FR2920779A1 - New cationic azo julolidine compounds useful as dye for coloring keratin fibers, preferably human keratin fibers such as hair - Google Patents

Abstract

Cationic azo julolidine compounds (I) and their organic or inorganic acid addition salts, solvates, tautomers, and optical and geometrical isomers as dye are new, where the electroneutrality of (I) is assured by one or more anionic counter-ions. Cationic azo julolidine compounds of formula (I) and their organic or inorganic acid addition salts, solvates, tautomers, and optical and geometrical isomers as dye are new, where the electroneutrality of (I) is assured by one or more anionic counter-ions. W 1cationic heteroaromatic radical comprising pyridinium radical of formula (IIa) or imidazole group of formula (IIb); L : sigma covalent bond or 1-20C bivalent hydrocarbon chain (optionally substituted and interrupted by one or more divalent groups and where the two divalent groups or their combinations are separated by 1-6C divalent hydrocarbon chain, preferably alkylene, comprising -N(R)-, -N +>(R)(R o)-, An ->, -O-, -S-, -C(O)-, cationic heterocycle or cationic heteroaryl (Het +>), non-cationic heterocycle comprising 5-10 membered chain or heteroaryl (optionally substituted)); R : 1-4C alkyl, 2-6C (poly)hydroxyalkyl, alkoxy(1-6C)alkyl, aryl, aryl(1-6C)alkyl, (1-4C)alkylcarbonylamino(1-6C)alkyl, amino(1-4C)alkyl of which amine is substituted by one or more 1-4C alkyl radical, alkyl(1-8C)carbonyl or 1-4C alkylcarbonylamino; R oH or R; Het +>5-10 membered cationic heterocycle (optionally saturated) or 5-10 membered cationic heteroaryl; R 11-6C alkyl, aryl, heteroaryl, aryl(1-6C)alkyl, heteroaryl(1-6C)alkyl (all optionally substituted), cycloalkyl(1-6C)alkyl or heterocycloalkyl(1-6C)alkyl; either R 21-4C alkyl, OH, 1-4C alkoxy, 2-4C (poly)hydroxyalkoxy, alkoxycarbonyl (R aC(O)-O-), alkylcarbonyloxy (R aC(O)-O-), amino group (optionally substituted by one or more 1-4C alkyl and optionally carrying at least one hydroxyl group, where the two alkyl radicals optionally together with nitrogen atom to form a 5 or 6 heterocyclic ring optionally substituted and carrying another heteroatom of N or O), alkylcarbonylamino group (R aC(O)-NR1a-), (di-)(alkyl)aminocarbonyl ((R a) 2N-C(O)), ureido group ((R a) 2N-CO-NR b-), guanidinium group ((R a) 2N-C(=NH 2>+)-NR b-), phenyl or halo; or CR 2R 26 membered condensed aromatic ring optionally substituted by one or more OH, 1-4C alkyl, hydroxycarbonyl (HO(O)C-), alkoxy carbonyl (R aO(O)C-), alkylsulfonylamino (R aS(O) 2NR b), 1-4C alkoxy, amino optionally substituted by one or two 1-4C alkyl and optionally carrying OH or methylcarbonylamino, where the two alkyl groups optionally together with nitrogen atom to form a 5 or 6 heterocyclic ring optionally carrying another heteroatom of N or O; Y 1H, alkaline metal, alkaline-earth metal, ammonium group (N +>Ralpha Rbeta Rgamma Rdelta ), phosphonium group (P +>Ralpha Rbeta Rgamma Rdelta ) or thiol protecting group; An : anionic counter-ion; R a, R b, Ralpha Rbeta Rgamma Rdelta : H or 1-4C alkyl; R1a : H or 1-4C alkyl; R 3H or R 2; R 4optionally substituted 1-6C alkyl or carboxy; m : 0-4; n : 0-6; x : 1 or 2; and y : 0 or 1. Provided that: L not comprising a group of diazo, hydrazino, aminooxy, nitro, nitroso and peroxide; when x is 2, then y is 0; when x is 1, then y is 1; the bond (a) in (IIa) and (IIb) connects the W 1group to N, preferably for (IIa), the bond (a) connects the pyridinium group to N in position 2 or 4, and for (IIb) the bond (a) connects the imidazolium groups to N in position 2, and in the case of formulae (IIa) and (IIb), when two R 2radicals carried by two adjacent carbon atoms form an aromatic cycle such; the bond (a) connects the W 1group to N by the intermediate of aromatic cycle; and the bond b in (IIa) or (IIa) connects the W 1group to the bond L by intermediate of methylene group. Independent claims are included for: (1) a coloring composition comprising (I) and at least a reducing agent; (2) a process for coloring keratin fibers comprising applying the composition on the fibers; and (3) a device with several compartments comprising a first compartment containing the composition and a second compartment containing a reducing agent. [Image] [Image].

Description

The present invention relates to cationic azo julolidine dyes with thiol / disulfide units for dyeing keratinous fibers.

It is known to dye keratinous fibers and in particular human keratin fibers, such as the hair, with dye compositions containing direct dyes. These compounds are colored molecules and dyes having an affinity for the fibers. It is known, for example, to use direct dyes of the nitrobenzene type, anthraquinone dyes, nitropyridines, dyes of the azo, xanthene, acridine, azine or triarylmethane type. Usually, these dyes are applied to the fibers, optionally in the presence of an oxidizing agent, if it is desired to obtain a simultaneous effect of lightening the fibers. Once the exposure time has elapsed, the fibers are rinsed, optionally washed and dried. The colorings which result from the use of direct dyes are temporary or semi-permanent dyes because the nature of the interactions which bind the direct dyes to the keratin fiber, and their desorption from the surface and / or the core of the fiber are responsible for their low dyeing power and their relative poor resistance to washes and perspiration. To increase the toughness of direct stains, it is known to use disulfide dyes. The documents WO2005 / 097051, EP 1647580 and WO 2006/136617 describe dyes with chromophores aza-imidazolium disulfides. WO 2006/136617 also describes the mixing of several disulfide dyes in order to access brown / brown shades. However, some disulfide dyes may have insufficient performance in terms of the rise of the color in the keratin fiber, selectivity between the root and the tip, and stability. In addition, certain dyes of the state of the art do not have a satisfactory resistance to external aggressions such as bad weather, successive shampoos or the sun, which causes a color shift over time. This disadvantage is particularly problematic when it occurs following shampooing, exposure to the sun or the combination of these two factors.

It is therefore still necessary to have very stubborn dyes that can be associated with each other to give a set of tints, colorings that do not show a color shift. The most sought-after hues are natural hues such as brown. One of the aims of the present invention is to provide disulfide dyes which do not have the drawbacks of existing direct disulfide dyes. This object is achieved with the present invention which relates to a process for dyeing keratinous fibers such as the hair, which consists in applying to the keratinous fibers a dyeing composition comprising, in a suitable cosmetic medium, at least one azo julolidine dye. cationic disulfide or thiol. In particular, the present invention provides dyes which make it possible to obtain natural shades after staining of the keratin fibers, resistant to external aggression over time. Certain disulfide dyes may furthermore have photostability properties superior to the dyes of the state of the art. The present invention therefore relates to cationic azo julolidine dyes disulphides or thiols of formula (I) below: WS H2 ~ Yl 1Y X 3 9 (I)

As well as their addition salts with an organic or inorganic acid, tautomers, optical isomers, geometric and solvates formula (I) in which: W1, represents a cationic heteroaromatic radical chosen from the following formulas (Ila) and (Ilb): 4 3, 5 (R 2) m (Ila); aa 3 An- (R 2) e 4 An (Ilb) with: the bond from formulas (IIa) and (Ilb) connects the group W to the azo group ; particularly for (IIa) the linkage connects the pyridinium group to the azo group in position 2 or 4, and for (Ilb) the a bond connects the imidazolium group to the azo group in position 2; in the case of the formulas (IIa) and (IIb) and when two radicals R2 carried by two adjacent carbon atoms form an aromatic ring, the link a may link the group W, to the azo group through said aromatic ring; the bond b resulting from the formulas (IIa) and (IIb) connects the group W, to the linking arm L via the methylene group; L represents a covalent bond 6 or a bivalent C1-C20i hydrocarbon chain, especially C, -C, O, optionally substituted, optionally interrupted by one or more divalent groups or combinations thereof, it being understood that two divalent groups or their combinations are separated by a C1-C6i divalent hydrocarbon chain, especially alkylene, said divalent groups being chosen from: i) N (R) -; -N + (R) (R o) -, An-; -O-, -S-, -C (O) -, with R, represents a group chosen from (C 1 -C 4) alkyl, (poly) hydroxy (C 2 -C 6) alkyl, (C 1 -C 6) alkoxy, aryl, such as phenyl, aryl (C 1 -C 6) alkyl such as benzyl, (C 1 -C 4) alkylcarbonylamino (C 1 -C 6) alkyl, amino (C 1 -C 4) alkyl whose amine is substituted by one or more identical alkyl radicals or different C 4 -C 4 alkyl (C 1 -C 6) carbonyl and (C 1 -C 4) alkylcarbonylamino; and R ° represents a hydrogen atom or R; ii) a cationic heterocycle or cationic heteroaryl Het +, An-, with As defined above and Het + representing a cationic heterocycle comprising from 5 to 10 members, saturated or unsaturated, or a cationic heteroaryl comprising from 5 to 10 members such as imidazolium piperazinium, benzimidazolium, pyrazolium; iii) a non-cationic heterocyclic ring comprising 5 to 10 ring members such as piperazinyl, and iv) an optionally substituted (hetero) aryl such as optionally substituted 1,3,5 triazine; with L not containing a diazo, hydrazino, aminooxy, nitro, nitroso, peroxide group;

R, is directly attached to the nitrogen atom, quaternized or not via a carbon atom and represents a group selected from: • an optionally substituted C1-C6 alkyl group such as methyl; An optionally substituted aryl group such as phenyl; an optionally substituted heteroaryl group such as pyridyl; an optionally substituted aryl (C 1 -C 6) alkyl group such as benzyl; An optionally substituted heteroaryl (C 1 -C 6) alkyl group such as pyridinylmethyl; A cycloalkyl (C 1 -C 6) alkyl group such as cyclohexylmethyl; and • a heterocycloalkyl (C 1 -C 6) alkyl group such as piperidinylmethyl;

R2 represents: • a C1-C4 alkyl group • a hydroxyl group • a C1-C4 alkoxy group • a C2-C4 (poly) hydroxyalkoxy group; An alkoxycarbonyl group (RaO-C (O) -) in which Ra represents a C1-C4 alkyl radical; an alkylcarbonyloxy group (RaC (O) -O-) in which Ra represents a C1-C4 alkyl radical; An amino group optionally substituted with one or more identical or different C1-C4 alkyl radicals optionally bearing at least one hydroxyl group, the two alkyl radicals possibly being able to form, with the nitrogen atom to which they are attached, a substituted or unsubstituted 5- or 6-membered heterocycle and optionally carrying another heteroatom identical to or different from nitrogen, for example oxygen; An alkylcarbonylamino group (RaC (O) -NR'a-) in which Ra represents a C1-C4 alkyl radical and R'a represents a hydrogen atom or a C1-C4 alkyl radical; A (di-) (alkyl) aminocarbonyl group ((Ra) 2 N-C (O)) in which the Ra radicals independently of each other, which may be identical or different, represent a hydrogen atom or a C 1 -C 4 alkyl radical; C4; A ureido group ((Ra) 2N-CO-NRb-) in which the radicals Ra and Rb, independently of one another, represent a hydrogen atom or a C1-C4 alkyl radical; A guanidinium group ((Ra) 2N-C (= NH 2 +) - NRb-) in which the radicals Ra and Rb, independently of each other, represent a hydrogen atom or a C 1 -C 4 alkyl radical; A phenyl group; a halogen atom, preferably chlorine, fluorine or bromine; Or two adjacent radicals R 2 can form, with the carbon atoms to which they are attached, a 6-membered aromatic fused ring, optionally substituted with one or more identical or different groups chosen from hydroxyl, C 1 -C 4 alkyl, hydroxycarbonyl ( HO (O) C-), alkoxycarbonyl (RaO (O) C-) wherein Ra is (C1-C4) alkyl, (alkyl) sulfonylamino (RaS (O) 2NRb) wherein Ra, are C1-alkyl; -C4 and Rb represents a hydrogen atom, a radical or a C1-C4 alkyl group; C1-C4 alkoxy; amino optionally substituted with one or two identical or different C1-C4 alkyl groups and optionally bearing at least one hydroxyl or methylcarbonylamino group, the two alkyl groups possibly being able to form, with the nitrogen atom to which they are attached, a heterocycle 5- or 6-membered ring optionally carrying another heteroatom identical to or different from nitrogen, for example oxygen; R3 represents a hydrogen atom or a radical as defined for R2; especially R3 represents a hydrogen atom or a hydroxyl group;

R4, independently of each other, represent a group selected from (C 1 -C 6) alkyl optionally substituted or carboxy; particularly R4 is (C1-C4) alkyl such as methyl, more particularly n is 4 and R4 are at the 4- and 8-positions of the julolidine group; An- represents an anionic counterion;

m represents an integer inclusive between 0 and 4;

N represents an integer inclusive between 0 or 6 more particularly between 0 and 4;

e is an integer inclusive between 0 and 2;

X is 1 or 2; y represents 0 or 1; with the proviso that: - when x is 2 then y is 0, and - when x is 1, then y is 1 and the compounds of the invention of formula (I) are such that the bond SY may be covalent (- SY) or ionic (-S- Y +) according to the nature of Y and the pH of the medium; Y represents: i) a hydrogen atom; ii) an alkali metal; iii) an alkaline earth metal; iv) an ammonium group: N + RaRRR7Rs or a phosphonium group: P + R1RPR7R5 with Ra, RR, R7 and R5, identical or different, representing a hydrogen atom or a (C1-C4) alkyl group; or v) a thiol protecting group; it being understood that: when Y represents a hydrogen atom or a thiol protecting group, then the SY bond is covalent; When Y represents an alkali metal, an alkaline earth metal, an ammonium group (N + RaRaRYRs) or a phosphonium group (P + RaRaRYRs), then the bond SY is ionic; the electroneutrality of the compounds being provided by one or more anionic counterion An-, identical or not. Another subject of the invention is a dyeing composition for dyeing keratinous fibers such as hair comprising, in a cosmetic medium, at least one cationic azulic azo disulfide or thiol dye of formula (I) as defined above, and optionally a reducing agent.

The subject of the invention is also a method for dyeing keratinous fibers, such as the hair, consisting in applying to the keratin fibers a dyeing composition comprising, in a suitable cosmetic medium, at least at least one cationic azulic azo dye or disulphide dye. thiol of formula (I) as defined above.

The dyeing process according to the invention makes it possible to color the keratinous fibers without degrading them, in a manner remanent with respect to shampoos, of common aggressions such as sun, perspiration, and hair treatments. This process also makes it possible to color keratinous fibers in a powerful, non-selective, homogeneous and chromatic way. Mixed with yellow, orange and red dyes this process also allows keratin fibers to be colored in natural shades such as browns and blacks without observing a significant bend over time. Moreover, the new dyes according to the invention have a better chemical stability. These dyes are more soluble and stable than the dyes of the state of the art in conventional cosmetic formulations containing in particular acidified water and organic solvents. It is possible, for example, to mention lower C1-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 monomethyl ether. as well as aromatic alcohols such as benzyl alcohol or phenoxyethanol, and mixtures thereof.

For the purposes of the present invention, and unless a different indication is given: • An alkyl radical is a saturated hydrocarbon radical C1-C16, particularly C1-C6, linear or branched, and monovalent.

An alkoxy radical is an alkyl-oxy or alkyl-O- radical for which the alkyl radical is a hydrocarbon radical, linear or branched, C1-C16 preferentially C1-C8.

An alkylthio radical is an alkyl-S- radical for which the alkyl radical is a hydrocarbon radical, linear or branched, C1-C16 preferentially C1-C8.

An alkyl radical or the alkyl part of a radical is said to be substituted when it comprises at least one substituent chosen from the following groups: hydroxyl, C 1 -C 4 alkoxy, (poly) hydroxyalkoxy at 02-06, - amino, amino substituted with one or more identical or different C1-C4 alkyl groups optionally bearing at least one hydroxyl group, said alkyl radicals being able to form with the nitrogen atom to which they are attached a 5- or 6-membered heterocyclic ring optionally comprising at least one other heteroatom which may or may not differ from nitrogen-amido, (C 1 -C 4) alkylcarbonylamino, the amine of which is optionally substituted by a C 1 -C 4 alkyl group. When the alkylthio group is optionally substituted, this implies that the alkyl group of the alkylthio is optionally substituted as defined above.

An aryl or heteroaryl radical or the aryl or heteroaryl part of a radical is said to be substituted when it comprises at least one substituent borne by a carbon atom, chosen from: an alkyl radical; C1-C16, preferably C1-C8, optionally substituted with one or more radicals chosen from hydroxyl, C1-C2 alkoxy, (poly) -hydroxyalkoxy radicals, 02-04, acylamino, amino substituted with two identical alkyl radicals; or different, C1-C4, optionally carrying at least one hydroxyl group or, the two radicals may form with the nitrogen atom to which they are attached, a 5- or 7-membered heterocycle, preferably 5 or 6 linkages, optionally comprising another heteroatom identical to or different from nitrogen; a halogen atom such as chlorine, fluorine or bromine; a hydroxyl group; a C1-C2 alkoxy radical; a (C 2 -C 4) -polyhydroxyalkoxy radical; an optionally amino radical substituted with one or two identical or different C 1 -C 4 alkyl radicals optionally bearing at least one hydroxyl or amino group with two optionally substituted C 1 -C 2 alkyl radicals; an (alkyl) carbonylamino radical (-NRa-CORb) in which the radical Ra is a hydrogen atom, a C1-C4 alkyl radical optionally bearing at least one hydroxyl group and the radical Rb is a C1-alkyl radical; -02.

The cyclic or heterocyclic part of a non-aromatic radical is said to be substituted when it comprises at least one substituent carried by a carbon atom chosen from the groups: a hydroxyl group, an alkoxy radical; C1-C4, a radical (poly) hydroxyalkoxy at 02-04, a (alkyl) carbonylamino radical ((RaCO-NRb-) in which the radical Rb is a hydrogen atom, a C1-C4 alkyl radical optionally carrying At least one hydroxyl group and the radical Ra is a C 1 -C 2 alkyl radical; an amino radical optionally substituted with two identical or different C 1 -C 4 alkyl groups optionally carrying at least one hydroxyl group, said alkyl radicals; may form with the nitrogen atom to which they are attached, a 5- or 6-membered heterocycle, optionally comprising at least one other heteroatom different or different from nitrogen.

• An aryl radical represents a mono or polycyclic carbon group, condensed or not, comprising from 6 to 22 carbon atoms, and at least one ring is aromatic; preferably the aryl radical is phenyl, biphenyl, naphthyl, indenyl, anthracenyl, or tetrahydronaphthyl.

A heteroaryl radical represents a mono- or polycyclic group, fused or non-fused, optionally cationic, comprising from 5 to 22 members, from 1 to 6 heteroatoms chosen from nitrogen, oxygen, sulfur and selenium, and wherein at least one ring is aromatic; preferably a heteroaryl radical is chosen from acridinyl, imidazolyl, benzimidazolyl, pyrazolyl, indazolyl, thiazolyl, benzothiazolyl, oxazolyl, benzoxazolyl, pyridinyl, quinolyl, isoquinolyl, benzoquinolyl, pyrazinyl, benzopyrazinyl, pyrrolyl, indolyl, pyridazinyl, benzo-pyridazinyl, triazolyl, benzotriazolyl, benzobistriazolyl, tetrazolyl, dihydrothiazolyl, imidazopyridinyl, naphthoimidazolyl, naphthooxazolyl, naphthopyrazolyl, oxadiazolyl, oxazolopyridyl, phenazinyl, phenooxazolyl, pyrazoyltriazyl, thiadiazolyl, thiazolopyridinyl, thiazoylimidazolyl, thiopyrylyl, xanthylyl and its ammonium salt.

A cyclic or cycloalkyl radical is a non-aromatic cycloalkyl radical, mono- or polycyclic, condensed or not, containing from 5 to 22 carbon atoms, which can comprise from one to several unsaturations; particularly the cyclic radical is cyclohexyl.

A sterically hindered cyclic radical is a cyclic radical, aromatic or not, substituted or unsubstituted, hindered by steric effect or constraint, comprising from 6 to 14 members, which can be bridged, as sterically hindered radicals, mention may be made of bicyclo [1.1. Butane, mesylates such as 1,3,5-trimethylphenyl, 1,3,5-triterbutylphenyl, 1,3,5-isobutylphenyl, 1,3,5-trimethylsilylphenyl and adamantyl.

• A heterocyclic radical or heterocycle is a non-aromatic mono- or polycyclic radical, condensed or not, containing from 5 to 22 members, comprising from 1 to 6 heteroatoms selected from the nitrogen atom, oxygen, and sulfur. An alkylene radical is a linear or branched, C1-C30 divalent, especially C1-C20, hydrocarbon-based chain optionally substituted by the same substituents as those of an optionally substituted alkyl group or by an Ra-Za-C (Z) group; with Za, Zb, identical or different, representing an oxygen atom, sulfur, or a group NRa ', and Ra, representing an alkali metal, a hydrogen atom, or an alkyl group and Ra' representing an atom of hydrogen or an alkyl group or is absent and in this case an anionic counterion An is also absent; Ra-Za-C (Z) is especially a carboxy group; particularly the alkylene chain is unsubstituted, such as methylene, ethylene or propylene. An optionally substituted C1-C20 bivalent hydrocarbon chain, optionally interrupted, is a saturated or unsaturated hydrocarbon chain, particularly C 2 -C 8, optionally comprising one or more conjugated or unsubstituted 7T double bonds; more particularly the hydrocarbon chain is saturated; said chain is optionally substituted with one or more identical or different substituents as defined above for the alkylene chain; said chain is optionally interrupted in the linking arm L by one or more divalent groups or combinations thereof, it implies that the chain may have one or more carbon atoms (preferably 1 to 3) substituted by one or more divalent groups (from 1 to 3 preferably) of L selected from i), ii) and iii) or substituted for example the combination of a group belonging to i) with a group belonging to ii), or the combination of a group belonging to to i) with a group belonging to iii) or the combination of two groups belonging to i) such that ùC (0) -NR-, -NRuC (0) -, -OC (0) -, - C (0) O-.

An organic or inorganic acid salt is more particularly chosen from a salt derived from i) hydrochloric acid HCl, ii) hydrobromic acid HBr, iii) sulfuric acid H 2 SO 4, iv) alkylsulphonic acids: Alk- S (O) 2OH such as methylsulfonic acid and ethylsulfonic acid; v) arylsulfonic acids: Ar-S (O) 2OH such as benzene sulfonic acid and toluene sulfonic acid; (vi) citric acid; vii) succinic acid; viii) tartaric acid; ix) lactic acid, X) oxalic acid and xi) alkoxysulfinic acids: Alk-O-S (O) OH such as methoxysulfinic acid and ethoxysulfinic acid; xi) aryloxysulfinic acids such as tolueneoxysulfinic acid and phenoxysulfinic acid; xii) phosphoric acid H3PO4i xiii) acetic acid CH3C (O) OH.

An anionic counterion is an anion or an anionic group associated with the cationic charge of the cosmetically acceptable dye; more particularly the anionic counterion is selected from i) halides such as chloride, bromide; ii) nitrates; iii) sulfonates, including C1-C6 alkylsulfonates: Alk-S (O) 2O- such as methylsulfonate or mesylate and ethylsulfonate; iv) arylsulfonates: Ar-S (O) 2O- such as benzenesulphonate and toluenesulphonate or tosylate; v) citrate; vi) succinate; (vii) tartrate; viii) lactate; ix) (alkyl) sulfates: (Alk-) O-S (O) O- such as hydrogen sulfate, methysulfate and ethylsulfate; x) arylsulfates: Ar-O-S (O) O- such as benzenesulphate and toluenesulphate; xi) alkoxysulfates: Alk-O-S (O) 2O- such as methoxy sulfate and ethoxysulfate; xii) aryloxysulfates: Ar-O-S (O) 2 O-, xiii) phosphate; (xiv) acetate; xv) oxalate; (xvi) a hydroxide; xvii) carbonates and hydrogen carbonates.

The solvates represent the hydrates as well as the association with linear or branched C1-C4 linear or branched alcohols such as methanol, ethanol, isopropanol and n-propanol. • When a cycle does not carry the maximum number of substituents, or the unsubstituted position (s) carry a hydrogen atom.

As indicated above, a first subject of the invention consists of compounds corresponding to the aforementioned formula (I).

A particular embodiment relates to the dyes of formula (I) in which R 1 represents a C 1 -C 16 alkyl radical; a C2-C6 monohydroxyalkyl radical; a C2-C6 polyhydroxyalkyl radical; a C1-C6 alkoxy (C1-C6) alkyl radical; an optionally substituted aryl radical, such as phenyl; an optionally substituted aryl (C1-C6) alkyl radical, such as benzyl; a C2-C6 amidoalkyl radical; a C2-C6 aminoalkyl radical, the amine of which is substituted with one or two identical or different C1-C4 alkyl radicals which are optionally substituted. More particularly, R 1 represents a radical chosen from i) C 1 -C 6 alkyl, ii) C 2 -C 6 monohydroxyalkyl; iii) C2-C6 polyhydroxyalkyl; iv) a C1-C6 alkoxy (C1-C6) alkyl radical; v) phenyl optionally substituted by at least one halogen atom such as chlorine, a hydroxyl group, an RCO-NH- group in which R represents a C 1 -C 4 alkyl radical or an amino radical substituted with two alkyl radicals; C1-C4 identical or different; vi) benzyl; vii) C1-C6 aminoalkyl; viii) C 1 -C 6 aminoalkyl wherein the amine is substituted with one or two identical or different C 1 -C 4 alkyl radicals. Advantageously, R 1 represents a C 1 -C 4 alkyl radical, such as methyl.

According to one particular variant of the invention, the dyes of formula (I) carry a radical R2, identical or different, representing a hydrogen atom or a group chosen from:

C1-C4 alkyl optionally substituted with one or more radicals chosen from hydroxyl, acylamino and amino radicals substituted with two identical or different C1-C2 alkyl radicals, optionally bearing at least one hydroxyl group, an alkoxy radical containing C1-C2; -amino; amino substituted with one or two identical or different C 1 -C 3 alkyl radicals optionally carrying at least one hydroxyl group, the two alkyl radicals possibly being able to form, with the nitrogen atom to which they are attached, a heterocycle 5- or 6-membered saturated or unsaturated, optionally substituted, optionally carrying another heteroatom identical to or different from nitrogen; -alkylcarbonylamino RC (O) -NR'- wherein R represents a C1-C4 alkyl radical and the radical R 'represents a hydrogen, a C1-C4 alkyl radical, and more preferably wherein R represents a methyl radical; carbamoyl ((R) 2 N-C (O) -) in which the R radicals, which may be identical or different, represent a hydrogen atom or a C 1 -C 4 alkyl radical optionally carrying at least one hydroxyl group; aminosulphonyl; hydroxyl; and - C1-C2 alkoxy. a phenyl radical optionally substituted with one or more radicals chosen from hydroxyl, acylamino and amino radicals substituted with two identical or different C1-C2 alkyl radicals, optionally bearing at least one hydroxyl group, a C1-alkoxy radical; C2; According to a preferred variant of the invention, the radical R2, independently of one another, represents:

a hydrogen atom; a methyl, ethyl, propyl, 2-hydroxyethyl, methoxy, ethoxy, 2-hydroxyethyloxy, 3-hydroxypropyloxy, 2-methoxyethyl radical; carbamoyl ((R) 2 N-C (O) -) in which the identical R radicals represent a hydrogen atom; a phenyl radical According to one particular variant of the invention, the dyes of formula (I) carry a radical R3, which may be identical or different, representing a hydrogen atom or a group chosen from:

C1-C4 alkyl optionally substituted with one or more radicals chosen from hydroxyl, acylamino and amino radicals substituted with two identical or different C1-C2 alkyl radicals, optionally bearing at least one hydroxyl group, an alkoxy radical containing Cl-C2; amino substituted with one or two identical or different C 1 -C 3 alkyl radicals, optionally bearing at least one hydroxyl group, the two alkyl radicals possibly being able to form, with the nitrogen atom to which they are attached, a heterocycle with 5 or 6-membered saturated or unsaturated, optionally substituted, optionally carrying another heteroatom identical to or different from nitrogen; alkylcarbonylamino RC (O) -NR'- wherein R represents a C1-C4 alkyl radical and the radical R 'represents a hydrogen, a C1-C4 alkyl radical, and more preferably wherein R represents a methyl radical; carbamoyl ((R) 2 N-C (O) -) in which the R radicals, which may be identical or different, represent a hydrogen atom or a C 1 -C 4 alkyl radical optionally carrying at least one hydroxyl group; aminosulphonyl; hydroxyl; and - C1-C2 alkoxy.

According to a preferred variant of the invention, the radical R 3 independently of each other represents: a hydrogen atom C 1 -C 2 alkyl; alkylcarbonylamino RC (O) -NH- wherein R represents a C1-C2 alkyl radical, and more preferably wherein R represents a methyl radical; hydroxyl; and C1-C2 alkoxy.

In particular, R2 is absent m or e are zero and R3 represents a hydrogen atom or a hydroxyl group.

According to another particular variant of the invention, relates to dyes of formula (I) for which two groups R2 carried by adjacent carbon atoms can form together with the carbon atom to which each is attached, a fused ring, optionally aromatic optionally substituted preferably with a (C 1 -C 4) alkyl radical such as methyl; a hydroxyl radical; a (C 1 -C 4) alkoxy radical such as methoxy; a (di) (C 1 -C 4) (alkyl) amino radical such as methylamino dimethylamino; a pyrrolidine radical; a sulfonylamino radical. More particularly, two R2 groups together form a benzo group.

According to one particular embodiment of the invention, the dyes of formula (I) have one or more radicals R4 representing, independently of one another, a C1-C4 linear alkyl radical, such as methyl radical.

According to a particular embodiment of the invention, the dyes of the invention of formula (i) are such that m = e = O.

According to another particular embodiment of the invention, the linker L is a chain which links the chromophore with the disulfide or the thiol.

According to a first variant of the invention, in formula (I), L can be represented by the following formula (III): ## STR2 ##

in which

D and D ', which may be identical or different, represent a C1-C6 alkylene chain optionally interrupted by one or more heteroatoms or by one or more groups bearing at least one heteroatom, preferably chosen from oxygen and nitrogen;

the link a 'links the arm D to the group W via the methylene group; the bond c connects the arm D 'to the disulfide or thiol group;

Z is an integer inclusive between 1 and 3, preferably z is 1 or 2

• the group R ", identical or different when z greater than or equal to 2, representing (IVa) • R5 and R6 independently of each other, represent a C1-C6 alkyl radical, a C1-C6 monohydroxyalkyl radical; C2-C6 polyhydroxyalkyl, (C1-C6) alkoxy (C1-C6) alkyl, aryl radical such as phenyl, (C1-C6) aryl radical such as benzyl, C1-C6 amidoalkyl radical; a C 1 -C 6 aminoalkyl radical; a C 1 -C 6 aminoalkyl radical, the amine of which is substituted with one or more identical or different C 1 -C 4 alkyl, C 1 -C 6 alkylcarbonyl, acylamino or alkyl (C -C6) sulfonyl; or R5 and R6 together with the nitrogen atom to which they are attached, form a cationic saturated ring with 5, 6 or 7 members may contain one or more heteroatoms, the cationic ring may be substituted by a halogen atom, a hydroxyl radical, a C1-C6 alkyl radical or a monohydroxyalkyl radical; C1-C6, a C2-C6 polyhydroxyalkyl radical, a C1-C6 alkoxy radical, an amido radical, a (C1-C6) alkylcarbonyl radical, a thio radical, a C1-C6 thioalkyl radical or an alkyl radical; (C 1 -C 6) thio, an amino radical, an amino radical substituted with one or more identical or different C 1 -C 6 alkyl, C 1 -C 6 alkylcarbonyl, acylamino or (C 1 -C 6) alkylsulphonyl radicals; and preferably unsubstituted; • An represents an anionic counterion; The bond c resulting from the formula (III) is connected to Y and the bond resulting from the formula (III) is connected to the methylene group;

According to a particular embodiment of the formula (IVa), R5, R6 independently of one another, are preferably chosen from a C1-C6 alkyl radical, a C1-C4 monohydroxyalkyl radical or a polyhydroxyalkyl radical. C2-C4, a (C1-C6) alkoxy (C2-C4) alkyl radical, a (C2-C6) amidoalkyl radical, a (C2-C6) dimethylaminoalkyl radical. Even more particularly, R5 and R6, independently of one another, represent a methyl, ethyl, 2-hydroxyethyl radical. According to this variant, D and D 'separately are preferably a C1-C6 alkylene chain which may be substituted, and preferably unsubstituted. According to this variant and advantageously, the divalent radical of formula (III) is such that y = 1, R "represents a radical of formula (IVa) in which R5 and R6 denote an unsubstituted C1-C2i linear alkyl radical and D and D 'denote an unsubstituted C1-C4 linear hydrocarbon chain, in particular D and D' represent an unsubstituted linear (C 1 -C 6) alkylene chain such as methylene, ethylene, propylene or butylene, and R "represents + N + R5R6-, An- with R5 and R6 representing a (C1-C4) alkyl group such as methyl.

According to another variant of the invention, the linking arm L is not cationic, and represents an alkylene group comprising from 1 to 20 carbon atoms, particularly from 1 to 10 carbon atoms, and more particularly from 1 to 6 carbon atoms. carbon atoms, optionally containing one or more heteroatoms or divalent groups, or combinations thereof, selected from oxygen atom, a group --N (R) - with R representing a hydrogen atom or a group (C, -C 4) ) alkyl, -SO 2 - and -C (O) -. Especially the divalent group is selected from C (O) -NR- or -NR-C (O) -. Alkylene groups are, for example, methylene, ethylene, propylene, butylene, pentylene or hexylene. Particularly, L is a linear, unsubstituted C1-C10 alkylene chain, or a divalent radical -CO-NH- (CPH2p) - where p is an integer between 1 and 10, advantageously p is an integer between 1 and 6. One particular embodiment relates to the thiol dyes of formula (I) with x and y which are equal to 1, and Y represents a hydrogen atom, or an alkali metal. Advantageously, Y represents a hydrogen atom. According to another particular embodiment of the invention, in formula (I) above, Y is a protecting group known to those skilled in the art such as those described in the books Protective Groups in Organic Synthesis, TW Greene, John Willey & Sons ed., NY, 1981, pp.193-217; Protecting Groups, P. Kocienski, Thieme, 3rd ed., 2005, chap. 5. Particularly, when Y represents a protecting group of the thiol group, Y is selected from the following radicals: (C 1 -C 4) alkylcarbonyl; (C 1 -C 4) alkylthiocarbonyl; (C 1 -C 4) alkoxycarbonyl; (C 1 -C 4) alkoxythiocarbonyl; C 1 -C 4 alkylthio thiocarbonyl; ^ (di) (C1-C4) (alkyl) aminocarbonyl; ^ (di) (C1-C4) (alkyl) aminothiocarbonyl; arylcarbonyl as phenylcarbonyl; aryloxycarbonyl; aryl (C 1 -C 4) alkoxycarbonyl; (di) (C1-C4) (alkyl) aminocarbonyl as dimethylaminocarbonyl; (C 1 -C 4) (alkyl) arylaminocarbonyl; carboxy; ester or (C 1 -C 4) alkoxycarbonyl as -CO 2 Et 2 SO 3 -; M + with M + representing an alkali metal such as sodium or potassium, or else An- or An'- of the formula (I) and M + are absent; Optionally substituted aryl such as phenyl, dibenzosuberyl, or 1,3,5-cycloheptatrienyl, optionally substituted heteroaryl; including in particular cationic or non-cationic heteroaryl, comprising from 1 to 4 following heteroatoms: i) monocyclic with 5, 6 or 7 members such as furanyl or furyl, pyrrolyl or pyrryl, thiophenyl or thienyl, pyrazolyl, oxazolyl, oxazolium, isoxazolyl, isoxazolium, thiazolyl, thiazolium, isothiazolyl, isothiazolium, 1,2,4-triazolyl, 1,2,4-triazolium, 1,2,3-triazolyl, 1,2,3-triazolium, 1,2,4-oxazolyl, 1,2,4-oxazolium, 1,2,4-thiadiazolyl, 1,2,4-thiadiazolium, pyrylium, thiopyridyl, pyridinium, pyrimidinyl, pyrimidinium, pyrazinyl, pyrazinium, pyridazinyl, pyridazinium, triazinyl, triazinium, tetrazinyl, tetrazinium azepine, azepinium, oxazepinyl, oxazepinium, thiepinyl, thiepinium, imidazolyl, imidazolium; ii) 8 to 11-membered bicyclics such as indolyl, indolinium, benzoimidazolyl, benzoimidazolium, benzoxazolyl, benzoxazolium, dihydrobenzoxazolinyl, benzothiazolyl, benzothiazolium, pyridoimidazolyl, pyridoimidazolium, thienocycloheptadienyl, these mono or bicyclic groups being optionally substituted by one or more groups such as (C 1 -C 4) alkyl as methyl, or polyhalo (C 1 -C 4) alkyl as trifluoromethyl; optionally substituted heterocycloalkyl, optionally cationic, the heterocycloalkyl group represents in particular a saturated or partially saturated monocyclic group with 5, 6 or 7 members comprising 1 to 4 heteroatoms chosen from oxygen, sulfur and nitrogen, such as di / tetrahydrofuranyl; , di / tetrahydrothiophenyl, di / tetrahydropyrrolyl, di / tetrahydropyranyl, di / tetra / hexahydrothiopyranyl, dihydropyridyl, piperazinyl, piperidinyl, tetramethylpiperidinyl, morpholinyl, di / tetra / hexahydroazepinyl, di / tetrahydropyrimidinyl these groups being optionally substituted with one or more groups such as C 1 -C 4) alkyl, oxo or thioxo; or the heterocycle represents the following group: ## STR1 ## wherein R '°, R'g, R'e, R' f, R'g and R'h, identical or different, represent a hydrogen atom or a (C 1 -C 4) alkyl group, or two R'g groups with R'h, and / or R'e with R'f form an oxo or thioxo group, or R'g with R'e together form a cycloalkyl; and v represents an integer inclusive of between 1 and 3; preferentially R '° to R'h represent a hydrogen atom; and An - represents a counterion; a group (N, N, N '- (tri -) (C 1 -C 4 alkyl)) imidocarbamate - C (= N'RH) NR'; R 'wherein R'h, R'; R '; the same or different represent a hydrogen atom or a group (C1-C4) alkyl; an aminium group -C (= N '+ R'hR'h') NR '; R' An- in which R'h, R'h R '; R'; identical or different represent a (C1-C4) alkyl group; and An- represents a counterion. Optionally substituted (di) aryl (C 1 -C 4) alkyl, such as 9-anthracenylmethyl, phenylmethyl or diphenylmethyl, optionally substituted by one or more groups, especially chosen from (C 1 -C 4) alkyl and (C 1 -C 4) alkoxy; such as methoxy, hydroxyl, alkylcarbonyl, (di) (C1-C4) (alkyl) amino such as dimethylamino; optionally substituted heteroaryl (C 1 -C 4) alkyl, the heteroaryl group is in particular, cationic or non-monocyclic, comprising 5 or 6 members and 1 to 4 heteroatoms chosen from nitrogen, oxygen and sulfur; , such as pyrrolyl, furanyl, thiophenyl, pyridyl, pyridyl N-oxide such as 4-pyridyl or 2-pyridyl-N-oxide, pyrylium, pyridinium, triazinyl, optionally substituted by one or more group such as alkyl particularly methyl preferably (di) heteroaryl (C 1 -C 4) alkyl is (di) heteroarylmethyl or (di) heteroarylethyl; C 1 R 2 R 3 with R 1, R 2 and R 3, which may be identical or different, representing a halogen atom or a group chosen from: - (C 1 -C 4) alkyl; - (C 1 -C 4) alkoxy; optionally substituted aryl such as phenyl optionally substituted by one or more groups such as (C 1 -C 4) alkyl, (C 1 -C 4) alkoxy, hydroxyl; - optionally substituted heteroaryl such as thiophenyl, furanyl, pyrrolyl, pyranyl, pyridyl, optionally substituted with a (C 1 -C 4) alkyl group; - P (Z1) R'1R'2R'3 with R'1, and R'2 identical or different represent a hydroxyl group, (C1-C4) alkoxy or alkyl, R'3 represents a hydroxyl group or (CI- C4) alkoxy, and Z1 represents an oxygen or sulfur atom; cyclic sterically hindered; and optionally substituted alkoxyalkyl such as methoxymethyl (MOM), ethoxyethyl (EOM) and isobutoxymethyl.

More particularly, the invention relates to dyes of formula (I) with Y representing: - a hydrogen atom; a C1-C4 alkylcarbonyl radical, preferably acetyl; an imidazolium radical optionally substituted by one or more C 1 -C 4 alkyl radicals; a radical C (= NH) NH 2; A C1-C4 alkoxycarbonyl radical, preferably the -CO2Et group; a (C1-C4) alkylpyridinium radical, preferably the methylpyridinium group. One particular embodiment relates to the disulfide dyes of formula (I) in which x = 2 and y = 0. According to one preferred embodiment of the invention, the compounds correspond to the following formulas: (R2) m NN 2An (n 10 2 ## EQU2 ## wherein R 1 (R 2) m (R 1)

(R2) e + LsSiSuL R1 NYN-/ / 2An N n 10 25 (le) ~ 2) e R1Y iN \ / LùS`Y An NN 'formulas (la) to (If) in which: R 1, R 2, R 3 R4, L, Y, m, e, n are as defined above; the electroneutrality of the molecule being respected by the presence of one or more anionic counter ions An as defined above. According to a particularly advantageous embodiment of the invention, the compounds of formulas (I) are chosen from the following compounds: ## STR2 ##

S N N 'N 2 Year 1 N N N,. NH An Me M N + N + ~ NNNSS Year Mes - + '/ N ~ Me Year Year Year NH Year Year 4 5 Year 6 Month Wed / + / + NNNN 7 Yr S Y H NH NH 9 10 11 23 Year o An Me Y / N N + + NNN NH 12 13 YE N Y Y Y Y Y 15 Y Y Y Y Y N ù N + Y N N N + Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y N Y N Y Y Y Y 22 Mr 23 Year 24 NH Year 25 2 Year 26 S SI Yr Year Year N \ NNN 27 28 S SI An Meù. + '/ NUme An Me An An NN Me NN 29 30 IS SH An An NH SH 33 34 1 M Thu Thu 31 32 Me NNNNN MeO SS MeO 35 36 Thu Me / + NN NH An 37 38 SS 39 40 H 41 42 N // N ~ N ~~ N \ N Me'N ~ An Year NN Yr Year 43 Y ear Y e N // N e 44 / _-- S'SN ---- NN H Y Y Y Y Y Y S S

N H H Y Y Y Y N 46 Y N N Y Y Y Y Y Y Y 47 48 IF N M Y N N Y 49 50 OH S An S An OH 51 Y Y Y Y 53 54 With An, identical or different, representing an anionic counterion.

The dyes according to the invention can in particular be obtained from preparation processes similar to those described, for example, in the documents US Pat. No. 3,173,907 and US Pat. No. 5,708,151.

According to a first embodiment, the method for synthesizing the compounds used in the invention may consist in carrying out the following steps: ## STR1 ## coupling with (R4) n L With W 1 which represents a group selected from (11'a) and (11'b): 4 35 a ù (R2) m {v ~~ 2 2 \ 6 N --- N N 5 R1 (II 'a ) (R2) e 4 Orb) With Gp, R2, m and e are as defined above and a is the bond that connects (II'a) or (II'b) to NH2 or the aza function.

According to this method, a first diazotization step of a 5- or 6-membered heteroaromatic amine A: W 1'-NH 2 is carried out in a manner known to those skilled in the art. Thus, said amine A is contacted in the presence of alkali metal nitrite such as sodium nitrite, or nitrosylsulfuric acid. Usually this reaction takes place at a temperature lower than or equal to that of the ambient, ie a temperature of between -15 ° C. and 30 ° C., preferably between -10 ° C. and 20 ° C., at a pH of between 8 and 12. More preferentially at acid pH between pH 3-6. In a conventional manner, the reaction takes place in the presence of a suitable solvent among which mention may be made of water, aliphatic alcohols comprising in particular up to 4 carbon atoms, organic acids for example carboxylic acid or sulphonic acid comprising up to 10 carbon atoms and / or minerals of the type of hydrochloric acid, sulfuric. Once the reaction has been carried out, the product obtained is coupled with a julolidine compound LBj. Usually this reaction is carried out in the presence of a solvent which may be that of the previous step. The temperature of this synthesis step is conventionally a temperature lower than or equal to that of the ambient temperature, ie between -15 ° C. and 30 ° C., preferably between -10 ° C. and 20 ° C., at a pH preferably between 0 and 8. The product can be isolated for the techniques known to those skilled in the art, for example by precipitation, recrystallization, evaporation of the solvent, or by preparative chromatography. The resulting product is then quaternized in the usual manner. For example, the product obtained can be brought into contact with an alkylating agent of the LOI type Gp-CH 2 -LSSL-CH 2 -Gp in the presence of an organic or aqueous, polar or apolar, protic or aprotic solvent, such as dichloromethane, potassium chloride or the like. toluene, esters such as ethyl acetate or isopropyl acetate, amides such as dimethylformamide (DMF), N-methylpyrrolidinone (NMP) or 1,3-Dimethyl-3,4,5 , 6-tetrahydro-2 (1H) -pyrimidinone (DMPU), nitriles such as acetonitrile or propionitrile, water at spontaneous or alkaline pH. Gp represents a leaving group such as chloride, bromide, tosylate, mesylate. For this last synthesis stage, the temperature is usually between 10 ° C. and 180 ° C., preferably between 20 ° C. and 100 ° C.

The product can be isolated for the techniques known to those skilled in the art as previously mentioned.

According to a second embodiment, the method for synthesizing the compounds used in the invention may consist in carrying out the following steps: (R4) n (R4) n 1 diazotating 2 coupling with: LEI IÇI According to this method, a first diazotization step of a julolidine amine compound LEI is carried out in a manner known to those skilled in the art. The conditions for implementing such a step have been summarized previously. Once the reaction has been carried out, coupling of the product obtained with a compound of a cationic imidazole heteroaromatic amine (W, 1 to yield the azo derivative j. The conditions for carrying out such a step have been summarized previously. With W "1 which represents a group (II" b): ## STR3 ## With Gp, R2, m and e are as defined above. R 2) e (n (11 With Gp, R 1, R 2, R 3, m and e are as previously defined, the resulting product is then quaternized in the presence of a C alkylating agent as previously set forth in the first embodiment of the present invention. The latter can be isolated for the techniques known to those skilled in the art as mentioned above According to a third embodiment, the process for synthesizing the compounds 10 used in the invention can consist of: implement the following steps: R4), (R4) n Gp \ L \ S'Y, Gp- (equivalent to An) 2 No. 1. Thiol deprotection 2. Thiol oxidation Y 'In the first step of this process, the quaternization of a non-cationic azo compound is carried out in a manner known to those skilled in the art. in the art, with a protected thiol compound bearing a nucleofugal group LFj to give the dyes of the invention S-protected by Y '. The conditions for carrying out such a step are similar to those mentioned above for the two previous embodiments. This step is followed by the deprotection of the thiol group in a manner carried out by the methods known to those skilled in the art. By way of example, to deprotect the thiol function of thiol dye, the methods of Protective Groups in Organic Synthesis, T.W. Greene, John Willey & Sons, Ed., NY, 1981, pp.193-217; Protecting Groups, P. Kocienski, Thieme, 3rd ed., 2005, chap. 5. The dye Q is then oxidized to form the disulfide dye according to the invention Qfl, which can be purified by conventional methods known to those skilled in the art. This last step is usually carried out at a temperature of between 10 ° C. and 180 ° C., preferably between 20 ° C. and 100 ° C.

According to one variant, the process for synthesizing the compounds used in the invention may consist in carrying out the following steps: R4) n excess of Gp ~ L ~ G

Nulophilic substitution by a compound Y'-SH -HGp Gp- (equivalent to An)

1. deprotection 2. 2. oxidation According to this method, a first quaternization step is carried out in the usual manner of a non-cationic julolidine azo compound with at least one equivalent of the compound Gp-CH 2 -L-Gp in the presence of a organic or aqueous, polar or apolar, protic or aprotic solvent such as dichloromethane, toluene, esters such as ethyl acetate or isopropyl acetate, amides such as dimethylformamide (DMF), N methylpyrrolidinone (NMP) or 1,3-dimethyl-3,4,5,6-tetrahydro-2 (1H) -pyrimidinone (DMPU), nitriles such as acetonitrile or propionitrile, pH water spontaneous or alkaline. Gp represents a leaving group such as chloride, bromide, tosylate, mesylate. This quaternization step leads to the compound F1-JI. Usually this step is carried out at a temperature between 10 ° C and 180 ° C, preferably between 20 ° C and 100 ° C. This step is followed by a nucleophilic attack of the HS-Y 'reagent on the linker L carrying the leaving group Gp to yield the thiol dye possibly protected by Y' (when Y = Y '), the dye M. The latter after deprotection if the thiol group is protected by a Y 'group, is followed by an oxidation step which leads to the formation of the disulfide dye. The conditions for carrying out such a step have been summarized below. Usually, the temperature is between 10 ° C and 180 ° C, preferably between 20 ° C and 100 ° C.

Protected thiol dyes of formula (12) for which x and y are 1 can be synthesized in two stages. The first step of preparing unprotected thiol dye (IH) according to methods known to those skilled in the art such as Thiols and organic Sulfides, Thiocyanates and Isothiocyanates, organic, Ullmann's Encyclopedia, Wiley-VCH, Weinheim, 2005 And the second step of protecting thiol function according to conventional methods known to those skilled in the art to lead to protected thiol dyes of formula (12). By way of example, to protect the thiol function of the thiol dye, the methods of Protective Groups in Organic Synthesis, T.W. Greene, John Willey & Sons, Ed., NY, 1981, pp.193-217; Protecting Groups, P. Kocienski, Thieme, 3rd ed., 2005, chap. 5. We can illustrate this method by the method consisting of i) generating thiol dyes of formula (IH) by reducing a dye to two chromophores, having a disulfide function -SS- such that (I1) and ii) to protect according to conventional methods, said thiol function of (1H) with the reagent 7 YR to access protected thiol dyes of formula (12). The thiol compound (I-H) may also be metallized with an alkali metal or alkaline earth metal Met * to yield the thiolate dye of formula (I-Met). Reducer 36 L 7 YR YùS / W1 N N N -RH (12) Metallization Met * ùS R (1-Met) with Y representing a thiol protecting group as defined above and Y not representing H; Met * representing an alkali metal or an alkaline earth metal, particularly sodium or potassium, it being understood that when the metal is an alkaline earth metal 2 thiolate-functional chromophores-S-may be associated with 1 Metal2 +; and with R3, R4, Y, n, W1, and L are as previously defined; R represents a leaving group nucleofuge, such as mesylate, tosylate, triflate or halide.

According to another possibility, a thiol compound protected by a protective group Y as defined previously prepared can be reacted according to one of the procedures described in the works cited above, said protected thiol compound comprising at least one nucleophilic function with a sufficient quantity, preferably equimolar, of a chromophore (a ") which comprises an electrophilic function to form a covalent bond E, see below the preparation of dyes of formula (I'2): E, WN L 'N / (\ 2) ## STR3 ## wherein R 3, R 4, W 1, n and Y 'are as defined above, the residue representing a nucleophilic group, E representing an electrophilic group, the bond generated after nucleophilic attack on the electrophilic n 'represents an integer inclusive between 1 and 10 and L' represents a hydrocarbon chain C1-C20, preferably C1-C10.The group formed by L'-E- (CH2) n, c CH2-L, according to the definitions given in formula (I) of the invention. By way of example, the covalent bonds E that can be generated are listed in the table below from the condensation of electrophiles with nucleophiles: Electrophiles E Nucleophilic ducts Covalent bonds E Activated esters * Amines Carboxamides Acyl azides * * Amines Carboxamides Acyl halides Amines Carboxamides Acyl halides Alcohols Esters Acyl cyanides Alcohols Esters Acyl cyanides Amines Carboxamides Alkyl halides Amines Alkylamines Halides of alkyls Carboxylic acids Esters Halides of alkyls Thiols Thioesters Halides of alkyls Alcohols Ethers Sulphonic acids and their Thiols Thioethers salts Sulphonic acids and their carboxylic acids Esters salts Sulphonic acids and their alcohols Ethers salts Anhydrides Alcohols Esters Anhydrides Amines Carboxamides Halides aryls Thiols Thioethers Halides aryl Amines Arylamines Aziridines Thiols Thioethers Carboxylic acids Amines Carboxamides Carboxylic Acids Alcohols Esters Carbodiimides N-Acylurea Carboxylic Acids Diazoalkanes Carboxylic Acids Esters Epoxides Thiols Thioethers Haloacetamides Thiols Thioethers Esters Imides Amines Amidines Isocyanates Amines Ureas Isocyanates Alcohols Urethanes 38 Isothiocyanates Amines Thioureas Maleimides Thiols Thioethers Sulphonic esters Amines Alkylamines Sulphonic esters Thiols Thioethers Sulphonic esters Carboxylic acids Esters Estersulfonic alcohols Alcohols Ethers Sulfonyl halides Amines Sulfonamides * Activated esters of the general formula ùCO-Part with Part representing a leaving group such as oxysuccinimidyl, oxybenzotriazolyl, optionally substituted aryloxy; ** Acyl azides can rearrange to give isocyanates.

An alternative to this method is to use an aza chromophore having an electrophilic acrylate function (-OCO-C = C-) on which an addition reaction is carried out which will generate an L bond. It will also be possible to use a thiol reagent (a). : Y-SH comprising a group Y as defined above, whose nucleophilic function SH can react on the carbon atom of the radical L in alpha of the halogen atom carried by a chromophore of the derivative azo jolulidine f, to lead to protected thiol dye of formula (12): R4) n HS-Y-HHaI with R3, R4, n, Gp L and (12) are as defined above ,. More particularly, it is possible to substitute a nucleofugal leaving group with a thiourea group (S = C (NRR) NRR) to generate the isothiouroniums, or with a mercaptoimidazole to generate a thioimidazole, which after alkylation will give a thioimidazolium. For example if the use of mercaptoimidazole (R), to lead to the S-protected dye by an imidazolium group (I "2): with R'd, R'd, R3, R4, L, Hal and An- are such than previously defined.

According to another possibility, certain protected thiol dyes (I'2) can be obtained by reacting a protected thiol compound with a compound carrying two carboxylic acid functions activated by conventional methods, for example reaction with a carbodiimide or with chloride of thionyl. The resulting product is then reacted with a chromophore and carrying a nucleophilic function, for example of the primary or secondary amine type, or of the aliphatic alcohol type. Sc1 with R3, R4, n, n ', E, Nu and (I'2) as previously defined. The group formed by L'-I- (CH 2) n 'constituting CH2-L, according to the definitions given above.

A synthetic variant is to combine with the first route, the previous route ie from two equivalents of the nucleophilic reagent with a disulfide disulfide reagent, it is possible to generate, after condensation, the disulfide dichromophoric product (I'1), the latter which can be reduced to form the thiol dye (I'-H) which in turn can either be protected to form the protected thiol dye (2) or be metallized with an alkali metal to yield the metallized dye (I-2). (Metal) (I "2) An- (corresponding to Gp) WN \ NR, SH R 'S / L c` N N (- H Hal 1PI N 10 2 & l (lu) According to another possibility, protected thiol dyes of formula (I "'2) can be obtained by reaction of a compound comprising a thiol group protected by a group Y' and a leaving group group Gp nucleofuge, such as for example mesylate, tosylate, triflate or halide with a chromophore L. (R4) n S ~ L ~ / WNY '~ N R3 (I ,,, 2) With R3, R4 , Gp, Y ', L are as defined above. By way of example, the quaternization of the pyridine group (I "'2) is carried out by adapting the quaternization described in document WO 2006/134043. Reference may be made to the Advanced Organic Chemistry, Reactions, Mechanisms and Structures book. , J. March, 4th Ed, John Willey & Sons, 1992, or TW W-N Y'-Si (CH2) n, ùL 'N Eù (CH2) SùSu (CH2) E Lil // W, NJ ~ L ~~ ## STR5 ## wherein Greene Protective Groups in Organic Synthesis, for more details on the operating conditions used for the processes mentioned above The thiol dyes formed can be converted into thiol dyes protected by the protection of the thiols using Conventional protecting groups The thiol dyes are metallated using also the conventional methods known to those skilled in the art such as those described in Advanced Organic Chemistry, Rea Mechanisms and Structures, J. March, 4th ed., John Willey & Sons, NY, 1992. Protected thiol dyes can be deprotected by conventional routes such as those described in Protective Groups in Organic Synthesis, TW Greene and John Willey. & Sons ed., NY, 1981; Protecting Groups, P. Kocienski, Thieme, S ed., 2005. The starting reagents are commercial or accessible by conventional methods known to those skilled in the art. By way of example, mention may be made of US 4579949.

Another subject of the invention relates to a composition for the dyeing of keratinous fibers comprising at least one dye of formula (I). In addition to the presence of at least one dye of formula (I), the composition of the invention may also contain a reducing agent. This reducing agent may be chosen from thiols, for example cysteine, homocysteine, thiolactic acid, the salts of these thiols, phosphines, bisulfite, sulphites, thioglycolic acid and its esters, especially the Glycerol monothioglycolate, and thioglycerol. This reducing agent may also be chosen from borohydrides and their derivatives, such as, for example, borohydride, cyanoborohydride, triacetoxyborohydride or trimethoxyborohydride salts: sodium, lithium, potassium, calcium, quaternary ammonium salts (tetramethylammonium, tetraethylammonium, tetra butylammonium, benzyltriethylammonium); catechol borane. The dye composition useful in the invention generally contains an amount of dye of formula (I) of between 0.001 and 50% relative to the total weight of the composition. Preferably, this amount is between 0.005 and 20% by weight and even more preferably between 0.01 and 5% by weight relative to the total weight of the composition.

The composition according to the invention may optionally comprise at least one additional disulfide or thiol dye as described in the documents WO2006 / 136617 and FR2876576. As non-limiting examples, a dye of formula (I) according to the invention which has a maximum absorption between 540 and 630 nm is advantageously associated with a dye of general formula (III) (azo disulfide red dyes) and / or a dye of general formula (IV) (disulfide dyes hydrazones yellow) in proportions such that the color obtained after the application of the composition to hair, rinsing and drying, allows obtaining an aesthetic coverage (natural, brown, with, if appropriate, copper, iridescent, mahogany, matte, red, purple hues) sufficiently intense and stable.

The azo disulfide red dyes are in particular of the following general formula (III): ## STR1 ## as well as their addition salts with an organic or mineral acid, solvate, hydrates, tautomers, geometrical isomers;

wherein R "independently of one another is hydrogen or NR" "C (O) R" "R ', R" ", R" "and R" " independently of each other, represent a hydrogen atom or a group selected from C, -C, 4 optionally substituted alkyl, C5-C, optionally substituted cycloalkyl; C2-C, 4alkyenyl optionally substituted; C5-C, oaryl (C, -C, Oalkyl) optionally substituted; C, -C, oalkyl (C5-C, oaryl) optionally substituted; C5-Cl0aryl optionally substituted. Lx independently of each other, represents a bivalent C1-C20, especially C1-C10, optionally substituted hydrocarbon-based chain, optionally interrupted by one or more divalent groups or combinations thereof, it being understood that two divalent groups or their combinations are interrupted by one or more C2-C6 divalent hydrocarbon chain, especially alkylene, said divalent groups being selected from ùN (R) -; -O-, -S-, -C (O) -, with R, represents a group chosen from C1-C4 alkyl, (poly) C2-C6 hydroxyalkyl, (C1-C6) alkoxyalkyl, aryl such as phenyl, aryl (C 1 -C 6) alkyl such as benzyl, (C 1 -C 4) alkylcarbonylamino (C 1 -C 6) alkyl, amino (C 1 -C 4) alkyl whose amine is substituted by one or more identical alkyl radicals or different C1-C4, (C1-C6) alkylcarbonyl and (C1-C4) alkylcarbonylamino; The yellow hydrazone disulfide dyes are in particular of the following general formula (IV): ## STR2 ##

as well as their addition salts with an organic or mineral acid, solvate, hydrates, tautomers, geometrical isomers; formula (IV) in which:

Rx and Ry independently of each other, represent a hydrogen atom, a halogen or a group selected from C1-C16alkyl optionally substituted, optionally interrupted by one or more heteroatoms, optionally substituted phenyl, Rz independently of each other, represent a hydrogen atom or a group NR "" C (O) R "", with R "" and R "" 'are as defined above; and Lx are as previously defined.

If present, the content of additional disulfide dye (s) / thiol (s) in the composition generally ranges from 0.001 to 20% by weight based on the weight of the composition, and preferably from 0.01 to 5% by weight relative to the weight of the composition.

The composition according to the invention may optionally comprise at least one additional direct dye different from the compounds of formula (I). This can be selected from neutral, acidic or cationic species.

By way of nonlimiting examples of additional direct dyes, mention may be made of nitro benzene dyes, azo, azomethine, methine, tetraazapenthamethine, anthraquinone, naphthoquinone, benzoquinone, phenotiazine indigo, xanthene, phenanthridine, phthalocyanine dyes, those derived from triarylmethane. and natural dyes, alone or in mixtures. It may for example be chosen from the following red or orange nitro-benzene dyes: 1-hydroxy-3-nitro-4-N- (γ-hydroxypropyl) amino benzene, N- (13-hydroxyethyl) amino- 3-nitro-4-amino benzene, 1-amino-3-methyl-4-N- (13-hydroxyethyl) amino-6-nitro benzene, 1-hydroxy-3-nitro-4-N- ( 13-hydroxyethyl) amino benzene, 1,4-diamino-2-nitrobenzene, 1-amino-2-nitro-4-methylamino benzene, N- (13-hydroxyethyl) -2-nitro-para-phenylenediamine, 1-Amino-2-nitro-4- (13-hydroxyethyl) amino-5-chloro-benzene, 2-nitro-4-amino-diphenylamine, -1-amino-3-nitro-6-hydroxybenzene. 1 - ([3-aminoethyl) amino-2-nitro-4 - ([3-hydroxyethyloxy) benzene, 1 - ([3, y-dihydroxypropyl) oxy-3-nitro-4 - ([3- hydroxyethyl) amino benzene, 1-hydroxy-3-nitro-4-aminobenzene, 1-hydroxy-2-amino-4,6-dinitrobenzene, 1-methoxy-3-nitro-4-β-hydroxyethyl ) amino benzene, 2-nitro-4'-hydroxydiphenylamine, 1-amino-2-nitro-4-hydroxy-5-methylbenzene. The additional direct dye may also be chosen from yellow and green-yellow nitro-benzene direct dyes, for example compounds selected from: 1-13-hydroxyethyloxy-3-methylamino-4-nitrobenzene; methylamino-2-nitro-5- (13, y-dihydroxypropyl) oxybenzene, 1- (13-hydroxyethyl) amino-2-methoxy-4-nitrobenzene, 1- (13-aminoethyl) amino-2- nitro-5-methoxybenzene, 1,3-di (13-hydroxyethyl) amino-4-nitro-6-chlorobenzene, 1-amino-2-nitro-6-methylbenzene, 1- (13-hydroxyethyl) amino-2-hydroxy-4-nitrobenzene, N- (13-hydroxyethyl) -2-nitro-4-trifluoromethylaniline, 4- (13-hydroxyethyl) amino-3-nitro- benzenesulfonic acid, 4-ethylamino-3-nitro-benzoic acid, 4- (13-hydroxyethyl) amino-3-nitro-chlorobenzene, 4- (13-hydroxyethyl) amino-3-nitro-methylbenzene, 4- (13'-dihydroxypropyl) amino-3-nitro-trifluoromethylbenzene, 1- (13-ureidoethyl) amino-4-nitrobenzene, 1,3-diamino- 4-nitrobenzene, 1-hydroxy-2-amino-5-nitrobenzene, 1-amino-2- [tris (hydroxymethyl) methyl] amino-5-nitro-benzene, 1- (13-hydroxyethyl) amino-2-nitrobenzene, 4- (13-hydroxyethyl) amino-3-nitrobenzamide. Mention may also be made of blue or violet nitrobenzene direct dyes, for example: 1 - ([3-hydroxyethyl) amino-4-N, N-bis- (3-hydroxyethyl) amino-2-nitrobenzene; 1- (γ-hydroxypropyl) amino 4-N, N-bis (13-hydroxyethyl) amino-2-nitrobenzene, 1- (13-hydroxyethyl) amino-4- (N-methyl, N-13-hydroxyethyl) amino 2-nitrobenzene, 1- (13-hydroxyethyl) amino 4- (N-ethyl, N-13-hydroxyethyl) amino-2-nitrobenzene, 5- (1-03-y-dihydroxypropyl) amino-4- (N-ethyl) N-13-hydroxyethyl) amino-2-nitrobenzene, - 2-nitroparaphenylenediamines of the following formula: NHRa NRbRc in which: - Rb represents a C1-C4 alkyl radical, a 13-hydroxyethyl or 13-hydroxypropyl radical or y- hydroxypropyl; Ra and Rc, which are identical or different, represent a 13-hydroxyethyl, -13-hydroxypropyl, γ-hydroxypropyl or 13α-dihydroxypropyl radical, at least one of Rb, Rc or Ra radicals representing a γ-hydroxypropyl radical; and Rb and Rc can not simultaneously denote a 13-hydroxyethyl radical when Rb is a hydroxypropyl radical, such as those described in French patent FR 2,692,572. Among the azo direct dyes that may be used according to the invention, mention may be made of azo dyes cationic agents described in patent applications WO 95/15144, WO 95/01772, EP 714954, FR 2 822 696, FR 2 825 702, FR 2 825 625, FR 2 822 698, FR 2 822 693 and FR 2 822 694. , FR 2 829 926, FR 2 807 650, WO 02/078660, WO 02/100834, WO 02/100369, FR 2 844 269. Among these compounds, mention may be made of the following dyes: dimethyl-2 - [[4- (dimethylamino) phenyl] azo] -1H-imidazolium, 1,3-dimethyl-2 - [(4-aminophenyl) azo] -1-chloride H-Imidazolium, 1-methyl-4 - [(methylphenylhydrazono) methyl] -pyridinium methylsulfate. The following dyes, described in COLOR INDEX INTERNATIONAL 3rd edition, may also be mentioned among the azo direct dyes: -Disperse Red 17 -Acid Yellow 9 -Acid Black 1 -Basic Red 22 -Basic Red 76 35 -Basic Yellow 57 NO2 - 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.

We may also mention 1- (4'-aminodiphenylazo) -2-methyl-4bis- (13-hydroxyethyl) aminobenzene and 4-hydroxy-3- (2-methoxyphenylazo) -1-naphthalene sulfonic 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 the following compounds: -1-N-methylmorpholiniumpropylamino-4-hydroxyanthraquinone -1-Aminopropylamino-4-methylaminoanthraquinone -1-Aminopropylaminoanthraquinone -5-13 1,4-hydroxyethyl-diaminoanthraquinone -2-aminoethylaminoanthraquinone -1,4-bis-3-yl-dihydroxypropylamino) -anthraquinone. Among the azine dyes, mention may be made of the following compounds: -Basic Blue 17 -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-Acid Blue 7 Among the indoamine dyes that can be used according to the invention, mention may be made of the following compounds: -2- [3-hydroxyethlyamino-5- [bis- ( 13-4'-hydroxyethyl) amino] anilino-1,4-benzoquinone -2- [3-hydroxyethylamino-5- (2'-methoxy-4'-amino) anilino-1,4-benzoquinone -3-N (2 1-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 - 3- [4'-N- (ethyl, carbamylmethyl) amino] -phenyl-ureido-6-methyl-1,4-benzoquinone imine.

The additional direct dyes may also be natural direct dyes. Among the natural direct dyes that may be used according to the invention, lawsone, juglone, alizarin, purpurine, carminic acid, kermesic 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.

If they are present, the content of additional direct dye (s) in the composition generally varies from 0.001 to 20% by weight relative to the weight of the composition, and preferably from 0.01 to 5% by weight. weight relative to the weight of the composition.

The dye composition may further contain one or more oxidation bases and / or one or more couplers conventionally used for dyeing keratinous fibers. Among the oxidation bases that may be mentioned are para-phenylenediamines, bisphenylalkylenediamines, para-aminophenols, bis-para-aminophenols, ortho-aminophenols, heterocyclic bases and their addition salts. mention may in particular be made of meta-phenylenediamines, meta-aminophenols, meta-diphenols, naphthalenic 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%. The oxidation base (s) present in the dyeing composition are in general each present in an amount of between 0.001% and 10% by weight relative to the total weight of the dyeing composition, preferably between 0.005% and 6% by weight.

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 and addition salts with a base such as alkali metal hydroxides such as sodium hydroxide, potassium hydroxide, ammonia, amines or alkanolamines.

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-C4i 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 they are present are preferably 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 90% by weight approximately. The dye composition may also contain various adjuvants conventionally used in compositions for dyeing hair, such as anionic, cationic, nonionic, amphoteric, zwitterionic surfactants or mixtures thereof, anionic, cationic, nonionic, amphoteric and zwitterionic 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 non-volatile silicones, modified or otherwise, such as aminosilicones, film-forming agents, ceramides, preserving agents, opacifying agents, conductive polymers.

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 dyeing composition is generally between 3 and 14 approximately, and preferably between 5 and 11 approximately. It can be adjusted to the desired value by means of acidifying or alkalizing agents usually used for dyeing keratin 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 (y): R ~ 1 / Raz N-Wa-N ~ Ra4 Rai (Y) in which Wa is a propylene residue optionally substituted by a hydroxyl group or a C1-C4 alkyl radical; Ra1, Ra2i Ra1 and Ra4i, which may be identical or different, represent a hydrogen atom, a C1-C4 alkyl radical or a C1-C4 hydroxyalkyl radical. The dye composition may be in various forms, such as in the form of liquid, cream, gel, or in any other form suitable for dyeing keratinous fibers, and in particular hair. Another subject of the invention relates to a process for dyeing keratinous fibers such as the hair, using a composition comprising at least one dye of formula (I) as defined above. According to a particular embodiment in the process of the invention, a reducing agent may be applied as a pre-treatment before the application of the composition containing at least one dye of formula (I). This pretreatment may be of short duration, in particular from 0.1 second to 30 minutes, preferably from 1 minute to 15 minutes with a reducing agent as mentioned above. According to another method, the composition comprises at least one dye of formula (I) and also contains at least one reducing agent as defined above. This composition is then applied to the hair. According to one variant, the reducing agent is added to the dyeing composition containing at least one dye of formula (I) at the time of use. According to another variant, the reducing agent is applied in post-treatment, after the application of the composition containing at least one dye of formula (I). The duration of the post-treatment with the reducing agent may be short, for example from 0.1 second to 30 minutes, preferably from 1 minute to 15 minutes, with a reducing agent as described above. According to a particular embodiment, the reducing agent is a thiol or borohydride type agent as described above. A particular embodiment of the invention relates to a process in which the dye of formula (I) can be applied directly to hair without reducing agents, free of pre or post-treatment reducers. A treatment with an oxidizing agent may optionally be associated. Any type of conventional oxidizing agent may be used in the art. Thus, it may be chosen from hydrogen peroxide, urea peroxide, alkali metal bromates, persalts such as perborates and persulphates, as well as the enzymes among which may be mentioned peroxidases, oxides, 2-electron reductases such as uricases and 4-electron oxygenases such as laccases. The use of hydrogen peroxide is particularly preferred. The oxidative pause time can be between 1 second and 40 minutes.

When the thiol dye of formula (I) for which x and y are equal to 1 comprises a group Y protecting the thiol function, the process of the invention comprises an additional deprotection step aimed at rendering the SH function in situ. By way of example, it is possible to deprotect the SY function of the dyes of the invention with the protective group by adjusting the pH as follows: Y: alkylcarbonyl deprotecting protecting group, pH> 9 arylcarbonyl, pH> 9 alkoxycarbonyl, pH> 9 aryloxycarbonyl, pH> 9 arylalkoxycarbonyl pH> 9 (di) (alkyl) aminocarbonyl, pH> 9 (alkyl) arylaminocarbonyl pH> 9 optionally substituted aryl such as phenyl, pH> 9 monocyclic 5-, 6- or 7-membered heteroaryl such as pH Oxazolium; 8 to 11-membered bicyclic heteroaryl such as pH> 9 benzoimidazolium, or benzoxazolium The deprotection step may be carried out during a hair pretreatment step such as, for example, the hair reduction pretreatment. According to one variant, the deprotection step may be carried out post-treatment or at the same time as the coloration. The application of the dye composition according to the invention is generally carried out at room temperature. It can however be carried out at temperatures ranging from 20 to 180 ° C.

The invention also relates to a multi-compartment device or "kit" of dyeing in which a first compartment contains a dye composition comprising at least one dye of formula (I) and a second compartment contains a reducing agent capable of reducing the functions disulphides of keratin materials and / or disulfide dye of formula (I). One of these compartments may further contain one or more other dyes of direct dye type or oxidation dye. It also relates to a multi-compartment device in which a first compartment contains a dye composition comprising at least one dye of formula (I); a second compartment contains a reducing agent capable of reducing the disulfide bond of the keratin materials and / or the disulfide dye of formula (I); a third compartment contains an oxidizing agent. Alternatively, the dyeing device contains a first compartment containing a dye composition which comprises at least one protected thiol dye of formula (I) with x and y equal to 1, a second compartment containing an agent capable of deprotecting the protected thiol to release the thiol , and optionally a third compartment comprising an oxidizing agent. Each of the above-mentioned devices may be equipped with a means for delivering the desired mixture onto the hair, for example such as the devices described in patent FR 2 586 913.

The examples which follow serve to illustrate the invention without, however, being limiting in nature.

EXAMPLE 1 - Compound 1 Synthesis of 1,1 '- (disulfanediyldiethane-2,1-diyl) bis [4 - {- 2,3,6,7-10 tetrahydro-1H, 5H-pyrddo [3,2] dibromide , 1-ij] quinolin-9-yldiazenyl] pyridinium] [1] Synthesis scheme: + BrS-SBr / N 80 ° C DMPU 2 Br [1]

0.37 g of 9- [pyridin-4-yldiazenyl] -2,3,6,7-tetrahydro-1H, 5H-pyrido [3,2,1-i] quinoline and 0.15 g 1-bromo -2 - [(2-bromoethyl) disulfanyl] ethane are stirred at 80 ° C in 3 mL 1,3-dimethyl-3,4,5,6-tetrahydro-2 (1H) -pyrimidinone (DMPU) After 5 h stirring a catalytic amount of potassium iodide is added. Stirring is maintained for 2 h. The reaction mixture is cooled and poured onto 100 mL of ethyl acetate. The precipitate obtained is filtered off, rinsed with ethyl acetate, dried and then redissolved three times in the following manner: solubilization in 10 ml of dichloromethane and 5 ml of ethanol, precipitation in ethyl acetate, filtration and washing with ethyl acetate. After these three reprocessings, it is dried under vacuum. 275 mg of black powder are collected. The analyzes show that the product is compliant.

EXAMPLE 2 - Compound 2 Synthesis of 1,1 '- {disulfanediylbis [ethane-2,1-diylimino (2-oxoethane-2,1-diyl)]] bis {4- (2,3,6,7-dichloride) tetrahydro-1H, 5H-pyrido [3,2,1-ij] quinolin-9-yldiazenyl] pyridinium]] ss 2 CI [2] Synthesis scheme: CI-H NH-CCI ON / - / O SS 2 CI 15 [2]

0.37 g of 9- [pyridin-4-yldiazenyl] -2,3,6,7-tetrahydro-1H, 5H-pyrido [3,2,1-ij] quinoline and 0.163 g of N, N '- (disulfanediyldiethane) -2,1-diyl) bis (2-chloroacetamide) are stirred at 80 ° C in 3 mL of 1,3-dimethyl-3,4,5,6-tetrahydro-2 (1H) -pyrimidinone (DMPU). After stirring for 5 h, a catalytic amount of potassium iodide is added. Stirring is maintained for 2 hours. The reaction mixture was cooled and poured onto 100 mL of ethyl acetate. The precipitate obtained is filtered, rinsed with ethyl acetate, dried and then redissolved three times in the following manner: solubilization in 10 ml of dichloromethane and 5 ml of ethanol, precipitation in ethyl acetate, filtration and washing with water. 'ethyl acetate. After these three reprocessings, it is dried under vacuum. 295 mg of black powder are collected. The analyzes show that the product is compliant.

Coloring process - compound [1] Preparation of composition A Compound [1] 0.3 g Benzyl alcohol 4 g Polyethylene glycol 60E 6 g Hydroxyethylcellulose 0.7 g Alkylpolyglucoside in aqueous solution 4.5 g 65% MA Demineralized water qs 100 g Preparation a composition B Thioglycolic acid 1M Sodium hydroxide qsp pH 8.5 Demineralized water qs 100g First staining process: One-time application At the time of use, the compositions A (9 ml) and B (1 ml) are mixed then apply the formulas on locks of natural white hair 90% white (BN), permed white hair (BP). The exposure time is 20 minutes at room temperature. The locks are then rinsed, shampooed and dried.

Second dyeing process: Two-step application Composition A is applied to locks of natural white hair (BN), of perma- ned white hair (BP). The exposure time is 10 minutes at room temperature. The locks thus treated are rinsed with water. Composition B is then applied to these same locks. The exposure time is 15 minutes at room temperature. The locks are then rinsed, shampooed and dried. In both cases a blue color is obtained on the white hair (BN) and (BP). Light and Shampoo Tenacity Study: A light fastness study was carried out by exposure to Xenotest on the hair strands of natural white and permed white hair previously colored according to the two coloring processes mentioned above, for 3 hours. The exposure conditions are 90W / m2, 60% relative humidity and with a chamber temperature of 35 ° C of exposure.

The locks once treated according to the above two coloring methods are shampooed according to 5 or 10 cycles of shampoo consisting of a shampoo followed by rinsing with running water and finally an air drying. These cycles are performed 5 or 10 times in succession. In shampoos, there is no visible bleeding, shampoo foam and rinsing water are not colored.

It appears visually that the stains obtained according to the two processes jointly withstand exposure to light and shampoos. In addition, the light degradation measurements show that the dyes of the invention are particularly light-stable.

Claims (21)

1. Dyestuff of formula (I): ## STR2 ## and its addition salts with an organic or mineral acid, tautomers, optical isomers, geometric and solvates formula (I) in which: W1 , represents a cationic heteroaromatic radical chosen from the following formulas (IIa) and (IIb): ## STR2 ## wherein R 1 is an (R 2) e 4 An (IIa) (IIb) with: the bond from formulas (IIa) and (IIb) connects the W1 group to the azo group; particularly for (IIa) the link a connects the pyridinium group to the azo group in position 2 or 4, and for (IIb) the a bond connects the imidazolium group to the azo group in position 2; in the case of the formulas (IIa) and (IIb) and when two radicals R2 carried by two adjacent carbon atoms form an aromatic ring, the linkage a can link the group W1 to the azo group through said aromatic ring; the bond b resulting from the formulas (IIa) and (IIb) connects the group W1 to the linking arm L via the methylene group; L represents a covalent link O or bivalent C1-C20 hydrocarbon chain, optionally substituted, optionally interrupted by one or more divalent groups or combinations thereof, it being understood that two divalent groups or their combinations are separated by a divalent C 1 -C 6 hydrocarbon chain , especially alkylene, said divalent groups being selected from: i) N (R) -; -N + (R) (R o) -, An-; -O-, -S-, -C (O) -, with R, represents a group chosen from C1-C4 alkyl, (poly) hydroxy C2-C6 alkyl, (C1-C6) alkoxy alkyl, aryl, aryl ( C, -C 6) alkyl, (C 1 -C 4) alkylcarbonylamino (C 1 -C 6) alkyl, amino (C 1 -C 4) alkyl, the amine of which is substituted by one or more identical or different C 1 -C 4 alkyl radicals, (C 1 -C 6) alkylcarbonyl and (C 1 -C 4) alkylcarbonylamino; and R ° represents a hydrogen atom or R; ii) a cationic heterocycle or cationic heteroaryl Het +, An-, with As defined above and Het + representing a cationic heterocycle comprising from 5 to 10 members, saturated or unsaturated, or a cationic heteroaryl comprising from 5 to 10 members; iii) a non-cationic heterocycle comprising from 5 to 10 members, and iv) an optionally substituted (hetero) aryl; with L not containing a diazo, hydrazino, aminooxy, nitro, nitroso, peroxide group; R 1 is directly attached to the nitrogen atom, whether or not quaternized via a carbon atom, and represents a group chosen from: an optionally substituted C 1 -C 6 alkyl group; An optionally substituted aryl group; • a heteroaryl group possibly; An optionally substituted aryl (C 1 -C 6) alkyl group; An optionally substituted heteroaryl (C 1 -C 6) alkyl group; A (C 1 -C 6) cycloalkyl alkyl group and a (C 1 -C 6) alkyl heterocycloalkyl group; R2 represents: • a C1-C4 alkyl group • a hydroxyl group • a C1-C4 alkoxy group • a C2-C4 (poly) hydroxyalkoxy group; An alkoxycarbonyl group (RaO-C (O) -) in which Ra represents a C1-C4 alkyl radical; An alkylcarbonyloxy group (RaC (O) -O-) in which Ra represents an alkyl radical is C1-C4; An amino group optionally substituted with one or more identical or different C1-C4 alkyl radicals optionally bearing at least one hydroxyl group, the two alkyl radicals possibly being able to form, with the nitrogen atom to which they are attached, a substituted or unsubstituted 5- or 6-membered heterocycle and optionally carrying another heteroatom identical to or different from nitrogen; An alkylcarbonylamino group (RaC (O) -NR'a-) in which Ra represents a C1-C4 alkyl radical and R'a represents a hydrogen atom or a C1-C4 alkyl radical; -) (alkyl) aminocarbonyl ((Ra) 2N-C (O)) in which the Ra radicals independently of each other, identical or not, represent a hydrogen atom, a C1-C4 alkyl radical; A ureido group ((Ra) 2N-CO-NRb-) in which the radicals Ra and Rb, independently of one another, represent a hydrogen atom or a C1-C4 alkyl radical; A guanidinium group ((Ra) 2N-C (= NH 2 +) - NRb-) in which the radicals Ra and Rb, independently of each other, represent a hydrogen atom or a C 1 -C 4 alkyl radical; • a phenyl group; • a halogen atom; Or two adjacent radicals R 2 can form, with the carbon atoms to which they are attached, a 6-membered aromatic fused ring, optionally substituted with one or more identical or different groups chosen from hydroxyl, C 1 -C 4 alkyl, hydroxycarbonyl ( HO (O) C-), alkoxycarbonyl (RaO (O) C-) wherein Ra is (C1-C4) alkyl, (alkyl) sulfonylamino (RaS (O) 2NRb) wherein Ra, are C1-C6alkyl; -C4 and Rb represents a hydrogen atom, a radical or a C1-C4 alkyl group; C1-C4 alkoxy; amino optionally substituted with one or two identical or different C1-C4 alkyl groups and optionally bearing at least one hydroxyl or methylcarbonylamino group, the two alkyl groups possibly being able to form, with the nitrogen atom to which they are attached, a heterocycle 5- or 6-membered ring optionally carrying another heteroatom identical to or different from nitrogen, for example oxygen; R3 represents a hydrogen atom or a radical as defined for R2; R4, independently of each other, represent a group selected from (C1-C6) optionally substituted alkyl or carboxy; An- represents an anionic counterion; m represents an integer inclusive between 0 and 4; n represents an integer inclusive between 0 or 6; e is an integer inclusive between 0 and 2; x represents 1 or 2; y represents 0 or 1; provided that: - when x is 2 then y is 0, and - when x is 1, then y is 1; 5Y represents: i) a hydrogen atom; ii) an alkali metal; iii) an alkaline earth metal; iv) an ammonium group: N + RaRRR7R5 or a phosphonium group: P + RaRRR7Rs with Ra, RR, R7 and R5, identical or different, representing a hydrogen atom or a (C 1 -C 4) alkyl group; or v) a thiol protecting group; it being understood that: the electroneutrality of the compounds being provided by one or more anionic counterion An-, identical or not. 10 2. Dye of formula (I) according to the preceding claim wherein x and y are 1, and Y represents a hydrogen atom, or an alkali metal. 3. Dye of formula (I) according to claim 1 wherein x and y are 1, and Y represents a protective group. 15 4. Coloring agent of formula (I) according to the preceding claim, in which Y represents a protective group chosen from the following radicals: (C 1 -C 4) alkylcarbonyl, C 1 -C 4 alkylthiocarbonyl, C 2 -C 4 C4) alkoxycarbonyl; (C 1 -C 4) alkoxythiocarbonyl; C 1 -C 4 alkylthio thiocarbonyl; di (C 1 -C 4) (alkyl) aminocarbonyl; di (C 1 -C 4) alkyl aminothiocarbonyl, arylcarbonyl, aryloxycarbonyl, aryl (C1-C4) alkoxycarbonyl, (di) (C1-C4) (alkyl) aminocarbonyl, (C1-C4) (alkyl) arylaminocarbonyl, carboxy; ester or (C 1 -C 4) alkoxycarbonyl; SO 3 -; M + with M + representing an alkali metal or then An- or An 'of the formula (I) and M + are absent; optionally substituted aryl; optionally substituted heteroaryl; heterocycloalkyl optionally substituted, optionally cationic, wherein R'h, R ', R', the same or different represent a hydrogen atom or a group ( C1-C4) alkyl Wherein R ', R', R ', R', R ', R', R ', R'; identical or different represent a (C1-C4) alkyl group; and An represents a counterion; optionally substituted di (aryl) (C1-C4) alkyl; optionally substituted (di) heteroaryl (C1-C4) alkyl; Wherein R1, R2 and R3, which may be identical or different, represent a halogen atom or a group selected from: - (C1-C4) alkyl; (C1-C4) alkoxy; optionally substituted aryl; optionally substituted heteroaryl; -P (Z1) R'1 R'2R'3 with R'1, and R'2 identical or different represent a hydroxyl group, (C1-C4) alkoxy or alkyl, R'3 represents a hydroxyl group or (C1- C4) alkoxy, and Z1 represents an oxygen or sulfur atom; cyclic sterically hindered; and optionally substituted alkoxyalkyl. 20 5. Colorant of formula (I) according to any one of the preceding claims wherein Y represents: - a hydrogen atom; a C1-C4 alkylcarbonyl radical; An imidazolium radical optionally substituted with one or more C1-C4 alkyl radicals. a -C (= NH) NH 2 radical; a C1-C4 alkoxycarbonyl radical; or - a (C1-C4) alkylpyridinium radical. 30 6. A disulfide dye of formula (I) according to any one of the preceding claims wherein x = 2 and y = 0. 7. Colorant of formula (1) according to any one of the preceding claims wherein m = e = 0. 8. A dye of formula (I) according to any one of the preceding claims belonging to any one of formulas (Ia) to (If): (R2) m L (R2) m (R n N N 'N 2An (NN N + ## EQU1 ## wherein R4) (R4) n (Ib) R2) e -R2) e, LxSiSiL / R; NUNC ~ ùN N, RI ,, NN 2An N (R4) n (le) R2) e / 1- \ + LùS R ~ NN ~ \ Y An ~ NN, o (If) formulas (la) to (If) in wherein R1, R2, R3, R4, L, m, e, n and An are as defined in any one of the claims. 9. A dye of formula (I) according to any one of the preceding claims of the following chemical structure: 2 Year 1Me Me N + N + NN NN NNI) ùN O NH SS Year An Me S \ S An NH Me Year 2 3 Me Me me Me / + NNNN An Me NH An Me An Meù. + 'NUme An AnAn 6Me / + / + NNNNNS An H NH 7 9 Year 10 1112 13Mon / + / + N rN N An HN 2 YEAR YEAR NNS YEAR 15 H YEAR 17 YEAR 18 YEAR OLD 19 YEAR 20 / -S.-S'SN '\ N ~ N // NHHN \ Year Year 21 Year Year 22 Month 23 Year 24N Y Year 25 2 Year 26 S YY Year Year N \ NNN 27 28S SI Year More. + '/ NUme An Me An An NN Me NN 29 30 IS SH An An NH SH 33 34 1 M T M M 31 32 M NNNN M NM O S SI MeO 35 M M / + / + N N 36 NH An 38 S SI 39 40H 41 42 N // N ~ N ~~ N \ N Me'N ~ An Y N N Y Y Y Y Y Y Y Y Y N Y N // N 44 Y H 45 S'S ~ \ NNHH Year YE 46 SSN ---- 'NN H Me An Year 47 48 SI SH Year NN 49 50OH Year An OH 51 Year Year 53 54 With An, identical or different, denoting anionic counterion. 10. Dyeing composition comprising in a suitable cosmetic medium, at least one dye of formula (I) as defined in any one of claims 1 to 9. 11. Dyeing composition according to the preceding claim comprising in a suitable cosmetic medium: at least one dye of formula (I) as defined in any one of claims 1 to 9; o and at least one reducing agent. 25 12. Dyeing composition according to the preceding claim wherein the reducing agent is chosen from: cysteine, homocysteine, thiolactic acid, the salts of these thiols, phosphines, bisulfite, sulfites, thioglycolic acid, and its esters, borohydrides and their derivatives, sodium, lithium, potassium, calcium, quaternary ammonium salts and catecholborane. 13. Composition according to any one of claims 10 to 12, wherein the dye of formula (I) is present in an amount of between 0.001 and 50% by weight relative to the total weight of the composition. 14. A process for dyeing keratin fibers, wherein a suitable dye composition comprising at least one dye of formula (I) according to any one of claims 10 to 13 is applied to the fibers. 15. The method of dyeing according to the preceding claim wherein when the dye of formula (I) comprises a protecting Y group, the application is preceded by a deprotection step. 16. A process according to any one of claims 14 or 15, wherein a reducing agent is applied before or after application of the dye of formula (I) as defined in claims 1 to 9. 17. The process according to any one of claims 14 to 16, wherein the composition comprises an oxidizing agent. 18. A method according to any one of claims 14 to 16 comprising a further step of applying to the keratin fibers an oxidizing agent. 30 19. Multi-compartment device wherein a first compartment contains a dye composition comprising a dye of formula (I) as defined in claims 1 to 9 and a second compartment contains a reducing agent. 20. Device according to the preceding claim comprising a third compartment which contains an oxidizing agent. 21. Use of dyes of formula (I) as defined in claims 1 to 9 74 for dyeing keratinous fibers.