FR2921379A1 - INDOLE DERIVATIVE STYRYL THIOL / DISULFIDE DERIVATIVE, TINCTORIAL COMPOSITION COMPRISING THE COLORANT, PROCESS FOR LIGHTENING KERATINIC MATERIALS FROM THAT COLORANT - Google Patents

Abstract

The invention relates to the dyeing of keratin materials using fluorescent dyes derived from indoles styryl thiols and disulfides.The invention relates to a dyeing composition comprising a fluorescent dye derived from indoles styryl thiols and disulfides, a process dyeing with lightening effect of keratin materials, in particular keratinous fibers, in particular human fibers such as the hair, using said composition. It also relates to new fluorescent dyes derived from styryl thiol and disulphide indoles and their uses in the lightening of keratin materials. This composition makes it possible to obtain a coloration with a lightening effect which is particularly tenacious and visible on dark keratinous fibers.

Description

The invention relates to the dyeing of keratin materials using fluorescent dyes derived from indoles styryl thiols. The invention relates to the dyeing of keratin materials using fluorescent dyes derived from indoles styryl thiols. and disulfides. It is known to dye keratinous 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 triarylmethane type. It is also known to use styryl hemicyanin direct dyes to stain keratin fibers in a powerful manner. These dyes with heteroaryl benzothiazolium group, benzoimidazolium are for example those described in patent applications EP 1166753 and EP 1166757. The coloring of keratin fibers from these conventional direct dyes does not significantly lighten the keratin fibers.

The lightening of the color of dark keratin fibers to lighter shades, possibly modifying the shade of these, constitutes an important demand. Conventionally, to obtain a lighter color, a chemical bleaching process is used. This method consists in treating the keratinous fibers, such as the hair, with a strong oxidizing system, generally consisting of hydrogen peroxide associated or not with persalts, most often in an alkaline medium. This bleaching system has the disadvantage of degrading keratinous fibers, especially the hair and altering 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 WO 03/028685 and WO 2004/091473, makes it possible to respect the quality of the keratinous fiber during the treatment. However, these fluorescent direct dyes do not have a satisfactory tenacity vis-à-vis external agents.

To increase the tenacity of the direct dyeings on clear keratinous fibers, it is known to use disulfide dyes, in particular with azo-imidazolium chromophores in patent applications WO 2005/097051 or EP 1647580, and chromophoric dyes pyridinium / indolizinium styryl in patent applications WO 2006/134043 and WO 2006/136617.

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 which make it possible to obtain lightening effects, in particular on naturally or artificially dark keratin fibers, which are stubborn in the face of successive shampoos, which do not degrade keratin fibers and which do not alter their cosmetic properties.

Another object of the invention is to color chromatically and remanent vis-à-vis the external aggressions keratin materials.

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 derived from indole styryl disulfide or thiol, chosen from the dyes of formulas (I) and (II): Het + LiS-Q n (Y) m (Y) mn ( 1) (II) their organic or inorganic acid salts, optical isomers, geometric isomers, and solvates such as hydrates; formulas (I) or (II) in which: n represents 1 or 2; m represents 0 or 1; p represents an integer inclusive between 1 and 4; - R 'and R3, identical or different, represent a hydrogen atom or an optionally substituted (C 1 -C 6) alkyl group; especially R 'and R3 represent a hydrogen atom or a methyl group; R2, which may be identical or different, represent a hydrogen atom, a halogen atom, a (C 1 -C 6) (alkyl) amino, cyano, hydroxy or (poly) halogen (C 1 -C 6) alkyl group such as trifluoromethyl, (C 1 -C 4) acyl (alkyl) amino, (C 1 -C 6) alkoxy, (C 1 -C 6) alkylthio, (poly) hydroxy (C 2 -C 6) alkoxy, (C 1 -C 6) alkylcarbonyloxy, ( C, -C 6) alkoxycarbonyl, (C 1 -C 6) alkylcarbonylamino, carbamoyl, (C 1 -C 6) alkylsulfonyl (C 1 -C 4) (alkyl) amino, (C 1 -C 4) (di) (alkyl) aminosulfonyl, carboxy or a (C 1 -C 16) alkyl group optionally substituted with a group selected from (C 1 -C 6) alkoxy, hydroxy; or when p is an integer greater than or equal to 2, two radicals R2 contiguous with the carbon atoms which carry them in position C4-05, or C5-C6 or C6-C ', together form a benzo ring; particularly R2 represents a hydrogen atom; - Het + represents a cationic heteroaryl radical chosen from those of the following formulas (A), (B), (C) and (D): (A) (B) R6 (C) formulas (A), (B), (C) ) and (D) in which: - either the nitrogen atom N 'contained in the 5-membered ring of the formula (A) is connected to the radical L of the formula (I), or the nitrogen atom N 'is connected to the radical R' of the formula (II) and then the link a of the same 5-membered ring is connected to the styryl group in the cis or trans position of the styryl double bond; either the nitrogen atom N, the 6-membered ring of the formula (B), (C) or (D) is connected to the radical L of the formula (I), or the nitrogen atom N, is connected to the radical R 'of the formula (II) and then the bond b of the same 6-membered ring is connected to the styryl in the cis or trans position of the styryl double bond; Z represents an oxygen, sulfur, selenium or an NR 'radical; Z 2 represents a nitrogen atom or a CR 8 radical; Z 3 represents a nitrogen atom or a CR 9 radical; Z4 represents a nitrogen atom or a CR10 radical; it being understood that the two radicals Z3 and Z4 can not simultaneously represent a nitrogen atom; and when Z1 represents an oxygen, sulfur, or selenium atom then Z2 represents a CR8 radical; - R5, R6, R8, R9 and R10, which may be identical or different, represent a hydrogen atom or a group chosen from: (C 1 -C 6) alkyl, (C 1 -C 6) alkoxy, (C 1 -C 5) alkylthio, carboxy, cyano, (di) (C 1 -C 6) (alkyl) amino, hydroxy, polyhydroxy (C 1 -C 6) alkyl, polyhydroxy (C 1 -C 6) alkoxy, polyhalo (C 1 -C 6) alkyl such trifluoromethyl, (C 1 -C 4) acyl (alkyl) amino, (C 1 -C 6) alkylcarbonyloxy, (C 1 -C 6) alkoxycarbonyl, (C 1 -C 6) alkylcarbonylamino, carbamoyl, (C 1 -C 6) - (C 1 -C 4) alkylsulfonyl (alkyl) amino and (di) (C 1 -C 4) (alkyl) aminosulfonyl; or two contiguous radicals R4 with R8 or R5 with R6 and / or R6 with R10 and / or R9 with R10 together with the carbon atoms which carry them a benzo ring an optionally substituted fused heterocycle or an optionally substituted fused heteroaryl; especially a benzo group; R 7 represents a hydrogen atom or an optionally substituted (C 1 -C 6) alkyl group; especially Het + represents one of the three formulas (A), (B) or (D); Q represents an anionic counterion; L represents an optionally substituted C1-C20 bivalent hydrocarbon chain, optionally interrupted by one or more divalent groups or combinations thereof selected from: -N + RR ° -, An-; -O-, -S-, -C (O) -, -S (O) 2- with R, R °, identical or different, selected from hydrogen, C1-C4 alkyl, hydroxyalkyl, aminoalkyl and An representing an anionic counterion or ii) a cationic heterocycle or cationic heteroaryl Het, +, An-, with An- is an anionic counterion and Het, + representing a heterocycle comprising from 5 to 10 members, saturated or no, or a heteroaryl comprising from 5 to 10 members such as imidazolium, piperazinium, piperidinium, pyrrolidinium, benzoimidazolium; especially L represents a (C 1 -C 6) alkylene chain such as methylene, ethylene, propylene, butylene or (CH 2), n -Ta- (CH 2) n- with m 'and n' are integers included inclusively between 1 and 6 with the sum m '+ n' which is an integer between 2 and 6, with Ta representing a bond -NR-C (O) -or -C (O) -NR-; Y represents: i) a hydrogen atom; ii) an alkali metal; iii) an alkaline earth metal; iv) an ammonium group: N + RaRaRYRs, An "- or a phosphonium group: P + RaRaRYRs, An" - with Ra, Ra, R7 and R8, identical or different, representing a hydrogen atom or a group (C, -C4) alkyl and, An "- an anionic counterion, or v) a thiol protecting group, it being understood that when n is 2 then m is zero, and when n is 1 then m is 1.

Another subject of the invention is a dyeing composition for dyeing keratin materials such as dark hair comprising, in a cosmetic medium, at least one fluorescent dye derived from indole styryl disulfide or thiol of formula (I) or (II) as defined above, and optionally a reducing agent. The invention also relates to novel fluorescent dyes derived from indole styryl disulfide or thiol 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 method of the invention makes it possible to obtain hair coloring, without degrading them, remaining with respect to shampoos, 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 keratinous fibers, particularly dark keratinous fibers and more particularly dark hair. Moreover, the new dyes according to the invention are particularly photostable. This method also makes it possible to color keratin fibers which are discolored in a powerful, low-selectivity, homogeneous and chromatic manner. For the purposes of the invention, the term "dark keratin material" is understood to mean that which has a luminescence L * encoded in the CIEL * a * b * system, less than or equal to 45 and preferably less than or equal to 40, while also knowing 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 in pitch before and after application of the compound of formula (I) and (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. The pitch ranges from 1 (black) to 10 (very light blonde), 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. For the purposes of the invention, the term "discolored hair" means hair whose pitch is greater than 6 and preferably greater than 8.

One means for measuring the lightening effect provided to the hair after application of the fluorescent dyes of the invention is to use the hair reflectance phenomenon.

Preferably, the composition should, after application to dark hair, 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. The term "superior" means a difference of at least 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 chosen from: C1-C16, preferably C1-C8, optionally substituted by one or more radicals selected from hydroxy, C1-C2 alkoxy, (poly) -hydroxyalkoxy C2-C4, acylamino, amino substituted by 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 heterocycle comprising from 5 to 7 members, preferably from 5 to 6-membered, saturated or unsaturated, optionally substituted, optionally comprising another heteroatom which is identical or different from nitrogen; A halogen atom such as chlorine, fluorine or bromine; • a hydroxyl group; A C1-C2 alkoxy radical; A C1-C2 alkylthio radical; A C2-C4 (poly) -hydroxyalkoxy 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 (C1-C4) alkyl radical, preferably methyl; An amino radical substituted with one or two identical or different C1-C6 alkyl radicals optionally carrying at least: i) a hydroxyl group; ii) an amino group optionally substituted by one or two C1-C3 alkyl radicals; optionally substituted, said alkyl radicals being able to form, with the nitrogen atom 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-C (O) -R '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 4 alkyl radical; C2; R2N-C (O) - in which the radicals R, which may be identical or different, represent a hydrogen atom or a C1-C4 alkyl radical optionally bearing at least one hydroxyl group; R'-S (O) 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 R 'radical represents an alkyl radical; C1-C4, a phenyl radical; R2N-S (O) 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 form or salified (preferably with an alkali metal or 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 nonaromatic radical may be substituted by at least one substituent carried by a carbon atom chosen from the following groups: • hydroxy, • C1-C4 alkoxy, • (poly) hydroxyalkoxy at 02-04, A C1-C2 alkylthio radical; RC (O) -N (R ') - 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 an alkyl radical C1-C2, amino substituted with two identical or different C1-C4 alkyl groups, optionally carrying at least one hydroxyl group; RC (O) -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 bearing at least one hydroxyl group, said alkyl radicals capable of forming, with the nitrogen atom to which they are attached, a 5- to 7-membered optionally substituted saturated or unsaturated heterocycle optionally comprising at least one other heteroatom which is different from or different from nitrogen; RO-C (O) - in which the R radical 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 at least one cycle is aromatic; preferably a heteroaryl radical is chosen from acridinyl, benzimidazolyl, benzobistriazolyl, benzopyrazolyl, benzo-pyridazinyl, benzoquinolyl, benzothiazolyl, benzotriazolyl, benzoxazolyl, pyridinyl, tetrazolyl, dihydrothiazolyl, imidazopyridinyl, imidazolyl, indolyl, isoquinolyl, naphthoimidazolyl, naphthooxazolyl, naphthopyrazolyl, oxadiazolyl, oxazolyl, oxazolopyridyl, phenazinyl, phenoxazolyl, pyrazinyl, pyrazolyl, pyrilyl, pyrazoyltriazyl, pyridyl, pyridinoimidazolyl, pyrrolyl, quinolyl, tetrazolyl, thiadiazolyl, thiazolyl, thiazolopyridinyl, thiazoylimidazolyl, thiopyrylyl, 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, which are identical or different, such as difurylmethyl, 1,1-difurylethyl, dipyrrolylmethyl and 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 comprise from 1 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 include 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 chosen from nitrogen, oxygen, sulfur and selenium; ; an alkyl radical is a C1-C16 hydrocarbon radical, linear or branched, preferably C1-C8; the optionally substituted expression attributed to the alkyl radical, that is to say that said alkyl radical may be substituted by one or more radicals chosen from i) hydroxyl, ii) C 1 -C 4 alkoxy, iii) acylamino, iv) amino optionally substituted by one or two identical or different C 1 -C 4 alkyl radicals, said alkyl radicals being capable of forming, with the nitrogen atom bearing them, a 5- to 7-membered heterocyl, optionally comprising another heteroatom different from or different from nitrogen; v) or a quaternary ammonium group - N + R'R "R" ', M- for which R', R ", R" ', which may be identical or different, represent a hydrogen atom, or a C1-C4 alkyl group or else -N + R'R "R" 'forms a heteroaryl such as imidazolium optionally substituted with a C1-C4 alkyl group, and M- represents the counterion of the corresponding organic, inorganic acid or halide an alkoxy radical is an alkyl-oxy or alkyl-O- radical for which the alkyl radical is a linear or branched C 1 -C 16 hydrocarbon-based radical, preferably C 10 -C 8 alkylthio radical is an alkyl-S-radical; for which the alkyl radical is a hydrocarbon radical, linear or branched C1-C16 preferentially C1-C8, when the alkylthio group is optionally substituted, this implies that the alkyl group is optionally substituted as defined above; the bounds defining 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) alkyl sulfonic acids: Alk-S (0) 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) 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; xiv) triflic acid CF3SO3H and xv) tetrafluoroboric acid HBF4; 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, including C1-C6 alkylsulphonates: Alk-S (O) 2O- such as methylsulphonate or mesylate and ethylsulphonate; iv) arylsulfonates: Ar-S (O) 20-such as benzenesulfonate and toluenesulphonate or tosylate; v) citrate; vi) succinate; (vii) tartrate; viii) lactate; ix) alkyl sulphates: Alk-O-S (O) O- such as 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) triflate; and xvi) borates such as tetrafluoroborate; the solvates represent the hydrates as well as the association with linear or branched C2-C4 linear or branched alcohols such as ethanol, isopropanol and n-propanol.

The fluorescent dyes derived from indoles styryl disulfides or thiols of formula (I) or (II) as defined above are fluorescent dyes ie able to absorb in the UV or visible radiation at an Xabs wavelength of between 250 and 800 nm and capable of reemitting in the visible range at an emission wavelength λm between 400 and 800 nm. Preferably, the fluorescent compounds of formulas (I) or (II) of the invention are dyes capable of absorbing in the visible Xabs between 400 and 800 nm and reemitting in the visible Xem between 400 and 800 nm. More preferably, the dyes of formulas (I) or (II) are fluorescent dyes capable of absorbing at an Xabs of between 420 nm and 550 nm and of reemitting in the visible at an Xem of between 470 and 600 nm. The compounds of the invention of formula (I) or (II) when n and m are 1, contain a function SY which can be in the covalent form -SY or ionic -S- Y + depending on the nature of Y and the pH middle. One particular embodiment relates to fluorescent dyes of indoles styryl disulfides or thiols of formula (I) or (II) with n and m which are 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) or (II) above, Y is a protecting group known to those skilled in the art, for example those described in 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 is a thiol protecting group, Y is selected from the following groups: (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; SO3; M + with M + representing an alkali metal such as sodium or potassium, or else Q- or An'- of the formula (I) or (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 C 1 -C 4) alkyl as methyl, or polyhalo (C 1 -C 4) alkyl as trifluoromethyl; iii) or tricyclic ABC according to: wherein the two rings A, Q 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 heterocycloalkyl represents in particular a saturated or partially saturated 5, 6 or 7 membered monocyclic group comprising from 1 to 4 heteroatoms selected from oxygen, sulfur and nitrogen, such as di / tetrahydrofuranyl, di / tetrahydrothiophenyl, di / tetrahydropyrrolyl, di / tetrahydropyranyl, di / tetra / hexa-hydrothiopyranyl, dihydropyridyl, piperazinyl, piperidinyl, tetramethylpiperidinyl, morpholinyl, di / tetra / hexahydroazepinyl, tetrahydropyrimidinyl these groups being optionally substituted by one or more groups such as (C1-C4) alkyl, oxo or thioxo; or the heterocycle represents the following group: R '; R'9 Nù (R'h N ~ (CR eR f) V f R'd An ,,, in which R '°, R'd, R'e, R'f, R'g and R'h, the same or different represent a hydrogen atom or a group (C1-C4) alkyl, or two groups R'g with R'h, and / or R'e with R "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'd to R'h represent a hydrogen atom, and An '"represents a counterion; isothiouronium;

^ -C (NR '° R'd) = N + R'eR'f; An 'with R'`, R'd, R'e and R'f, identical or different, represent a hydrogen atom or a (C1-C4) alkyl group; preferentially R'd at R'f represent a hydrogen atom; and An "- represents a counterion;

isothiourea;

-C (NR'dR'd) = NR'e; with R ", R'd and Rie are as defined previously;

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

(Di) heteroaryl (C 1 -C 4) alkyl optionally substituted, the heteroaryl group is in particular, cationic or non-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 such as 4-pyridyl or 2-pyridyl-N-oxide, pyrylium, pyridinium, triazinyl, optionally substituted with one or more group such as alkyl particularly methyl preferably (di) heteroaryl (C 1 -C 4) alkyl is (di) heteroarylmethyl or (di) heteroarylethyl;

CR 1 R 2 R 3 with R ', R 2 and R 3, which may be identical or different, representing a halogen atom or a group selected 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, hydroxy; - optionally substituted heteroaryl such as thiophenyl, furanyl, pyrrolyl, pyranyl, pyridyl, optionally substituted with a (C 1 -C 4) alkyl group; - P (Z ') R''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 ( C 1 -C 4) alkoxy, and Z 'represents an oxygen or sulfur atom;

Cyclic sterically hindered; and

optionally substituted alkoxyalkyl such as methoxymethyl (MOM), ethoxyethyl (EOM) and isobutoxymethyl. According to a particular embodiment, protected thiol dyes of formula (I) or (II)

Wherein m and n are 1, have a cationic aromatic 5- or 6-membered monocyclic moiety Y i) containing from 1 to 4 heteroatoms selected 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: R '\

N + R, d in which R '° and R'd, which may be identical or different, represent a hydrogen atom or a (C 1 -C 4) alkyl group; preferentially R '° to R'd represent a (C 1 -C 4) alkyl group such as methyl; and An "'represents a counterion, particularly Y represents a group selected 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 (C1-C4) alkyl groups including methyl. In particular Y represents an alkali metal or a protective group such as: - (C 1 -C 4) alkylcarbonyl such as methylcarbonyl or ethylcarbonyl; arylcarbonyl, such as phenylcarbonyl; - (C 1 -C 4) alkoxycarbonyl; -aryloxycarbonyl; aryl (C 1 -C 4) alkoxycarbonyl; - (di) (C1-C4) (alkyl) aminocarbonyl such as dimethylaminocarbonyl; - (C 1 -C 4) (alkyl) arylaminocarbonyl; optionally substituted aryl such as phenyl; 5- or 6-membered monocyclic heteroaryl such as imidazolyl or pyridyl; 5- to 6-membered cationic monocyclic heteroaryl such as pyrylium, pyridinium, pyrimidinium, pyrazinium, pyridazinium, triazinium, imidazolium; these groups being optionally substituted by one or more, identical or different, (C1-C4) 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 the following formula: Me, Nf Me An-isothiouronium;

-C (NH2) = N + H2; An "isothiourea; -C (NH2) = NH; SO3, M + with M + representing an alkali metal such as sodium or potassium, or else Q- or An 'of the formula (I) or (II) and M + are absent According to one particular embodiment of the invention, the dyes of formula (I) or (II) are disulphide dyes with n = 2 and m = 0. By way of example, mention may be made of the dyes of formula ( l) or (II) following M + -Me Me + N 1 2 3 4 6 + -M e Me SS ~ Me 2 Yr + 7 8 9 10 11 12 Me-N O 13 \ N.Me Me Me S ~ _N \ Me 2 Yr P N + ~ N Me Me 14 N + N My ONN` Me 2 An ~ + Me Me Me H ~, N ~ NSSO MeO 15 Me N ~ NO 1 2 An N NMe / Me Ss "S ~ O OMe IMe 16 * N / \ NOSS Me N Me / + 2 An H ~ S-SAN Ô N \ L.Me N 17 Me H Me 2 An H SS ~ ON * Me 18 \ / N- Me Me, N Me \ N ~ N / A N / A 19 Me-N N + O N.Me \ H ~ S ~ N / Me N / A Me 2 N / A N + N ~ Me MeO 20 N.Me \ Me Me-N O N + MeO \ '~ N \ S \ H ~ S ~ NN Me Me 2 An Ô N + N ~ Me * 21 MeùN ~ \ / \ N Me N + Me ~ SS ~ Me N \ / \, NùMe 4 YEAR 22 + \ / N Me I N + -Me ## STR1 ## Me ~ S ~ S An Me N \ S Me O 26 N + An HO ùN {\ An 27 / N SH Me MeN An O 28 / "NOE Me Me 29 Me N MeS + 30 ## STR2 ## Me Me 31 MeS Me 2An- with An-, identical or different, representing an anionic counterion.

For all the examples of the embodiments of preparation which follow new fluorescent dyes derived from indoles styryl thiols and disulfides of formula (I) and (II), the person skilled in the art can protect beforehand the reactive functions such as the functions ketones then deprotect them for the purposes of the synthesis reaction, by conventional methods known protection / deprotection such as those described in the books cited above TW Greene John Willey & Sons ed., NY, 1981, or P. Kocienski Protecting Groups, P. Kocienski, Thieme, S ed., 2005. Protected thiol dyes of formula (IY) or (II-Y) for which m and n are 1 can be synthesized in two steps. The first step of preparing the unprotected (IH) or (II-H) thiol dye 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 (IY) or (II-Y). 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 fluorescent dyes derived from indoles styryl thiols of formula (IH) or (II-H) by reduction of a fluorescent dye derived from indole styryl with two chromophores , having a disulfide function -SS- such that (IS) or (II-S) and ii) to be protected according to conventional methods said thiol function of (IH) or (II-H) with the reagent 7 Y'R to access fluorescent dyes derived from protected styryl thiol indoles of formula (IY) or (II-Y). The thiol (1-H) or (II-H) compound may also be metallized with an alkaline or alkaline earth metal Met * to yield the thiolate dye of formula (I-Met) or (II-Met).

## STR2 ## wherein Y 'represents a protecting group of thiol function; Met * represents 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 R 'to R3, Het +, L and Q- are as previously defined; Y 'represents a protecting group of thiol function; and R represents a leaving group nucleofuge, such as, for example, mesylate, tosylate, triflate or halide. According to another possibility, a thiol compound protected by a protecting 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 amount , preferably equimolar, of a chromophore or fluorescent derivative derived from indole styryl, and which comprises an electrophilic function to form a covalent bond E; see below the preparation of dyes of formula (I'-Y) and (I'-Y): W-u- (CH2) ,. ## STR2 ## not,

(II'-Y) R with R 'to R3, Het + and Q- are as defined above; m 'and n' are integers inclusive between 1 and 6 with the sum m '+ n' which is an integer between 2 and 6, W-u representing a nucleophilic group; E representing an electrophilic group; and E representing the bond generated after nucleophilic attack on the electrophile. 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: Electrophilic E Nucleophiles ~ u Covalent bonds E Activated esters * Acyl azides ** Amines Amines Carboxamides Carboxamides 24 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 Alcohols Alcohols Ethers Sulfonic acids and their salts Thiols Thioethers Sulfonic acids and their salts Carboxylic acids Esters Sulfonic acids and their salts Alcohols Ethers Anhydrides Alcohols Esters Anhydrides Amines Carboxamides Halides of aryls Thiols Thioethers Halides of 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 Imidic Esters Amines Amidines Isocyanates Amines Urea Isocyanates Alcohols Urethanes Isothiocyanates Amines Thioureas Maleimides Thiols Thioethers Sulphonic Esters Amines Alkylamines Sulphonic Esters Thiols Thioethers Sulphonic Esters Carboxylic Acids Esters Sulfon Esters 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 a fluorescent chromophore derived from indole styryl having an electrophilic acrylate function (-OCO-C = C-) on which an addition reaction is carried out which will generate an L bond.

It is also possible to use a thiol reagent (a): Y'-SH comprising a group Y 'as defined previously, whose nucleophilic function SH can react on the carbon atom of the radical L in alpha of the halogen atom carried by a fluorescent chromophore derived from indole styryl of ai or garlic, to yield protected thiol dye of formula (IY) or (II-Y) as defined above: (R2) p HS-Y '- HHaI Hét' L \ Q-Hal HS-Y '- HHaI Hal (a1) with R' to R3, Het +, L, p and Q- (IY) and (II-Y) are as previously defined, and Hal represents a halogen atom nucleofuge 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 from chromophores j or (a'1) as defined above if the thiouré group is a thioimidazolium (Ji), to lead to the S-protected dye by an imidazolium group (I "-Y) or (II" - Y): (1 "-Y) N - ((/.NTR'd ~ / An - HHaI R'c, SH N --- (

L, NR'd -An-HHaI SH R'cs (a1) with j, (a'1), R ',, R'd, R' to R3, Het +, L, p, Q-, Hal and An - are as defined above.

Another variant may make it possible to access the compound (I "-Y) or (II" -Y) from cyclic thiourea of the imidazoline type (b '), followed by the alkylation of said imidazoline with the aid of R'd-Gp with Gp leaving group such as chloride, bromide, tosylate, mesylate: SH R'd, - HHaI ILü N - (N a R'c \ N

Het-L Alkylation N R'd-Gp QS Rc i iN / \ Het + - L N - \ \ QSI Gp (I "-Y) R'd R 'L'Q (al) - HHaI SH R'd, N ~ N R'uHet 'Alkylation R'd-Gp R'c \ (Ii "-Y) with R' ,, R'd, R 'to R3, Het +, p, L, j, (a'1 ), Q-, Hal and Gp are as previously defined. One variant is to use in place of the halide comprising the fluorescent chromophore derived from indole styryl or (a'1) a chromophore comprising another type of nucleofuge such as tosylate mesylate. According to another possibility, certain protected thiol dyes (I'-Y) or (II'-Y) can be obtained by reacting a protected thiol compound with a compound carrying two carboxylic acid functional groups activated according to conventional methods (for example: example reaction with a carbodiimide or with thionyl chloride). The resulting product is then reacted with a chromophore or fluorescent derivative derived from indole styryl and carrying a nucleophilic function, for example of the primary or secondary amine type, or of the aliphatic alcohol type (R2). P / mou E- (CH2) 7SY '(rY) Het (CH2) m' Lcj Q / Yu E- (CH2), SY '- (CH2) m, (WY) with R1 to R3, Het +, L, p, m ', n', Q-, E, Wu, (I'-Y) and (II'-Y) as defined above Another variant is to use a thiolactone derivative from particular nucleophilic chromophores fc and c'1 to yield derivatives (I'-H) or (II'-H) comprising a linker L interrupted by an amide function as represented by the scheme below: (R2) P L21 NHR Het + ( ## STR2 ## ## STR2 ## ## STR5 ## wherein R 1 to R 3, Het +, Q-, p, n 'and m', as defined above, G 'representing an oxygen atom, sulfur atom. or a group NR 'with R' rep with a hydrogen atom or an alkyl radical, and R representing a hydrogen atom, a C1-C4 alkyl, C1-C4 hydroxyalkyl or a (C1-C4) alkyl radical. The thiolactone derivative is preferably chosen with n '= 3 and G' represents an oxygen atom. Derivatives (I'H) or (II'-H) with free SH function can then be protected or metallized as seen previously.

According to another possibility, the protected thiol dyes of the formula (OH) and (II "- Y) can be obtained by reaction of a compound comprising a thiol group protected by a group Y 'and a group leaving group Gp nucleofuge, such as mesylate, tosylate, triflate or halide with a fluorescent chromophore or (c ") derived from indole styryl. L Gp SY 'Het L. SY' (II "'- Y) / \ Het + L ~ Gp SY' (I ,,, - Y) With R 'to R3, Het +, L, p and Q- are as defined previously, and Het of the reagent represents a group selected from (A '), (B'), (C ') and (D'): R6 RS i4 (A ') (B') (C ') (D') With Z 2, Z 2, Z 3 and Z 4 are as defined above, a or b represent the bond which links the groups (A ') to (D') with the styryl radical of (c ") and Z 'represents an atom of hydrogen or a group activating the nucleophilia of the nitrogen atom of the c-indole. The activating group Z 'is conventionally used by those skilled in the art to activate a nitrogen atom contained in a heteroaryl such as indole Z 'R6 representing an alkali metal such as sodium, lithium, potassium or a magnesium MgX, with X representing a halogen atom such as bromine, may be mentioned as non-exhaustive. use of reagents comprising Li, K, Na, MgX, is carried out once the other functions These reagents were previously protected according to the methods as described in Protective Groups in Organic Synthesis, TW Greene, John Willey & Sons ed., NY, 1981, or Protecting Groups, P. Kocienski, Thieme, 3rd ed., 2005. As an example of compounds containing a protected thiol group (I "'- Y) or (II"' - Y), contains a leaving group nucleofuge R, such as mesylate, tosylate, or triflate which can undergo nucleophilic attack of the amine of the fluorescent chromophore derived from indole styryl or (c "), as follows: where LR fm SY 'Where \ R' SY 'cim - ROH (II"' - Y) According to another possibility, the dyestuffs derived from indole styryl thiols of formula (I) or (II) according to the invention can be obtained by reaction of a compound comprising a thiol group optionally protected by Y 'as defined above and an electrophilic group Lfl or (f ') with a compound derived from indole c omprenant a nucleophilic group. By way of example, an aldehyde or a thioaldehyde may be condensed when G 'represents an oxygen atom or a sulfur with an activated methylene such as the cationic heteroaryl derivative jj or j carrying an activated methyl group connected to Het + via the link a or b groups (A), (B), (C) or (D) to generate an ethylene bond> C = C <. This reaction is commonly referred to as Knoevenagel condensation: ## STR1 ## with R 'to R3, L, Q-, p, (## STR1 ## IY) and (II-Y) are as defined above and to Het + is as defined above except that for j and feLl the methyl group is carried by the link a or b of groups (A), (B), (C) or (D).

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 reagent (II-S) from 2 equivalents of indole derivative 1 optionally activated on the nitrogen atom of the indole by Z ', and an equivalent of disulfide reagent comprising two leaving groups Gp, to yield the derivative carrying two functional groups C (G ') -disulfide 3 which can in turn be condensed with two equivalents of cationic heteroaryl compound Het + with activated methyl group 4 to give to SI. Embedded image wherein R ', R 2, R 3, p, L, Het +, Q- are as previously defined, Z' representing a hydrogen atom or a group activating the nucleophilia of the indole nitrogen atom, Gp representing a nucleofugal leaving group, such as, for example, mesylate, tosylate, triflate alkoxy, or halide. It is also possible to synthesize the reagent (IS) from 2 equivalents of methyl-terminated heteroaryl derivative to give the disulfide derivative which can in turn be condensed with two equivalents of indole derivative bearing two functions ûC (G '). ) - 6 to drive to (IS).

## STR4 ## with Het representing a group selected from (A '), (B'), (C ') and (D '): R 6 (A') (B ') (C') (D ') wherein Z 1, Z 2, Z 3 and Z 4 are as previously defined, a or b represent the bond which links the groups (A') ') to (D') the methyl group of the reagent Het-CH3; R ', R2, R3, p, L and Het + are as previously defined; and Gp- represents the subsequent counter-ion from Gp such as mesylate, tosylate, triflate alk-O-, or halide. The counter ions Gpdes compounds of the invention, above may be replaced by counter-ions Q-other natures from methods known to those skilled in the art including ion exchange resin. Reference may be made to Advanced Organic Chemistry, Reactions, Mechanisms and Structures, J. March, 4th Ed, John Willey & Sons, 1992 or TW Greene Protective Groups in Organic Synthesis, for further details on operating conditions. for the processes mentioned above. The styryl thiol styryl fluorescent dyes formed can be converted to YS protected Y-indol styryl indole dyes by the protection of the HSH thiol using conventional protecting groups. The dyes derived from indole styryl thiols are metallated using also the conventional methods known to those skilled in the art such as those described in Advanced Organic Chemistry, Reactions, Mechanisms and Structures, J. March, 4th Ed, John Willey & Sons, NY, 1992.

The fluorescent dyes derived from protected thiol styryl indoles may be deprotected by conventional routes such as those described in Protective Groups in Organic Synthesis, T. W. Greene, John Willey & Sons ed., NY, 1981; Protecting Groups, P. Kocienski, Thieme, S ed., 2005.

The composition of the invention contains at least one fluorescent dye derived from indole styryl disulfide, thiol or protected thiol of formula (I) or (II). In addition to the presence of at least one 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, for example salts of borohydride, cyanoborohydride, triacetoxyborohydride, trimethoxyborohydride: sodium, lithium, potassium, calcium salts, quaternary ammoniums (tetramethylammonium, tetraethylammonium, tetra-n-butylammonium). benzyltriethylammonium); catechol borane. The dye composition useful in the invention generally contains an amount of dye of formula (I) or (II) 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, mention may be made of para-phenylenediamines, bisphenylalkylenediamines, para-aminophenols, bis-para-aminophenols, ortho-aminophenols, heterocyclic bases and their addition salts. Among these couplers, it is possible to mention 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 dyeing composition, preferably between 0.005 and 60/0. 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-C4, such as ethanol and isopropanol; polyols and polyol ethers such as 2-butoxyethanol, propylene glycol, propylene glycol monomethyl ether, diethylene glycol monoethyl ether and monomethyl ether, as well as aromatic alcohols such as benzyl alcohol or phenoxyethanol, and mixtures thereof.

The solvents when present are 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. 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): RR / az 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; Raii Ra2i Rai and Ra4i, which are 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. The subject of the invention is also a method for dyeing keratinous substances, in particular keratinous fibers, more particularly dark hair, consisting of applying to them a dyeing composition comprising, in a cosmetic medium, at least one fluorescent dye derived from indole styryl disulfide or thiol, chosen from the fluorescent dyes of formulas (I) and (II) as defined above. According to a particular embodiment in the process of the invention, a reducing agent may be applied in pre-treatment before the application of the composition containing at least one fluorescent dye derived from indole styryl of formula (I) or (II). This pretreatment may be of short duration, especially from 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 derived from indole styryl of formula (I) or (II) and also contains at least one reducing agent as defined above. This composition is then applied to the hair. When the fluorescent dye derived from indole styryl thiol of formula (I) or (II) for which m and n are equal to 1 comprises a group Y protecting the thiol function, the method of the invention may be preceded by a step of deprotection aimed at restoring 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 pH> 9 phenyl, monocyclic 5-, 6- or 7-membered heteroaryl pH> 9 such as oxazolium; 8 to 11-membered bicyclic heteroaryl such as pH> 9 as benzoimidazolium, or benzoxazolium The deprotection step can also be carried out during 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 fluorescent dye derived from indole styryl of formula (I) or (II) at the time of use. According to another method, the composition comprising at least one fluorescent dye derived from indole styryl of formula (I) or (II) also contains at least one reducing agent as defined above. This composition is then applied to the hair. According to another variant, the reducing agent is applied in post-treatment, after the application of the composition containing at least one fluorescent dye derived from indole styryl of formula (I) or (II). The duration of the post-treatment with the reducing agent may be short, for example from 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 derived from indole styryl 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 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 duration of the possible post-treatment with an oxidizing agent is between 1 second to 10 minutes.

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" for dyeing in which a first compartment contains a dye composition comprising at least one fluorescent dye derived from indole styryl of formula (I) or (II) and a second compartment contains a reducing agent capable of reducing the disulfide functions of the keratin materials and / or the fluorescent dye derived from indole styryl disulfide of formula (I) or (II). 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 derived from indole styryl of formula (I) or (II); a second compartment contains a reducing agent capable of reducing the disulfide bond of the keratin materials and / or the indole styryl disulfide-derived fluorescent dye of formula (I) or (II); a third compartment contains an oxidizing agent. Alternatively, the dyeing device contains a first compartment containing a dye composition which comprises at least one fluorescent dye derived from indole styryl thiol protected of formula (I) or (II) with m and n equal to 1, a second compartment containing an agent capable of deprotecting the protected thiol to release the thiol, and possibly a third compartment comprising an oxidizing agent. 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 dyes of the examples below have been fully characterized by standard spectroscopic and spectrometric methods.

EXAMPLES EXAMPLES OF SYNTHESIS Example 1 Synthesis of Di-Methane-sulphonate del, 1 '- (disulfanediyldiethane-2,1-diyl) bis {4- [2- (1-methyl-1H-indol-3-yl) vinyl] pyridinium } [1] Me NN Synthesis scheme: HO ~~ iS • S ~ iOH O AcOEt / TEA 2 ùS'cl O

## STR2 ## Procedure 1: Synthesis of dimethanesulfonate disulfanediyldiethane-2,1-diol 5 10 g of 2,2'-dithiodiethanol and 14.44 g of triethylamine (TEA) are diluted in 100 mL of ethyl acetate (AcOEt). At 0 ° C., 16.35 g of methanesulfonyl chloride diluted in 35 ml of ethyl acetate are added dropwise to the reaction medium with rapid stirring. 7.22 g of triethylamine are introduced, stirring is continued at ambient temperature for 4 h 30 min. 8.2 g of methanesulfonyl chloride are added dropwise at 15 ° C., and the stirring is then maintained at ambient temperature for 17 hours. The precipitate is filtered and washed with 3 times 50 ml of ethyl acetate. The organic phases are extracted with 100 ml of ice water, 100 ml of water, 3 times 50 ml of a saturated solution of sodium hydrogencarbonate (NaHCO 3), twice with 20 ml of saturated sodium chloride solution. (NaCl), then dried over anhydrous sodium sulfate (Na 2 SO 4). The ethyl acetate is evaporated, and 17.49 g of pale yellow translucent oil are collected. The analyzes show that the product is compliant and pure.

Step 2: Synthesis of 1,1 '- (disulfanediyldiethane-2,1-diyl) bis (4-methylpyridinium) Dimethhanesulfonate

3.51 g of 4 picoline and 5 g of disulfanediyldiethane-2,1-diyl dimethanesulphonate are diluted in 5 ml of N-methylpyrrolidinone (NMP) and then heated at 80 ° C. with stirring for 2 h. Stirring is maintained at room temperature for 17 hours. The reaction medium is supplemented with 50 ml of ethyl acetate, then filtered, washed with 3 times 100 ml of ethyl acetate, and dried under vacuum under P2O5. 7.29 g of brown powder are collected. The analyzes indicate that the product is compliant and pure.

Step 3: Synthesis of dimethanesulfonate del, 1 '- (disulfanediyldiethane-2,1-diyl) bis {4- [2- (1-methyl-1H-indol-3-yl) vinyl] pyridinium} [1] 1.22 g 1-methyl-1H-indole-3-carbaldehyde, 8 mL of isopropanol, and 630 L of pyrrolidine are mixed with stirring for 10 minutes. 440 L of acetic acid are added and the mixture is stirred at room temperature for 20 minutes. 1.91 g of 1,1 '- (disulfanediyldiethane-2,1-diyl) bis (4-methylpyridinium) dimethanesulfonate in 7 ml of isopropanol are added to the reaction mixture which is stirred for 3 days at room temperature. The reaction mixture is poured into 55 ml of ethyl acetate, it is filtered and washed with 50 ml of ethyl acetate and then dried. 2.4 g of dark green powder are collected. The analyzes indicate that the product is compliant and pure. 1H NMR (400 MHz, MeOH-d4) 2.71 (s, 6H), 3.31 (t, 4H), 3.75 (s, 6H), 4.64 (t, 4H), 7.02 (d, 2H), 7.28 (2 t, 4H), 7.38 (d, 2H), 7.67 (s, 2H), 7.87 (d, 4H), 7.96 (d, 2H) 7.98 (d, 2H), 8.45 ( d, 4H).

COLORING EXAMPLE Staining method - compound [1] Preparation of composition A Disulfide dye [1] 5x10.4 mol% 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 100g Preparation of a composition B Thioglycolic acid 1M Sodium hydroxide qsp pH 8.5 Demineralized water qs 100g At the time of use, the compositions A (9 ml) and B (1 ml) are mixed, then applies the formulas on strands of natural white hair with 90% of white (BN), permed white (BP) or chestnut of pitch 4 (HT4). The exposure time is 20 minutes at room temperature (RT). After rinsing with running water a fixative (Dulcia Vital II) diluted by 10 with water is applied for 5 minutes at RT. After rinsing with running water and shampooing the locks are air dried. In shampoos, there is no visible bleeding, shampoo foam and rinsing water are not colored. (i) Optical brightening on dark wicks: A lightening of the hair thus treated is observed with dye 1: the wicks of pitch 4 became visually brighter than untreated control wicks. The lightening performance of the compositions according to the invention and their persistence with respect to successive shampoos were also expressed as a function of the reflectance of the hair. These reflectances are compared to the reflectance of a lock of untreated HT4 pitch hair. The reflectance is measured using a KONIKAMINOLTA 8, CM 3600d spectrophotocolorimeter and after irradiation of the hair with visible light in the wavelength range of 400 to 700 nanometers.

It is found that the reflectance of a lock of hair treated with a composition according to the invention comprising the compound [1] is greater than that of the untreated hair. The treated locks therefore appear clearer. 41 7 6- 5- 4 3- 2 -0ù Dark hair HT4 ùaùColourant 1 o O o o o o o o D o ~ oO # O 3 3 rx rx hhh 0 Hair coloring white BN and BP: Natural white hair ( BN) and permanent white (BP) are bright orange colored. L * (D65) a * (D65) b * (D65) Natural whites (BN) 60.45 1.49 16.08 Dye 1 52.92 25.54 60.72 Permeated whites (BP) 60.93 1, 84 17.02 Color 1 51.59 22.74 59.08 Dark hair (HT4) 20 2.69 3.02 Color 1 21.67 2.47 6.93 ii) Remanence with respect to successive shampooinqs: The treated locks 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. 10

Results: Visual observations During shampoos, there is no visible bleeding, shampoo foam and rinsing water are not colored. The color observed and the lightening effect remain visible on the hair of tone 4 thus treated. Iii) Light-fastness: A light-fastness study was carried out by exposure to Xenotest on strands of natural white hair (BN) and white permed (BP) stained beforehand according to the coloring process, during 3 hours. The exposure conditions are 90W / m2, 60% relative humidity and with a chamber temperature of 35 ° C.

Results: Visual Observations After 3 hours of exposure to light, the natural white and permed white hair colored with the dye of the invention are almost unchanged. The results show that the dyes made with dye 1 of the invention have a very satisfactory light fastness. 42

Claims (7)

1. Fluorescent dye of formula (I) or (II): Het + Si (Q) n, nn (I) (II) their organic or inorganic acid salts, optical isomers, geometric isomers, and solvates such as hydrates ; formulas (I) or (II) in which: n represents 1 or 2; m represents 0 or 1; p represents an integer inclusive between 1 and 4; - R 'and R3, identical or different, represent a hydrogen atom or an optionally substituted (C1-C6) alkyl group; R2, which may be identical or different, represent a hydrogen, halogen atom, a (C1-C6) (alkyl) amino, cyano, hydroxy, (poly) halo (C1-C6) alkyl group such as trifluoromethyl; , (C1-C4) acyl) (alkyl) amino, (C1-C6) alkoxy, (C1-C6) alkylthio, (poly) hydroxy (C2-C6) alkoxy, (C1-C6) alkylcarbonyloxy, (C1-C6) alkoxycarbonyl, ( C1-C6) alkylcarbonylamino, carbamoyl, (C1-C6) alkylsulfonyl (C1-C4) (alkyl) amino, (C1-C4) (di) (alkyl) aminosulfonyl, carboxy, or optionally substituted (C1-C16) alkyl group by a group selected from (C1-C6) alkoxy, hydroxy; or when p is an integer greater than or equal to 2, two radicals R2 contiguous with the carbon atoms which carry them in position C4-05, or C5-C6 or C6-C ', together form a benzo ring; -Het + represents a cationic heteroaryl radical chosen from those of formulas (A), (B), (C) and (D) following: \ `//. Wherein R 6 1 / Z 3 1 r 1 (A) (B) (C) (D) formulas (A), (B), (C) and (D) in which: - is the nitrogen atom N contained in the 5-membered ring of the formula (A) is connected to the radical L of the formula (I), ie the nitrogen atom Ni is connected to the radical R 1 of the formula (II) and then the bond the same 5-membered ring is connected to the styryl group in the cis or trans position of the styryl double bond; or to the nitrogen atom N, of the 6-membered ring of the formula (B), (C) or (D) ) is connected to the radical L of the formula (I), ie the nitrogen atom N, is connected to the radical R1 of the formula (II) and then the bond b of the same 6-membered ring is connected to the styryl in position cis or trans of the styryl double bond; Z 1 represents an oxygen atom, sulfur atom, selenium atom or an NR 7 radical; Z 2 represents a nitrogen atom or a CR 8 radical; Z 3 represents a nitrogen atom or a nitrogen atom; CR9 radical; Z4 represents a nitrogen atom or a CR10 radical; that the two radicals Z3 and Z4 can not simultaneously represent a nitrogen atom; and when Z1 represents an oxygen, sulfur, or selenium atom then Z2 represents a CR8 radical; - R5, R6, R8, R9 and R10, which may be identical or different, represent a hydrogen atom or a group chosen from: (C 1 -C 6) alkyl, (C 1 -C 6) alkoxy, (C 1 -C 6) alkylthio , carboxy, cyano, (di) (C 1 -C 6) (alkyl) amino, hydroxy, polyhydroxy (C, -20 alkylsulfonyl (C 1 -C 4) (alkyl) amino and (di) (C 1 -C 4) (alkyl) aminosulphonyl or two contiguous radicals R4 with R8 or R5 with R6 and / or R6 with R9 and / or R9 with R10 together with the carbon atoms which carry them a benzo ring form an optionally substituted fused heterocycle or a fused heteroaryl optionally substituted, R 7 represents a hydrogen atom or an optionally substituted (C 1 -C 6) alkyl group, Q represents an anionic counterion, L represents an optionally substituted C1-C20 bivalent hydrocarbon chain, optionally interrupted i) by one or more divalent groups or combinations thereof selected from: ùNR-; -N + RR ° -, An-; -O-, -S-, -C (O) -, -S (O) 2- with R, R °, identical or different, selected from hydrogen, C1-4 alkyl, hydroxyalkyl, aminoalkyl and An - representing an anionic counterion or ii) a cationic heterocycle or cationic heteroaryl Het, +, An-, with An- is an anionic counterion and Het, + representing a heterocycle comprising from 5 to 10 members, C6) alkyl , (C 1 -C 6) polyhydroxyalkoxy, (C 1 -C 6) polyhaloalkyl such as trifluoromethyl, (C 1 -C 4) acyl (alkyl) amino, (C 1 -C 6) alkylcarbonyloxy, (C 1 -C 6) ) alkoxycarbonyl, (C 1 -C 6) alkylcarbonylamino, carbamoyl, (C 1 -C 6) -saturated or unsaturated, or a heteroaryl comprising 5 to 10 members; ; Y represents: i) a hydrogen atom; ii) an alkali metal; iii) an alkaline earth metal; iv) an ammonium group: N + RaRRRYRs, An "- or a phosphonium group: P + RaRRRYRs, An" - with Ra, RR, R7 and R8, which may be identical or different, representing a hydrogen atom or a group (C, -C4) alkyl and An "- an anionic counterion, or v) a thiol protecting group, it being understood that when n is 2 then m is zero, and when n is 1 then m is 1. 2. Fluorescent dye of formula (I) or (II) according to the preceding claim wherein m and n are 1, and Y represents a hydrogen atom, or an alkali metal. 3. Fluorescent dye of formula (I) or (II) according to claim 1 wherein m and n are 1, and Y represents a protective group. 4. Fluorescent dye of formula (I) or (II) according to the preceding claim wherein Y represents a protective group 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; aryloxycarbonyl; aryl (C 1 -C 4) alkoxycarbonyl; ^ (di) (C1-C4) (alkyl) aminocarbonyl; (C 1 -C 4) (alkyl) arylaminocarbonyl; carboxy; SO3; M + with M + representing an alkali metal or else An-or An 'of the formula (I) and M + are absent; optionally substituted aryl; optionally substituted heteroaryl; optionally substituted heterocycloalkyl, optionally cationic, the following group: R'9 R'h (CR'eR'f), R'4 An "'in which R' °, R'd, R'e, R'f , R'9 and R'h, identical or different, represent a hydrogen atom or a (C1-C4) alkyl group, or else two R'9 groups with R'h, and / or R'e with R'f form an oxo or thioxo group, or else R'9 with R'e together form a cycloalkyl, and v represents an integer inclusive of between 1 and 3, preferably R "to R'h represent a hydrogen atom; and An "- represents a counterion; isothiouronium; -C (NR" R'd) = N + R'eR'f; With R ', R'd, R'e and R'f, identical or different, represent a hydrogen atom or a (C 1 -C 4) alkyl group and An "- is as defined previously; • -C (NR '° R'd) = NR'e; with R ", R'd and R'e are as defined previously; optionally substituted di (aryl) aryl (C 1 -C 4) alkyl; (di) heteroaryl (C1-C4) alkyl optionally substituted; Wherein R 1, R 2 and R 3 are identical or different, representing a halogen atom or a group selected from: - (C 1 -C 4) alkyl; - (C 1 -C 4) alkoxy; optionally substituted aryl; - optionally substituted heteroaryl -P (Z ') R''R'2R'3 with R' ', and R'2 identical or different represent a hydroxyl group, (Cf-C4) alkoxy or alkyl, R'3 represents a grouping hydroxy or (Cf-C4) alkoxy, and Z 'represents an oxygen or sulfur atom; Cyclic sterically hindered; and • optionally substituted alkoxyalkyl. 5. Fluorescent dye of formula (I) or (II) according to any one of the preceding claims wherein Y represents an alkali metal or a protecting group selected from: (C 1 -C 4) alkylcarbonyl; arylcarbonyl; 25- (C 1 -C 4) alkoxycarbonyl; aryloxycarbonyl; -aryl (C 1 -C 4) alkoxycarbonyl; - (di) (C1-C4) (alkyl) aminocarbonyl; - (C 1 -C 4) (alkyl) arylaminocarbonyl; optionally substituted aryl; 5- or 6-membered cationic monocyclic heteroaryl optionally substituted by one or more, identical or different, (C 1 -C 4) alkyl groups; 8 to 11-membered cationic bicyclic heteroaryl optionally substituted with one or more identical or different (C 1 -C 4) alkyl groups; cationic heterocycle of the following formula: Me N Me A - isothiouronium; -C (NH2) = N + H2; An "'-; with An"' - representing an anionic counterion; Isothiourea; -C (NH2) = NH; and - S03; M + with M + representing an alkali metal or else An "or An'- of the formula (I) and M + are absent. 6. Fluorescent disulfide dye of formula (I) or (II) according to any one of the preceding claims wherein n = 2 and m = 0. 7 "Fluorescent dye of formula (I) or (II) according to any one of the preceding claims chosen from the following dyes: 1 SS 2 An + + -Me Me N 2 3 4 6 7 8 + û Me Me ss 2 Year N 0 N me H Me N Me 2 An SS 0 9 10 11 12 13 14Me MeO 15 N ~ / NO Me S ~ ~ = S Me NH OMe ûN + 2 Year H \ _5 SAN O Me ~ Me Me S 16 N ~ + S \ - Me \ NO Me N / H ~ tiN {-N 2An SSO MeùN {H Me N + ûMe 17 Ô 2 Year H ~ S_S ~ NN Me N ù 18 MeN Me N + N \ Me 2 YE S_S ~ N N • Me ## EQU1 ## 26 ç An An An An An 27 {{{{{{{{{{{{{\ \ {{{{{• • • • • • • • • • • • • • • • • • • • • Me 31 With a, identical or different, representing an anionic counterion 8. A dyeing composition comprising, in a suitable cosmetic medium, a fluorescent dye of formula (I) or (II) as defined in a US Pat. any of claims 1 7. Dyeing composition according to the preceding claim 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; o and at least one reducing agent. 10. Dyeing composition according to the preceding claim wherein the agédéducteur is selected 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 and catecholborane salts. 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 method for dyeing keratin materials, wherein a suitable dye composition comprising at least one fluorescent dye of formula (I) or (II) according to any one of claims 8 to 11 is applied to the materials. according to the preceding claim wherein when the fluorescent dye of formula (I) or (II) comprises a protective Y group, the application is preceded by a deprotection step. 14. A process for dyeing keratinous materials according to claim 12 or 13, characterized in that the keratin materials are dark keratinous fibers having a pitch of less than or equal to 6. 15. Process according to any one of the preceding claims. Claims 12 to 14, wherein the reducing agent is applied before or after the application of the fluorescent dye of formula (I) or (II) as defined in claims 1 to 7. 16. A process according to any of claims 12 at 15, wherein the composition comprises an oxidizing agent. 17. A method according to any one of claims 12 to 16 comprising a further step of applying an oxidizing agent to the keratin fibers. 18. Multi-compartment device in which a first compartment contains a dye composition comprising a fluorescent dye of formula (I) or (II) 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 of formula (I) or (II) 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 6.10