FR2912143A1 - Fluorescent dyes for lightening dark hair, comprise new quat. pyridinium salts substituted with a chain containing a vinyl group, a benzene ring, an imine group, linking groups and a terminal protected thiol group - Google Patents

Abstract

Fluorescent dyes comprising a quat. pyridinium salt substituted with a chain containing a vinyl group, a benzene or naphthalene ring, an imine group, various linking groups and a terminal protected thiol group are new. Fluorescent protected thiol dyes of formula (I) are new (and their salts, optical or geometrical isomers and solvates such as hydrates). R aaryl-(1-4C alkyl) or 1-6C alkyl (optionally substituted with OH or amino), 1-4C alkylamino or dialkylamino (optionally with the two alkyl groups and the linking nitrogen forming a 5- to 7-membered ring which may also conatin another hetero-atom); R bH, aryl-(1-4C alkyl) or optionally substituted 1-6C alkyl; R g, R' gH, amino, 1-4C alkylamino, dialkylamino, alkoxy, alkylcarbonyloxy, alkoxycarbonyl, alkylcarbonylamino or alkylsulfonylamino, trifluoromethyl, acylamino, or 1-3C alkyl; R h, R' hH, halogen, 1-4C alkyl, dialkylamino, alkylcarbonylamino or alkylsulfonylamino, or acylamino; or two groups : R g and R' g and/or R h and R' h on two adjacent carbons may form a benzene, indene, fused heterocycloalkyl or fused heteroaryl ring (all optionally substituted with halogen, amino, 1-4C alkylamino etc. (as for R g), CN, carboxy, OH, trifluoromethyl, acylamino, 1-4C alkoxy, 2-4C (poly)hydroxyalkoxy, acylamino, carbamoyl, aminosulfonyl or 1-16C alkyl (optionally substituted with OH, CN, COOH, amino, 1-12C alkoxy or 1-4C (di)alkylamino, or two such alkyl groups plus the nitrogen may form a ring as above)); R i, R' iH or 1-4C alkyl; R 1-R 4H or 1-4C alkyl; dotted lines (present or absent) : a fused benzene ring; T acovalent bond, -NR- or -NRR 0+>-, or a heterocycloalkyl or heteroaryl group (cationic or not); if T a is a covalent bond, Y : optionally substituted aryl, heteroaryl, heterocycloalkyl, (di)arylalkyl or (di)heteroarylalkyl, or a sterically-hindered cyclic group; if T a is one of the other types of groups, Y : H, alkali or alkaline earth metal, optionally substituted ammonium or phosphonium, or a protective group for thiol functions; R, R 0>H, 1-4C alkyl, 1-4C hydroxyalkyl or aryl-(1-4C alkyl); m, n : 0-6; (m+n) : 1-10; M : anion. If (I) contains other cationic parts, these will be associated with one or more anions so as to achieve electrical neutrality. Independent claims are also included for (1) coloring compositions containing (I) in a cosmetically-acceptable medium (2) coloring compositions containing (I) and reducing agent(s) in a cosmetically-acceptable medium (3) a method for coloring keratinous materials by treatment with compositions containing (I), possibly in presence of a reducing agent capable of reducing disulfide bonds in these materials (4) a multi-compartment device in which one compartment contains a composition containing (I) and a second compartment contains a reducing agent as above. [Image].

Description

DYEING COMPOSITION COMPRISING THIOL FLUORESCENT COLOR, CHARGING

  The invention relates to the dyeing of keratinous fibers using thiol fluorescent dyes with external cationic charge. EXAMINATION OF THE KERATINIC MATERIALS

  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. The colorations 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 bleaching system has the drawback of degrading keratin materials, in particular keratinous fibers, especially human fibers such as the hair, and of 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 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.

  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. 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 externally cationic charge-bearing thiol pyridinium dye chosen from the following dyes of formula (I): R (I): T.sub.2 (CR.sub.1 R.sub.2) m - (CR.sub.3 R.sub.4), Rb their organic or inorganic acid salts, optical isomers, geometric isomers, and solvates such as hydrates;

  formula (I) in which: Ra represents an aryl (C1-C4) alkyl group or a (C1-C6) alkyl group optionally substituted by a hydroxy or amino group, C1-C4 alkylamino, (C1-C4) dialkylamino, said alkyl radicals 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 from nitrogen; preferably Ra represents a (C1-C3) alkyl group optionally substituted by a hydroxyl group, or a benzyl group;

  Rb represents a hydrogen atom, an aryl (C 1 -C 4) alkyl group or an optionally substituted (C 1 -C 6) alkyl group; in particular Rb represents a hydrogen atom or a (C1-C3) alkyl or benzyl group;

  Rg and R'g, which are identical or different, represent a hydrogen atom, an amino group, (C1-C4) alkylamino group, (C1-C4) dialkylamino group, trifluoromethyl group, an acylamino group or (C1-C4) alkoxy group ( C1-C4) alkylcarbonyloxy, (CIC4) alkoxycarbonyl, (C1-C4) alkylcarbonylamino, (C1-C4) alkylsulfonylamino, a (C1-C3) alkyl radical;

  Rh and R'h, which may be identical or different, represent a hydrogen atom, a halogen atom, a (C 1 -C 4) -alkylamino group, a (C 1 -C 4) alkylcarbonylamino group or an acylamino group, C4) alkylsulfonylamino, or a (C1-C4) alkyl radical; particularly Rh and R'h represent a hydrogen atom, or a (C 1 -C 3) alkyl group;

  Or two groups Rg and R'g; Rh and R'h carried by two adjacent carbon atoms together form a benzo, indeno ring, a fused heterocycloalkyl or fused heteroaryl group; the benzo, indeno, heterocycloalkyl or heteroaryl ring being optionally substituted by a halogen atom, an amino group, (C 1 -C 4) alkylamino, (C 1 -C 4) dialkylamino, cyano, carboxy, hydroxy, trifluoromethyl, acylamino, C 1 -C 4 alkoxy, C 2 -C 4 (poly) hydroxyalkoxy, (C 1 -C 4) alkylcarbonyloxy (C 1 -C 4) alkoxycarbonyl, (C 1 -C 4) alkylcarbonylamino, acylamino, carbamoyl, (C 1 -C 4) alkylsulfonyl- amino, an aminosulfonyl radical, or a (C 1 -C 16) alkyl radical optionally substituted with a group chosen from (C 1 -C 12) alkoxy, hydroxy, cyano, carboxy, amino, (C 1 -C 4) alkylamino and (C, -C4) dialkylamino, or the two alkyl radicals carried by the nitrogen atom of the amino group form a heterocycle comprising from 5 to 7 members and optionally comprising another heteroatom identical to or different from that of the nitrogen atom; especially Rg and R'g together form a benzo group;

  - R; and R ', which may be identical or different, represent a hydrogen atom or a (C 1 -C 4) alkyl group; especially a hydrogen atom;

  - R ,, R2, R3, R4, identical or different, represent a hydrogen atom or a group (C1-C4) alkyl particularly R ,, R2, R3 and R4 represent a hydrogen atom; - present or absent, represents a benzo group; Ta is: i) a covalent bond a; ii) or a radical selected from R, R, R + R, R, R, R, R, R, R, R, R, R, R, R, R, R, R, R, R, R, R, R, R, R, R, R or R, C4; or an aryl (C1-C4) alkyl, iii) is a heterocycloalkyl or heteroaryl, cationic or non-cationic, preferably monocyclic, containing one or two heteroatoms, particularly two nitrogen atoms, and comprising in particular 5 to 7 members such as imidazolium; or a saturated 6-membered heterocycle: with A representing an oxygen atom, sulfur atom or a CH 2 group, NR, where R is as defined above and An- represents anionic counterion; preferentially Ta represents a covalent bond;

  m and n, which are identical or different, represent an integer inclusive between 0 and 6 with m + n represents an integer inclusive of between 1 and 10; particularly the sum m + n is an integer inclusive between 2 and 4; preferentially when Ta is a covalent bond a, m + n is an integer equal to 2; when Ta represents a covalent bond a, Y represents a group chosen from: o optionally substituted aryl such as phenyl, dibenzosuberyl, or 1,3,5-cycloheptatrienyl, o optionally substituted heteroaryl, especially aromatic, cationic or non-cationic, comprising from 1 at 4 heteroatoms such as: i) 5-, 6- or 7-membered monocyclic heteroaryl 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 heteroaryl such as indolyl, indolinium, benzoimidazolyl, benzoimidazolium, benzoxazolyl, benzoxazolium, dihydrobenzoxazolinyl, benzothiazolyl, benzothiazolium, pyridoimidazolyl, pyridoimidazolium, thienocycloheptadienyl, these mono or bicyclic groups being optionally substituted with one or more groups such as C1-C4) alkyl as methyl, or polyhalo (C1-C4) alkyl as trifluoromethyl; iii) or tricyclic heteroaryl ABC according to: 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 heterocycloalkyl represents in particular a saturated or partially saturated 5, 6 or 7 membered monocyclic group comprising 1 to 4 heteroatoms selected 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 (C1-C4) alkyl, oxo or thioxo; or the heterocycle represents the following group: ## STR2 ## wherein R ', R'd, R'e, R'f , R'g and R '", which may be identical or different, represent a hydrogen atom or an alkyl group, or else two R'g groups with R'", and / or R'e with R'f form an oxo group or thioxo, or R'g with R'e together form a cycloalkyl, and v represents an integer inclusive between 1 and 3, preferably R 'to R' "represent a hydrogen atom, and An represents a counter-ion anionic; optionally substituted o (di) arylalkyl such as 9-anthracenylmethyl, phenylmethyl or diphenylmethyl, optionally substituted with one or more groups chosen in particular from (C1-C4) alkyl, (C1-C4) alkoxy such as methoxy, hydroxy, (C1- C4) alkylcarbonyl, (di) (C1-C4) (alkyl) amino such as dimethylamino; o (di) heteroarylalkyl optionally substituted, the heteroaryl group is especially, cationic or not, m onocyclic, 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 groups such as (C1-C4) alkyl particularly methyl, advantageously (di) heteroarylalkyl is (di) heteroarylmethyl or (di) heteroarylethyl; cyclic sterically hindered such as the adamantyl group; when Ta represents ùN (R) ù, ùN + (R) (R) ù, a heterocycloalkyl or heteroaryl radical, cationic or non-cationic; Y represents a group chosen from i) a hydrogen atom; ii) an alkali metal; iii) an alkaline earth metal; iv) an ammonium group: N + RaRRR7Rs or a phosphonium group: P + RaRRR7Rs with Ra, RR, R7 and R5, which may be identical or different, representing a hydrogen atom or a (C 1 -C 4) alkyl group; or v) a thiol protecting group; and - M 'representing an anionic counterion, it being understood that when the compound of formula (I) contains other cationic parts, it is associated with one or more anionic counter-ions making it possible to achieve the electroneutrality of the formula (I).

  Another subject of the invention is a dye composition comprising, in a suitable cosmetic medium, at least one thiol fluorescent dye chosen from the dyes of formula (I) as defined above, and optionally a reducing agent.

  The invention also relates to new thiol fluorescent dyes of formula (I) 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 keratinous substances, in particular human keratinous fibers, in particular the hair, without degrading said material, which is persistent with regard 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 keratinous fibers, particularly dark keratinous fibers and more particularly dark hair.

  For the purposes of the invention, dark keratin material is understood to mean that which has an L * luminescence in the C.I.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 in pitch before and after application of the compound of formula (I). 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 treatment 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.

  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 range of wavelengths from 500 to 700 nanoameters greater 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 "upper" 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 may be substituted with at least one substituent carried by a carbon atom, chosen from: • a C1-C16 alkyl radical preferably C1-C6; 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; 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 or an acylamino group (-NR-COR ') in wherein the radical R is a hydrogen atom, a C1-C4 alkyl radical optionally bearing at least one hydroxyl group and the radical R 'is a C1-C2 alkyl radical; A carbamoyl 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 carrying at least one hydroxyl group; An alkylsulphonylamino radical (R'SO2-NR-) in which the radical R represents a hydrogen atom, a C1-C4 alkyl radical optionally bearing at least one hydroxyl group and the radical R 'represents an alkyl radical; C1-C4; An aminosulfonyl radical ((R) 2 N-SO 2 -) in which the radicals R, 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 radical; carboxylic acid in acid or salified form (preferably with an alkali metal or an ammonium, substituted or not); • 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 portion of a non-aromatic radical may be substituted by at least one substituent carried by a carbon atom selected from the groups: • hydroxy, • C 1 -C 4 alkyl, • C 1 -C 4 alkoxy, • (poly ) C2-C4 hydroxyalkoxy; • C1-C2 alkylthio radical; RCO-NR'- in which the radical R 'is a hydrogen atom or a C 1 -C 4 alkyl radical and the radical R is a hydrogen atom, a C 1 -C 2 alkyl radical or a substituted amino group; identical or different alkyl groups C1-C4 said alkyl radicals being able to form with the nitrogen atom to which they are attached, a heterocycle comprising 5 to 7 members, optionally substituted saturated or unsaturated optionally comprising at least one other heteroatom different or not nitrogen; RCO-O- in which the radical R is a C 1 -C 4 alkyl radical, amino substituted with two identical or different C 1 -C 4 alkyl groups, said alkyl radicals being able to form, 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 non-nitrogen heteroatom; RO-CO- in which the radical R is a C 1 -C 4 alkyl radical, amino substituted with two identical or different C 1 -C 4 alkyl groups, said alkyl radicals being able to form, 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 non-nitrogen heteroatom; 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 at least one of which cycle is aromatic; preferably heteroaryl is selected from acridinyl, benzimidazolyl, benzobistriazolyl, benzopyrazolyl, benzopyridazinyle, benzoquinolyl, benzothiazolyl, benzotriazolyl, benzoxazolyl, pyridinyl, tetrazolyl, di hydrothiazolyle, 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, 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 cycloalkyl radical, mono- or polycyclic, condensed or otherwise, containing from 5 to 22 carbon atoms, which can 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, mesytyls such as 1,3,5-trimethylphenyl, 1,3,5-triterbutylphenyl, 1,3,5-isobutylphenyl, 1,3,5-trimethylsilylphenyl and adamantyl; a heterocyclic radical is a non-aromatic mono or polycyclic radical, condensed or otherwise, 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 carrying them, a 5- to 7-membered heterocycle optionally comprising another heteroatom different from or different from nitrogen; an alkoxy radical is an alkyl-oxy or alkyl-O- radical for which the alkyl radical is a hydrocarbon radical, linear or branched, C1-C16, preferably C1-C8; an alkylthio radical is an alkyl-S- radical for which the alkyl radical is a hydrocarbon radical, linear or branched, C1-C16 preferably C1-C8; 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) alkylsulphonic acids: Alk- S (O) 2OH such as methylsulfonic acid and ethylsulfonic acid; v) arylsulfonic acids: Ar-S (O) 2OH such as benzene sulfonic acid and toluene sulfonic acid; (vi) citric acid; vii) succinic acid; viii) tartaric acid; ix) lactic acid, x) 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 H3PO4; xiii) acetic acid CH30OOH; 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) alkylsulfites: Alk-O-S (O) O- such as methysulfite and ethylsulfite; x) arylsulfites: Ar-O-S (O) O- such as benzenesulphite and toluenesulphite; xi) alkylsulfates: Alk-O-S (O) 2O- such as methyl sulfate and ethylsulfate; xii) arylsulfates: Ar-O-S (O) 2O-, xiii) phosphate; (xiv) acetate; xv) triflate; and xvi) borates such as tetrafluoroborate The thiol fluorescent dyes of formula (I) are compounds capable of absorbing in 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 Xem between 400 and 800 nm. Preferably, the thiol fluorescent compounds of formula (I) are dyes capable of absorbing in the visible range, Xabs between 400 and 800 nm, and of reemitting in the visible range, Xem between 400 and 800 nm. More particularly, the fluorescent dyes are dyes capable of absorbing at an Xabs wavelength between 420 nm and 550 nm and reemitting in the visible at a wavelength λm between 470 and 600 nm. One particular embodiment of the invention relates to the dyes of formula (I) in which Ta represents a (C 1) n (R) n, (R) (R) n, a heterocycloalkyl or heteroaryl radical, cationic or non-cationic. More particularly the thiol fluorescent dyes of formula (I) with SY function where Y represents a hydrogen atom or an alkali metal, preferably Y represents a hydrogen atom. According to another particular embodiment of the invention, in the aforementioned formula (I) in which Ta represents ùN (R) ù, ùN + (R) (R) ù, Y is a protective group and the protecting group is chosen. among those 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.

  The fluorescent compounds of the invention contain a SY function which may be in the covalent -S-Y or ion -S-Y + form depending on the nature of Y and the pH of the medium. Particularly when Y represents a protecting group for the thiol function, Y is chosen from the following radicals: - (C1-C4) alkylcarbonyl; - (C1-C4) alkylthiocarbonyl; - (C1-C4) alkoxycarbonyl; - (C1-C4) alkoxythiocarbonyl; - (C1-C4) alkylthiothiocarbonyl; - (di) (C1-C4) (alkyl) aminocarbonyl; - (di) (C1-C4) (alkyl) aminothiocarbonyl; arylcarbonyl, such as phenylcarbonyl; aryloxycarbonyl; aryl (C1-C4) alkoxycarbonyl; - (di) (C1-C4) (alkyl) aminocarbonyl such as dimethylaminocarbonyl; - (C1-C4) (alkyl) arylaminocarbonyl; carboxy; - S03; M + with M + representing an alkali metal such as sodium or potassium, or else M 'of the formula (I) and M + are absent; optionally substituted heteroaryl, in particular aromatic groups, cationic or otherwise, 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 alkyl as methyl, or polyhaloalkyl as trifluoromethyl; iii) or tricyclic ABC according to: 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 especially represents 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 alkyl, oxo or thioxo; or the heterocycle represents the following group: ## STR2 ## wherein R ', R'g, R'e, R'f , R'g and R'h, identical or different, represent a hydrogen atom or an alkyl group, or two groups R'g with R'h and / or R'e with R'f form an oxo group or thioxo, or else R'g 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 the 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 an alkyl group; preferentially R 'to R' f represent a hydrogen atom; and An represents the counterion; isothiourea -C (NR 'R'd) = NR'e with R', R'g, R'e are as defined previously; optionally substituted (di) arylalkyl such as 9-anthracenylmethyl, phenylmethyl or diphenylmethyl optionally substituted by one or more groups chosen in particular from alkyl, alkoxy such as methoxy, hydroxy, alkylcarbonyl, (di) (alkyl) amino such as dimethylamino; - (di) heteroarylalkyl 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 groups, furanyl, thiophenyl, pyridyl, pyridyl N-oxide 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) heteroarylalkyl is (di) heteroarylmethyl or (di) heteroarylethyl; -CR'1R'2R'3 with R'1, R'2 and R'3 identical or different, representing a halogen atom or a group selected from: alkyl optionally substituted such as methyl, ethyl; optionally substituted alkoxy such as methoxy or ethoxy; optionally substituted aryl such as phenyl optionally substituted with one or more groups such as alkyl, alkoxy, hydroxy; optionally substituted heteroaryl such as thiophenyl, furanyl, pyrrolyl, pyranyl, pyridyl, optionally substituted with an alkyl group; - P (Z ') R "1R" 2R "3 with R" 1, and R "2 identical or different represent a hydroxyl, alkoxy or alkyl group, R" 3 represents a hydroxyl or alkoxy group, and Z' represents an atom oxygen or sulfur .; cyclic sterically hindered; and optionally substituted alkoxyalkyl.

  In particular Y represents an alkali metal or a protective group such as: - (C1-C4) alkylcarbonyl such as methylcarbonyl or ethylcarbonyl; arylcarbonyl, such as phenylcarbonyl; - (C1-C4) alkoxycarbonyl; -aryloxycarbonyl; aryl (C1-C4) alkoxycarbonyl; - (di) (C1-C4) (alkyl) aminocarbonyl such as dimethylaminocarbonyl; - (C1-C4) (alkyl) arylaminocarbonyl; optionally substituted aryl such as phenyl; 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, (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 the following formula: Me N +

  N-Me An-> isothiouronium -C (NH2) = N + H2; An; - isothiourea -C (NH 2) = NH; According to a particular embodiment, the protected thiol fluorescent dyes of formula (I) comprise 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'd An- in which R 'and R'd, 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.

  According to another particular embodiment when Ta represents a covalent bond, the protected thiol fluorescent dyes of formula (I) comprise a cationic aromatic 5- or 6-membered monocyclic heteroaryl moiety 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 by one or more groups such as alkyl such as methyl, or polyhaloalkyl such as trifluoromethyl; iii) or heterocyclic according to: R '\

  N R'd An in which R 'and R'd, identical or different, represent an alkyl group; Preferably R 'to R'd represent an alkyl group such as methyl; and An represents an anionic 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, benzimidazolium, benzoxazolium, benzothiazolium, these groups being optionally substituted by one or more (C1-C4) alkyl groups including methyl.

  According to a particular embodiment of the invention, the thiol fluorescent dyes of the invention are of formula (Ia), (Ib) or (Ic) each having an ethylene group which connects the pyridinium part to the phenyl in the ortho or para position is in positions 4-4 ', 4-2', or 2-4 'for (la) and (lb) or else in positions 4-5' or 2-5 'for (Ic): 3' 2 'S (CH2 m (CH 2), R'b a / -SY (CRIR2) m \ (CR3R4) n Rb a T \ / SY Nu (CR1R2) m (CR3R4) ## STR3 ## wherein:

  R'a represents a benzyl or alkyl group optionally substituted with a hydroxyl group such as methyl, ethyl or hydroxyethyl;

  R'b represents a hydrogen atom; a benzyl or alkyl group such as methyl or ethyl; ^ T'a represents a bond 6; a group. -N + (R) (R) - with R and R, identical or different, representing an alkyl group such as methyl; or T'a is an imidazolium group;

  Y 'represents a group selected from imidazolium, thiazolium; oxazolium; 1,2,4-triazolium; pyridinium; pyrimidinium; benzoxazolium and benzothiazolium; these groups being substituted with one or more groups, identical or different, alkyl group such as methyl or ethyl;

  m and n, which are identical or different, represent an integer inclusive between 1 and 6 with m + n represents an integer between 2 and 6 inclusive; especially when T'a represents a bond 6, then the sum m + n is an integer equal to 2;

  M 'represents an anionic counterion

  it being understood that when the compound of formula (Ia) contains other cationic parts, it is associated with one or more anionic counter-ions making it possible to reach the electroneutrality of formula (Ia); Wherein R 1, R b, R 2, R 1, R 2, R 2, R 3, R 4, Ta, m, n, Y are as previously defined; - Rg and R'g, identical or different, represent a hydrogen atom, a halogen atom, an amino group, (C 1 -C 4) alkylamino, (C 1 -C 4) dialkylamino, cyano, carboxy, hydroxy, trifluoromethyl C 1 -C 4 alkoxycarbonyloxy, (C 1 -C 4) alkylcarbonyloxy, (C 1 -C 4) alkoxycarbonyl, (C 1 -C 4) alkylcarbonylamino, acylamino, carbamoyl, (C 1 -C 4) alkylsulfonylamino, amino-sulfonyl, or a (C1-C16) alkyl radical optionally substituted with a group chosen from (C1-C12) alkoxy, hydroxy, cyano, carboxy, amino, (C1-C4) alkylamino and (C1-C4) dialkylamino, or then the two alkyl radicals carried by the nitrogen atom of the amino group form a heterocycle comprising from 5 to 7 members and optionally comprising another heteroatom identical to or different from that of the nitrogen atom; especially Rg and R'g represent a hydrogen atom, a halogen atom or a (C1-C3) alkyl group, advantageously Rg and R'g represent a hydrogen atom; - Rh and R'h borne by two adjacent carbon atoms, together form a benzo ring, indeno, a fused heterocycloalkyl or fused heteroaryl group; the benzo, indeno, heterocycloalkyl or heteroaryl ring being optionally substituted with a halogen atom, an amino group, (C 1 -C 4) alkylamino, (C 1 -C 4) dialkylamino, cyano, carboxy, hydroxy, trifluoromethyl, acylamino or alkoxy group; C1-C4, (poly) hydroxyalkoxy C2-C4, (C1-C4) alkylcarbonyloxy (C1-C4) alkoxycarbonyl, (C1-C4) alkylcarbonylamino, acylamino, carbamoyl, (C1-C4) alkylsulfonyl-amino, an aminosulphonyl radical, or a (C 1 -C 16) alkyl radical optionally substituted with a group chosen from (C 1 -C 12) alkoxy, hydroxy, cyano, carboxy, amino, (C 1 -C 4) alkylamino and (C 1 -C 4) dialkylamino, or the two alkyl radicals carried by the nitrogen atom of the amino group form a heterocycle comprising from 5 to 7 members and optionally comprising another heteroatom identical to or different from that of the nitrogen atom; especially Rg and R'g together form a benzo group; and

  formula (Ic) in which: Ra, Rb, R, R, R, R2, R3, R4, Ta, m, n, Y are as defined above; - Rg, R'g, Rh and R'h, identical or different, represent a hydrogen atom, a halogen atom, an amino group, (C 1 -C 4) alkylamino, (C 1 -C 4) dialkylamino, cyano carboxy, hydroxy, trifluoromethyl, acylamino, (C1-C4) alkoxy, (C2-C4) polycarboxylic hydroxyalkyl (C1-C4) alkylcarbonyloxy, (C1-C4) alkoxycarbonyl, (C1-C4) alkylcarbonylamino, acylamino, carbamoyl, ( C1-C4) alkylsulfonylamino, amino-sulfonyl, or a (C1-C16) alkyl radical optionally substituted with a group chosen from (C1-C12) alkoxy, hydroxy, cyano, carboxy, amino, (C1-C4) alkylamino and (C1 -C4) dialkylamino, or the two alkyl radicals carried by the nitrogen atom of the amino group form a heterocycle comprising from 5 to 7 members and optionally comprising another heteroatom identical to or different from that of the nitrogen atom; especially Rg, R'g, Rh and R'h represent a hydrogen atom, a halogen atom or a (C1-C3) alkyl group, advantageously Rg, R'g, Rh and R'h represent a hydrogen atom; .

  By way of example of protected thiol fluorescent dyes, mention may be made in particular of the following dyes: ## EQU1 ## ## STR2 ## SK \ N 2An- \ ù N / N \ NN An- 3 4 / \ / • N \ N 2An- ~ S ~ N ~ 2An- ùN 'S ~ N / 5 6 ùN \ 2An- ùN + \ / N \ N + 2An- \ \ N '7 8 15 n NN \ / NN 7 S -N \ / N \ I, 2An / \ ~ i 3An- ùN / \ N \ 9 10 N SH -N ù N + â \ An- 2An- 11 12 \ / \. 2An -N + \ / \ + NS ~ N \ ~ N \ 2An- 13 14 Ho o An ~ sso3 ù An, M + 15 16 ùN + \ N \ \ ùN + \ / • SH 3An- N 'N \ / An- 17 18 S SH ùN + \ N ~ / N the \ Year 2 Year 19 20 ùN ~~ \ 0 ùN ~~ ù \ / \ N 0 / \ N / N An-An- 21 22 N 2An-2An- 23 24 \ n + N \ N 2An- N \ \ N \ / 2An / 25 26 \ / N \ / N / N 2An- ùN • s SN / N / \ 2An- 27 28 \ NN 2An- N + \ N 2An- 29 30 N ù N 2An- 2An 31 32 / / N \ \ * ùN + / N \ \ + ùN * 2An- / NS / N 2An 33 34 \ + \ + / \ sù _ / s-sl 2An 2An36 \ + \ + N --- N NN / \ N "N3 \ \ 2An ùN 2An- 37 38 \ + \ + / N ~ s / \ N \ -N * \ / N \ N 2An \ 2An- 39 40 / \ \ + 2An - s - << rN ù 2An 41 42 N - \ + / \ / sN 0 'S 2An N + \ / N \ 2An- 43 44 S / N -N s- JNN / \ / HO ~ N + \ / \ n + ù 2An 2An- 45 46 \ N ~ N + \ + 2An- / ~ S / 2An 47 48 \ -N + \ N / - \ N ~ N / NH \ ::, ...- j N / -N \ N ~ S - \ '/ / \ d 2An 49 50 \ n -N 2An \ / N \ / N - \ S -N 3An N ~ S ~ / N. N \ N 51 52 / \ N ~ 2An- N 2An -N + \ N / \ + ~ -S ~ N 1 M \ '\ HN \ N 53 54 \ / 2An- - \ N / 2An N \ NH "55 56 / 2An -N + N N- 2An ## EQU1 ## 57 ## STR2 ## N + N + N + N + N + N + N + N / N 2 N 2An 63 64 with An-, identical or different, representing an anionic counterion; and M + representing an alkali metal.

  With An-, identical or different, represent an anionic counterion such as halides, such as chloride, bromide; nitrates; sulfonates, including C1-C6 alkylsulfonates: Alk-S (O) 20- such as methylsulfonate or mesylate and ethylsulfonate; arylsulfonates: Ar-S (O) 20- such as benzenesulphonate and toluenesulphonate or tosylate; citrate; succinate; tartrate; lactate; alkyl sulphates: Alk-O-S (O) O- such as methylsulfate and ethylsulfate; arylsulfates: Ar-O-S (O) O- such as benzenesulphate and toluenesulphate; alkoxysulfates: Alk-O-S (O) 20- such as methoxy sulfate and ethoxysulfate; aryloxysulfates: Ar-O-S (O) 20-, phosphate; acetate; triflate; and borates such as tetrafluoroborate.

  The protected thiol dyes of formula (I) can be synthesized in two stages. The first step of preparing the unprotected 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 (I). By way of example, to protect the thiol function of the thiol dye, the methods of Protectin Groups in Organic Synthesis, T.W. Greene, John Willey & Sons ed., NY, 1981, pp.193-217; Protecting Groups, P. Kocienski, Thieme, 3rd ed., 2005, chap. 5. We can illustrate this method by the method consisting of i) generating thiol fluorescent dyes by reducing a fluorescent dye to two chromophores bearing a disulfide function -SS- such that (A) and ii) to be protected by conventional methods said function thiol compounds (I ') to access the protected thiol fluorescent dyes of formula (I "): Rb R' / N / Ta ~ / Sui ~ / Tai Nu (CRIR2) m (CR3R4) n (CR3R4) n ( CR1R2) m Rh Rb (A) / Ta SH ii) 2 YR Ni (CRIR2) m (CR3R4) n -HR R'g Rb M '~ Ra R' (I ') with R1, R2, R3, R4, Ra , Rb, Rg, R'g, Rh, R'h, R, R ', Y, m, n and M' are as defined above and R represents a leaving group nucleofuge, such as, for example, mesylate, tosylate According to another possibility, a thiol compound protected by a protective group Y as defined previously prepared can be reacted according to one of the procedures described in the works cited above, said co protected thiol compound comprising at least one nucleophilic function with a sufficient, preferably equimolar, amount of a "reactive fluorescent chromophore" or a compound comprising such a "reactive fluorescent chromophore" j. In other words, it comprises a nucleofugal function to form a covalent bond E as can be schematized below: RRN (CR 1 R 2), 7 E + u (CR 3 R 4) n SY Rb N (CR 1 R 2) 71 (C R 3 R 4) ## STR2 ## Reducing 2 g (1 ") with R1, R2, R3, R4, Ra, Rb, Rg, R'g, Rh, R'h, R, R ', Y, m, n and M 'are as defined above, Wu representing a nucleophilic amine or heterocycloalkyl heteroaryl group, E representing a nucleofugal group such as, for example, mesylate, tosylate, triflate or halide such as bromine, iodine or chlorine; .

  E represents a radical chosen from: ## STR1 ## with R and R as defined above, heterocycloalkyl and heteroaryl, cationic or non-cationic. It is also possible to use a thiol reagent Y-SH comprising a group Y whose nucleophilic function SH can react on the carbon atom alpha to the halogen atom carried by the fluorescent chromophore to give the fluorescent dye thiol protected by Formula (I): R LHS-Y N, (CR 1 R 2) 7 T ~ (CR 3 R 4) n Hal (I) -HHa I -N R R M R with R 1, R 2, R 3, R 4, R a, R b, R 6, R g, Rh, Rh, R, R ', Ta, Y, m, n and M' are as defined above, and Hal represents a nucleofugal halogen atom such as bromine, iodine or chlorine.

  It is also possible to use a thioacid (for example thioacetic acid) which will act on a halide carried by the fluorescent chromophore: ## STR1 ## with Ra, Rb, Rg, R'g, Rh, R'h, R, R ', m, n, Hal, M' are as defined above and R 'represents a (C1-C6) alkyl group.

  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 thioimidazolinium ([3), -H Hal the reaction scheme is as follows: SH R'c, NR + (R) Rh N ~ / S NI An R'cx R'a Rb N / Hal N with Ra, Rb, R'g, R'd, Rg, R'g, Rh, R'h, R, R ', m, n, Hal, An- and M' are as defined previously. An alternative is to use in place of the halide comprising the fluorescent chromophore 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') to conduct after alkylation by an 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.

  Rc` - (SH RcN NN Rb N Rb + N --- N / 'S I', R'a Rb A nucleofuge leaving group may also be substituted by thiosulphate salts (for example sodium thiosulfate or potassium) to generate Bunte salts (-SOO3-, Na 'or K +): N --- N / Ha' Rb m 'with Ra, Rb, Rg, R'g, Rh, R'h, R, R'; , m, n, Hal, M 'are as defined above and M + representing an alkali metal such as sodium or potassium.

  According to another possibility, certain protected thiol fluorescent dyes (I ") can be obtained by reacting a protected thiol compound with a compound carrying a nucleofugal function reacted with a fluorescent chromophore carrying a LcI nucleophilic function, of primary or secondary amine type, heterocycloalkyl, or heteroaryl: RN (CR 1 R 2) m Ar + E (CR 3 R 4) 7SY (1 ") Rb Lcj with R 1, R 2, R 3, R 4, Ra, Rb, Rg, R'g, Rh, R 1, R 1, R ', Ta, Y, m, n, M', E, Wu and (I ") as defined above According to another possibility, the protected thiol fluorescent dyes of formula (I) may be obtained by reaction of a compound comprising a thiol group protected by a Y group, and a previously activated hydroxy group in a nucleofugal leaving group, such as, for example, mesylate, tosylate, triflate or halide with a fluorescent chromophore carrying a nucleophilic function. primary amine l when Rb represents a hydrogen atom, or secondary amine. ## EQU1 ## where R1, R2, R3, R4, Ra, Rb, Rg, R g, Rh, Rh, Ri, R ', Ta, Y, m, n, M' and E are as defined above. By way of example, a compound containing a protected thiol group contains a leaving group R, such as, for example, mesylate, tosylate, or triflate, which can undergo the nucleophilic attack of the amine carried by the styryl fluorescent chromophore: SY g NH2 Another alternative comes from the use of halides as a leaving group SY. According to another possibility, the thiol fluorescent dyes of formula (I) according to the invention can be obtained by reaction of a compound comprising a protected thiol group and a Lfl electrophilic group with a compound comprising a nucleophilic group. By way of example, an aldehyde or ketone may be condensed when G represents an oxygen atom with an activated methylene such as alkylpyridinium to generate an ethylene> C = C <bond. This reaction is commonly known as Knoevenagel condensation. The term "activated methylenes" is understood to mean, for example, those mentioned in the DE19951134 patent. 1,2-Dialkylpyridinium and in particular 1,2-dimethylpyridinium may be mentioned in particular: R.sub.R N (CRIR.sub.2) m Ta.sub.2 (CR.sub.3 R.sub.4) nSub.S Rb -H.sub.2 H.sub.2

  ## STR5 ## wherein R 1, R 2, R 3, R 4, R a, R b, R 6, R ', R, R', R ', Ta, Y, m, n, M' as defined above and G representing an oxygen atom, sulfur or an N (R) group with R representing a hydrogen atom or a (C 1 -C 4) alkyl group.

  Another variant of this reaction scheme is to carry out the Knoevenagel coupling reaction subsequently, ie from the intermediate, the amino group NR'R "can react with one equivalent of reagent Gp- (CR3R4) -Gp to lead to which itself can react with a Y'SH protected thiol derivative to give the LD aldehyde intermediate This intermediate can undergo the Knoevenagel condensation reaction with the alkylpyridinium to yield the protected naphthyl thiol fluorescent dye (I "). nucleofuge on a thiol compound which may be substituted with a primary amine function, for example carried by a styryl fluorescent chromophore: R Rh Hal-a ~ SY 'NH2 -H Hal g N (CR1R2) m T ~ (CR3R4) n SY Rb Rb Nu (CR 1 R 2) m Gp f 91 HNR'R "Rb Nu (CR 1 R 2) m NR'R" + HGp 1 R 'R "N (CR 1 R 2) m N (CR 3 R 4) n SY' Rb Gp LL.Z Knoevenagel I + Lei -H2G Gpu (CR3R4) ## STR2 ## (CR3R4), SY '

Rb Gp (1 ,,) of protection

R 'R "

(CR1R2) 7, N (CR3R4) n SH

  Rb Gp (1 "with R ', R", R1, R2, R3, R4, Ra, Rb, Rg, R'g, Rh, R'h, R ;, m, n, Y', and M 'such As defined, Gp represents a leaving group such that a halogen atom, especially Br, I, or a tosylate group, mesylate, triflate, and Gp-, represents the anionic counterion that is consecutive after leaving the leaving group Gp.

  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 thiol fluorescent dyes formed can be converted to Y-protected thiols fluorescent dyes by the protection of thiols using conventional protecting groups. The thiol fluorescent dyes may also be metallated using 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 protected thiol dyes may be deprotected by conventional routes such as those described in Protective Groups in Organic Synthesis, TW Greene, John Willey & Sons ed., NY, 1981; Protecting Groups, P. Kocienski, Thieme, 3rd ed., 2005. The starting reagents are commercial or accessible by conventional routes known to those skilled in the art. By way of example, to synthesize the fluorescent dye with two naphthyl chromophores, bearing a disulfide function -SS- (A '), it is possible to start from a difunctionalized naphthyl reagent comprising at position 2 a GR nucleotide group with R representing a group ( CI-C4) alkyl, mesylate, tosylate, or triflate and G representing an oxygen atom, sulfur or a group N (R) with R representing a hydrogen atom or a group (C, C4) alkyl and comprising position 6 an electrophilic aldehyde or thioaldehyde group. Two equivalents of this reagent can react with the diamine-dialkyl disulphide C to conduct after condensation with the dialdehyde / thioaldehyde disulfide LUI which can condense with two equivalents of alkylpyridinium (fg) to form the compound (A '). 2 T SiRb (CRi R2) n, a (CR3R4) (CR3R4) (CRRz) m G1R R 'n TS 2 Rb, N1 (C RZ) ä (CR3R4) ,, H Knoevenagel 2 hr Y ru RbN ## STR2 ## ## STR ############################################################################################################################################################################################################################################################################### & Sons, 1992 or TW Greene Protective Groups in Organic Synthesis, for more details on the operating conditions used for the processes mentioned above.

  The composition of the invention contains at least one thiol fluorescent dye of formula (I). In addition to the presence of at least one thiol fluorescent dye of formula (I), the composition of the invention may also contain a reducing agent. This reducing agent may be chosen from thiols, for example cysteine, homocysteine, thiolactic acid, the salts of these thiols, phosphines, bisulfite, sulphites, thioglycolic acid and its esters, especially the glycerol monothioglycolate, and thioglycerol. This reducing agent may also be chosen from borohydrides and their derivatives, such as, for example, borohydride, cyanoborohydride, triacetoxyborohydride or trimethoxyborohydride salts: sodium, lithium, potassium, calcium, quaternary ammonium salts (tetramethylammonium, tetraethylammonium, tetra butylammonium, benzyltriethylammonium); catecholborane. The dye composition useful in the invention generally contains a quantity of thiol fluorescent dyes of formula (I) of between 0.001 and 50% relative to the total weight of the composition. Preferably, this amount is between 0.005 and 20% by weight and even more preferably between 0.01 and 5% by weight relative to the total weight of the composition. The 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, bis-phenylalkylenediamines, 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. 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): Rat / R a2 N-Wa-N Ra4 Ra (y) in which Wa is a propylene residue optionally substituted by a hydroxyl group or a C1-C4 alkyl radical; Ra1, Ra2, Ra3 and Ra4, which may be identical or different, represent a hydrogen atom, a C1-C4 alkyl radical or a C1-C4 hydroxyalkyl radical. The dye composition may be in various forms, such as in the form of liquid, cream, gel, or in any other form suitable for dyeing keratinous fibers, and in particular hair.

  The dyeing process of the invention consists in applying the composition of the invention to keratin materials, in particular keratin fibers, in particular human fibers such as the hair, more particularly the dark hair, the dyeing composition of the invention comprising at least minus a thiol fluorescent dye of formula (I). According to a particular embodiment in the process of the invention, a reducing agent may be applied as a pre-treatment before the application of the composition containing at least one thiol fluorescent dye of formula (I). 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 thiol fluorescent dye of formula (I) also contains at least one reducing agent as defined above. This composition is then applied to the hair. When the thiol fluorescent dye (I) comprises a thiol-protecting group Y, 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 the protective group by adjusting the pH as follows: Y: alkylcarbonyl deprotection 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 aryl optionally substituted such pH> 9 as phenyl, monocyclic heteroaryl with 5, 6 or 7 pH> 9 members such as oxazolium; 8 to 11-membered 9-membered bicyclic heteroaryl such as benzoimidazolium or benzoxazolium The deprotection step may also be carried out in the course of a hair pretreatment step such as, for example, the hair reduction pretreatment.

  According to another dyeing method, the composition comprising at least one thiol fluorescent dye of formula (I) also contains at least one reducing agent as defined above. This composition is then applied to the hair. According to one variant, the reducing agent is added to the dye composition containing at least one protected thiol fluorescent dye (I) at the time of use. According to another variant, the reducing agent is applied post-treatment, after the application of the composition containing at least one protected thiol fluorescent dye (I). The duration of the post-treatment with the reducing agent may be short, for example from 0.1 second to 30 minutes, preferably from 1 minute to 15 minutes, with a reducing agent as described above. According to a particular embodiment, the reducing agent is a thiol or borohydride type agent as described above. A particular embodiment of the invention relates to a method in which the thiol fluorescent dye of formula (I) can be applied directly to hair without reducing agents, free from 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. This oxidizing agent may be applied to the fibers before or after the application of the composition containing at least one thiol fluorescent dye of formula (I).

  The application of the dye composition according to the invention is generally carried out at room temperature. It can however be carried out at temperatures ranging from 20 to 180 C.

  The invention also relates to a multi-compartment device or "kit" of dyeing in which a first compartment contains a dye composition comprising at least one thiol fluorescent dye of formula (I) and a second compartment contains a reducing agent capable of reducing the disulfide functions of keratin materials. 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 thiol fluorescent dye of formula (I); a second compartment contains a reducing agent capable of reducing the disulfide bond of the keratin materials; a third compartment contains an oxidizing agent. Another variant relates to a multi-compartment device or dyeing kit comprising a first compartment which contains a composition with at least one protected fluorescent dye of formula (I) and a second compartment comprising a composition containing a deprotection agent such as a base .

  Each of the above-mentioned devices may be equipped with means for delivering the desired mixture onto the hair, for example such as the devices described in patent FR 2 586 913. The following examples serve to illustrate the invention without however to be 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-methyl-4 - {(E) -2- [4- (methyl {2 - [(1-methyl-1H-imidazol-2-yl) sulfanyl] ethyl chloride} amino) phenyl] vinyl} pyridinium [1] N and NN / [1] Synthesis scheme: ## STR1 ## Procedure:

  Steps 1 and 2: Synthesis of 4 - ((E) -2- {4 - [(2-chloroethyl) - (methyl) amino] phenyl} vinyl) -1-methylpyridinium methyl sulfate

  4.99 g of 4-picoline diluted in 25 ml of dichloromethane (CH 2 Cl 2) are stirred and heated at 40 ° C. 5 ml of dimethyl sulphate diluted in 20 ml of CH 2 Cl 2 are added dropwise to the reaction medium. The mixture is kept at 42 ° C. for 30 minutes after the addition, then 20 ml of isopropanol are added. 1.87 g of pyrrolidine diluted in 30 ml of isopropanol are added. The mixture is stirred and heated at 60 ° C. for 5 minutes. 10.5 g of 4 - [(2-chloroethyl) (methyl) amino] benzaldehyde are added. The mixture is stirred for 2 hours at 52 ° C. and then at room temperature for 48 hours. The reaction mixture is diluted in 50 ml of ethanol and then stored at -25 ° C. for 12 hours. The precipitate obtained is filtered at ambient temperature, washed with 100 ml of acetone, with 3 times 100 ml of ethyl ether and dried under vacuum in the presence of P2O5. 15.1 g of orange crystals are collected. The analyzes indicate that the product is compliant.

Step 3: Synthesis of 1-methyl-4 - {(E) -2- [4- (methyl {2 - [(1-methyl-1H-imidazol-2-yl) sulfanyl] ethyl} amino) phenyl] chloride vinyl} pyridinium [1] 5 g of 4 - ((E) -2- {4 - [(2-chloroethyl) (methyl) amino] phenyl} vinyl) methylpyridinium methyl sulfate, 2.15 g of 2-mercapto-1- methylimidazole and 20 ml of ethanol (EtOH) are stirred and heated at 70 ° C. for 48 hours. 2.15 g of 2-mercapto-1-methylimidazole diluted in 3 ml of EtOH are added to the reaction mixture, the mixture is stirred at 72 ° C. for 72 hours. 20 ml of isopropanol and 2 ml of water are added to the cooled reaction mixture at -10 ° C. The oil is separated from the supernatant, washed with ethyl acetate (AcOEt) and then solubilized in 100 ml of ethanol and stored at -25 C for 48h. The crystals obtained are filtered, washed with 20 ml of ethanol, with 3 times 100 ml of AcOEt, and then dried under vacuum in the presence of P2O5. 5.79 g of brown powder is collected. The analyzes indicate that the product is compliant. 1 H NMR (400 MHz, ppm, DMSO-d6) 2.96 (s, 3H), 3.51 (t, 2H), 3.67 (s, 3H), 3.68 (t, 2H), 4.20 (s, 3H). ), 6.75 (d, 2H), 7.20 (d, 1H), 7.57 (d 2H), 7.72 (, 1H), 7.76 (d, 1H), 7.91 (d, 1H), 8.07 ( d, 2H), 8.73 (d, 2H). Example 2 Synthesis of methyl sulfate / 4 - ((E) -2- {4 - [{2 - [(1,3-dimethyl-1H-imidazol-3-ium-2-yl) sulfanyl] ethyl chloride } (methyl) amino] phenyl} vinyl) -1-methylpyridinium [2] [2] An N [N] [N] [2] Synthetic Scheme CI [1] Acon NMP / ACN N / S N 2 An An Operating Procedure

A solution of 2 g of 1-methyl-4 - {(E) -2- [4- (methyl {2 - [(1-methyl-1H-imidazol-2-yl) sulfanyl] ethyl} amino) phenyl chloride ] vinyl} pyridinium [1] in 2 mL of N-methylpyrrolidinone (NMP) and 8 mL of acetonitrile (ACN) are stirred at 70 ° C for 20 min. 500 μL dimethylsulphate is added to the mixture. Stirring and heating are maintained for 1h30. 500 mg of sodium acetate are added. After 4h, 1 mL of dimethylsulphate is added and the stirring is maintained for 15 hours at room temperature. 50 ml of acetonitrile are added. The precipitate obtained is filtered. 100 ml of acetone are introduced into the filtrate, the oil thus obtained is washed with 3 times 100 ml of acetone and then resolubilized in 50 ml of isopropanol and stored at -25 ° C. for 48 hours. The precipitate formed is filtered off, washed with 10 ml of iPrOH, with 3 times 20 ml of ethyl acetate and then dried under vacuum in the presence of P2O5. 1.11 g of brown powder are collected. The analyzes indicate that the product is in the form of mixed salts of chloride and methylsulfate. 1 H NMR (400 MHz, ppm, MeOH-d6) 3.06 (s, 3H), 3.35 (t, 2H), 6.68 (s, 5.44H, methylsulphate), 3.77 (t, 2H), 3.79 (t. , 6H), 4.24 (s, 3H), 6.82 (d, 2H), 7.15 (d, 1H), 7.64 (d, 2H), 7.5 (s, 2H), 7.83 (d , 1H), 8.00 (d, 2H), 8.55 (d, 2H).

EXAMPLES OF COLORING

  Example 1: Coloring process A lock of 1 g of hair of pitch 4 is placed at the bottom of the same [2] bowl. 1 mL of ammonium 8.5 thioglycolate molar solution 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 aqueous solution containing 49 mg of compound [1] 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 2 Coloring Process

  A wick of 1 g hair of pitch 4 are arranged at the bottom of the same bowl. 1 mL of ammonium 8.5 thioglycolate molar solution 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 aqueous solution containing 63 mg of compound [2] 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.

  Persistence with respect to successive shampoos: The wicks 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 and 2, there is no visible bleeding, the foam of the shampoos and the rinsing water are not colored. The observed color is preserved and the lightening effect remains visible on the skin. 4 pitch hair so treated. Results in the L * a * b25 system The color of the locks before and after the 5 washes was evaluated in the L * a * b * system using a MINOLTA CM 2600D spectrophotometer, (Illuminant D65). In this system L * a * b *, L * represents the intensity of the color, a * indicates the green / red color axis 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 coloration between the locks of HT4 hair, stained and washed is measured by (4E) according to the following equation:

  0 E = I (L * ù Lo *) 2 + (a * ù ao *) 2 + (b * ù

  In this equation, L *, a * and b * represent the measured values before staining and Lo *, ao * and bo * represent the values measured before staining (or shampooing). The higher the value of AE, the greater the difference in color between the HT4 locks and the colored locks. L a * b * Wick HT4 16,16 2,88 2.95 Wick HT4 19,79 11, 02 11,72 12.50 Compound [1] Wick HT4 21,45 11,36 12,87 14.08 Compound [1] after 5 shampoos Wick HT4 20,76 8,65 14,18 5.91 Compound [2] Wick HT4 22,16 9,13 14,43 6.84 Compound [2] after 5 shampoos The results in the table above show that the color changes very slowly. 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. 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 a lock of untreated HT4 pitch hair. The reflectance is measured using a KONIKAMINOLTA spectrophotocolorimeter, CM 2600d and after irradiation of the hair with visible light in the wavelength range of 400 to 700 nanometers. Reflectance of strands treated with compound 1 at application and after 5 shampoos 00 ~~ O ~, ~ 0 X00 ~, ~ 0 00 ~, \ 0 D00 0, ~ 0 000 0J O, 10 000 Wavelength ( nm) 6-5-4-3-2-1-0 reference --Compound 1 Compound 1 - 5 shampoos Reflectance of wicks treated with compound 2 on application and after 5 shampoos X00 x, 10 100 eX00 ex, 10 X00 e000 0 ~ 0 O, 10 000 Wavelength (nm) reference

- Compound 2

  Compound 2 - 5 shampoos 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 composition of the invention evolve very little even after 5 shampoos. Thus, the coloration and the lightening effect on the hair remain almost unchanged, which shows a very good resistance to shampoos of the dyes of the invention.

Claims (21)

  1. Protected thiol fluorescent dye of formula (I) below: Ta SY1 (CR1R2) m - "(CR3R4) n Rb (I) its organic or inorganic acid salts, optical isomers, geometric isomers, and solvates such as hydrates; formula (I) in which: Ra represents an aryl (C1-C4) alkyl group or a (C1-C6) alkyl group optionally substituted by a hydroxy or amino group, C1-C4 alkylamino, (C1-C4) dialkylamino; , said alkyl radicals being capable of forming, with the nitrogen atom bearing them, a 5- to 7-membered heterocyl, optionally comprising another heteroatom which may or may not be different from nitrogen; Rb represents a hydrogen atom or an aryl group; (C1-C4) alkyl or an optionally substituted (C1-C6) alkyl group; Rg and R'g, which may be identical or different, represent a hydrogen atom, an (C1-C4) alkylamino group, C4) dialkylamino, trifluoromethyl, acylamino, (C1-C4) alkoxy (C1-C4) alkylcarbonyloxy, (CIC4) a alkoxycarbonyl, (C1-C4) alkylcarbonylamino, (C1-C4) alkylsulfonylamino, a (C1-C3) alkyl radical; Rh and R'h, which may be identical or different, represent a hydrogen atom, a halogen atom, a (C 1 -C 4) -alkylamino group, a (C 1 -C 4) alkylcarbonylamino group or an (C 1 -C 4) acylamino group; alkylsulfonylamino, or a (C1-C4) alkyl radical; or two groups Rg and R'g; Rh and R'h carried by two adjacent carbon atoms together form a benzo, indeno ring, a fused heterocycloalkyl or fused heteroaryl group; the benzo, indeno, heterocycloalkyl or heteroaryl ring being optionally substituted with an halogen atom, an amino, (C1-C4) alkylamino, (C1-C4) dialkylamino, cyano, carboxy, hydroxy, trifluoromethyl, acylamino or C1-C6 alkoxy group; C4, (poly) hydroxyalkoxy C2-C4, (C1-C4) alkylcarbonyloxy (C1-C4) alkoxycarbonyl, (C1-C4) alkylcarbonylamino, acylamino, carbamoyl, (C1-C4) alkylsulfonylamino, aminosulfonyl, or a (C1-C16) alkyl radical optionally substituted with a group chosen from (C1-C12) alkoxy, hydroxy, cyano, carboxy, amino, (C1-C4) alkylamino and (C1-C4) dialkylamino, or else the two alkyl radicals carried by the nitrogen atom of the amino group form a heterocycle comprising from 5 to 7 members and optionally comprising another heteroatom identical to or different from that of the nitrogen atom; - R; and R ', which may be identical or different, represent a hydrogen atom or a (C 1 -C 4) alkyl group; - RI, R2, R3, R4, identical or different, represent a hydrogen atom or a group (C1-C4) alkyl; present or absent, represents a benzo group; Ta is: i) a covalent bond a; ii) either a radical selected from the group consisting of R, R, R, R, R, R, R, R, R, R, R3, R4, R4, R4, R4, R4, R4, R4, R4, R4, R4, R4, R4 and R4; C4; or an aryl (C1-C4) alkyl, iii) a heterocycloalkyl or heteroaryl radical, cationic or non-cationic; m and n, which are identical or different, represent an integer inclusive between 0 and 6 with m + n represents an integer inclusive of between 1 and 10; When Ta represents a covalent link a, Y represents a group chosen from: o optionally substituted aryl; optionally substituted heteroaryl; Optionally substituted heterocycloalkyl, optionally cationic; o (di) arylalkyl optionally substituted; Optionally substituted 20o (di) heteroarylalkyl; cyclic sterically hindered; when Ta represents ùN (R) ù, ùN + (R) (R) ù, a heterocycloalkyl or heteroaryl radical, cationic or non-cationic; Y represents a group chosen from i) a hydrogen atom; ii) an alkali metal; iii) an alkaline earth metal; iv) an ammonium group: N + RaRRR7Rs or a phosphonium group: P + RaRRR7Rs with Ra, RR, R7 and R5, which may be identical or different, representing a hydrogen atom or a (C 1 -C 4) alkyl group; or v) a thiol protecting group; and - M 'representing an anionic counterion, it being understood that: - when the compound of formula (I) contains other cationic parts, it is associated with one or more anionic counter-ions making it possible to achieve electroneutrality of the formula (I).   2. Fluorescent dye according to claim 1, wherein when Ta represents a non-cationic or non-cationic heterocycloalkyl or heteroaryl radical, Y represents a hydrogen atom or an alkali metal.   3. Fluorescent dye according to claim 1, in which when Ta represents unN (R) ù, ùN + (R) (R) ù, a heterocycloalkyl or heteroaryl radical, cationic or non-cationic; Y represents a protective group of the following thiol group: - (C1-C4) alkylcarbonyl; - (C1-C4) alkylthiocarbonyl; - (C1-C4) alkoxycarbonyl; - (C1-C4) alkoxythiocarbonyl; - (C1-C4) alkylthiothiocarbonyl; - (di) (C1-C4) (alkyl) aminocarbonyl; - (di) (C1-C4) (alkyl) aminothiocarbonyl; arylcarbonyl; aryloxycarbonyl; aryl (C1-C4) alkoxycarbonyl; - (di) (C1-C4) (alkyl) aminocarbonyl; - (C1-C4) (alkyl) arylaminocarbonyl; -carboxy; - SO3; M + with M + representing an alkali metal or M 'of the formula (I) and M + are absent; optionally substituted aryl; optionally substituted heteroaryl; optionally substituted heterocycloalkyl; 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 an alkyl group; - isothiourea -C (NR 'R'd) = NR'e; with R ', R'd, R'e as defined above; - (di) arylalkyl optionally substituted; optionally substituted (di) heteroarylalkyl; - CR'1R'2R'3 with R'1, R'2 and R'3 identical or different, representing a halogen atom or a group selected from: optionally substituted alkyl; optionally substituted alkoxy; optionally substituted aryl; optionally substituted heteroaryl; - P (Z ') R "1R" 2R "3 with R"' and R "2, identical or different, represent a hydroxy, alkoxy or alkyl group, R" 3 represents a hydroxyl or alkoxy group, and Z1 represents an atom oxygen or sulfur; cyclic sterically hindered; and optionally substituted alkoxyalkyl.   4. Fluorescent dye according to any one of claims 1 and 3, wherein when Ta represents ùN (R) ù, ùN + (R) (R) ù, a heterocycloalkyl or heteroaryl radical, cationic or non-cationic; Y is a protecting group selected from: (C1-C4) alkylcarbonyl; arylcarbonyl; (C1-C4) alkoxycarbonyl; aryloxycarbonyl; aryl (C 1 -C 4) alkoxycarbonyl; ^ (di) (C1-C4) (alkyl) aminocarbonyl; (C1-C4) (alkyl) arylaminocarbonyl; optionally substituted aryl; monocyclic 5- or 6-membered heteroaryl; 8 to 11-membered cationic bicyclic heteroaryl; cationic heterocycle of the following formula: Me N-N-butyl-N-thiothonium -C (NH2) = N + H2; Year-; isothiourea -C (NH 2) = NH 2 and SO 3, M +.   5. Fluorescent dye according to claim 1, wherein when Ta represents a bond Y represents a cationic aromatic 5- or 6-membered monocyclic moiety comprising: from 1 to 4 heteroatoms selected from oxygen, sulfur and nitrogen; ii) an 8 to 11-membered bicyclic cationic heteroaryl, said mono or bicyclic groups being optionally substituted by one or more groups; iii) or the following heterocyclic: R, d An in which R 'and R'd, identical or different, represent a hydrogen atom or an alkyl group; and An- represents the counter-ion   6. Fluorescent dye according to any one of the preceding claims, chosen from thiol fluorescent dyes of formula (Ia), (Ib) or (Ic) each having an ethylene group which connects the pyridinium moiety to the phenyl in the ortho or para position is in positions 4-4 ', 4-2', or 2-4 'for (la) and (lb) or else in positions 4-5' or 2-5 'for (Ic): 3' 7 4 / T ' N (CH 2) m (CH 2), R 'b Ta ä ... SY 1 \ (CRIR 2) m (CR 3 R 4) n 2 R R b b N + 2 1 R 1 Ra (la) in which R 1a represents a benzyl or alkyl group optionally substituted by a hydroxyl group; R'b represents a hydrogen atom; ^ T'a represents a bond 6; a group. -N + (R) (R) - with R and R, identical or different, representing an alkyl group; or T'a is an imidazolium group; Y 'represents a group selected from imidazolium, thiazolium; oxazolium; 1,2,4-triazolium; pyridinium; pyrimidinium; benzoxazolium and benzothiazolium; these groups being substituted with one or more groups, identical or different, alkyl group; m and n, which are identical or different, represent an integer inclusive between 1 and 6 with m + n represents an integer between 2 and 6 inclusive; M 'represents an anionic counter-ion, it being understood that when the compound of formula (Ia) contains other cationic parts, it is associated with one or more anionic counter-ions making it possible to reach the electroneutrality of the formula ( the) ; formula (Ib) wherein - Ra, Rb, R, R ', R1, R2, R3, R4, Ta, m, n, Y are as defined in any one of claims 1 to 4; - Rg and R'g, identical or different, represent a hydrogen atom, a halogen atom, an amino group, (C1-C4) alkylamino, (C1-C4) dialkylamino, cyano, carboxy, hydroxy, trifluoromethyl, acylamino, (C1-C4) alkoxy, (poly) hydroxyalkoxy C2-C4, (C1-C4) alkylcarbonyloxy, (C1-C4) alkoxycarbonyl, (C1-C4) alkylcarbonylamino, acylamino, carbamoyl, (C1-C4) alkylsulfonylamino, amino sulfonyl, or a (C1-C16) alkyl radical optionally substituted with a group chosen from (C1-C12) alkoxy, 4hydroxy, cyano, carboxy, amino, (C1-C4) alkylamino and (C1-C4) dialkylamino, or the two alkyl radicals carried by the nitrogen atom of the amino group form a heterocycle comprising from 5 to 7 members and optionally comprising another heteroatom identical to or different from that of the nitrogen atom; - Rh and R'h borne by two adjacent carbon atoms, together form a benzo ring, indeno, a fused heterocycloalkyl or fused heteroaryl group; the benzo, indeno, heterocycloalkyl or heteroaryl ring being optionally substituted by a halogen atom, an amino group, (Cr C4) alkylamino, (C1-C4) dialkylamino, cyano, carboxy, hydroxy, trifluoromethyl, acylamino, C1-C6 alkoxy; C4, (poly) hydroxyalkoxy (C2-C4), (C1-C4) alkylcarbonyloxy (C1-C4) alkoxycarbonyl, (C1-C4) alkylcarbonylamino, an acylamino, carbamoyl, (C1-C4) alkylsulfonylamino radical, an aminosulphonyl radical, or a (C1-C16) alkyl radical optionally substituted with a group chosen from (C 1 -C 12) alkoxy, hydroxy, cyano, carboxy, amino, (C 1 -C 4) alkylamino and (C 1 -C 4) dialkylamino, or two alkyl radicals carried by the nitrogen atom of the amino group form a heterocycle comprising from 5 to 7 members and optionally comprising another heteroatom identical to or different from that of the nitrogen atom; formula (Ic) in which: Ra, Rb, R, R ', R1, R2, R3, R4, Ta, m, n, Y are as defined in any one of claims 1 to 4; - Rg, R'g, Rh and R'h, identical or different, represent a hydrogen atom, a halogen atom, an amino group, (C 1 -C 4) alkylamino, (C 1 -C 4) dialkylamino, cyano carboxy, hydroxy, trifluoromethyl, acylamino, (C1-C4) alkoxy, (poly) hydroxyalkoxy (C2-C4), (C1-C4) alkylcarbonyloxy, (CIC4) alkoxycarbonyl, (C1-C4) alkylcarbonylamino, acylamino, carbamoyl, (CIC4) alkylsulfonylamino, amino-sulphonyl, or a (C1-C16) alkyl radical optionally substituted with a group chosen from (C1-C12) alkoxy, hydroxy, cyano, carboxy, amino, (C1-C4) alkylamino and (C1-C4) dialkylamino or both alkyl radicals carried by the nitrogen atom of the amino group form a heterocycle comprising from 5 to 7 members and optionally comprising another heteroatom identical to or different from that of the nitrogen atom; especially Rg, R'g, Rh and R'h represent a hydrogen atom, a halogen atom or a (C1-C3) alkyl group.   7. Fluorescent dye according to any one of the preceding claims, selected from the following dyestuffs: ## STR1 ## wherein: ## STR1 ## \ / 2An- N \ N An- 3 4 / \ / • N \ \ N 01 N 2An- S ~ N ~ S ~ N / 2An- -N '6 ùN \, 2An- -N \ / N, 2An ## EQU1 ## ## STR2 ## N + \ / \ N /. s ~ ss ùN ù \ N \ N \ 2An 2An- 13 14 ~ S ~ o ~ sso3 HO ùN \ N \ An, M + An 15 16 \ SH ùN + N ~ N N + J ## EQU1 ## \ N / 2An- \ \ 23 24 NU 2An ùN + \ / N 2An- \ / rù "N 'N \ \ N \ / N \ 25 26 / \ / N \ s ~ i -N ± \ S ~~ N 2An N / -N + 2An- 27 28 / \ NN - \ N N + '2An 2An 29 30 2An s_ N 2An- 31 32 \ / N \ S \. -N + \ / N \ \. / N S / ùN * 2An- 2An \ 33 34 / \ N s ùN \ / s 2An- \ 2An N \ N + \ \ 35 / \ \. \ 2An- N --- N N-N SNj S ~ NJ 2An 37 38 \ N \ \. -N '\ / N \ \. 2An- N \ / NI / N 2An- 39 40 / \ \ 2An- \ / N \ I ~ N ù 2An 41 42 2An N + \ / \ + 2An N / ù / N \ 43 44 N ù NN -N + 'S ~ JSNN 2An \ 2An- 45 46 / \ N + `N + \ / N N + \ I ~ S ~ 2An N \ 2An- 47 48 / -NN -N + \ N / 3 2An- H IN 3An \ 49 50 / \ n N \ 2An N \ N \ / N - \ S -NN / s \ N = (3An \ N + '/ 51 52 / \ N- / \ sN) ùN \ N / N \ N ~ N \ M \ 2An- 2An (\ /) OH 53 54 / \ 2An- "2An- \" 55 56 / \ N- N N- \ ") -N + \ / H / / 2An- 2An_ 57 58 s ~ i 2An- S hiN -N + N 2An \ 59 60 2An 2An-61 62 / \ N \ 2An-2An \ 63 64 with An-, identical or different, representing an anionic counterion, and M + representing an alkali metal.   8. dye composition comprising in a suitable cosmetic medium, a thiol fluorescent dye of formula (I) as defined in any one of claims 1 to 7.   9. Dyeing composition comprising in a suitable cosmetic medium, at least one thiol fluorescent dye (I) as defined in any one of claims 1 to 8 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. A method for dyeing keratin materials, wherein a dye composition is applied to the materials, comprising in a suitable cosmetic medium, at least one thiol fluorescent dye of formula (I) as defined in any one of claims 1 to 7. optionally in the presence of a reducing agent capable of reducing the disulfide bonds of the keratin materials.   12. The method of dyeing according to the preceding claim wherein when the thiol fluorescent dye of formula (I) comprises a protective Y group, the application is preceded by a deprotection step.   13. A method of dyeing keratinous material according to the preceding claim characterized in that the keratin materials are dark keratinous fibers.   The method of any one of claims 11 to 13 wherein the reducing agent is applied before or after the application of the thiol fluorescent dye.   The process of any one of claims 11 to 14, wherein the composition comprises an oxidizing agent.   16. A process according to any one of claims 11 to 14 comprising a further step of applying an oxidizing agent to the keratin fibers. 6030   17. A process according to any one of claims 11 to 16, wherein the thiol fluorescent dye of formula (I) is present in an amount of between 0.001 and 50% by weight relative to the total weight of the composition.   18. A multi-compartment device in which a first compartment contains a dye composition comprising a thiol fluorescent dye as defined in claims 1 to 7 and a second compartment contains a reducing agent capable of reducing the disulfide bonds of the keratin materials.   19. Device according to the preceding claim comprising a third compartment which contains an oxidizing agent.   20. Use of protected thiol fluorescent dyes as defined in claims 1 to 7 for dyeing human keratin fibers, wherein human keratin fibers are dark.   21. Use according to the preceding claim for the lightening of dark keratinous fibers.