WO2007110536A2 - Dyeing composition containing a thiol/disulphide fluorescent colorant comprising an ortho-pyridinium group with an uninterrupted alkylene chain and an internal cationic charge, and method for lightening keratin materials using said colorant - Google Patents

Abstract

The invention relates to a dyeing composition containing a thiol/disulphide fluorescent colorant comprising ortho-pyridinium groups and an uninterrupted alkylene chain, and to a method for colouring keratin materials, especially keratin fibres, particularly human keratin fibres such as hair, with a lightening effect, using said composition. The invention also relates to novel thiol/disulphide fluorescent colorants and the uses thereof for lightening keratin materials. Said composition produces a lightening effect which is especially tenacious and visible on dark keratin fibres.

Description

 DYEING COMPOSITION COMPRISING A FLUORESCENT THIOL DISULFIDE DYE WITH ORTHO-PYRIDINIUM GROUP AND A NON-ALKYLENE CHAIN

INTERRUPTED AND WITH INTERNAL CATIONIC LOAD, PROCESS FOR LIGHTENING KERATINIC MATERIALS FROM THAT COLORANT

The invention relates to the dyeing of keratin materials using fluorescent thiol / disulfide dyes comprising an ortho-pyridinium group and an uninterrupted alkylene chain. It is known to dye keratin fibers, especially human fibers, by direct dyeing. The method conventionally used in direct dyeing consists in applying to the keratin fibers direct dyes which are colored and dyeing molecules having an affinity for the fibers, allowing them to diffuse and then rinsing the fibers. The direct dyes which are conventionally used are, for example, dyes of the nitrobenzene type, anthraquinone dyes, nitropyridines, dyes of the azo, xanthene, acridine, azine or triaryl methane type.

The colorings that result from the use of direct dyes are temporary or semi-permanent dyes because the nature of the interactions that bind the direct dyes to the keratinous fiber, and their desorption of the surface and / or the core of the fiber are responsible their low dyeing power and their poor resistance to washes or perspiration.

Furthermore, the coloration of keratinous fibers from conventional direct dyes does not make it possible to significantly lighten the keratin fibers.

The lightening of the color of keratinous fibers, more particularly dark to lighter shades, possibly modifying the shade of these, constitutes an important demand.

Conventionally, to obtain a lighter coloration is implemented a chemical bleaching process. This method consists in treating keratin materials such as keratinous fibers, in particular the hair, by a strong oxidizing system, generally consisting of hydrogen peroxide associated or not with persalts, most often in an alkaline medium.

This discoloration system has the disadvantage of degrading materials keratin, in particular keratin fibers, especially human fibers such as the hair and to alter their cosmetic properties. The fibers tend to become rough, more difficult to disentangle and more fragile. Finally, the lightening or the bleaching of keratinous fibers by oxidizing agents is incompatible with the treatments for modifying the shape of said fibers, particularly in the straightening treatments.

Another lightening technique consists in applying fluorescent direct dyes to dark hair. This technique described in particular in the documents FR 2830189 and WO 2004/091473 makes it possible to respect the quality of the keratinous fiber during the treatment, but the fluorescent dyes employed do not exhibit satisfactory resistance to shampooing.

To increase the tenacity of the direct dyes, it is known to fix direct dyes by covalent bonding to the hair. For example, it is known to react dyes with reactive groups with the residues of cystine or cysteine very numerous in keratin fibers, see for example Journal of the Society of Dyers and Colourists, Guise and Stapleton, 91., 259-264 (1975); Journal of Cosmetic Chemistry, 42, 1-17 (1991); CA 2024509;

In addition it is known to protect the thiol function (s) contained in a molecule to be grafted to the hair before applying them to said hair WO99 / 51194. However, this application does not mention the use of fluorescent dyes for coloring or lightening hair.

Other disulfide dyes known for dyeing keratinous fibers are disulfide derivatives of aminothiophenol derivatives. Such dyes are described, for example, in patent FR 1156407. These dyes can be used under relatively mild conditions, in the presence of a slightly reducing medium or after a reducing pretreatment of the hair. However, these dyes may cause color turns during application.

Finally, the document WO 2005/097051 describes disulfide aza-imidazolium dyes for the direct dyeing of keratin fibers. The object of the present invention is to provide novel systems for dyeing keratin materials, in particular human keratinous fibers, in particular the hair, which do not have the drawbacks of existing bleaching processes. In particular, one of the aims of the present invention is to provide direct dyeing systems for obtaining lightening effects especially on keratin fibers naturally or artificially dark, tenacious against successive shampoos, which do not degrade keratin fibers and which do not alter their cosmetic properties.

This object is achieved with the present invention which relates to a process for dyeing keratin materials, in particular keratinous fibers, in particular human fibers such as the hair, more particularly the dark hair, consisting in applying to the keratin materials a dye composition. comprising, in a suitable cosmetic medium, at least one fluorescent dye chosen from the following dyes of formula (I) and (II):

their organic or inorganic acid salts, optical isomers, geometric isomers, and solvates such as hydrates; formula (I) in which:

> R _c , R ' _c , R _d and R' _d identical or different, represent a hydrogen atom, a group aryl (Ci-C ₄ ) alkyl, or a group (dC ₆ ) alkyl; R _c , R ' _c , R _d and R' _d particularly represent a hydrogen atom or a group (C _r C ₄ ) alkyl;

> R _9, R _'g, R _"g, R" _g, R _h, R' _h, R _"h and R"_'h ,, identical or different, represent a hydrogen, halogen, an amino group, (di) (Ci-C ₄₎ alkylamino, cyano, carboxy, hydroxy, trifluoromethyl, acylamino, alkoxy -C ₄ (poly) hydroxyalkoxy, C ₂ -C _4, (C ₄₎ alkylcarbonyloxy (Ci-C ₄₎ alkoxycarbonyl, (C ₁ -C ₄ ) alkylcarbonylamino, acylamino, carbamoyl, (C ₁ -C ₄ ) alkylsulphonylamino, an amino-sulphonyl radical, or a (C ₁ -C ₁₆ ) alkyl radical optionally substituted with a group selected from (C ₁ -C ₁₂ ) alkoxy; , hydroxy, cyano, carboxy, amino, (di) (C ₁ -C ₄ ) alkylamino, particularly R ₉ , R ' _g , R " _g , R'" _g , R _h , R ' _h , R "h, and R'" _h , represent a hydrogen atom or a (C ₁ -C ₄ ) alkyl group; advantageously a hydrogen atom;

R'i, R "i, R" and R "" i, identical or different, represent a hydrogen atom, or a group (C _r C ₄ ) alkyl; particularly R'i, R ", R '" and

R "" i represents a hydrogen atom;

m and m ', identical or different, represent an integer inclusive between 1 and 10; especially an integer inclusive between 2 and 4; preferentially m and m 'are 2; > M ¹ representing an anionic counterion; and

Y represents: i) a hydrogen atom; ii) an alkali metal; iii) an alkaline earth metal; iv) an ammonium group: N ⁺ R ^α R ^{| 3} R ^γ R ^δ or a phosphonium group: P ⁺ R ^α R ^β R ^γ R ^δ with R ^α , R ^β , R ^γ and R ^δ , identical or different, representing a hydrogen atom or a (CrC ₄ ) alkyl group; or v) a thiol protecting group; Being heard that :

- When the compound of formula (I) or (II) contains other cationic parts, it is associated with one or more anionic counter-ions to achieve the electroneutrality of formula (I) or (II). Another subject of the invention is a dyeing composition comprising, in a suitable cosmetic medium, at least one fluorescent dye of formula (I) or (II) as defined above, and a reducing agent.

The invention also relates to new fluorescent dyes of formula (I) or (II) as defined above. The dyeing process according to the invention makes it possible to visibly stain dark keratin materials, in particular dark human keratin fibers, especially dark hair.

In addition, the process of the invention makes it possible to obtain a coloration of the keratin materials, in particular human keratinous fibers, in particular the hair, without degrading said material, which is persistent with respect to shampoos, of the common aggressions (sun, perspiration). , and other hair treatments. The process of the invention also makes it possible to obtain a lightening of keratin materials such as keratin fibers, especially dark keratinous fibers, and more especially dark hair.

For the purposes of the invention, dark keratin material is understood to mean that which has an encrypted luminescence L * in the IC system. E. L * a * b *, less than or equal to 45 and preferably less than or equal to 40, knowing moreover that L * = 0 is equivalent to black and L * = 100 to white.

For the purposes of the invention, the term naturally or artificially dark hair, hair whose pitch is less than or equal to 6 (dark blonde) and preferably less than or equal to 4 (chestnut).

The lightening of the hair is evaluated by the variation of "pitch" before and after application of the compound of formula (I) or (II).

The notion of "tone" is based on the classification of natural nuances, a tone separating each nuance from that which follows it or immediately precedes it. This definition and the classification of natural shades is well known to hair professionals and published in the book "Science of hair treatments" Charles ZVIAK 1988, Ed Masson, p. 215 and 278.

Heights range from 1 (black) to 10 (very light blond), a unit corresponding to a tone; the higher the number, the clearer the nuance.

An artificially colored hair is a hair whose color has been modified by a coloring treatment, for example a coloration with direct dyes or oxidation dyes.

Preferably, the composition must, after application to hair, for example chestnut, bring to the results below.

We are interested in the reflectance performance of hair when irradiated with visible light in the wavelength range of 400 to 700 nanometers.

The reflectance curves are then compared as a function of the wavelength, of the hair treated with the composition of the invention and of the untreated hair.

- The curve corresponding to the treated hair must show a reflectance in the wavelength range from 500 to 700 nanometers higher than the curve corresponding to untreated hair.

This means that, in the wavelength range of 540 to 700 nanometers, there is at least one range where the reflectance curve corresponding to the treated hair is greater than the reflectance curve corresponding to the untreated hair. "Superior" means a difference of less than 0.05% reflectance, and preferably at least 0.1%. This does not prevent that there may exist in the wavelength range from 540 to 700 nanometers, at least one range where the reflectance curve corresponding to the treated hair is superimposable, or less than the reflectance curve corresponding to the untreated hair.

Preferably, the wavelength where the difference is greatest between the reflectance curve of the treated hair and that of the untreated hair is in the wavelength range of 500 to 650 nanometers, and preferably in the the wavelength range from 550 to 620 nanometers. For the purposes of the present invention, and unless a different indication is given:

the "aryl" or "heteroaryl" radicals or the aryl or heteroaryl part of a radical may be substituted by at least one substituent borne by a carbon atom, chosen from: • a C ₁ -C ₁₆ alkyl radical, preferably Ci-Cs, optionally substituted with one or more radicals selected from hydroxy, alkoxy d-C ₂ , (poly) -hydroxyalkoxy C ₂ -C ₄ , acylamino, amino substituted with two alkyl radicals, identical or different , at C _r C ₄ , optionally carrying at least one hydroxyl group or, the two radicals being able to form, with the nitrogen atom to which they are attached, a heterocycle comprising

5- to 7-membered, preferably 5- or 6-membered, optionally substituted saturated or unsaturated group optionally comprising another heteroatom identical to or different from nitrogen; . a halogen atom such as chlorine, fluorine or bromine; • a hydroxyl group;

. a C ₁ -C ₂ alkoxy radical;

A C ₁ -C ₂ alkylthio radical;

. a (C ₂ -C ₄ ) polyhydroxyalkoxy radical;

An amino radical; A 5- or 6-membered heterocycloalkyl radical;

. a 5- or 6-membered optionally cationic heteroaryl radical, preferentially imidazolium, and optionally substituted with a (C ₁ -C ₄ ) alkyl radical, preferably methyl;

An amino radical substituted with one or two identical alkyl radicals or dC ₆ optionally containing at least: i) a hydroxyl group, ii) an amino group optionally substituted with one or two optionally substituted C ₁ -C ₃ alkyl radicals, said alkyl radicals being able to form with the atom of nitrogen to which they are attached, an optionally substituted 5 to 7-membered heterocyclic ring, saturated or unsaturated, optionally comprising at least one other heteroatom different from or different from nitrogen,

. -NR-COR 'in which the radical R is a hydrogen atom, a C ₁ -C ₄ alkyl radical optionally bearing at least one hydroxyl group and the R' radical is a C ₁ -C ₂ alkyl radical;

. (R) ₂ N-CO- in which the R radicals, which may be identical or different, represent a hydrogen atom or a C ₁ -C ₄ alkyl radical optionally bearing at least one hydroxyl group; R ¹ SO ₂ -NR- in which the radical R represents a hydrogen atom, a C ₁ -C ₄ alkyl radical optionally bearing at least one hydroxyl group and the radical R 'represents a C ₁ -C ₄ alkyl radical, a phenyl radical;

(R) ₂ N-SO ₂ - in which the R radicals, which may be identical or different, represent a hydrogen atom, a C ₁ -C ₄ alkyl radical optionally bearing at least one hydroxyl group,

A carboxylic radical in acid or salified form (preferably with an alkali metal or an ammonium, substituted or unsubstituted);

. a cyano group; A polyhaloalkyl group comprising from 1 to 6 carbon atoms and from 1 to 6 halogen atoms, which are identical or different, the polyhaloalkyl group is, for example, trifluoromethyl;

the cyclic or heterocyclic part of a non-aromatic radical may be substituted by at least one substituent carried by a carbon atom chosen from the groups:

. hydroxy,

• C ₁ -C ₄ alkoxy,

. (poly) hydroxyalkoxy C ₂ -C ₄ ,

A C ₁ -C ₂ alkylthio radical; . RCO-NR'- in which the radical R 'is a hydrogen atom, a C ₁ -C ₄ alkyl radical optionally bearing at least one hydroxyl group and the radical R is a C ₁ -C ₂ alkyl radical, amino substituted by two identical or different C ₁ -C ₄ alkyl groups optionally carrying at least one hydroxyl group;

RCO-O- in which the radical R is a C ₁ -C ₄ alkyl radical, amino substituted with one or two identical or different C ₁ -C ₄ alkyl groups optionally carrying at least one hydroxyl group, said alkyl radicals being able to form with the nitrogen atom to which they are attached, an optionally substituted saturated or unsaturated 5- to 7-membered heterocyclic ring optionally comprising at least one other heteroatom different from or different from nitrogen;

RO-CO- in which the radical R is a C ₁ -C ₄ alkyl radical optionally carrying at least one hydroxyl group; a cyclic, heterocyclic radical or a non-aromatic part of an aryl or heteroaryl radical may also be substituted with one or more oxo or thioxo groups;

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

a "diarylalkyl" radical represents a group comprising, on the same carbon atom of an alkyl group, two identical or different aryl groups, such as diphenylmethyl or 1,1-diphenylethyl; a "heteroaryl radical" represents a mono- or polycyclic group, condensed or not, optionally cationic, comprising from 5 to 22 members, from 1 to 6 heteroatoms chosen from nitrogen, oxygen, sulfur and selenium; , and of which at least one cycle is aromatic; preferably heteroaryl is selected from acridinyl, benzimidazolyl, benzobistriazolyl, benzopyrazolyl, benzopyridazinyle, benzoquinolyl, benzothiazolyl, benzotriazolyl, benzoxazolyl, pyridinyl, tetrazolyl, dihydrothiazolyl, imidazopyridinyl, imidazolyl, indolyl, isoquinolyl, naphthoimidazolyle, naphthooxazolyle, naphthopyrazolyle, oxadiazolyl, oxazolyl, oxazolopyridyl , phenazinyl, phenoxazolyl, pyrazinyl, pyrazolyl, pyrilyl, pyrazoyltriazyl, pyridyl, pyridinoimidazolyl, pyrrolyl, quinolyl, tetrazolyl, thiadiazolyl, thiazolyl, thiazolopyridinyl, thiazoylimidazolyl, thiopyryl, triazolyl, xanthylyl and its ammonium salt;

a "diheteroarylalkyl" radical represents a group comprising, on the same carbon atom of an alkyl group, two heteroaryl groups, identical or different, such as difurylmethyl, 1,1-difurylethyl, dipyrrolylmethyl, dithienylmethyl;

a "cyclic radical" is a non-aromatic, mono or polycyclic cycloalkyl radical, condensed or not, containing from 5 to 22 carbon atoms, which may contain from 1 to several unsaturations; particularly the cyclic radical is cyclohexyl;

a "cyclic sterically hindered" 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 [1.1.0] butane, mesytyls such as 1,3,5-trimethylphenyl, 1,3,5-triterbutylphenyl, 1,3,5-isobutylphenyl, 1,3,5-trimethylsillylphenyl and adamantyl ;

a "heterocyclic radical or heterocycle" is a mono- or polycyclic non-condensed radical, condensed or not, containing from 5 to 22 members, comprising from 1 to 6 heteroatoms chosen from nitrogen, oxygen, sulfur and selenium;

an "alkyl radical" is a linear or branched C ₁ -C ₆ hydrocarbon-based radical, preferably dC ₈ ;

the expression "optionally substituted" assigned to the alkyl radical implies that said alkyl radical may be substituted by one or more radicals chosen from i) hydroxyl, ii) optionally substituted C ₁ -C ₄ alkoxy, iii) acylamino, iv) amino radicals; by one or two identical or different C ₁ -C ₄ alkyl radicals, said alkyl radicals being capable of forming, with the nitrogen atom carrying them, a 5- to 7-membered heterocyl, optionally comprising another heteroatom which may or may not be different; nitrogen; v) or a quaternary ammonium group -N R'R "R '", M ^" for which R', R", R '", identical or different, represent a

hydrogen atom, or a C ₁ -C ₄ alkyl group, or else -N R'R "R '" forms a heteroaryl such as imidazolium optionally substituted by a C ₄ -alkyl group, and M represents the counter-ion of organic acid, mineral or the corresponding halide,

an "alkoxy radical" is an alkyl-oxy or alkyl-O- radical for which the alkyl radical is a hydrocarbon radical, linear or branched, Ci-Ci ₆ preferentially; an "alkylthio radical" is an alkyl-S- radical for which the alkyl radical is a hydrocarbon radical, linear or branched, C ₁ -C ₁₆ preferably C ₁ -C ₈ ; when the alkylthio group is optionally substituted, this implies that the alkyl group is optionally substituted as defined above;

the boundaries delimiting the range of a range of values lie within this range of values;

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) from alkylsulfonic acids: Alk-S (O) ₂ OH such as methylsulfonic acid and ethylsulfonic acid; v) arylsulfonic acids: Ar-S (O) ₂ OH such as benzene sulfonic acid and toluene sulfonic acid; (vi) citric acid; vii) succinic acid; viii) tartaric acid; ix) lactic acid, x) alkoxysulfinic acids: Alk-OS (O) OH such as methoxysulfinic acid and ethoxysulfinic acid; xi) aryloxysulfinic acids such as tolueneoxysulfinic acid and phenoxysulfinic acid; xii) phosphoric acid H ₃ PO ₄ ; xiii) acetic acid CH ₃ COOH; xiv) triflic acid CF ₃ SO ₃ H and xv) tetrafluoroboric acid HBF ₄ ;

an "anionic counterion" is an anion or an anionic group associated with the cationic charge of the dye; more particularly the anionic counterion is selected from i) halides such as chloride, bromide; ii) nitrates; iii) sulphonates, of which C ₁ -C ₆ alkylsulphonates: Alk-S (O) ₂ O ^' such as methylsulphonate or mesylate and ethylsulphonate; iv) arylsulfonates: Ar-S (O) ₂ O ^"as benzenesulfonate and toluenesulfonate or tosylate; v) citrate; vi) succinate; vii) tartrate; viii) lactate; ix) alkyl sulfates: AIk -OS (O) O ^'such as méthysulfate and ethyl sulfate; x) aryl sulfates: Ar-OS (O) O ^"such as toluenesulfate and benzenesulfate; xi) alkoxysulfates: Alk-OS (O) ₂ O ^' such as methoxy sulfate and ethoxysulfate; xii) aryloxysulfates: Ar-OS (O) ₂ O ^", xiii) phosphate; xiv) acetate; xv) triflate; and xvi) borates such as tetrafluoroborate. The fluorescent dyes of formula (I) or (II) are compounds capable of absorbing in UV or visible radiation at a wavelength λ _abs of between 250 and 800 nm and capable of reemitting in the visible range at a emission wavelength λ _em between 400 and 800 nm. Preferably the fluorescent compounds of the invention are dyes capable of absorbing in the visible λ _abs between 400 and 800 nm and reemitting in the visible λ _em between 400 and 800 nm. More preferably, the fluorescent dyes of formula (I) or (II) are dyes capable of absorbing at an _abs λ between 420 nm and 550 nm and reemitting in the visible at an λ _em between 470 and 600 nm.

The fluorescent compounds of the invention contain a SY function which can be in the covalent -SY or ionic -S ^" Y ^{+ form} depending on the nature of Y and the pH of the medium.

One particular mode relates to fluorescent dyes of formula (II) with SY function where 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 (II) above, Y is a protective 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, 3 ^èmΘ ed., 2005, c. 5.

Especially when Y represents a protective group of the thiol function, Y is chosen from the following radicals:

(C ₁ -C ₄ ) alkylcarbonyl; (CrOOalkylthiocarbonyl;

• (Ci-C ₄₎ alkoxycarbonyl;

• (CrCXOalkoxythiocarbonyl;

• (Ci-C ₄₎ alkylthio-thiocarbonyl;

• (di) (C ₁ -C ₄ ) (alkyl) aminocarbonyl; (Di) (CrC ₄ ) (alkyl) aminothiocarbonyl;

Arylcarbonyl as phenylcarbonyl;

Aryloxycarbonyl;

• aryl (CrC ₄ ) alkoxycarbonyl; (Di) (CrC ₄ ) (alkyl) aminocarbonyl as dimethylaminocarbonyl;

• (Ci-C ₄₎ (alkyl) arylaminocarbonyl;

• carboxy;

• SO ₃ ^" M ⁺ with M ⁺ representing an alkali metal such as sodium or potassium, or M 'of the formula (II) 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 bicyclic compounds 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 CrC ₄ ) alkyl as methyl, or polyhalo (C ₁ -C ₄ ) alkyl as trifluoromethyl; iii) or tricyclic ABC following:

wherein the two rings A, C optionally comprise a heteroatom, and the ring B is a 5-, 6- or 7-membered particularly 6-membered ring and contains at least one heteroatom such as pyperidyl, pyranyl; 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:

wherein R ^'c, R' ^d, R ^'Θ, R' ^f, R ^'9 and R' ^h, identical or different, represent a hydrogen atom or a (Ci-C ₄₎ alkyl, or else two groups R ' ⁹ with R' ^h , and / or R ' ^Θ with R' ^f form an oxo or thioxo group, or else R ' ⁹ with R' ^Θ together form a cycloalkyl; and v represents an integer inclusive of between 1 and 3; preferentially R ' ^c to R' ^h represent a hydrogen atom; and An ^" represents a counterion;

• isothiouronium -C (NR ' ^c R' ^d ) = N ⁺ R ' ^Θ R'^f; An ^"with R ^'c, R' ^d, R ^'Θ and R' ^f, like or different, represent a hydrogen atom or a (dC ₄₎ alkyl; preferably, R ^'c to R' ^f represent a hydrogen atom, hydrogen, and An ^" represents a counterion;

• isothiourea -C (NR ' ^c R' ^d ) = NR '^Θ; with R ' ^c , R' ^d and R ' ^Θ as defined above;

Optionally substituted (di) aryl (C _r C ₄ ) alkyl such as 9-anthracenylmethyl, phenylmethyl or diphenylmethyl optionally substituted with one or more groups chosen in particular from (C ₁ -C ₄ ) alkyl, (C _r C ₄ ) alkoxy, for example methoxy, hydroxy, (C ₁ -C ₄ ) alkylcarbonyl, (di) (C ₁ -C ₄ ) (alkyl) amino such as dimethylamino;

(Di) heteroaryl (C _r C ₄ ) optionally substituted alkyl, the heteroaryl group is in particular, cationic or otherwise, monocyclic, comprising 5 or 6 members and 1 to 4 heteroatoms selected from nitrogen, oxygen and sulfur, such as pyrrolyl, furanyl, thiophenyl, pyridyl, pyridyl N-oxide groups such as 4-pyridyl or 2-pyridyl-N-oxide, pyrylium, pyridinium, triazinyl, optionally substituted with one or more groups such as alkyl particularly methyl, advantageously (di) heteroaryl (CrC ₄ ) alkyl is (di) heteroarylmethyl or ( di) heteroarylethyl;

• CR 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 (CrC ₄ ) alkyl, (CrC ₄ ) alkoxy, hydroxy; optionally substituted heteroaryl such as thiophenyl, furanyl, pyrrolyl, pyranyl or pyridyl, optionally substituted with a (C ₁ -C ₄ ) alkyl group;

- P (Z ¹ ) R ' ¹ R ¹² R' ³ with R ' ¹ , and R' ² identical or different represent a hydroxyl group, (C ₁ -C ₄ ) alkyl or alkyl, R ' ³ represents a hydroxyl group or C _r C ₄ ) alkoxy, and Z ¹ represents an oxygen or sulfur atom;

Sterically hindered cyclic such as the adamantyl group; and

Optionally substituted alkoxy (CrC ₄ ) alkyl such as methoxymethyl (MOM), ethoxyethyl (EOM) and isobutoxymethyl. According to a particular embodiment, the heterocyclic protected thiol protected fluorescent dyes of formula (II) contain a cationic aromatic 5- or 6-membered monocyclic moiety Y i) heteroaryl comprising from 1 to 4 heteroatoms chosen from oxygen, sulfur and nitrogen, such as oxazolium, isoxazolium, thiazolium, isothiazolium, 1,2,4-triazolium, 1,2,3-triazolium, 1,2,4-oxazolium, 1,2,4-thiadiazolium, pyrylium, pyridinium pyrimidinium, pyrazinyl, pyrazinium, pyridazinium, triazinium, tetrazinium, oxazepinium, thiepinyl, thiepinium, imidazolium; ii) cationic 8 to 11-membered bicyclic heteroaryl such as indolinium, benzoimidazolium, benzoxazolium, benzothiazolium, these mono or bicyclic heteroaryl groups being optionally substituted with one or more groups such as alkyl as methyl, or polyhalo (C ₁ -C ₄ ) alkyl as trifluoromethyl; iii) or heterocyclic according to:

wherein R ' ^c and R' ^d , identical or different, represent a hydrogen atom or a group (dC ₄ ) alkyl; preferentially R ' ^c to R' ^d represent a grouping

(dC ₄ ) alkyl such as methyl; and An ^" represents a counterion.

Especially Y represents a group chosen from oxazolium, isoxazolium, thiazolium, isothiazolium, 1,2,4-triazolium, 1,2,3-triazolium, 1,2,4-oxazolium, 1,2,4-thiadiazolium, pyrylium, pyridinium , pyrimidinium, pyrazinium, pyridazinium, triazinium and imidazolium, benzoimidazolium, benzoxazolium, benzothiazolium, these groups being optionally substituted by one or more (CrC ₄ ) alkyl groups including methyl.

In particular Y represents an alkali metal or a protective group such as:

(CrC ₄ ) alkylcarbonyl such as methylcarbonyl or ethylcarbonyl; arylcarbonyl, such as phenylcarbonyl;

> (CrC ₄ ) alkoxycarbonyl;

> aryloxycarbonyl;

> aryl (CrC ₄ ) alkoxycarbonyl;

> (di) (C ₁ -C ₄ ) (alkyl) aminocarbonyl as dimethylaminocarbonyl; (C ₁ -C ₄ ) (alkyl) arylaminocarbonyl;

optionally substituted aryl such as phenyl;

monocyclic 5- or 6-membered heteroaryl such as imidazolyl or pyridyl;

Cationic monocyclic 5- to 6-membered heteroaryl such as pyrylium, pyridinium, pyrimidinium, pyrazinium, pyridazinium, triazinium, imidazolium; these groups being optionally substituted by one or more, identical or different, (C ₁ -C ₄ ) alkyl groups such as methyl;

8 to 11-membered cationic bicyclic heteroaryl such as benzoimidazolium, or benzoxazolium; these groups being optionally substituted by one or more, identical or different, (C ₁ -C ₄ ) alkyl groups such as methyl; cationic heterocycle of following formula:

> isothiouronium -C (NH ₂ ) = N ⁺ H ₂ ; An ^" ;

> isothiourea -C (NH ₂ ) = NH;

> SO ₃ ^" , M ⁺ with M ⁺ representing an alkali metal such as sodium or potassium, or else M 'of formula (II) and M ⁺ are absent.

According to a particular embodiment, the fluorescent dyes of formula (I) or (II) comprise an amino group NR _c R _d and / or a group NR ' _c R' _d on the phenyl group in the ortho or para position or in 2 or 4 phenyl as shown for (la) and (IIa):

with R _CJ R _dj R _'Cj R' _dj R _9, R _'g> R _"g> R"'_g> R _n, R _'hj R _"hj R" _hj R ¹ ,, R' ,, R ¹ ",, R"",, m, m 'and M' are as previously defined

By way of example of fluorescent dyes, mention may be made in particular of the following compounds:

With Me representing anionic counterion

Protected thiol dyes of formula (M ') can be synthesized in two stages. The first step of preparing the unprotected thiol dye (HH) 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 the thiol function according to conventional methods known to those skilled in the art to lead to protected thiol dyes of formula (H '). By way of example, to protect the thiol -SH function of the thiol dye, the methods of the "Protective Groups in Organic Synthesis", TW Greene, John Willey & Sons ed., NY, 1981, pp.193-217; "Protecting Groups", P. Kocienski, Thieme, 3 ^èmΘ Ed., 2005, ch. 5.

We can illustrate this method by the method consisting of i) generating thiol fluorescent dyes of formula (HH) by reducing a fluorescent dye to two chromophores bearing a disulfide function -SS- such that (I ¹ ) and ii) to protect according to conventional methods, said thiol function of (HH) with the reagent 7 Y'R to access protected fluorescent thiol dyes of formula (M '). The thiol compound [N; H) may also be metallized with an alkali metal or alkaline earth metal Met * to yield the fluorescent dye thiolate of formula (H ").

with Y 'representing a protecting group of thiol function; 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 Metal ²⁺ ; and R _9, R _'g, R _h, R' _h, R'j, R "i, R _c, R _d, m and M 'are as defined above; Y' represents a thiol protecting group; and R of Y'R represents a leaving group nucleofuge, such as, for example, mesylate, tosylate, triflate or halide.

It is also possible to use a thiol reactant Y'-SH comprising a group Y 'as defined previously, the nucleophilic function SH of which can react on the carbon atom in alpha of the halogen atom carried by the fluorescent chromophore (a). to lead to the protected thiol fluorescent dye of formula (H '):

with R _9, R _'g, R _hj R' _hj R'j, R ', R _0, R _d, M', m and (I ') are as defined above, and Hal representing a halogen atom nucleofugic such as bromine, iodine or chlorine.

More particularly, it will be possible to substitute a nucleofugal leaving group with a thiourea group (S = C (NRR) NRR) to generate the isothiouroniums. For example, if the thiourea group is a thioimidazolium (β), the reaction scheme is as follows:

with R ₉ , R ' _g , R _h , R' _h , R'i, R ", R ₀ , R _d , M 'and m are as previously defined, a variant is to use instead of halide comprising the chromophore fluorescent (a ") a chromophore comprising another type of nucleofuge such as tosylate, mesylate.

According to another variant it is possible to generate an imidazoline intermediate from the halide comprising the fluorescent chromophore (a ") and a thioimidazoline (b ¹ ) to conduct after alkylation with a reagent R-Gp with R representing an alkyl group and Gp a leaving group such as a halogen such as chlorine, bromine, iodine, or a mesylate or tosylate group, fluorescent compound (H "").

By way of example, a compound containing a protected thiol group, contains a leaving group nucleofug OR, such as mesylate, tosylate, or triflate, which can undergo the nucleophilic attack of the amine carried by the styryl fluorescent chromophore:

Another alternative comes from the use of halides as nucleofugal leaving group on a thiol compound which can be substituted by a primary amine function, for example carried by a styryl fluorescent chromophore:

According to another possibility, the thiol fluorescent dyes of formula (II) according to the invention can be obtained by reaction of a compound comprising a thiol group Y as defined above and an electrophilic group (f) with a pyridinium compound comprising a nucleophilic group. By way of example, an aldehyde, ketone or thioaldehyde, thioketone may be condensed when G 'represents an oxygen atom or a sulfur with an "activated methylene" such as al kyl pyridinium (e) to generate a bond ethylene> C = C <. This reaction is commonly known as "Knoevenagel" condensation. By "activated methylenes" is meant those which contain 2 of the pyridinium group a methylene group Rj-CH ₂ -:

with R, R ', R _9, R' _g, R _hj R _'hj R'j, R "i, m, and M' as defined hereinbefore and G 'represents an oxygen or sulfur atom.

Reference may be made to the book Advanced Organic Chemistry, "Reactions, Mechanisms and Structures", J. March, 4 ^èmΘ Ed, John Wiley & Sons, 1992, or TW Greene "Protective Groups in Organic Synthesis" for more details on the operating conditions used for the processes mentioned above.

The thiol fluorescent dyes formed can be converted to protected thiol stain -SY 'by protecting the thiol -SH using conventional protecting groups. The thiol fluorescent dyes are metallated by also using the conventional methods known in the art such as those described in Advanced Organic Chemistry, "Reactions, Mechanisms and Structures", J. March, 4 ^èmΘ Ed, John Wiley & Sons, NY , 1992.

Protected thiol dyes may be deprotected by conventional routes such as those described in the "Protective Groups in Organic Synthesis", TW Greene, John Willey & Sons ed., NY, 1981; "Protecting Groups", P. Kocienski, Thieme, 3 ^èmΘ ed. 2005.

The starting reagents are commercial or accessible by conventional methods known to those skilled in the art. By way of example, it is possible to synthesize the fluorescent dye of formula (I ') from 2 equivalents of pyridine derivative 1 and one equivalent of disulfide reagent comprising two leaving groups Gp, to yield dipyridinium disulfide salt 3 which can in turn, condense with two equivalents of aryl compound with aldehyde / thioaldehyde group f to give (I ').

with Gp representing a leaving group nucleofuge, for example mesylate, tosylate, triflate or halide. Against the ions Gp ^"of ∞mposés (I ¹⁾ above may be replaced by ions against M 'other natures from methods known to those skilled in the art in particular by ion exchange resin.

The dissymmetrical disulfide dyes of formula (I) may be synthesized in one step by reacting an unprotected thiol fluorescent dye with a Y'-protected thiol fluorescent dye to form the disulfide dye of formula (I).

with R _9, R _'g, R _h, R' _h, R'j, R ", R _CJ R _d, M 'and m are as defined above .; Y' represents a protective group of thiol function. It will refer to the book Advanced Organic Chemistry, "Reactions,

Mechanisms and Structures ", J. March, 4 ^ed. Ed, John Willey & Sons, 1992 or TW Greene" Protective Groups in Organic Synthesis ", for more details on the operating conditions implemented for the processes mentioned above.

The thiol fluorescent dyes formed can be converted to protected thiol stain -SY 'by protecting the thiol -SH using conventional protecting groups. The thiol fluorescent dyes are also metal using conventional methods known to those skilled in the art such as those described in Advanced Organic Chemistry, "Reactions, Mechanisms and Structures ", J. March, 4 ^èmΘ Ed, John Wiley & Sons, NY, 1992.

Protected thiol dyes may be deprotected by conventional routes such as those described in the "Protective Groups in Organic Synthesis", TW Greene, John Willey & Sons ed., NY, 1981; "Protecting Groups", P. Kocienski, Thieme, 3 ^èmΘ ed. 2005.

The composition of the invention contains at least one fluorescent dye of formula (I) or (II). In addition to the presence of at least one fluorescent dye of formula (I) or (II), 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 a quantity of fluorescent dye of formula (I) or (II) 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 dye composition may further contain additional direct dyes. These direct dyes are, for example, chosen from neutral, acidic or cationic nitro-benzene direct dyes, neutral azo, acid or cationic direct dyes, tetraazapentamethine dyes, neutral or acidic or cationic quinone dyes, in particular neutral anthraquinone dyes and direct azine dyes. , triarylmethane direct dyes, indoamine direct dyes and natural direct dyes. Among the natural direct dyes that may be mentioned are lawsone, juglone, alizarin, purpurin, 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. The dye composition may 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.

Among these couplers, there may be mentioned 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. Examples of organic solvents that may be mentioned are lower C ₁ -C ₄ 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.

The solvents when present are preferably present in proportions preferably of between 1 and 40% by weight approximately relative to the total weight of the dye composition, and even more preferably between 5 and 30% by weight approximately. According to one variant, the invention contains a reducing agent capable of reducing the disulfide bonds of keratin. This reducing agent is as defined above.

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 (γ): ^R ^ 1 / ^R a2

NW ₃ HSI

R ₄ ^R a3 (γ) wherein _W is a propylene residue optionally substituted by hydroxy or an alkyl group Ci-C _{4; R} i, R a2, R a3 and R _a4j identical or different, represent a hydrogen atom, an alkyl radical or C ₄ -C ₄ hydroxyalkyl.

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.

According to a particular embodiment in the method of the invention, a reducing agent may be applied pre-treatment before the application of the composition containing at least one fluorescent dye of formula (I) or (II).

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); catecholborane.

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 comprising at least one fluorescent dye of formula (I) or (II) also contains at least one reducing agent as defined above. This composition is then applied to the hair.

When the thiol fluorescent dye of formula (II) comprises a group Y protecting the thiol function, the process of the invention may be preceded by a deprotection step aimed at rendering the SH function in situ. By way of example, it is possible to deprotect the SY function with Y protective group by adjusting the pH as follows:

The deprotection step can also be carried out in the course of a hair pretreatment step such as, for example, the reducing pretreatment of the hair.

According to one variant, the reducing agent is added to the dyeing composition containing at least one thiol fluorescent dye of formula (I) or (II) 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 fluorescent dye of formula (I) or (II). 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 method in which the fluorescent dye of formula (I) or (II) 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 can be chosen from hydrogen peroxide, urea peroxide, bromates of alkali metals, persalts such as perborates and persulfates, and enzymes including peroxidases, 2-electron oxidoreductases such as uricases and 4-electron oxygenases such as laccases. The use of hydrogen peroxide is particularly preferred. This oxidizing agent may be applied to the fibers before or after the application of the composition containing at least one fluorescent dye of formula (I) or (II).

The application of the dye composition according to the invention is generally carried out at room temperature. It may 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 fluorescent dye thiol of formula (I) or (II) and a second compartment contains a reducing agent capable of reducing the disulfide functions of keratin materials and / or the disulfide fluorescent 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 fluorescent dye of formula (I) or (II); a second compartment contains a reducing agent capable of reducing the disulfide bond of the keratin materials; 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 fluorescent dye of formula (II) and a second compartment containing an agent capable of deprotecting the protected thiol to release the thiol.

Each of the devices mentioned above can 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. The thiol fluorescent dyes of the examples below have been fully characterized by conventional spectroscopic and spectrometric methods. EXAMPLES

EXAMPLES OF SYNTHESIS

Example 1 Synthesis of 1,1 '- (disulfanediyldiethane-2,1-diyl) bis (2 - {(E) -2- [4- (dimethylamino) phenyl] vinyl} pyridinium dibromide [1]

[1]

Diagram of synthesis

Step 1: Synthesis of 1,1 '- (disulfanediyldiethane-2,1-diyl) bis (2-methyl-pyridinium) dibromide A mixture of 56 g of 1-bromo-2 - [(2-bromoethyl) disulfanyl] ethane and 15 ml of β-methylpyrrolidinone (NMP) is added dropwise to 35 g of 2-picoline with stirring at 80 ° C. ⁰ C. the mixture (white suspension) is kept stirred for 30 min at 80 ⁰ C, 100 mL of acetonitrile (ACN) were added, stirring is maintained at 80 ⁰ C for 90 min. After cooling, the solid obtained is filtered, washed with 100 ml of ACN and then dried. 56.2 g of brown powder are collected. 45 g of this powder are suspended in 300 ml of isopropanol (iPrOH) at reflux. Once the temperature is lowered to 40 ^° C., the solid is filtered, washed with 3 times 100 ml of iPrOH and dried under vacuum.

Light beige product, 40.56 g. Analyzes in accordance with the expected structure.

Step 2: Synthesis of 1,1 '- (disulfanediyldiethane-2,1-diyl) bis (2 - {(E) -2- [4- (dimethylamino) phenyl] vinyl} pyridinium dibromide [1]

150 mg of pyrrolidine then 129 mg of acetic acid are added to a solution of 297 mg of 4-dimethylaminobenzaldehyde in 2 ml of methanol (MeOH). After stirring for 18 h at room temperature, 495 mg of (disulfanediyldiethane-2,1-diyl) bis (2-methylpyridinium) dibromide are added to the mixture and the stirring is maintained at room temperature for 7 days. After filtration, washing with MeOH and drying under vacuum, 312 mg of orange powder are collected. Analyzes in accordance with the expected structure. ¹ H NMR (400 MHz, MeOH-O ₄ ): 3.02 (s, 6H), 3.22 (t, 2H), 5 (t, 2H), 6.72 (m, 2H), 7.19 (d, 1H), 7.63 ( m, 3H), 7.76 (d, 1H), 8.3 (m, 2H), 8.59 (m, 1H).

Example 2 Synthesis of 2 - {(E) -2- [4- (dimethylamino) phenyl] vinyl bromide} -1-

(2-sulfanylethyl) pyridinium [2]:

Diagram of synthesis

Synthesis of 2 - {(E) -2- [4- (dimethylamino) phenyl] vinyl} -1- (2-sulfanylethyl) pyridinium salt [2]

73 mg of the compound [1] are dissolved in 10 ml of water / ethanol mixture (v / v 1/1); 60 mg (2 eq) of 3- [bis (2-carboxyethyl) phosphino] propanoic acid hydrochloride hydrate in solution in 1 mL water and 21 mg (4 eq) sodium bicarbonate solution in 1 mL of water are added to the mixture. After stirring for 30 minutes at 40 ° C. under an inert atmosphere, the analyzes indicate that the mixture contains most of the expected product [2].

LC-MS analysis: LC-DAD (400-700 nm) Column: Waters XTerra MS C18 5μm (4.6 x 50) mm

Mobile Phase: A: Water + Formic Acid 0.1% / B: ACN

Linear gradient: T (min) A% / B%: 0 min 95/5; 8min 0/100

Flow rate: 1 mL / min.

Detection: UV diode array λ = 400-700nm

Retention time t = 4.2 min

Relative purity> 95%

MS (ESI +) m / z = 285 corresponds to the mass peak of the expected product monocation [2]

Example 3 Synthesis of S- [6- (2 - {(E) -2- [4- (dimethylamino) phenyl] vinyl} -pyridinium-1-yl) hexyl] thiosulfate [3]

[3]

Diagram of synthesis

- S o ^'s - iPrOH O-Na

N / A

[3] Operating mode

Step 1: Synthesis of 1- (6-bromo-hexyl) -2-methyl-pyridinium bromide To 244 g of 1,6-dibromohexane heated at 80 ^° C., 18.6 g are added dropwise with stirring. 2-picoline for 4 hours. Heating and stirring are maintained for 7 hours. 250 ml of heptane are added to the mixture heated at 110 ^° C. for 15 minutes. The oily phase obtained is taken up with 250 ml of heptane and heated at 80 ° C. for 15 minutes, and left stirring at room temperature for 48 hours. The white solid formed is extracted with 500 mL of hot iPrOH and the insoluble material is filtered. The filtrate is purified by successive recrystallizations in methyl ethyl ketone (MEK), (1 L then 500 mL). The crystals are filtered, washed with 25 ml of MEK and then dried. 30.2 g of crystals are collected. The analyzes indicate that the product is compliant.

Step 2: Synthesis of 1- (6-bromohexyl) -2 - {(E) -2- [4- (dimethylamino) phenyl] vinyl} pyridinium bromide

3.55 g of pyrrolidine diluted in 10 ml of MeOH is added a solution of 7.47 g of dimethylaminobenzaldehyde (DMAB) solubilized in 21 mL of MeOH with stirring at room temperature for 5 min. 3 g of acetic acid are added to the reaction medium. 16.86 g of 1- (6-bromo-hexyl) -2-methyl-pyridinium bromide solubilized in 18 ml of MeOH are introduced into the reaction medium, which is stirred at room temperature for 24 hours. The precipitate obtained is filtered, washed with 3 times 50 ml of ethyl acetate (AcOEt) and then dried under vacuum under P ₂ O ₅ . 13.7 g of brilliant bright orange fine powder are collected. The analyzes indicate that the product is compliant.

Step 3: Synthesis of S- [6- (2 - {(E) -2- [4- (dimethylamino) phenyl] vinyl} pyridinium-1-yl) hexyl] thiosulfate [3] 2 g of bromide of 1 ( 6-bromohexyl) -2 - {(E) -2- [4- (dimethylamino) phenyl] vinyl} pyridinium are solubilized in 10 ml of iPrOH, 1.06 g of sodium thiosulfate are added to the reaction mixture which is brought at reflux (72 ° C). After 45 min. stirring, 8 mL of water are added. After stirring for 17 hours under reflux, the reaction mixture is cooled to ambient temperature, the precipitate formed is filtered, washed with 3 times 20 ml of iPrOH and then dried. 1.45 g of red powder are collected. The analyzes indicate that the product is compliant. ¹ H NMR (400 MHz, DMSO-Of ₆₎ 1.38 (m, 4H), 1.64 (m, 2H), 1.81 (m, 2H), 2.83 (t, 2H), 3.04 (s, 6H ), 4.71 (t, 2H), 6.81 (d, 2H), 7.25 (d, 1H), 7.7-7.75 (d and dd, 3H), 7.92 (d, 1H), 8.34 (dd, 1H), 8.45 (d, 1H), 8.8 (d, 1H)

Example 4 Synthesis of 2 - {(E) -2- [4- (dimethylamino) phenyl] vinyl} -1- (6-sulfanyl-hexyl) pyridinium salt [4]

[4] Diagram of synthesis

[4]

Step 1: Synthesis of 2 - {(E) -2- [4- (dimethylamino) phenyl] vinyl} -1- (6-sulfanyl-hexyl) pyridinium salt

700 mg of 2 - {(E) -2- [4- (dimethylamino) phenyl] vinyl} -1- [6- (sulfosulfanyl) hexyl] pyridinium bromide [3] are solubilized in 8 ml of hydrochloric acid. - 6N in TiPrOH. The reaction mixture is heated at 50 ^° C. for 30 min and then cooled to ambient temperature. The reaction medium containing a fine white precipitate is introduced into 30 ml of a saturated solution of NaHCO ₃ . The analyzes indicate that the thiosulfate salt is fully converted to thiol. Salt is a mixed salt of bromide, chloride and hydrogencarbonate.

Step 2 - 1,1 '- (Disulfanediyldihexane-6,1-diyl) bis (2 - {(E) -2- [4- (dimethylamino) phenyl] vinyl} pyridinium salt) [4]

To a solution obtained as indicated above, 1 ml of 1N sodium hydroxide is added. A suspension of 700 mg of 2 - {(E) -2- [4- (dimethylamino) phenyl] vinyl} -1- [6- (sulfosulfanyl) hexyl] pyridinium bromide in 20 ml of MeOH is added. The mixture is boiled at 50 ^° C. for 4 h and is then kept at ambient temperature for 18 h. The red oil obtained is solubilized in 20 ml of hot water; the mixture is allowed to return to ambient temperature for 18 hours. The solid formed is taken up in 50 mL of hot iPrOH, filtered, the precipitate is extracted with 4 times 20 mL of MeOH. After adding 100 mL of acetone and 12h at 4 ° C, a decant oil, it is taken up in 25 mL of iPrOH, filtered and concentrated in vacuo. 636 mg of red solid are collected. The analyzes indicate that the product conforms to the expected structure. Salt is a mixed salt of bromide, chloride and hydrogen carbonate. ¹ H NMR (400 MHz, MeOH-O ₄ ): 1.48 (m, 8H), 1.68 (m, 4H), 1.94 (m, 4H), 2.65 (t, 4H), 3.06 (s, 12). H), 4.67 (t, 4H), 6.79 (d, 4H), 7.17 (d, 2H), 7.64-7.69 (dd and d, 6H), 7.84 (d, 2H), 8.29 (dd; , 2H), 8.37 (d, 2H), 8.64 (d, 2H).

Example 5 Synthesis of 2 - {(E) -2- [4- (dimethylamino) phenyl] vinyl} -1- (6-sulfanyl-hexyl) pyridinium salt [5]

[5] Diagram of synthesis

[5]

Synthesis of 2 - {(E) -2- [4- (dimethylamino) phenyl] vinyl} -1- (6-sulfanyl-hexyl) -pyridinium salt [5]

84 mg of compound [4] are dissolved in 10 mL of 1: 1 water / ethanol; 60 mg

(2 equiv) of 3- [bis (2-carboxyethyl) phosphino] propanoic acid hydrochloride hydrate in solution in 1 mL of water and 21 mg (4 eq) of sodium bicarbonate dissolved in 1 mL of water are added to the mixture. After stirring for 30 minutes at 40 ° C. under an inert atmosphere, the analyzes indicate that the mixture contains most of the expected product [5].

LC-MS analysis: LC-DAD (400-700 nm)

Column: Waters XTerra MS C18 5μm (4.6 x 50) mm

Mobile Phase: A: Water + Formic Acid 0.1% / B: ACN

Linear gradient: T (min) A% / B%: 0 min 95/5; 8min 0/100

Flow: 1mL / min.

Detection: UV diode array λ = 400-700nm

Retention time t = 5.1 min. Relative purity> 95% MS (ESI +) m / z = 341 corresponds to the mass peak of the expected product monocation [5] EXAMPLES OF COLORING

Example 1: Staining process with the compounds [1] and [4] Preparation of a composition A

Disulfide dye [1] or [4] 10 ^-3 mol%

Benzyl alcohol 4 g

Polyethylene Glycol 6OE 6 g

Hydroxyethylcellulose 0.7 g

Alkylpolyglucoside in 65% aqueous solution MA 4.5 g

Demineralized water qs 100g

Preparation of a composition B

Thioglycolic acid 1 M

Sodium hydroxide qsp pH 8.5

Demineralized water qs 100g

At the time of use, compositions A (9 ml) and B (1 ml) are mixed, and then the mixture obtained is applied to a lock of 1 g of dark hair (pitch 4) for 30 minutes at room temperature. (The locks are returned and re-impregnated after 15 minutes).

After rinsing with running water and drying, a lightening of the hair thus treated is observed: the lock of pitch 4 became visually clearer than untreated control locks.

Example 2: Coloring process with the compound [2]

10 ml of fresh solution of the compound [2] of Example 2 are applied to a lock of 1 g of hair of pitch 4 placed at the bottom of the same bowl for 30 minutes at room temperature (the locks are turned over and re-treated after 15 minutes). The locks are then rinsed with running water and dried. After staining, the pitch lock 4 became visually brighter than untreated control locks. Example 3: Coloring process with the compound [3]

A lock of 1 g of hair of pitch 4 is arranged at the bottom of the same bowl. 1 ml of molar solution of ammonium thioglycolate at pH 8.5 are diluted with 9 ml of water. The solution thus obtained is applied to the locks and left to act for 30 minutes. The locks are rinsed with running water and then put back in a bowl. 10 ml of fresh solution of the compound [3] of Example 3 are applied for 30 minutes at room temperature (the locks are inverted and re-impregnated after 15 minutes).

The locks are then rinsed with running water and dried. After staining, the pitch lock 4 became visually brighter than untreated control locks.

Example 4: Method of staining with the compound [5]

10 ml of fresh solution of the compound [5] of Example 5 of the synthesis are applied to a lock of 1 g of hair of pitch 4 arranged at the bottom of the same bowl for 30 minutes at room temperature (the locks returned and re-impregnated after 15 minutes). The locks are then rinsed with running water and dried. After staining, the pitch lock 4 became visually brighter than untreated control locks.

Remanence vis-à-vis successive shampoos:

The locks thus treated are divided in two, one half is subjected to 5 successive shampoos in a cycle which comprises wetting the locks with water, washing with a conventional shampoo, rinsing with water followed by drying. Visual observations

During the shampoos of Examples 1, 2 and 3, there is no visible bleeding, the foam of the shampoos and the rinsing water are not colored. The color observed on the locks is preserved and the lightening effect remains. visible on the hair of pitch 4 thus treated. Results in the L ^* a ^* b ^{* system} :

The color of the locks before and after the 5 washes was evaluated in the L * a * b * system by means of a KONICA MINOLTA® CM 2600 spectrophotocolorimeter (Illuminant D65). In this system L * a * b *, L * represents the intensity of the color, a * indicates the axis of green / red color and b * the blue / yellow color axis. The higher the L value, the lighter or less intense the color. Conversely, the lower the value of L, the darker or more intense the color. The higher the value of a * the higher the shade is red and the higher the value of b * the hue is yellow. The variation of the color between the locks of hair of HT 4 and the locks of hair after treatment (coloration, or coloration and successive washings) is measured by ΔE according to the following equation:

ΔE = V (L ^* - L ₀ ^* ) ² + (a ^* - a ₀ ^* ) ² + (b ^* - b ₀ ^* ) ²

In this equation, L *, a * and b * represent the values measured before treatment (staining) and L ₀ *, ao * and bo * represent the values measured after treatment (staining, or staining and successive washes)

The results of the table show that there is no significant difference in color variation even after 5 shampoos. Thus the coloration and the lightening effect on the hair remain virtually unchanged which shows a very good resistance to shampoos dyes of the invention.

Reflectance results:

The lightening performance of the compositions according to the invention and their persistence with respect to successive shampoos were expressed as a function of the reflectance of the hair. These reflectances are compared to the reflectance of an untreated strand of HT4 pitch hair.

The reflectance is measured using a KONIKA-MINOLTA spectrophotocolorimeter ⁽ S, CM 260Od) and after irradiation of the hair with visible light in the wavelength range of 400 to 700 nanometers.

Reflectance of wicks treated with compound 1 on application and after 5 shampoos

- Reference

- Compound 1

Compound 1 - 5 shampoos oooooooooooooooc Wavelength (nm)

It is firstly noted that the reflectance of a lock of hair treated with a composition according to the invention is greater than that of untreated hair. The treated locks therefore appear clearer.

In addition, the results show that the reflectance of the locks of hair of pitch 4 treated with the compositions of the invention evolve very little even after 5 shampoos. Thus the coloration and the lightening effect on the hair remain virtually unchanged which shows a very good resistance to shampoos dyes of the invention.

Claims

1. Fluorescent dye of formula (I) or (II):

its organic or inorganic acid salts, optical isomers, geometric isomers, and solvates such as hydrates; formula (I) in which:

> Ro R'o Rd and R ' _d identical or different, represent a hydrogen atom, a group aryl (Ci-C ₄ ) alkyl, or a group (dC ₆ ) alkyl; > R _9, R _'g, R _"g, R" _g, R _h, R' _h, R _"h and R"_'h, identical or different, represent a hydrogen atom, halogen, amino, (di) (C _r -C ₄₎ alkylamino, cyano, carboxy, hydroxy, trifluoromethyl, acylamino, alkoxy -C ₄ (poly) hydroxyalkoxy, C ₂ -C _4, (C _r C ₄₎ alkylcarbonyloxy (-C C ₄ ) alkoxycarbonyl, (C ₁ -C ₄ ) alkylcarbonylamino, acylamino, carbamoyl, (C ₁ -C ₄ ) alkylsulphonylamino, an aminosulfonyl radical, or a (C ₁ -C ₆ ) alkyl radical optionally substituted with a group chosen from (C ₁ -C ₂ ) alkoxy, hydroxy, cyano, carboxy, amino, (di) (C ₁ -C ₄ ) alkylamino;

R 1, R ", R" and R "" j, which may be identical or different, represent a hydrogen atom or a (C ₁ -C ₄ ) alkyl group; m and m ', identical or different, represent an integer inclusive between 1 and 10;

> M ¹ representing an anionic counterion; and

Y represents: i) a hydrogen atom; ii) an alkali metal; iii) an alkaline earth metal; iv) an ammonium group: N ⁺ F ^ R ¹³ R ⁷ R ⁵ or a phosphonium group: P ⁺ R ^α R ^β R ^γ R ^δ with R ^α , R ^β , R ^γ and R ^δ , identical or different, representing a hydrogen atom or a group (dC ₄ ) alkyl; or v) a thiol protecting group; it being understood that: - when the compound of formula (I) or (II) contains other cationic parts, it is associated with one or more anionic counter-ions making it possible to reach the electroneutrality of formula (I) or (II).

2. Fluorescent dye of formula (II) according to the preceding claim wherein Y represents a hydrogen atom, or an alkali metal.

3. Fluorescent dye of formula (II) according to claim 1 wherein Y represents a protective group.

4. Fluorescent dye of formula (II) according to the preceding claim wherein Y represents a protective group chosen from the following radicals:

(C _r C ₄ ) alkylcarbonyl; . (C _r C ₄ ) alkylthiocarbonyl;

• (CrC ₄ ) alkoxycarbonyl;

. (C _r C ₄ ) alkoxythiocarbonyl;

• (CrC ₄ ) alkylthiothiocarbonyl;

. (di) (CrC ₄ ) (alkyl) aminocarbonyl; (Di) (CrC ₄ ) (alkyl) aminothiocarbonyl;

. arylcarbonyl;

Aryloxycarbonyl;

. aryl (CrC ₄ ) alkoxycarbonyl;

(Di) (CrC ₄ ) (alkyl) aminocarbonyl; . (CrC ₄ ) (alkyl) arylaminocarbonyl;

• carboxy;

. SO ₃ ^" ; M ⁺ with M ⁺ representing an alkali metal or M 'of the formula (II) and M ⁺ are absent; optionally substituted aryl; • optionally substituted heteroaryl;

. optionally substituted heterocycloalkyl, optionally cationic;

. isothiouronium -C (NR ' ^c R' ^d ) = N ⁺ R ' ^Θ R'^f; An ^"with R ^'c, R' ^d, R ^'Θ and R' ^f, like or different, represent a hydrogen atom or a (C _r C ₄₎ alkyl; preferably R ' ^c to R' ^f represent a hydrogen atom; and An ^" represents a counter ion: isothiourea -C (NR ' ^c R' ^d ) = NR ' ^Θ , with R' ^c , R ' ^d and R' ^Θ as defined previously;

• (di) aryl (CrC ₄ ) optionally substituted alkyl; . (di) optionally substituted heteroaryl (CrC ₄ ) alkyl;

. CR 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;

optionally substituted heteroaryl;

- P (Z ¹ ) R ' ¹ R ¹² R' ³ with R ' ¹ , and R' ² identical or different represent a hydroxyl group, (C ₁ -C ₄ ) alkyl or alkyl, R ' ³ represents a hydroxyl group or C _r C ₄ ) alkoxy, and Z ¹ represents an oxygen or sulfur atom;

. sterically hindered cyclic; and

• optionally substituted alkoxy (dC ₄ ) alkyl.

5. Fluorescent dye of formula (II) according to any one of the preceding claims wherein Y represents an alkali metal or a protective group chosen from:

> (CrC ₄ ) alkylcarbonyl;

> arylcarbonyl;

> (CrC ₄ ) alkoxycarbonyl;

>aryloxycarbonyl;> aryl (CrC ₄ ) alkoxycarbonyl;

> (di) (C ₁ -C ₄ ) (alkyl) aminocarbonyl;

> (CrC ₄ ) (alkyl) arylaminocarbonyl;

optionally substituted aryl;

cationic monocyclic heteroaryl with 5, 6 members; 8 to 11-membered cationic bicyclic heteroaryl;

cationic heterocycle of following formula:

> isothiouronium -C (NH ₂ ) = N ⁺ H ₂ ; An ^" ;

> isothiourea -C (NH ₂ ) = NH; and

> SO ₃ ^" ; M ⁺ with M ⁺ representing an alkali metal or else M 'of the formula (II) and M ⁺ are absent.

6. Fluorescent dye of formula (I) or (II) which contain the group R _c R _d N and / or R ' _c R' _d N in the phenyl group relative to the ethylene group to which said phenyl is attached.

7. Fluorescent dye of formula (I) or (II) according to any one of the preceding claims, chosen from the following colorants:

8. dye composition comprising in a suitable cosmetic medium, a fluorescent dye of formula (I) or (II) as defined in any one of claims 1 to 7.

9. Dyeing composition comprising in a suitable cosmetic medium, at least one fluorescent dye of formula (I) or (II) as defined in any one of claims 1 to 7 and at least one reducing agent.

10. 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, as well as its esters, borohydrides and their derivatives, the sodium, lithium, potassium, calcium and quaternary ammonium salts; catecholborane.

11. Composition according to any one of claims 8 to 10, wherein the fluorescent dye of formula (I) or (II) is present in an amount of between 0.001 and 50% by weight relative to the total weight of the composition.

12. A process for dyeing keratin materials, wherein a dye composition as defined in any one of Claims 8 to 11, comprising, in a suitable cosmetic medium, at least one fluorescent dye of formula (I) or (II) as defined in any one of claims 1 to 7, optionally in the presence of a reducing agent.

13. The method of coloring according to the preceding claim wherein when the thiol fluorescent dye of formula (II) comprises a protective Y group, the application is preceded by a deprotection step.

14. A method of dyeing keratin materials according to any one of claims 12 or 13 characterized in that the keratin materials are dark keratinous fibers having a pitch of less than or equal to 6.

15. The method according to any one of claims 12 to 14 wherein the reducing agent is applied before or after the application of the fluorescent dye of formula (I) or (II).

The process of any one of claims 12 to 15, wherein the composition comprises an oxidizing agent.

17. Method according to any one of claims 12 to 15 comprising an additional step of applying to the keratin fibers an oxidizing agent.

18. A multi-compartment device in which a first compartment contains a dye composition comprising a fluorescent dye as defined in claims 1 to 7 and a second compartment contains a reducing agent.

19. Device according to the preceding claim comprising a third compartment which contains an oxidizing agent.

20. Use of fluorescent dyes as defined in claims 1 to 7 for dyeing dark human keratin fibers.

21. Use according to the preceding claim for lightening dark keratin fibers.

22. Use according to claims 20 or 21 characterized in that the keratinous fibers have a pitch of less than 6.