl-4- [ (methylphenylhydrazono) methyl] - pyridinium methyl sulfate.

Among the azo direct dyes, mention may also be made 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, Disperse Black 9.

Mention may also be made of 1- (4' -aminodiphenylazo) -2- methyl-4-bis (β-hydroxyethyl) aminobenzene and 4-hydroxy- 3- (2-methoxyphenylazo) -1-naphthalenesulfonic acid. Among the quinone direct dyes, mention may be made 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, Basic Blue 99, and also the following compounds : l-N-methylmorpholiniumpropylamino-4-hydroxy- anthraquinone, l-aminopropylamino-4-methylaminoanthra- quinone, 1-aminopropylaminoanthraquinone, 5-β-hydroxy- ethyl-1, 4-diaminoanthraquinone, 2-aminoethylamino- anthraquinone, 1, 4 -bis ( β, γ-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, 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, Acid Blue 7.

Among the indoamine dyes, mention may be made of the following compounds:

2-β-hydroxyethylamino-5- [bis (β-4' -hydroxyethyl) 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-benzoquinoneimine;

3-N- (3' -chloro-4' -methylamino) phenylureido-6-methyl- 1, 4-benzoquinoneimine;

3- [4' -N- (ethyl, carbamylmethyl) amino] phenylureido-6- methyl-1 , 4-benzoquinoneimine .

Among the natural direct dyes, mention may be made of lawsone, juglone, alizarin, purpurin, carminic acid, kermesic acid, purpurogallin, protocatechaldehyde, indigo, isatin, curcumin, spinulosin and apigenidin. Extracts or decoctions containing these natural dyes, and especially henna-based poultices or extracts, may also be used.

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

Among the oxidation bases, mention may be made of para- phenylenediamines, bis (phenyl) alkylenediamines, para- aminophenols, bis-para-aminophenols, ortho-aminophenols and heterocyclic bases, and the addition salts thereof.

Among the couplers, mention may be made especially of meta-phenylenediamines, meta-aminophenols, meta- diphenols, naphthalene-based couplers and heterocyclic couplers, and the addition salts thereof.

The coupler (s) is (are) each generally present in an amount of between 0.001% and 10% by weight and preferably between 0.005% and 6% by weight relative to the total weight of the dye composition.

The oxidation base(s) present in the dye composition is (are) each generally present in an amount of between 0.001% and 10% by weight and preferably between 0.005% and 6% by weight relative to the total weight of the dye composition.

In general, the addition salts of the oxidation bases and couplers used in the context of the invention are especially chosen from the salts of addition with an acid, such as the hydrochlorides, hydrobromides, sulfates, citrates, succinates, tartrates, lactates, tosylates, benzenesulfonates, phosphates and acetates, and the salts of addition with a base, such as alkali metal hydroxides, for instance sodium hydroxide, potassium hydroxide, ammonia, amines or alkanolamines . The medium that is suitable for dyeing, also known as the dye support, is a cosmetic medium generally comprising water or a mixture of water and of at least one organic solvent. Examples of organic solvents that may be mentioned include lower Ci-C₄ alkanols, such as ethanol and isopropanol; polyols and polyol ethers, for instance 2-butoxyethanol, propylene glycol, propylene glycol monomethyl ether and diethylene glycol monoethyl ether and monomethyl ether, and also aromatic alcohols, for instance benzyl alcohol or phenoxyethanol, and mixtures thereof.

When they are present, the solvents are preferably present in proportions preferably of between 1% and 50% by weight approximately, and even more preferentially between 5% and 40% by weight approximately, relative to the total weight of the dye composition.

The dye composition may also contain various adjuvants conventionally used in hair dye compositions, such as anionic, cationic, nonionic, amphoteric or zwitterionic surfactants or mixtures thereof, anionic, cationic, nonionic, amphoteric or zwitterionic polymers or mixtures thereof, mineral or organic thickeners, and in particular anionic, cationic, nonionic and amphoteric polymeric associative thickeners, antioxidants, penetrants, sequestrants, fragrances, buffers, dispersants, conditioning agents, for instance volatile or non-volatile, modified or unmodified silicones such as amino silicones, film-forming agents, ceramides, preserving agents, opacifiers and conductive polymers.

The above adjuvants are generally present in an amount for each of them of between 0.01% and 20% by weight relative to the weight of the composition.

Needless to say, a person skilled in the art will take care to select this or these optional additional compound (s) such that the advantageous properties intrinsically associated with the dye composition in accordance with the invention are not, or are not substantially, adversely affected by the envisaged addition (s) .

The pH of the dye composition is generally between 3 and 14 approximately. It may be adjusted to the desired value by means of acidifying or basifying agents usually used in the dyeing of keratin fibres, or alternatively using standard buffer systems.

According to one particular mode of the invention, when the dye composition comprises at least one dye of formulae (I) to (IV) , the composition has a pH of between 6 and 11.

According to another particular mode of the invention, when the composition comprises at least one dye precursor of formula (I' ) to (IV ) , the composition has a pH of between 6 and 11.

Among the acidifying agents, examples that may be mentioned include mineral or organic acids, for instance hydrochloric acid, orthophosphoric acid, sulfuric acid, carboxylic acids, for instance acetic acid, tartaric acid, citric acid or lactic acid, and sulfonic acids.

Among the basifying agents, examples that may be mentioned include aqueous ammonia, alkali metal carbonates, alkanolamines such as monoethanolamine, diethanolamine and triethanolamine, and also derivatives thereof, sodium hydroxide, potassium hydroxide and the compounds of formula (γ) below:

^R^1 f ^Ra2

N-W-N

^Ra4 ^XRa3 _(γ) 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 or a Ci-C₄ alkyl or Ci-C₄ hydroxyalkyl radical.

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

Another subject of the invention is a process for dyeing keratin fibres, in particular the hair, which consists in applying to 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 formulae (I) to (IV) or a dye precursor of formulae (I' ) to (IV ) as defined previously.

After a leave-in time, the keratin fibres are rinsed to reveal dyed fibres. The leave-in time is generally between 3 and 50 minutes approximately and preferably 5 to 40 minutes approximately.

The application of the dye composition according to the invention is generally performed at room temperature. However, it may be performed at temperatures ranging from 20 to 80⁰C.

The examples that follow serve to illustrate the invention without, however, being limiting in nature. The dyes of the examples below were fully characterized via the standard spectroscopic and spectrometric methods . EXAMPLES

EXAMPLES OF SYNTHESIS

Example 1 : Synthesis of 2- [5-amino-l- (2-hydroxyethyl) lff-pyrazol-4-ylamino] -5- (2-hydroxyethyl- amino) [1, 4] benzoquinone 1 (compound (Ia))

1.4 g of 2- (4, 5-diaminopyrazol-l-yl) ethanol sulfate (1 eq.), 24 ml of water, 880 mg of 3, 4-dihydro-2#- benzo [ 1, 4 ] oxazin-6-ol (1 eq.) and 24 ml of ethanol are introduced, respectively, into a three-necked round- bottomed flask equipped with a thermometer, a condenser and a dropping funnel. The mixture is stirred and the pH is then adjusted to 9.7 with aqueous 20% ammonia solution. 2 ml of 9% aqueous hydrogen peroxide solution are then added and the reaction medium is stirred for 4 hours at room temperature.

The solid formed is filtered off, washed with water and then dried under vacuum. 440 mg of 2- [5-amino-l- (2- hydroxyethyl) -liϊ-pyrazol-4-ylamino] -5- (2-hydroxyethyl- amino) [ 1, 4 ] benzoquinone (Ia) are obtained.

Example 2: Synthesis of 3-amino-4- [5-amino-l- (2-hydroxy- ethyl) -liϊ-pyrazol-4-ylimino] -2-chloro-6- methylcyclohexa-2, 5-dienone 2 (compound

(Ib))

4.7 g (19.6 mmol) of 2- (4, 5-diaminopyrazol-l-yl) ethanol sulfate (1 eq.), 40 ml of water, 3.9 g (20.2 mmol) of 3, 4-dihydro-2iϊ-benzo [ 1 , 4 ] oxazin-6-ol (1 eq.) and then 40 ml of water and 80 ml of ethanol are introduced into a three-necked round-bottomed flask equipped with a thermometer, a condenser and a dropping funnel, and the mixture is stirred. The pH is adjusted to 9.7 with 14 ml of aqueous 20% ammonia solution.

A solution of 9 g of ammonium persulfate in 30 ml of water is then added over 10 minutes. The reaction medium is stirred at room temperature for 4 hours and the solid formed is then filtered off, washed with water, with 50/50 water/ethanol and then dried under vacuum. 5.6 g of 3-amino-4- [5-amino-l- (2-hydroxyethyl) - liϊ-pyrazol-4-ylimino] -2-chloro-6-methylcyclohexa-2, 5- dienone (Ib) are obtained.

Example 3: Synthesis of 2- [5-amino-l- (2-hydroxyethyl) - lff-pyrazol-4-ylamino] -4- [5-amino-l- (2-hydroxy- ethyl) -liϊ-pyrazol-4-ylimino] -5-hydroxycyclo- hexa-2, 5-dienone 3 (compound (Id))

12 g (50 mmol) of 2- (4, 5-diaminopyrazol-l-yl) ethanol sulfate (1 eq. ) 2.8 g (25 mmol) of 3-hydroxyphenol

(0.5 eq.), 250 ml of water and 250 ml of ethanol are introduced, respectively, into a round-bottomed flask. The mixture is stirred at room temperature and the pH is adjusted to 9.6 with 20 ml of aqueous 20% ammonia solution, and air is bubbled through the reaction medium.

After 24 hours, the ethanol of the reaction medium is evaporated off and the solid formed is then filtered off, washed with water and then dried under vacuum.

700 mg of 2- [5-amino-l- (2-hydroxyethyl) -l/J-pyrazol-4- ylamino] -4- [5-amino-l- (2-hydroxyethyl) -lH-pyrazol-4- ylimino] -5-hydroxycyclohexa-2, 5-dienone (Id) are obtained.

Example 4: Synthesis of 4- [5-amino-l- (2-hydroxyethyl) lff-pyrazol-4-ylimino] - 3-hydroxy-2 -methyl - cyclohexa-2, 5-dienone 4 (compound (Ie) )

120 mg (0.5 mmol) of 2- (4, 5-diaminopyrazol-l-yl) ethanol

(1 eq.) , 2 ml of water, 62 mg (0.5 mmol) of 2-methyl-3- hydroxyphenol and then 2 ml of ethanol are introduced into a round-bottomed flask containing 30 ml of ethanol. The mixture is stirred at room temperature, the pH is adjusted to 9.6 with 20 ml of aqueous 20% ammonia solution, and 228.2 mg (1 mmol) of ammonium persulfate (2 eq.) are added.

After stirring for 3 hours, the solid formed is filtered off, washed with water and then dried under vacuum.

mg of 4- [5-amino-l- (2-hydroxyethyl) -lH-pyrazol-4- ylimino ] -3-hydroxy-2 -methylcyclohexa-2 , 5-dienone ( Ie ) are obtained .

Example 5 : Synthesis of 3-amino-4 - [ 5-amino- l - ( 2 -hydroxy- ethyl ) - liϊ-pyrazol-4 -ylamino ] -2-chloro- 6- methylphenol 5 ( compound ( 2b ) )

Argon is bubbled through a round-bottomed flask containing 1.5 ml of 0.5M sodium hydroxide, and 30 mg

(0.1 mmol) of 3-amino-4- [5-amino-l- (2-hydroxyethyl) -IH- pyrazol-4-ylimino] -2-chloro-6-methylcyclohexa-2, 5- dienone 2 (1 eq.) are added. The reaction medium is stirred at room temperature and 0.5 ml of ethanol is then added to dissolve the mixture. 250 mg (1.42 mmol) of sodium hydrosulfite (14 eq.) are then added. After stirring for 5 minutes, the solution decolourizes. The pH of the reaction medium is then brought to 6 with acetic acid, and the ethanol is then evaporated off. The precipitate obtained is filtered off under argon and then dried under vacuum. 9 mg of 3-amino-4- [5-amino-

1- (2-hydroxyethyl) -liϊ-pyrazol-4-ylamino] -2-chloro-6- methylphenol (2b) are obtained.

Example 6: Synthesis of 2-amino-5- { [5-amino-l- (2- hydroxyethyl) -lH-pyrazol-4-yl] amino } -6- { [5- amino-1- (2-hydroxyethyl) -lH-pyrazol-4- yl] imino }pyridin-3 ( 6H) -one (compound (In))

To a solution of 14 ml of ethanol and 14 ml water, 0.5 g of de 2- (4, 5-diamino-lH-pyrazol-l-yl) ethanol sulfate are introduced, and 0.193 g of 2-aminopyridin-3-ol are added.

The mixture is stirred at room temperature and the pH is adjusted to 9.5 with aqueous 20% ammonia solution in water, and the reaction mixture is stirred at room temperature for 5 hours. The solid crude product is then filtrated, washed with water.118 mg of expected product (In) 2-amino-5- { [5-amino-l- (2-hydroxyethyl) -IH- pyrazol-4-yl ] amino } -6- { [ 5-amino-l- (2-hydroxyethyl) -IH- pyrazol-4-yl] imino }pyridin-3 ( 6H) -one are obtained.

Claims

1. Compound chosen from those of formulae (I) to (IV) or (I' ) to (IV ) :

(111) (IV)

salts thereof with an organic or mineral acid, geometrical isomers thereof, tautomers thereof, and solvates thereof such as the hydrates; in which formulae (I) to (IV) or (I') to (IV) :

• Ri represents:

- a hydrogen atom, - a Ci-C₅ alkyl radical, or

- a Ci-C₅ alkyl radical functionalized with a group chosen from: i) hydroxyl, i i ) Ci-C₄ al koxy, i ϋ ) amino , iv) amido , v) di (C1-C3) alkylamino, vi) imidazolyl, vii) phenyl optionally substituted with a chlorine atom, a trifluoromethane radical or a methyl radical;

• R₂ represents:

- a hydrogen atom,

- a bromine atom, - a Ci-C₅ alkyl radical, or

- a phenyl radical;

• R₃ and R₄ represent, independently of one another:

- a hydrogen atom,

- a Ci-C₅ alkyl radical, or - a Ci-C₅ alkyl radical functionalized with a group chosen from: i) hydroxyl, ii) Ci-C₄ alkoxy, iii) amino, iv) amido, v) di (C1-C3) alkylamino, and vi) imidazolyl;

• R₅ represents:

- a hydrogen atom or - a Ci-C₄ alkyl radical;

• Re represents:

- a hydrogen atom or

- a radical corresponding to formula (V) below:

(V)

in which formula (V) R₁, R₂, R₃ and R₄ have the same meaning as previously.

2. Compound according to the preceding claim, for which R₂ represents a hydrogen atom or a C₁-C₅ alkyl radical .

3. Compound according to any one of the preceding claims, for which R₁ represents a C₁-C₅ alkyl radical, or a C₁-C₅ alkyl radical functionalized with a hydroxyl group .

4. Compound according to any one of the preceding claims, for which R₃ and R₄ represent a hydrogen atom.

5. Compound of formula (I) and (IV) or (I') and (IV) according to any one of the preceding claims, for which Re represents a radical (V) in which R₂, R3 and R₄ represent a hydrogen atom and R₁ represents a C₁-C₅ alkyl radical functionalized with a hydroxyl group.

6. Compound according to any one of the preceding claims of formulae (I) to (IV) and (I') to (IV), chosen from the following compounds: 2- [5-Amino-l- (2-hydroxyethyl) -IH- pyrazol-4-ylamino] -5- (2- hydroxyethylamino) [1,4] benzoquinone

Family of formula (III)

[la)

3-Amino-4- [5-amino-l- (2-hydroxyethyl) -liϊ-pyrazol-4-ylimino] -2- chloro-6-methylcyclohexa-2, 5-dienone Family of formula (II)

lib)

(Ic)

5-hydroxycyclohexa-2, 5-dienone

Family of formula (I)

:id)

4- [5-Amino-l- (2-hydroxyethyl) -IH- pyrazol-4-ylimino] -3-hydroxy-2- methylcyclohexa-2, 5-dienone

Family of formula (I)

(Ie)

7. Dye composition comprising, in a suitable cosmetic medium, at least one compound of formulae (I) to (IV) or (I' ) to (IV ) according to any one of the preceding claims .

8. Composition according to the preceding claim, in which the compound of formulae (I) to (IV) or (I' ) to (IV) is present in an amount of between 0.001% and 30% by weight relative to the total weight of the composition .

9. Composition according to either of Claims 7 and 8, in which, when the composition comprises at least one compound of formulae (I) to (IV) , the composition has a pH of between 6 and 11.

10. Composition according to either of Claims 7 and 8, in which, when the composition comprises at least one compound of formulae (I' ) to (IV ) , the composition has a pH of between 6 and 11.

11. Composition according to any one of Claims 7 to 10, which also comprises at least one oxidizing agent.

12. 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.

13. Composition according to any one of Claims 7 to 12, which also comprises at least one adjuvant chosen from anionic, cationic, nonionic, amphoteric and zwitterionic surfactants or mixtures thereof, anionic, cationic, nonionic, amphoteric or zwitterionic polymers or mixtures thereof, mineral or organic thickeners, antioxidants, penetrants, sequestrants, fragrances, buffers, dispersants, conditioning agents, film-forming agents, ceramides, preserving agents, opacifiers and conductive polymers.

14. Process for dyeing keratin fibres, in which a suitable dye composition according to any one of the preceding Claims 7 to 13 is applied to the materials.

15. Use of a compound of formulae (I) to (IV) or (I') to (IV ) as defined in any one of Claims 1 to 6, for dyeing keratin fibres.