WO2007122341A2

WO2007122341A2 - Specific monocationic monochromophoric hydrazone compounds containing a 2-(benz)imidazolium unit, their synthesis, dyeing compositions comprising them, method of dyeing keratin fibres

Info

Publication number: WO2007122341A2
Application number: PCT/FR2007/051112
Authority: WO
Inventors: Hervé David; Bérangère Baril; Andrew Greaves
Original assignee: L'oréal
Priority date: 2006-04-13
Filing date: 2007-04-13
Publication date: 2007-11-01
Also published as: WO2007122341A3

Abstract

The present invention relates to monocationic monochromophoric compounds of formula (I), in which R1 represents a hydrogen or an alkyl, phenyl, benzyl, alkylcarbonyl, alkylsulphonyl, arylsulphonyl, aminosulphonyl or aminocarbonyl radical; R5 represents an alkyl, phenyl, benzyl or trialkylsilyl radical; R2 and R3 represent a halogen or an alkyl, aryloxy, arylamino, hydroxyl, alkoxy, (poly)hydroxyalkoxy, alkoxycarbonyl, alkylcarbonyloxy, amino, alkylcarbonylamino, aminocarbonyl, ureido, aminosulphonyl, alkylthio, alkylsulphonylamino, cyano, trifluoromethyl, thio, alkylsulphinyl, alkylsulphonyl, phenyl, thiophene, imidazole, trialkylsilyl or nitro radical; R4 represents a hydrogen or an alkyl, amino, alkylcarbonylamino, ureido, alkylsulphonylamino, hydroxycarbonyl, alkoxycarbonyl, phenyl or benzyl radical; R6 and R7 represent a hydrogen or an alkyl, alkylcarbonyl, alkoxycarbonyl, alkoxyaryl, aminoaryl, aminocarbonyl, alkylsulphonyl, phenyl or benzyl radical, n is between 0 and 4, n' is between 0 and 2, the electroneutrality of the compounds of formula (I) being ensured by virtue of one or more cosmetically acceptable anions An. The present invention further relates to dyeing compositions comprising said compounds as direct dyes, and to a method of dyeing keratin fibres employing this composition, and a multi-compartment device. It also relates, finally, to processes for synthesizing compounds of formula (I).

Description

MONOCATIONIC MONOCHROMOPHORIC COMPOUNDS PARTICULAR

TYPE HYDRAZONE COMPRISING A 2- (BENZ-) IMIDAZOLIUM PATTERN, THEIR

SYNTHESIS, TINCTORIAL COMPOSITIONS COMPRISING SAME, PROCESS FOR

COLORING OF KERATIN FIBERS

The subject of the present invention is particular mono-specific monochromophoric dyes of the hydrazone type of particular formula comprising a 2- (benz-) imidazolium unit, dyeing compositions comprising, in a medium which is suitable for dyeing keratin fibers, such compounds as dyestuff. direct, a process for staining keratin fibers using this composition, as well as a device with several compartments. It likewise relates to a process for synthesizing such compounds.

It is known to dye keratinous fibers and in particular human keratinous fibers, such as the hair, with dye compositions containing direct dyes. These compounds are colored molecules and dyes having an affinity for the fibers. It is known, for example, to use direct dyes of the nitrobenzene type, anthraquinone dyes, nitropyridines, azo, xanthene, acridine, azine or triarylmethane type dyes, or even aromatic direct dyes comprising a hydrazone function.

Direct dyes with hydrazone function are interesting compounds but they have the disadvantage of not allowing access in the majority of cases, only in shades ranging from yellow to orange. In very rare cases, hydrazone dyes provide other nuances. For example, the acridinium type hydrazone dyes of patent GB924601 provide violet shades, and the hydrazone type dyes with 2-oxopyrimidinium pattern of the FR1532806 patent provide shades ranging from yellow to violet.

However, these dyes are unstable under alkaline conditions and lightening. They also show poor resistance to repeated shampoos.

It has surprisingly been found that the range of colors obtainable from this family of direct dyes can be substantially extended, these dyes being stable under lightening alkaline conditions. Thus, the compounds according to the invention make it possible to obtain shades of up to violet. To obtain such a variation was a priori far from being obvious because the known hydrazone type dyes have a color that varies relatively little even when the nature of the group carried by the aromatic nucleus and being in para of the hydrazone function passes from an atom from hydrogen to a halogen atom, or to an alkoxy group.

These and other objects are achieved by the present invention which therefore relates to monocation compounds comprising a hydrazone function of formula (I) below, its mesomeric forms as well as its addition salts with an acid and its solvates:

Formula in which:

^* The R radical represents: a hydrogen - an alkyl radical in C ₁ -C ₂ 0, optionally substituted, optionally interrupted by one or more heteroatoms and / or by one or more groups comprising at least one heteroatom, preferably selected from the oxygen, nitrogen, sulfur, CO, SO, SO ₂ or combinations thereof; the alkyl radical not having a nitro, nitroso, peroxo or diazo function; a phenyl radical optionally substituted by a benzyl radical optionally substituted by an alkylcarbonyl radical (R-CO-) in which R represents a C ₁ - alkyl radical;

C ₄ . an alkylsulfonyl radical (RSO ₂ -) in which R represents a C ₁ -C ₄ alkyl radical. an arylsulfonyl radical (R ¹ SO ₂ -) in which R 'represents an optionally substituted phenyl or benzyl radical. a (di-) (alkyl) aminosulfonyl radical ((R) ₂ N-SO ₂ -) in which the R radicals independently represent a hydrogen or a C ₁ -C ₄ alkyl radical. a (di-) (alkyl) aminocarbonyl (R) ₂ N-CO- radical in which the R radicals independently represent a hydrogen or a C ₁ -C ₄ alkyl radical.

^The radicals R 5, identical or different, represent: an alkyl radical in C ₁ -C _20, optionally substituted, optionally interrupted by one or more heteroatoms and / or by one or more groups comprising at least one heteroatom, preferably selected from the oxygen, sulfur, CO, SO, SO ₂ or combinations thereof; the alkyl radical having no nitro, nitroso, peroxo or diazo function and being necessarily attached to the quaternized or non-quaternized nitrogen atom of the imidazolium ring via a carbon atom, a trimethylsilyl C ₁ - alkyl radical; C ₄ . an optionally substituted phenyl radical an optionally substituted benzyl radical ^* The radicals R ₂ and R ₃ , independently of one another, identical or different, represent: a halogen atom - an optionally substituted C ₁ -C ₆ alkyl radical, optionally interrupted by one or more heteroatoms and / or with one or more groups comprising at least one heteroatom preferably chosen from oxygen, nitrogen, sulfur, CO, SO, SO ₂ or their combinations a hydroxyl radical - a C ₁ -C alkoxy radical ₄ ; a C ₂ -C ₄ (poly) hydroxyalkoxy group, an alkoxycarbonyl radical (RO-CO-) in which R represents a C ₁ -C ₄ alkyl radical;

C ₄ . an alkylcarbonyloxy radical (RCO-O-) in which R represents a C ₁ - alkyl radical;

C ₄ . an optionally substituted aryloxy radical, a (di-) arylamino radical optionally substituted with an amino radical optionally substituted with one or two identical or different C ₁ -C ₄ alkyl radicals, optionally bearing at least one hydroxyl or C ₁ -C ₂ alkoxy group, said alkyl radicals which can optionally form, with the nitrogen atom to which they are attached, a 5- or 7-membered, optionally substituted, optionally aromatic, saturated or unsaturated heterocycle optionally comprising another heteroatom which is identical or different from nitrogen; an alkylcarbonylamino radical (RCO-NR'-) in which the radical R represents a C ₁ -C ₄ alkyl radical and R 'represents a hydrogen or a C ₁ -C ₄ alkyl radical. - a (di-) (alkyl) aminocarbonyl ((R) ₂ N-CO-) group in which the R radicals, independently of each other, represent a hydrogen or a C ₁ -C ₄ alkyl radical. a ureido radical (N (R) ₂ -CO-NR'-) in which the radicals R, independently of each other, represent a C ₁ -C ₄ alkyl radical and R 'represents a hydrogen or a C ₁ -C ₄ alkyl radical; ₁ -C ₄ . - a (di-) (alkyl) aminosulfonyl radical ((R) ₂ N-SO ₂ -) in which the radical R represents a hydrogen atom or a C ₁ -C ₄ alkyl radical. an alkylthio radical (RS-) in which the radical R represents a C ₁ -C ₄ alkyl radical. an alkylsulphonylamino radical (RSO ₂ -NR'-) in which the radical R represents a C ₁ -C ₄ alkyl radical and the radical R 'represents a hydrogen atom or a C ₁ -C ₄ alkyl radical. a cyano radical (-C≡N) a phenyl radical a thiophene radical an imidazole radical - a trimethylsilylalkyl radical (CrC ₄ ) a nitro radical a trifluoromethyl radical (-CF ₃ ) a thio radical (-SH) an alkylsulfinyl radical (RSO-) in which the radical R represents a C ₁ -C ₄ alkyl radical. an alkylsulphonyl radical (RSO ₂ -) in which the radical R represents a C ₁ -C ₄ alkyl radical.

^* Ri can form a radical R ₂ ortho to the NR ₁ group and the nitrogen atom substituted by R _1, a saturated or unsaturated 5 or 6 membered substituted or unsubstituted.

^* Two radicals R ₂ may form adjacent each other and with the carbon atoms to which they are attached, a (hetero) cyclic aromatic or nonaromatic, 5- or 6-membered, substituted or unsubstituted;

^* Two adjacent radicals R ₃ can form together and with the carbon atoms to which they are attached, an aromatic 5- or 6-membered, substituted or unsubstituted;

The radical R ₄ represents: a hydrogen atom, an optionally substituted C ₁ -C ₁₆ alkyl radical, optionally interrupted by one or more heteroatoms and / or by one or more groups comprising at least one preferably chosen heteroatom; among oxygen, nitrogen, sulfur, CO, SO, SO ₂ , or combinations thereof; the alkyl radical having no nitro, nitroso, peroxo or diazo function, an amino radical optionally substituted by one or two identical or different C ₁ -C ₄ alkyl radicals, optionally carrying at least one hydroxyl or C ₁ -C ₄ alkoxy group; ₁ -C ₂ , said alkyl radicals possibly being able to form, with the nitrogen atom to which they are attached, a 5- or 6-membered saturated or unsaturated or aromatic heterocycle which is optionally substituted, optionally comprising at least one other heteroatom which is identical to or different from the nitrogen, an alkylcarbonylamino radical (RCO-NR'-) in which the radical R represents a C ₁ -C ₄ alkyl radical and R 'represents a hydrogen, a C ₁ -C ₄ alkyl radical. a ureido radical (N (R) ₂ -CO-NR'-) in which the radicals R, independently of each other, represent a C ₁ -C ₄ alkyl radical and R 'represents a hydrogen or a C ₁ -C ₄ alkyl radical; ₁ -C ₄ . an alkylsulphonylamino radical (RSO ₂ -NR'-) in which the radical R represents a C ₁ -C ₄ alkyl radical and R 'represents a hydrogen, a C ₁ -C ₄ alkyl radical, a hydroxycarbonyl radical or an alkoxycarbonyl radical; C ₁ -C ₄ phenyl radical optionally substituted benzyl radical optionally substituted

The radicals R ₆ and R ₇ , which are identical or different, represent: a hydrogen atom - an optionally substituted C ₁ -C ₁₆ alkyl radical, optionally interrupted by one or more heteroatoms and / or by one or more groups comprising at least one at least one heteroatom preferably selected from oxygen, nitrogen, sulfur, CO,

SO ₁ SO ₂ or combinations thereof; the alkyl radical not containing a nitro, nitroso, peroxo or diazo function, an alkoxyaryl radical (-Ph-OR) in which the radical R represents a C ₁ -C ₄ alkyl radical or a (di-) (alkyl) aminoaryl radical (-Ph- N (R) ₂ ) in which the radicals R independently of one another represent a C 1 -C ₄ alkyl radical optionally substituted by a hydroxyl or an alkylsulfonyl radical (RSO ₂ -) in which the R radical represents a C 1 -C alkyl radical; ₁ -C ₄ an aminocarbonyl radical, a (di) alkyl (Ci-C ₄ ) aminocarbonyl radical optionally a CH ₃ CO- radical, an optionally substituted phenyl, an optionally substituted benzyl

^* R ₆ and R ₇ may optionally form with the nitrogen atom to which they are attached, a heterocycle comprising 5 to 7 membered, saturated or unsaturated, optionally substituted, optionally comprising another heteroatom identical to or different from the nitrogen

^* One of R ₆ or R ₇ may also form with the nitrogen atom to which it is attached and with a radical R ₂ located ortho to the group NR ₆ R _7, a saturated or unsaturated 5 or 6 substituted or unsubstituted

^* R ₆ and R ₇ may form with the nitrogen atom to which they are attached and each with a radical R ₂ located ortho to the group NR ₆ R _7, a saturated or unsaturated 5 or 6 membered substituted or no

^* n is an integer between 0 and 4, when n is less than 4, the unsubstituted carbon atom (s) carry (s) a hydrogen atom

^* n 'is an integer between 0 and 2, when n' is less than 2, the unsubstituted carbon atom (s) carries (s) a hydrogen atom ^* the electroneutrality of the compounds of formula (I) being ensured by one or more cosmetically acceptable anions An, identical or not.

The present invention also relates to dye compositions comprising, in a medium suitable for dyeing keratinous fibers, such compounds, as direct dyes.

It further relates to a method for dyeing keratinous fibers comprising contacting a composition according to the invention with said fibers, dry or wet, for a time sufficient to obtain the desired effect. It also relates to a multi-compartment device comprising, in a first compartment, the composition according to the invention, and in a second compartment, an oxidizing composition.

A final subject of the invention is finally constituted by several processes for the preparation of the compounds according to the invention.

It has been found that the hydrazone-functional compounds as defined above make it possible to widen the color pallet and exhibit good toughness with respect to external agents such as, in particular, shampoos, and this, even when the keratin fiber is sensitized. They are also stable in lightening alkaline conditions.

Moreover, these compounds can constitute synthetic intermediates for dyes comprising several identical or different chromophores connected to each other by one or more connecting arms.

But other features and advantages of the present invention will emerge more clearly from the description and examples which will be presented.

In what follows and unless another indication is given, the boundaries delimiting a range of values are included in this area.

For the purposes of the present invention, and unless a different indication is given:

An alkyl radical is linear or branched,

Alkyl or the alkyl part of a radical is said to be substituted "when it comprises at least one substituent selected from the groups: • hydroxy, alkoxy -C ₄ (poly) hydroxyalkoxy, C ₂ -C _4,

Amino optionally substituted with one or more identical or different C ₁ -C ₄ alkyl groups optionally bearing at least one hydroxyl group, said alkyl radicals being able to form, with the nitrogen atom to which they are attached, a 5-membered heterocyclic ring; or 6 members, optionally comprising at least one other heteroatom different or different from nitrogen. Preferably, the alkyl group does not bear alkyl-S0 ₂ -0-, aryl-SO ₂ -O- with an aryl group substituted with an alkyl radical. An aryl or heteroaryl radical or the aryl or heteroaryl part of a radical is said to be "substituted" when it comprises at least one substituent carried by a carbon atom, chosen from

A C ₁ -C ₁₆ , preferably C ₁ -C ₈ , alkyl radical optionally substituted with one or more radicals chosen from hydroxyl and C ₁ -C ₂ alkoxy radicals,

(poly) -hydroxyalkoxy C ₂ -C ₄ , acylamino, amino substituted with two identical or different alkyl radicals, C ₁ -C ₄ , optionally bearing at least one hydroxyl group or, the two radicals may form with the nitrogen atom to which they are attached, a 5- or 7-membered heterocyclic ring, preferably 5 or 6-membered, optionally comprising another heteroatom identical or different from the nitrogen; a halogen atom such as chlorine, fluorine or bromine;

A hydroxyl group or a C ₁ -C ₂ alkoxy radical; a (C ₂ -C ₄ ) polyhydroxyalkoxy radical; An amino radical optionally substituted with one or two identical or different C ₁ -C ₄ alkyl radicals optionally bearing at least one hydroxyl or amino group with two optionally substituted C ₁ -C ₂ alkyl radicals;

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

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

A (di-) (alkyl) aminosulphonyl radical ((R) ₂ N-SO ₂ -) in which the radicals R, which may be identical or different, represent a hydrogen atom or a C ₁ - alkyl radical;

C ₄ optionally bearing at least one hydroxyl group.

The cyclic or heterocyclic part of a non-aromatic radical or a (hetero) cyclic radical is said to be substituted when it comprises at least one substituent borne by a carbon atom chosen from the groups hydroxyl and C ₁ -C ₄ alkoxy. C ₂ -C ₄ (poly) hydroxyalkoxy, alkylcarbonylamino ((RCO-NR'-) in which the radical R 'is a hydrogen atom or a C ₁ -C ₄ alkyl radical optionally carrying at least one hydroxyl group and the radical R is a C ₁ -C ₂ alkyl radical, amino substituted with two identical or different C ₁ -C ₄ alkyl groups; optionally bearing at least one hydroxyl group, said alkyl radicals being able to form, with the nitrogen atom to which they are attached, a 5- or 6-membered heterocycle, optionally comprising at least one other heteroatom which may or may not be different from nitrogen.

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

According to a particular embodiment of the invention, the radical R ₁ represents: a hydrogen, a C 1 -C 6 alkyl radical, optionally substituted with at least one hydroxyl group, with at least one C ₁ -C ₂ alkoxy group, by at least one a group a hydroxycarbonyl group, optionally by at least one amino group optionally substituted with one or two identical or different C ₁ -C ₂ alkyl radicals; a phenyl radical optionally substituted by at least one halogen atom such as chlorine, bromine, iodine, fluorine; by at least one hydroxyl and / or amino group. a benzyl radical optionally substituted with at least one hydroxyl and / or amino group. - an alkyl radical (dC ₄₎ an alkyl carbonyl (C-rC ₄₎ sulfonyl chloride.

Preferably, the radical R 1 represents a hydrogen atom; a methyl radical, a 2-hydroxyethyl radical, a 3-methoxypropyl radical, a (di-) (methyl) aminoethyl radical, a CH ₃ CO- radical, a CH ₃ SO ₂ - radical, a phenyl radical or a benzyl radical; substituted with one or two hydroxy, amino groups or combinations thereof.

According to a more particular variant of the invention, R ₁ represents a hydrogen atom; a methyl radical; a 2-hydroxyethyl radical; a radical CH ₃ CO-, a radical CH ₃ SO ₂ -; an unsubstituted benzyl radical.

According to a more specific variant of the invention, the radicals R5, which may be identical or different, represent a C ₁ -C ₁₆ , preferably C ₁ -C ₈ , alkyl radical which is optionally substituted, optionally interrupted by one or more heteroatoms and or by one or more groups comprising at least one heteroatom, preferably chosen from oxygen, nitrogen, sulfur, CO, SO, SO ₂ or combinations thereof; the alkyl radical having no nitro, nitroso, peroxo or diazo function.

A trimethylsilylalkyl radical C ₁ -C ₄ - a phenyl radical optionally substituted benzyl radical optionally substituted. Preferably, the radicals R ₅ , identical or different, represent a radical methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, 2-hydroxyethyl, 3-hydroxypropyl, 6-hydroxyhexyl, 2-methoxyethyl, 3-methoxypropyl, 3- trimethylsilylpropyl, 2 - ((di-) methyl) aminopropyl, 3 - ((di-) methyl) aminopropyl, phenyl, 4-chlorophenyl, benzyl, 4,6-dihydroxybenzyl.

According to a still more particular variant of the invention, the radicals R ₅ , which may be identical or different, represent the methyl, ethyl, propyl, butyl, 3-trimethylsilylpropyl, 4-chlorophenyl and benzyl radicals.

More particularly, the radicals R ₂ , R 3, which may be identical or different, represent: a halogen atom chosen from bromine, chlorine, fluorine and iodine. an optionally substituted C ₁ -C ₁₆ alkyl radical, optionally interrupted by one or more heteroatoms and / or by one or more groups comprising at least one heteroatom preferably chosen from oxygen, nitrogen, sulfur, CO, SO

SO ₂ or combinations thereof; the alkyl radical not having a nitro, nitroso, peroxo or diazo function, a hydroxyl radical or an alkoxy radical in dC ₄ ; a (poly) hydroxyalkoxy, C ₂ -C ₄ to 1 alkoxy (CrC ₄₎ alkyl carbonyl radical (C-ι-C ₄₎ alkylcarbonyloxy optionally substituted aryloxy radical; an amino radical optionally substituted by one or two alkyl radicals CrC ₄ , which may be identical or different, optionally bearing at least one hydroxyl or C ₁ -C ₂ alkoxy group, said alkyl radicals possibly being able to form, with the nitrogen atom to which they are attached, a 5- or 7-membered saturated heterocycle or unsaturated, optionally substituted, optionally aromatic, optionally comprising another heteroatom identical to or different from nitrogen; by one or two radicals phenyl, aminophenyl, N, N-diethylaminophenyl or methoxyphenyl - an alkyl radical (C ₁ -C ₄ ) carbonylamino in which the amino function is substituted or not by a C ₁ -C ₄ alkyl radical, an aminocarbonyl radical, a (di) group alkyl (CrC ₄ ) aminocarbonyl a ureido radical optionally substituted by one or more C ₁ -C ₄ alkyl radicals an aminosulfonyl radical, (di) alkyl (CrC ₄ ) aminosulfonyl radical - an alkyl radical (dC ₄ ) thio an alkyl radical ( CrC ₄ ) sulfonylamino wherein the amino function is substituted or unsubstituted by a C ₁ -C ₄ alkyl radical a cyano radical a phenyl radical - a thiophene radical an imidazole radical a trimethylsilylalkyl (C ₁ -C ₄ ) radical, a nitro radical, a trifluoromethyl radical, a thio radical, a (C ₁ -C ₄ ) alkyl sulfinyl radical or an alkyl (dC ₄ ) sulphonyl radical.

Preferably, the radicals R ₂ , R 3, which may be identical or different, represent: a halogen atom chosen from chlorine and fluorine. a hydroxyl or a C 1 -C 6 alkyl radical optionally substituted by one or more hydroxy or ((di-) alkyl) amino or sulphonylamino, optionally interrupted by one or more heteroatoms and / or by one or more groups comprising at least one heteroatom preferably chosen; among oxygen, sulfur, SO, SO ₂ or combinations thereof; the alkyl radical having no nitro, nitroso, peroxo or diazoun hydroxyl radical function, a dC ₄ alkoxy radical; a (C ₁ -C ₄ ) alkoxycarbonyl radical; an optionally substituted aryloxy radical; an optionally substituted amino radical:

With one or two identical or different C ₁ -C ₄ alkyl radicals, optionally bearing at least one hydroxyl or C ₁ -C ₂ alkoxy group,

• by one or two phenyl, aminophenyl N, N-diethylaminophenyl, methoxyphenyl or - an alkyl radical (-C ₄₎ alkoxycarbonylamino wherein the amino function is unsubstituted or substituted with alkyl C ₁ -C ₄ aminocarbonyl radical aminosulfonyl, (di) (C ₁ -C ₄ ) alkylaminosulfonyl an alkyl radical (CrC ₄ ) thio - a phenyl radical a trimethylsilylalkyl radical (CrC ₄ ) a trifluoromethyl radical a thio radical.

More particularly, the radicals R ₂ and R 3, which may be identical or different, represent: a chlorine or fluorine atom, a methyl, an ethyl, a propyl, a butyl, a pentyl or a hexyl

2-hydroxyethyl, 3-hydroxypropyl, 6-hydroxyhexyl hydroxyl - methoxy, ethoxy, propoxy hydroxycarbonyl methoxycarbonyl, ethoxycarbonyl, phenyloxy, phenylamino, amino - (di) methylamino, (di) ethylamino, aminophenylamino or methoxyphenylamino, 4 - N, N - diethylaminophenylamino, methylcarbonylamino, aminocarbonyl - aminosulfonyl, dimethylaminosulfonyl, methylthio radical a phenyl radical a trimethylsilylpropyl radical a trifluoromethyl radical - a thio radical.

According to another particular embodiment of the invention, the compounds of formula (I) are such that two adjacent radicals R ₂ form between each other and with the carbon atoms to which they are attached, a cyclic, optionally aromatic radical comprising 5 or 6 links, substituted or not.

According to this particular embodiment, two adjacent radicals R ₂ form between them and with the carbon atoms to which they are connected, a 6-membered aromatic ring radical, unsubstituted.

According to another embodiment, two adjacent radicals R 3 may form between each other and with the carbon atoms to which they are attached, a 6-membered aromatic ring, substituted or unsubstituted. Preferably, if said aromatic ring is substituted, it is substituted by one or more radicals chosen from hydroxyl, amino, diethylamino, hydroxycarbonyl, methoxycarbonyl, chlorine, methyl, ethyl, methoxy. According to this particular embodiment, two adjacent radicals R 3 form between them and with the carbon atoms to which they are connected, a 6-membered aromatic ring radical, unsubstituted.

Advantageously, the radical R ₄ represents more particularly: a hydrogen atom

- an alkyl radical -C _8, optionally substituted, preferably unsubstituted dC _4, and even more advantageously methyl hydroxycarbonyl radical alkoxycarbonyl C ₁ -C ₂ - phenyl a benzyl radical optionally substituted with one or two hydroxyl groups, amino groups or their combination, preferably an unsubstituted benzyl radical.

Preferably, the radical R ₄ represents a hydrogen atom, a methyl radical, a methoxycarbonyl radical, ethoxyethyl, optionally a hydroxycarbonyl radical, a phenyl radical or a benzyl radical.

As regards the radicals R ₆ and R ₇ , the latter, which may be identical or different, more particularly represent: a hydrogen atom an optionally substituted C 1 -C 6 alkyl radical, optionally interrupted by one or more heteroatoms and / or by one or more groups comprising at least one heteroatom preferably selected from oxygen, nitrogen, sulfur, CO, SO, SO ₂ or combinations thereof; the alkyl group having not any nitro, nitroso, peroxo or diazo phenyl optionally substituted by one or more alkoxy radicals C ₁ -C ₄ alkyl and / or by one or more radicals (di -) (alkyl (Ci-C ₄₎ - ) amino. a benzyl optionally substituted with one or more hydroxyl and / or amino, an aminocarbonyl radical, a (di) alkyl (dC ₄ ) aminocarbonyl radical - optionally a CH ₃ CO- radical.

Preferably, the radicals R ₆ and R ₇ , which may be identical or different, represent:

A hydrogen atom

Methyl, ethyl, 2-hydroxyethyl, 3-hydroxypropyl, 3-methoxypropyl - phenyl

A benzyl

2,4-dihydroxybenzyl

A methoxyphenyl

An aminophenyl - a diethylaminophenyl optionally a radical CH ₃ CO-.

^* n is an integer between 0 and 4, when n is less than 4, the unsubstituted carbon atom (s) carries (s) a hydrogen atom. Preferably, n is between 0 and 2. ^* n 'is an integer between 0 and 2, when n' is less than 2, the unsubstituted carbon atom (s) carry (s) a hydrogen atom

According to an advantageous variant of the invention, the compounds of formula (I) are such that the radicals R ₆ and R ₇ , in particular in the case of alkyl radicals as defined above, form with the nitrogen atom to which they are attached, a heterocycle to 5, 6 or 7-membered, preferably saturated, optionally comprising another heteroatom identical or different from nitrogen, such as preferably oxygen.

By way of example of such a group, mention may be made of the pyrrolidine, piperidine, piperazine, morpholine, homopiperazine and homopiperidine rings.

According to a second advantageous variant of the invention, the compounds of formula (I) are such that one of the radicals R ₆ or R ₇ may also form with the nitrogen atom to which it is attached and with a radical R ₂ located in ortho of the NR ₆ R _{7 group} , a saturated or unsaturated 5- or 6-membered heterocycle substituted or unsubstituted, more particularly by a hydroxyl or methoxy group;

For example, the group -NR ₆ R ₇ , with the aromatic ring optionally substituted by a hydroxyl may correspond to the following compounds:

According to a third advantageous variant of the invention, the compounds of formula (I) are such that the two radicals R ₆ and R ₇ can form with the nitrogen atom to which they are attached and each with a radical R ₂ located in ortho of the NR ₆ R _{7 group} , a saturated or unsaturated 5- or 6-membered heterocycle substituted or unsubstituted, more particularly by a hydroxyl or methoxy group.

In the formulas of the compounds of formulas (I), An represents an anion or a mixture of anions, organic or inorganic, making it possible to balance the charge (s) of the compounds of formula (I), for example chosen from a halide such as chloride bromide, fluoride, iodide; a hydroxide; sulphate; a hydrogen sulfate; an alkylsulfate for which the linear or branched alkyl part is C1-Cβ, such as the methylsulphate or ethylsulphate ion; carbonates and hydrogen carbonates; salts of carboxylic acids such as formate, acetate, citrate, tartrate, oxalate; alkylsulphonates for which the linear or branched alkyl part is C ₁ -C _6, such as the methylsulphonate ion; arylsulphonates for which the aryl part, preferably phenyl, is optionally substituted with one or more C ₁ -C ₄ alkyl radicals such as, for example, 4-tolylsulphonate; alkylsulfonyls such as mesylate.

The acid addition salts of the compounds of formulas (I) may be by way of example the addition salts with an organic or inorganic acid such as hydrochloric acid, hydrobromic acid or sulfuric acid. or (alkyl- or phenyl) sulfonic acids such as p-toluenesulfonic acid or methylsulfonic acid.

The solvates of the compounds of formulas (I) represent the hydrates of such compounds and / or the combination of a compound of formula (I) with a linear or branched Ci-C ₄ alcohol such as methanol, ethanol, isopropanol, n-propanol.

According to a particular embodiment, the compounds of formula (I) are represented by the following formulas, as well as their resonant forms and / or their addition salts with an acid and / or their solvates:

OH

Year

Year

Year in which the radicals R 1, R ₄ , R ₅ , An are as defined above.

In particular, the particular mono-hydrazone monochromophoric dyes of particular formula comprising a 2- (benz-) imidazolium unit of formula (I) according to the present invention are represented by the following compounds:

Year

in which An is as defined above.

Another subject of the invention relates to processes for the preparation of the compounds which have just been described.

According to a first variant of the invention, these compounds can be prepared by implementing the following steps: (a) Condensation of a heteroaromatic aldehyde or ketone with a hydrazine derivative

(R ₃ K (a) protic

(N) (III) (IV)

(b) Quaternization of the heterocyclic nucleus

According to this method, a first condensation step of a hydrazine derivative is carried out in the presence of a heteroaromatic aldehyde or ketone in a manner known to those skilled in the art (see, for example, patent GB924601) .

Usually this reaction takes place at a temperature between -20 ° C and 120 ° C, preferably between 0 ° C and 70 ° C.

Typically, the reaction takes place in a suitable solvent such as water; alcohols such as methanol, ethanol, propanol; dimethylformamide, tetrahydrofuran, N-methylpyrrolidone, 1,3-dimethyl-2-oxohexahydropyrimidine or a mixture thereof.

This reaction is usually carried out in the presence of a catalytic amount of an acid chosen in particular from organic acids such as acetic acid, propionic acid, para-toluenesulphonic acid or inorganic acids such as sulfuric 'hydrochloric acid.

Once the reaction has been carried out, a quaternization reaction is carried out in a second step in the presence of an inorganic base (MgO, K ₂ CO ₃ , Na ₂ CO ₃ , ...) or an organic salt (CH ₃ CO ₂ Na, ...). Usually this reaction is carried out in a solvent which may be that of the preceding step or in another suitable organic solvent such as ethyl acetate, 1,2-dichloroethane, toluene

The alkylating agent R ₅ X may be an alkyl halide such as, for example, methyl iodide, 1-bromopropyl or 3-chlorohexane or an alkyl or arylsulphonate such as, for example, methyl 4-toluenesulphonate or benzyl 4-toulenesulphonate, or else dialkylsulphate such as, for example, dimethylsulphate, diethylsulphate or dipropylsulphate.

The temperature is conventionally between 0 and 100 ° C., preferably between 20 ° C. and 70 ° C. By way of example, this first method can be used for the preparation of the following compound:

(M ')

The compound (IM ') shown above can be obtained using the operating protocol described in Org. Lett, 3, 23, 2001, 3803-3806 or WO99 / 43643.

According to a second variant of the invention, the compounds which have just been described can be prepared by implementing the following steps:

(a) Condensation of a heteroaromatic aldehyde or ketone with a hydrazine derivative

Polar solvent (a) protic acid catalysis

(V) (Vl) (VII) x = 1, Br, Cl x = I, Br, Cl

(b) Alkylation of the heterocyclic skeleton

(c) Amination reaction of the aromatic ring

x = 1, Br, Cl (VIII) (IX)

(d) Alkylation reaction of one of the nitrogen atoms of the hydrazone function:

AgβMt alkylaMt

(IX)

The conditions of steps (a) and (b) that were previously described in the context of the first synthetic variant are also applicable in the case of this variant.

In the third step, a coupling reaction is carried out between the aryl halide previously obtained and an aliphatic or aryl amine HNR ₆ R ₇ in a manner known to those skilled in the art.

When HNR ₆ R ₇ is an aliphatic amine, the amination reaction can be done via copper catalysis (CuI, Cu ₂ O, etc.). By way of example, this step can be carried out on the basis of the operating protocols described in the following publications: - Org. Lett. 4, 4, 2002, 581-584

- Org. Lett. 5, 6, 2003, 793-796

Tetrahedron 61, 27, 2005, 6553-6560

When HNR ₆ R ₇ is an aliphatic or aromatic amine, the amination reaction can be carried out via palladium catalysis (Pd ₂ (dba) ₃ , Pd (OAc) ₂ , etc.). By way of example, this step may be carried out on the basis of the operating protocols described in the following publications:

J. Org. Chem. 69, 2004, 9135-9142 - Ang. Chem. Int. Ed. Engl, 34, 12, 1995, 1348-1350

Once the reaction has been carried out, an alkylation reaction is carried out in a fourth step in the presence of an inorganic base (MgO, K ₂ CO ₃ , Na ₂ CO ₃ , etc.).

The alkylating agent R ₁ X may be an alkyl halide such as, for example, methyl iodide, 1-bromopropyl, 3-chlorohexane or an alkyl or arylsulphonate, for example methyl 4-toluenesulphonate or benzyl. 4-toulenesulfonate, or dialkylsulfate such as, for example, dimethylsulfate, diethylsulfate or dipropylsulfate. Usually this reaction is carried out in another suitable organic solvent such as dichloromethane, isopropanol, ethyl acetate, 1,2-dichloroethane, toluene

The temperature is conventionally between 0 and 100 ° C., preferably between 20 ° C. and 70 ° C.

By way of example, this second method can be used for the preparation of the

According to a third variant of the invention, the compounds which have just been described can be prepared by implementing the following steps:

(a) Quaternization reaction of the heterocyclic nucleus:

b) Copulation reaction of a diazonium salt on an activated system.

(c) alkylation reaction

According to this method, a first quaternization step of the compound (XI) is carried out in the presence of an organic base or an organic salt. The conditions for implementing this step are the same as those explained previously.

The compounds (X) are commercial or can be obtained, for example, according to the following operating protocols:

- Farmaco, 5, 57, 2002, 363-367. - US Patent 4746669

In a second step, a coupling reaction of a diazonium salt obtained from an aromatic amine (XII) is carried out on the compound (XI) previously obtained in a manner known to those skilled in the art (see FIG. example the patent FR2123267).

Usually this reaction is carried out in the presence of a suitable solvent among which may be mentioned water, alcohols such as methanol, ethanol, propanol.

The temperature is typically between -20 and 40 ° C, preferably between -5 ° C and 20 ° C.

The pH of the reaction is between 1 and 13, preferably between 3 and 12. The pH may be controlled using organic or inorganic acids such as acetic acid, propionic acid or hydrochloric acid. hydrobromic acid, hydroiodic acid, acid sulfuric or with the aid of inorganic bases such as potassium, sodium, cesium carbonates, sodium hydroxides, potassium hydroxides, lithium hydroxides, etc.

In this second step, it is possible to use commercially available diazonium salts such as:

It is also conceivable to synthesize them beforehand from the aromatic amines (XII) patent FR2123267);

It should be noted that these aromatic amines (XII) are themselves commercial or can be synthesized, for example by using patents FR2806299, FR2807650, DE3016216, DE3433594 and EP911317.

Once the second step has been carried out, an alkylation reaction is carried out in the presence of an inorganic base, under the conditions detailed for the preceding synthesis variants.

Another subject of the present invention consists of a composition comprising, in a medium suitable for dyeing keratin fibers, at least one compound of formula (I), or its addition salts with an acid, as direct dye .

The concentration of compound of formula (I) or in each of the compounds of formula (I) can vary between 0.001 and 20% by weight relative to the total weight of the dyeing composition, more particularly between 0.01 to 10% by weight, and preferably between 0.05 and 5% by weight.

The composition according to the invention may further comprise an oxidation base. This oxidation base may be chosen from the oxidation bases conventionally used in oxidation dyeing, for example para-phenylenediamines, bis-phenylalkylenediamines, para-aminophenols, ortho-aminophenols and heterocyclic bases.

Among the para-phenylenediamines, para-phenylenediamine, paratoluylenediamine, 2-chloro-para-phenylenediamine, 2,3-dimethyl-para-phenylenediamine, 2,6-dimethyl-para-phenylenediamine and 2,6-diethyl-para-phenylenediamine may be mentioned by way of example; , 2,5-dimethyl-para-phenylenediamine, N, N-dimethyl-para-phenylenediamine, N, N-diethyl-para-phenylenediamine, N, N-dipropyl-para-phenylenediamine, 4-amino-N, N-diethyl-3-methylaniline, N, N-bis- (β-hydroxyethyl) paraphenylenediamine, 4-N, N-bis- (β-hydroxyethyl) amino-2-methylaniline, 4-N, N-bis- (β-hydroxyethyl) amino-2-chloroaniline , 2-β-hydroxyethyl paraphenylenediamine, 2-fluoro-para-phenylenediamine, 2-isopropyl-para-phenylenediamine, N- (β-hydroxypropyl) para-phenylenediamine, 2-hydroxymethyl-para-phenylenediamine, N, N-dimethyl-3-methyl-para-phenylenediamine, N N- (ethyl, β-hydroxyethyl) paraphenylenediamine, N- (β, dihydroxypropyl) paraphenylenediamine, the N- (4'-aminophenyl) paraphenylenediamine, N-phenyl paraphenylenediamine, 2-β-hydroxyethyloxy para-phenylenediamine, 2-β-acetylaminoethyloxy para-phenylenediamine, N- (β-methoxyethyl) paraphenylenediamine, 4-aminophenylpyrrolidine, 2-thienyl paraphenylene diamine, 2-β-hydroxyethylamino-5-amino toluene and their addition salts with an acid.

Of the paraphenylenediamines mentioned above, paraphenylenediamine, paratoluylenediamine, 2-isopropyl paraphenylenediamine, 2-β-hydroxyethyl paraphenylenediamine, 2-β-hydroxyethyloxy paraphenylenediamine, 2,6-dimethyl paraphenylenediamine, 2,6-diethyl paraphenylenediamine, 2,3-dimethyl paraphenylenediamine, N, N-bis- (β-hydroxyethyl) paraphenylenediamine, 2-chloro-para-phenylenediamine, 2-β-acetylaminoethyloxy-para-phenylenediamine, and their acid addition salts are particularly preferred .

Among the bis-phenylalkylenediamines, N, N'-bis- (β-hydroxyethyl) N, N'-bis (4'-aminophenyl) -1,3-diamino propanol, N, may be mentioned by way of example. , N'-bis- (β-hydroxyethyl) N, N'-bis- (4'-aminophenyl) ethylenediamine, N, N'-bis- (4-aminophenyl) tetramethylenediamine, N, N'-bis- ( β-hydroxyethyl) -N, N'-bis- (4-aminophenyl) tetramethylenediamine, N, N'-bis- (4-methyl-aminophenyl) tetramethylenediamine, N ₁ N'-bis (ethyl) -N, N ' -bis- (4'-amino, 3'-methylphenyl) ethylenediamine, 1,8-bis (2,5-diamino phenoxy) -3,6-dioxaoctane, and their addition salts with an acid. Among para-aminophenols, there may be mentioned, for example, para-aminophenol,

4-amino-3-methylphenol, 4-amino-3-fluoro phenol, 4-amino-3-hydroxymethylphenol, 4-amino-2-methylphenol, 4-amino-2-hydroxymethylphenol, 4-amino-2- methoxymethyl phenol, 4-amino-2-aminomethyl phenol, 4-amino 2- (β-hydroxyethylaminomethyl) phenol, 4-amino-2-fluoro phenol, and their addition salts with an acid. Among the ortho-aminophenols, there may be mentioned by way of example, 2-amino phenol, 2-amino-5-methylphenol, 2-amino-6-methylphenol, 5-acetamido-2-amino phenol, and their addition salts with an acid.

Among the heterocyclic bases that may be mentioned by way of example are pyridine derivatives, pyrimidine derivatives and pyrazole derivatives. Among the pyridine derivatives, mention may be made of the compounds described for example in patents GB 1 026 978 and GB 1 153 196, such as 2,5-diaminopyridine, 2- (4-methoxyphenyl) amino 3-amino pyridine, 2,3-diamino-6-methoxy pyridine, 2- (β-methoxyethyl) amino-3-amino-6-methoxy pyridine, 3,4-diamino pyridine, and their addition salts with an acid. Among the pyrimidine derivatives, mention may be made of the compounds described, for example, in DE 2 359 399; JP 88-169,571; JP 05 163 124; EP 0 770 375 or patent application WO 96/15765 such as 2,4,5,6-tetraaminopyrimidine, 4-hydroxy 2,5,6-triaminopyrimidine, 2-hydroxy 4,5,6-triaminopyrimidine, 2,4-dihydroxy-5,6-diaminopyrimidine, 2,5,6-triaminopyrimidine, and pyrazolopyrimidine derivatives, such as those mentioned in patent application FR-A-2 750 048 and among which mention may be made of pyrazolo - [1,5-a] -pyrimidine-3,7-diamine; 2,5-dimethyl pyrazolo [1,5-a] pyrimidine-3,7- diamine; pyrazolo [1,5-a] pyrimidine-3,5-diamine; 2,7-dimethyl pyrazolo [1,5-a] pyrimidine-3,5-diamine; 3-amino pyrazolo [1,5-a] pyrimidin-7-ol; 3-amino pyrazolo [1,5-a] pyrimidin-5-ol; 2- (3-amino pyrazolo [1,5-a] pyrimidin-7-ylamino) ethanol, 2- (7-amino pyrazolo [1,5-a] pyrimidin-3-ylamino) - ethanol, 2 - [(3-amino-pyrazolo [1,5-a] pyrimidin-7-yl) - (2-hydroxyethyl) amino] ethanol, 2 - [(7-amino-pyrazolo [ 1,5-a] pyrimidin-3-yl) - (2-hydroxyethyl) amino] ethanol, 5,6-dimethyl pyrazolo [1,5-a] pyrimidine-3,7-diamine, 2,6-dimethyl pyrazolo [1,5-a] pyrimidine-3,7-diamine, 2,5-N, 7-N-7-tetramethyl-pyrazolo [1,5-a] pyrimidine-3, 7-diamine, 3-amino-5-methyl-7-imidazolylpropylamino pyrazolo [1,5-a] pyrimidine and their addition salts with an acid and their tautomeric forms, when tautomeric equilibrium exists.

Among the pyrazole derivatives, mention may be made of the compounds described in patents DE 3 843 892, DE 4 133 957 and patent applications WO 94/08969, WO 94/08970, FR-A-2 733 749 and DE 195 43 988 as 4,5-diamino-1-methyl pyrazole, 4,5-diamino-1- (β-hydroxyethyl) pyrazole, 3,4-diamino pyrazole, 4,5-diamino-1- (4'-chlorobenzyl) pyrazole, 4,5-diamino-1,3-dimethyl pyrazole, 4,5-diamino-3-methyl-1-phenylpyrazole, 4,5-diamino-1-methyl-3-phenylpyrazole, 4-amino-1,3-dimethyl 5-hydrazino pyrazole, 1-benzyl 4,5-diamino-3-methyl pyrazole, 4,5-diamino-3-tert-butyl-1-methyl pyrazole, 4,5-diamino-1-tert-butyl-3-methyl-pyrazole 4,5-diamino 1- (β-hydroxyethyl) 3-methyl pyrazole, 4,5-diamino-1-ethyl-3-methyl-pyrazole, 4,5-diamino-1-ethyl-3- (4'-methoxyphenyl) pyrazole, 4,5-diamino-1-ethyl-3-hydroxymethyl pyrazole, 4,5-diamino-3-hydroxymethyl-1-methyl pyrazole, 4,5-diamino-3-hydroxymethyl-1-isopropyl pyrazole, 4,5-diamin o 3-methyl-1-isopropyl pyrazole, 4-amino-5- (2'-aminoethyl) amino-1,3-dimethyl-pyrazole, 3,4,5-triamino-pyrazole, 1-methyl-3,4,5-triamino pyrazole, 3,5-diamino-1-methyl-4-methylamino pyrazole, 3,5-diamino 4- (β-hydroxyethyl) amino-1-methyl pyrazole, and their addition salts with an acid.

The composition according to the invention may also contain one or more couplers conventionally used for dyeing keratinous fibers. Among these couplers, there may be mentioned meta-phenylenediamines, meta-aminophenols, meta-diphenols, naphthalenic couplers and heterocyclic couplers.

By way of example, mention may be made of 2-methyl-5-aminophenol, 5-N- (β-hydroxyethyl) amino-2-methylphenol, 6-chloro-2-methyl-5-aminophenol and 3-amino phenol, 1,3-dihydroxybenzene, 1,3-dihydroxy-2-methylbenzene, 4-chloro-1,3-dihydroxybenzene, 2,4-diamino- (β-hydroxyethyloxy) benzene, 2- amino 4- (β-hydroxyethylamino) 1-methoxybenzene, 1,3-diamino benzene, 1,3-bis (2,4-diaminophenoxy) propane, 3-ureido aniline, 3-ureido 1-dimethylamino benzene , sesamol, 1-β-hydroxyethylamino-3,4-methylenedioxybenzene, α-naphthol, 2-methyl-1-naphthol, 6-hydroxyindole, 4-hydroxyindole, 4-hydroxy N-methyl indole, 2-amino-3-hydroxy pyridine, 6-hydroxybenzomorpholine, 3,5-diamino-2,6-dimethoxypyridine, 1-N- (β-hydroxyethyl) amino-3,4-methylene dioxybenzene, 2,6-bis- (β-hydroxyethylamino) toluene and their addition salts with an acid. In the composition of the present invention, the coupler or couplers are generally present in an amount of between 0.001 and 10% by weight of the total weight of the dye composition and more preferably from 0.005 to 6% by weight. The oxidation base (s) are present in an amount preferably of between 0.001% to 10% by weight relative to the total weight of the dye composition, and more preferably from 0.005% to 6% by weight.

In general, the addition salts with an acid that can be used in the context of the dyeing compositions of the invention for the oxidation bases and the couplers are chosen in particular from hydrochlorides, hydrobromides, sulphates and citrates. succinates, tartrates, lactates, tosylates, benzenesulfonates, phosphates and acetates.

The composition according to the invention may optionally comprise at least one additional direct dye other than the compounds of formula (I). This can be chosen from cationic or nonionic species. By way of non-limiting examples, mention may be made of nitrobenzene dyes, azo, azomethine, methine, tetraazapenthamethine, anthraquinone, naphthoquinone, benzoquinone, phenotiazine indigo, xanthene, phenanthridine, phthalocyanine dyes, those derived from triarylmethane and natural dyes. alone or in mixtures. It may for example be chosen from the following red or orange nitrobenzene dyes:

1-hydroxy-3-nitro-4-N- (γ-hydroxypropyl) amino benzene,

N- (β-hydroxyethyl) amino-3-nitro-4-amino benzene,

1-amino-3-methyl-4-N- (β-hydroxyethyl) amino-6-nitro benzene, 1-hydroxy-3-nitro-4-N- (β-hydroxyethyl) amino benzene,

1,4-diamino-2-nitrobenzene,

1-amino-2-nitro-4-methylamino benzene,

N- (β-hydroxyethyl) -2-nitro-para-phenylenediamine,

1-amino-2-nitro-4- (β-hydroxyethyl) amino-5-chloro-benzene, 2-nitro-4-amino-diphenylamine,

1-amino-3-nitro-6-hydroxybenzene.

1- (β-aminoethyl) amino-2-nitro-4- (β-hydroxyethyloxy) benzene,

1- (β, γ-dihydroxypropyl) oxy-3-nitro-4- (β-hydroxyethyl) amino benzene,

1-hydroxy-3-nitro-4-aminobenzene, 1-hydroxy-2-amino-4,6-dinitrobenzene,

1-methoxy-3-nitro-4- (β-hydroxyethyl) amino benzene,

2-nitro-4'-hydroxydiphenylamine,

1-amino-2-nitro-4-hydroxy-5-methylbenzene.

The additional direct dye may also be chosen from yellow and yellow-green nitro benzene direct dyes, for example compounds selected from: 1-β-hydroxyethyloxy-3-methylamino-4-nitrobenzene,

1-methylamino-2-nitro-5- (β, γ-dihydroxypropyl) oxybenzene,

1- (β-hydroxyethyl) amino-2-methoxy-4-nitrobenzene,

1- (β-aminoethyl) amino-2-nitro-5-methoxy-benzene, 1,3-di (β-hydroxyethyl) amino-4-nitro-6-chlorobenzene,

1-amino-2-nitro-6-methyl-benzene,

1- (β-hydroxyethyl) amino-2-hydroxy-4-nitrobenzene,

N- (β-hydroxyethyl) -2-nitro-4-trifluoromethylaniline,

4- (β-hydroxyethyl) amino-3-nitro-benzenesulfonic acid, 4-ethylamino-3-nitro-benzoic acid,

4- (β-hydroxyethyl) amino-3-nitro-chlorobenzene,

4- (β-hydroxyethyl) amino-3-nitro-methylbenzene,

4- (β, γ-dihydroxypropyl) amino-3-nitro-trifluoromethylbenzene,

1- (β-ureidoethyl) amino-4-nitrobenzene, 1,3-diamino-4-nitrobenzene,

1-hydroxy-2-amino-5-nitrobenzene,

1-amino-2- [tris (hydroxymethyl) methyl] amino-5-nitro-benzene,

1- (β-hydroxyethyl) amino-2-nitrobenzene,

4- (β-hydroxyethyl) amino-3-nitrobenzamide. Mention may also be made of blue or violet nitrobenzene direct dyes, for example:

1- (β-hydroxyethyl) amino-4-N, N-bis- (β-hydroxyethyl) amino-2-nitrobenzene,

1- (γ-hydroxypropyl) amino 4-N, N-bis- (β-hydroxyethyl) amino-2-nitrobenzene,

1- (β-hydroxyethyl) amino-4- (N-methyl, N-β-hydroxyethyl) amino-2-nitrobenzene, 1- (β-hydroxyethyl) amino-4- (N-ethyl, N-β-hydroxyethyl) ) amino 2-nitrobenzene,

4- (β, γ-dihydroxypropyl) amino-4- (N-ethyl, N-β-hydroxyethyl) amino-2-nitrobenzene,

the 2-nitroparaphenylenediamines of the following formula:

NRbRc in which: Rb represents a C 1 -C 4 alkyl radical, a β-hydroxyethyl or β-hydroxypropyl or γ-hydroxypropyl radical;

Ra and Rc, which may be identical or different, represent a β-hydroxyethyl, -β-hydroxypropyl, γ-hydroxypropyl or β, γ-dihydroxypropyl radical, at least one of Rb, Rc or Ra radicals representing a γ-hydroxypropyl radical and Rb and Rc can not simultaneously designate a β-hydroxyethyl radical when Rb is a γ-hydroxypropyl radical, such as those described in French patent FR 2,692,572. Among the azo direct dyes that may be used according to the invention, mention may be made of the cationic azo dyes described in patent applications WO 95/15144, WO 95/01772 and EP 714954.

Among these compounds, the following dyes may be mentioned in particular: 1,3-dimethyl-2 - [[4- (dimethylamino) phenyl] azo] -1H-imidazolium chloride, 1,3-dimethyl-2-chloride [ (4-Aminophenyl) azo] -1H-imidazolium, 1-methyl-4 - [(methylphenylhydrazono) methyl] -pyridinium methylsulfate. Mention may also be made, among the azo direct dyes, of the following dyes, described in the COLOR INDEX INTERNATIONAL 3rd edition: -Disperse Red 17 -Acid Yellow 9 -Acid Black 1 -Basic Red 22

-Basic Red 76-Basic Yellow 57-Basic Brown 16-Acid Yellow 36 -Acid Orange 7

-Acid Red 33 -Acid Red 35 -Basic Brown 17 -Acid Yellow 23 -Acid Orange 24

-Disperse Black 9.

There may also be mentioned 1- (4'-aminodiphenylazo) -2-methyl-4bis- (β-hydroxyethyl) aminobenzene and 4-hydroxy-3- (2-methoxyphenylazo) -1-naphthalenesulfonic acid.

Among the quinone direct dyes, mention may be made of the following dyes: -Disperse Red 15

-Solvent Violet 13 -Acid Violet 43 -Disperse Violet 1 -Disperse Violet 4 -Disperse Blue 1

-Disperse Violet 8 -Disperse Blue 3 -Disperse Red 1 1 -Acid Blue 62 -Disperse Blue 7

-Basic Blue 22 -Disperse Violet 15 -Basic Blue 99 as well as the following compounds:

-1-N-methylmorpholiniumpropylamino-4-hydroxyanthraquinone -1-Aminopropylamino-4-methylaminoanthraquinone

-1-Aminopropylaminoanthraquinone -5-β-hydroxyethyl-1,4-diaminoanthraquinone -2-aminoethylaminoanthraquinone -1,4-bis (β, γ-dihydroxypropylamino) -anthraquinone. Among the azine dyes, mention may be made of the following compounds:

-Basic Blue 17 -Basic Red 2.

Among the triarylmethane dyes that can be used according to the invention, mention may be made of the following compounds: -Basic Green 1

-Acid blue 9 -Basic Violet 3 -Basic Violet 14 -Basic Blue 7 -Acid Violet 49

-Basic Blue 26 -Acid Blue 7

Among the indoamine dyes that can be used according to the invention, mention may be made of the following compounds: 2-β-hydroxyethlyamino-5- [bis- (β-4'-hydroxyethyl) amino] anilino-1,4-benzoquinone

2-β-hydroxyethylamino-5- (2'-methoxy-4'-amino) anilino-1,4-benzoquinone 3-N (2'-chloro-4'-hydroxy) phenyl-acetylamino-6-methoxy-1, 4-Benzoquinone imine 3-N (3'-Chloro-4'-methylamino) phenyl-ureido-6-methyl-1,4-benzoquinone imine 3- [4'-N- (ethyl, carbamylmethyl) amino] phenyl -ureido-6-methyl-1,4-benzoquinone imine.

Among the tetraazapentamethine type dyes that can be used according to the invention, mention may be made in particular of 2 - ((E) - {(E) - [(1,3-dimethyl-1,3-dihydro-2H-imidazol-2) 2-{(E) - [(1Z) -N- (1,3-dimethyl) -1,3-dimethyl-1H-imidazol-3-yl} -methylidene) hydrazono] methyl} diazenyl) 1, 3-dihydro-2H-imidazol-2-ylidene) ethane hydrazonoyl] diazenyl} -1,3-dimethyl-1H-imidazol-3-ium, 4-methoxy-2 - (()) - chloride (1 E) -1 - [(2E) - (4-methoxy-1-methylpyridin-2 (1H) -ylidene) hydrazono] ethyl] diazenyl) -1-methylpyridinium, 1-methyl-2- chloride ( (E) - {(1 E) -1 - [(2E) - (1-methylpyridin-2 (1H) -ylidene) hydrazono] ethyl} diazenyl) pyridinium, 1- (2-hydroxyethyl) -2-hydroxyethyl chloride - [(E) - ((1E) -1 - {(2E) - [1- (2-hydroxyethyl) pyridin-2 (1H) -ylidene] hydrazono} ethyl) diazenyl] pyridinium, the chloride of methyl-2 - ((E) - {(E) - [(2Z) - (1-methylpyridin-2 (1H) - ylidene) hydrazono] methyl} diazenyl) pyridinium, 1- (2-hydroxyethyl) -2 - [(E) - ((E) - {(2E) - [1 - (2-hydroxyethyl) pyridin-2) acetate (1H) -ylidene] hydrazono} methyl) diazenyl] pyridinium.

Among the natural direct dyes that may be used according to the invention, lawsone, juglone, alizarin, purpurine, carminic acid, kermesic acid, purpurogalline, protocatechaldehyde, indigo, isatin , curcumin, spinulosin, apigenidine. It is also possible to use the extracts or decoctions containing these natural dyes, and in particular poultices or extracts made from henna.

If present, the content of additional direct dye (s) in the composition generally varies from 0.001 to 20% by weight relative to the weight of the composition, and preferably from 0.01 to 10% by weight. weight relative to the weight of the composition.

The appropriate medium for dyeing, also called dyeing medium, is generally constituted by water or a mixture of water and at least one organic solvent to solubilize compounds that are not sufficiently soluble in water .

More particularly, the organic solvents are chosen from monoalcohols or diols, linear or branched, preferably saturated, comprising 2 to 10 carbon atoms, such as ethyl alcohol, isopropyl alcohol, hexylene glycol (2-methyl 2,4-pentanediol), neopentyl glycol and 3-methyl-1,5-pentanediol; aromatic alcohols such as benzyl alcohol, phenylethyl alcohol; glycols or glycol ethers such as, for example, ethylene glycol monomethyl, monoethyl and monobutyl ethers, propylene glycol or its ethers such as, for example, propylene glycol monomethyl ether, butylene glycol, dipropylene glycol; as well as the alkyl ethers of diethylene glycol, especially of C ₁ -C ₄ , such as, for example, diethylene glycol monoethyl ether or monobutyl ether, alone or as a mixture.

The usual solvents described above, if they are present, usually represent from 1 to 40% by weight, more preferably from 5 to 30% by weight, relative to the total weight of the composition.

The dyeing composition in accordance with the invention 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 polymers. ionic, amphoteric, zwitterionic 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 unmodified, film-forming agents, ceramides, preserving agents, opacifying agents. These 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 such that the advantageous properties intrinsically attached to the oxidation dyeing composition according to the invention are not, or not substantially impaired by the addition or additions envisaged.

The pH of the dye composition according to the invention is generally between 3 and 12 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:

Ra _χ Rb

N W- N

Rc Rd wherein W is a propylene residue optionally substituted by a hydroxyl group or an alkyl radical in dC ₄ ; R _a, R b, R _c and R _d, identical or different, represent a hydrogen atom, an alkyl radical -C ₄ hydroxyalkyl or Ci-C _4. The dye composition according to the invention may be in various forms, such as in the form of liquids, creams, gels, pastes or in any other form suitable for dyeing keratinous fibers, and especially human hair.

The composition according to the invention may further comprise at least one oxidizing agent.

In this case, we speak of ready-to-use compositions.

By ready-to-use composition is meant in the sense of the present invention, the composition intended to be applied immediately to the keratinous fibers, that is to say that it can be stored as it is before use or result from extemporaneous mixing of two or more compositions.

According to this variant, the composition of the invention comprises at least one oxidizing agent in order notably to obtain a lightening of the fibers. The oxidizing agents conventionally used for dyeing keratin fibers are, for example, peroxide hydrogen, urea peroxide, alkali metal bromates, persalts such as perborates and persulfates, peracids and oxidase enzymes, among which mention may be made of peroxidases, 2-electron oxidoreductases such as uricases and 4-electron oxygenases such as laccases. According to one particular embodiment, the composition contains a peroxide-type oxidizing agent and / or a persalt-type oxidizing agent, for example a mixture of hydrogen peroxide and persulfates, hydrogen peroxide alone or persulfate alone.

The content of oxidizing agent is generally between 1 and 40% by weight, relative to the weight of the ready-to-use composition, preferably between 1 and 20% by weight relative to the weight of the ready-to-use composition. .

Generally, the oxidizing composition used is an aqueous composition and may be in the form of a solution or an emulsion.

Usually, the oxidant-free composition is mixed with about 0.5 to 10 equivalents by weight of the oxidizing composition. It should be noted that the pH of the ready-to-use composition is more particularly between 4 and 12, preferably between 7 and 11.5.

The pH of the composition may be adjusted by means of an alkalinizing or acidifying agent, chosen in particular from those mentioned above, in the context of the description according to the invention.

The subject of the invention is also a dyeing method which comprises the application of a dyeing composition according to the invention to keratinous fibers, dry or wet.

The application to the fibers of the dye composition comprising the compound (s) of formula (I) or its addition salts with an acid, optionally at least one oxidation base optionally associated with at least one coupler, optionally at least one additional direct dye, can be implemented in the presence of oxidizing agent.

This oxidizing agent may be added to the composition comprising the compound (s) of formula (I) and any additional oxidation bases, couplers and / or direct dyes, either at the time of use or directly on the keratinous fiber. . The oxidizing composition may also contain various adjuvants conventionally used in compositions for dyeing hair and as defined above.

The pH of the oxidizing composition containing the oxidizing agent is such that, after mixing with the dyeing composition, the pH of the resulting composition applied to the keratinous fibers preferably varies between 4 and 12 approximately, and even more preferably between 7 and 1. 1, 5. It can be adjusted to the desired value by means of acidifying or alkalizing agents usually used in dyeing keratinous fibers and as defined above.

The composition which is finally applied to the keratin fibers may be in various forms, such as in the form of liquids, creams or gels. or in any other form suitable for dyeing keratin fibers, and especially human hair.

According to a particular embodiment, the composition according to the invention is free of oxidation base and coupler.

The composition applied may optionally comprise at least one oxidizing agent.

The composition is therefore applied to the keratin fibers, dry or wet, and then left for a sufficient exposure time to obtain the desired color.

Whichever variant is chosen (with or without an oxidizing agent), the exposure time is generally between a few seconds and one hour, preferably between 3 and 30 minutes.

The temperature at which the composition is allowed to act is generally between 15 and 220 ° C, more particularly between 15 and 80 ° C, preferably between 15 and 40 ° C.

At the end of the exposure time, the composition is removed by rinsing with water, optionally followed by washing with a shampoo, then optionally drying.

Another object of the invention is a multi-compartment device or "kit" of dyeing in which a first compartment contains the dye composition of the invention and a second compartment contains the oxidizing composition. This device may be equipped with means for delivering the desired mixture onto the hair, such as the devices described in patent FR-2,586,913.

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

EXAMPLE

Example 1-

Synthesis of 2 - ((1E) -2-methoxy-N- [4-r (4-methoxyphenyl) amino] phenyl] -N-methyl-2-oxoethanehydrazonoyl) -1,3-dimethyl-1H-methosulphate salt

3,1-benzimidazol-3-ium T61.

Step 1 :

Compound I Compound 2

Compound 1 is commercial.

In a 10OmL flask surmounted by a condenser, the compound 1 (20g) solubilized in 20 mL of a 35% hydrochloric acid solution is stirred. 100 ml of methanol are subsequently added. The reaction medium is heated at reflux for 48 hours.

After reaction, the solvents are removed under reduced pressure.

The residue obtained is purified on a flash silica column (eluent DCIWMeOH (9/1)). After concentration, 8.65 g of a beige powder corresponding to compound 2 are obtained.

The NMR spectra and the mass spectra are in accordance with the expected compound 2.

2nd step :

In a three-necked flask of 50 ml surmounted by a condenser, 1 g of compound 2 in solution in 5 ml of THF is stirred; Sodium acetate (0.47 g, 1.1 eq) and dimethylsulphate (1.09 ml, 2.2 eq) are then added. The reaction medium is refluxed for 12 hours.

After reaction, the reaction medium is cooled. The white precipitate formed during the reaction is filtered and then solubilized in 100 ml of a 0.1M aqueous sodium hydroxide solution. The aqueous phase is then extracted with dichloro-methane and then dried over sodium sulphate, filtered and concentrated. The powder obtained is then dried under active vacuum. 0.74 g of a pale yellow powder corresponding to compound 3 are obtained.

The NMR spectra and the mass spectra are in accordance with the expected compound 3.

Step 3:

Compound 4 is commercial.

In a three-necked flask of 50 ml surmounted by a condenser, compound 3 (0.7 g, 1 eq) dissolved in 6 ml of methanol and 2 ml of water is stirred at room temperature. Compound 4 (0.61 g, 1.1 eq.) Previously dissolved in 4 ml of methanol is then added at ambient temperature. The reaction medium is left at room temperature with stirring for 12 hours. The pH of the reaction medium is then adjusted to 11 with a 1N sodium hydroxide solution.

A precipitate is formed. This is filtered and then dried under active vacuum.

0.61 g of a brown powder corresponding to compound 5 are obtained.

The NMR spectra and the mass spectra are in accordance with the expected compound.

Step 4:

Composed JS Compound 6

In a 50 ml three-neck flask surmounted by a condenser, the compound 5 (0.28 g, 1 eq.), Potassium carbonate (0.076 g, 1.1 eq) in solution in 8 ml of dichloromethane. The reaction medium is then heated to reflux. Dimethyl sulfate () is then added to the previous mixture. The reaction medium is left under reflux with stirring for 12 hours. After reaction, the reaction medium is cooled and then evaporated to dryness. The resulting residue is then purified by semi-preparative HPLC.

After purification, 0.121 g of a dark brown powder corresponding to compound 6 are obtained.

The NMR spectra and the mass spectra are in accordance with the expected compound 6. Example 2

Synthesis of 2-1 (1 E) -N-r4- (diethylamino) phenyl-2-methoxy-N-methyl-2-oxoethanehydrazonoyl | -1,3-dimethyl-1H-benzimidazol-3-ium Methosulfate Salt T91.

Step 1

Compound 7 is commercial.

In a three-necked flask of 50 ml surmounted by a condenser, compound 3 (1 g, 1 eq) solubilized in 5 ml of water is stirred at room temperature. Compound 7 (0.87 g, 1.1 eq.) Is then added, dissolved beforehand in 8 ml of methanol. The reaction medium is left at room temperature with stirring for 12 hours. The pH of the reaction medium is then adjusted to 1 with 0.1 N sodium hydroxide solution.

A precipitate is formed. This is filtered and then dried under active vacuum.

0.23 g of a brown powder corresponding to compound 8 are obtained.

The NMR spectra and the mass spectra are in accordance with the expected compound 8.

2nd step K ₂ CO ₃

Compound 8 Compound 9_

In a 50 ml three-neck flask surmounted by a condenser, compound 8 (0.3 g, 1 eq.), Potassium carbonate (0.09 g, 1.1 eq) in solution in 5 ml of dichloromethane. The reaction medium is then heated to reflux. Dimethyl sulphate (62 μl, 1.1 eq.) Is then added to the above mixture. The reaction medium is left under reflux with stirring for 12 hours. After reaction, the reaction medium is cooled and then evaporated to dryness.

The resulting residue is then purified by semi-preparative HPLC.

After purification, 0.08 g of a dark brown powder corresponding to compound 9 are obtained.

The NMR spectra and the mass spectra are in accordance with the expected compound 9.

Example 3

Synthesis of 2-r (1E) -2-methoxy-N-methyl-2-oxo-N- (4-pyrrolidin-1-yl-1-naphthyl) ethanehydrazon H-1,3-dimethyl-1 Methosulfate Salt H-benzimidazol-3-ium H 51.

Step 1 :

In a 50 ml three-necked flask with a condenser, compound 10 (1 g, 1 eq.), Compound H (2 ml, 5 eq.) Dissolved in 1 ml of isopropanol is stirred. The reaction medium is then heated at 85 ° C. for 4.5 hours. After reaction, the reaction medium is cooled and then evaporated to dryness. The heterogeneous medium is then poured into 200 ml of a mixture of water and ice.

The precipitate formed is then filtered, washed several times with water and then dried under active vacuum in the presence of P ₂ O 5.

1.13 g of a yellow powder corresponding to compound 12 are obtained.

The NMR spectra and the mass spectra are in accordance with the expected compound Λ 2.

2nd step

Compose λ2 Compose J2

In a one liter reactor, compound 12 (10.5 g), palladium on carbon (10-30%) (1.1 g) dissolved in 500 ml of ethanol is stirred. The reaction medium is then heated to 50 ° C. Hydrogen is then introduced (22 bar) to the above mixture. The reaction medium is left under hydrogen at 50 ° C. for 1 hour. After reaction, the reaction medium is cooled and filtered.

The homogeneous solution obtained is then poured into a dilute solution of hydrochloric acid (5N isopropanol) and stirred for an additional hour.

A precipitate is formed gradually. This is filtered washed with diisopropyl ether and then dried under vacuum.

11.8 g of a light pink powder corresponding to compound 13 are obtained.

The NMR spectra and the mass spectra are in accordance with the expected compound 13. Step 3

In a 50 ml three-necked flask equipped with a condenser and a thermometer, the compound 13 (2 g, 1 eq.) Is stirred at 0 ° C. and then solubilized in 5 ml of water. ml of acetic acid and 1 ml of 35% hydrochloric acid.

A first solution consisting of sodium nitrite (0.61 g, 1.1 eq) solubilized in 2 ml of water previously cooled to 0 ° C is then slowly added to the preceding reaction medium. The reaction medium is then stirred at 0 ° C. for 1 hour. A sulphamic acid tip is added to the previous mixture.

A second solution consisting of compound 3 (3.19 g, 1 eq.) Solubilized in 3 ml of water and previously cooled to 0 ° C. is then slowly added to the preceding reaction medium. This is then left stirring at 0 ° C for 30 minutes.

Subsequently, the pH of the reaction mixture is reduced to 8 with a 10M sodium hydroxide solution. A precipitate appears. This is filtered and washed several times with water.

Purification: The precipitate is then solubilized in ethyl acetate, and then extracted several times with water. The organic phase is then dried over sodium sulfate, filtered and then evaporated to dryness.

1.7 g of a dark yellow powder corresponding to compound 14 are obtained.

The NMR spectra and the mass spectra are in accordance with the expected compound 14.

Step 4 K ₀ CO,

Compound 14 Compound 15

In a 50 ml three-neck flask surmounted by a condenser, the compound 14 (0.4 g, 1 eq.), Potassium carbonate (0.137 g, 1.1 eq.) Dissolved in 5 ml of dichloromethane. The reaction medium is then heated to reflux. Dimethyl sulfate (0.103 ml, 1.2 eq.) Is then added to the above mixture. The reaction medium is left under reflux with stirring for 12 hours. After reaction, the reaction medium is cooled and then evaporated to dryness. The resulting residue is then purified by semi-preparative HPLC.

After purification, 0.061 g of a brown powder corresponding to the compound 15 are obtained.

Examples of dyes: The dye compositions were prepared in the following proportions Solution 1:

Solution 2: pH 9.5 BUFFER

Solution 3: BUFFER pH 7

At pH 7, the coloring compositions are obtained by dissolving the dye indicated below (5 × 10 ^-3 mol / l) in solution 1 and then adding an equivalent volume of buffer solution 3.

Under lightening alkaline conditions, the coloring compositions are obtained by dissolving the dye indicated below (5 × 10 ^-3 mol / l) in solution 1 and then adding an equivalent volume of buffer solution 2 and a volume of oxygenated water at 40 ° C. volumes.

Each composition is applied to gray hair at 90% white, (1g of wick for 6g of solution). After 30 minutes break, the locks are rinsed, washed with a standard shampoo, rinsed again and then dried.

The following dyeing results were obtained

Claims

Monocontaining monochromophoric compounds comprising a hydrazone function of the following formula (I), its mesomeric forms as well as its addition salts with an acid and its solvates:

Formula in which: The radical R 1 represents: hydrogen, an optionally substituted C ₁ -C ₂ alkyl radical, optionally interrupted by one or more heteroatoms and / or by one or more groups comprising at least one heteroatom, preferably chosen from oxygen; , nitrogen, sulfur, CO, SO, SO ₂ or combinations thereof; the alkyl radical having no nitro, nitroso, peroxo or diazo function, an optionally substituted phenyl radical, a benzyl radical optionally substituted by an alkylcarbonyl radical (R-CO-) in which R represents a C ₁ -C ₄ alkyl radical. an alkylsulfonyl radical (RSO ₂ -) in which R represents a C ₁ -C ₄ alkyl radical. an arylsulfonyl radical (R ¹ SO ₂ -) in which R 'represents an optionally substituted phenyl or benzyl radical. a (di-) (alkyl) aminosulfonyl radical ((R) ₂ N-SO ₂ -) in which the R radicals independently represent a hydrogen or a C ₁ -C ₄ alkyl radical. a radical (di-) (alkyl) aminocarbonyl (R) ₂ N-CO-) in which the R radicals independently represent a hydrogen, a C ₁ -C ₄ alkyl radical.

The radicals R5, which are identical or different, represent: an optionally substituted C ₁ -C ₂₀ alkyl radical, optionally interrupted by one or more heteroatoms and / or by one or more groups comprising at least one heteroatom, preferably chosen from oxygen, sulfur, CO, SO, SO ₂ or combinations thereof; the alkyl radical having no nitro, nitroso, peroxo or diazo function and being necessarily attached to the quaternized or non-quaternized nitrogen atom of the imidazolium ring via a carbon atom a trimethylsilyl C ₁ -C ₄ alkyl radical. an optionally substituted phenyl radical or an optionally substituted benzyl radical

The radicals R ₂ and R ₃ , independently of one another, which are identical or different, represent: a halogen atom an optionally substituted C ₁ -C ₆ alkyl radical, optionally interrupted by one or more heteroatoms and / or by a or more groups comprising at least one heteroatom preferably selected from oxygen, nitrogen, sulfur, CO, SO, SO ₂ or combinations thereof, a hydroxyl radical and a C ₄ alkoxy radical; a C ₂ -C ₄ (poly) hydroxyalkoxy group, an alkoxycarbonyl radical (RO-CO-) in which R represents a C ₁ -C ₄ alkyl radical;

C ₄ . an aryloxy radical optionally substituted with a (di-) arylamino radical optionally substituted with an amino radical optionally substituted by one or two identical or different C ₁ -C ₄ alkyl radicals, optionally bearing at least one hydroxyl or C ₁ -C ₂ alkoxy group; said alkyl radicals possibly being able to form, with the nitrogen atom to which they are attached, a 5- or 7-membered, optionally substituted, optionally aromatic, saturated or unsaturated heterocycle optionally comprising another heteroatom which is identical or different from nitrogen; an alkylcarbonylamino radical (RCO-NR'-) in which the radical R represents a C ₁ -C ₄ alkyl radical and R 'represents a hydrogen or a C ₁ -C ₄ alkyl radical. a (di-) (alkyl) aminocarbonyl ((R) ₂ N-CO-) group in which the R radicals, independently of each other, represent a hydrogen or a C ₁ -C ₄ alkyl radical. a ureido radical (N (R) ₂ -CO-NR'-) in which the radicals R, independently of each other, represent a C ₁ -C ₄ alkyl radical and R 'represents a hydrogen or a C ₁ -C ₄ alkyl radical; ₁ -C ₄ .

A (di-) (alkyl) aminosulfonyl radical ((R) ₂ N-SO ₂ -) in which the radical R represents a hydrogen atom or a C ₁ -C ₄ alkyl radical. an alkylthio radical (RS-) in which the radical R represents a C ₁ -C ₄ alkyl radical. an alkylsulphonylamino radical (RSO ₂ -NR'-) in which the radical R represents a C ₁ -C ₄ alkyl radical, and the radical R 'represents a hydrogen atom, an alkyl radical

C ₁ -C ₄ . a cyano radical (-C≡N) a phenyl radical - a thiophene radical an imidazole radical a trimethylsilylalkyl radical (Ci-C ₄ ) a nitro radical a trifluoromethyl radical (-CF ₃ ) a thio radical (-SH) - an alkylsulfinyl radical (RSO-) in which the radical R represents a C ₁ -C ₄ alkyl radical . an alkylsulfonyl radical (RSO ₂ -) in which the radical R represents a C ₁ -C ₄ alkyl radical.

^* R ₁ can form a radical R ₂ ortho to the NR ₁ group and the nitrogen atom substituted by R _1, a saturated or unsaturated 5 or 6 membered substituted or unsubstituted.

The radical R ₄ represents: a hydrogen atom an optionally substituted C ₁ -C ₁₆ alkyl radical, optionally interrupted by one or more heteroatoms and / or by one or more groups comprising at least one heteroatom preferably chosen from oxygen, nitrogen, sulfur, CO,

SO, SO ₂ , or combinations thereof; the alkyl radical having no nitro, nitroso, peroxo or diazo function, an amino radical optionally substituted by one or two identical or different C ₁ -C ₄ alkyl radicals, optionally carrying at least one hydroxyl or C ₁ -C ₄ alkoxy group; ₁ -C ₂ , said alkyl radicals possibly being able to form, with the nitrogen atom to which they are attached, a 5- or 6-membered saturated or unsaturated or aromatic heterocycle which is optionally substituted, optionally comprising at least one other heteroatom which is identical to or different from the 'nitrogen. an alkylcarbonylamino radical (RCO-NR'-) in which the radical R represents a C ₁ -C ₄ alkyl radical and R 'represents a hydrogen or a C ₁ -C ₄ alkyl radical. a ureido radical (N (R) ₂ -CO-NR'-) in which the radicals R, independently of each other, represent a C ₁ -C ₄ alkyl radical and R 'represents a hydrogen or a C ₁ -C ₄ alkyl radical; ₁ -C ₄ . an alkylsulphonylamino radical (RSO ₂ -NR'-) in which the radical R represents a C ₁ -C ₄ alkyl radical and R 'represents a hydrogen, a C ₁ -C ₄ alkyl radical, a hydroxycarbonyl radical or a C alkoxycarbonyl radical; ₁ -C ₄ a phenyl radical optionally substituted an optionally substituted benzyl radical * The radicals R ₆ and R ₇ , which may be identical or different, represent: a hydrogen atom an optionally substituted C ₁ -C ₁₆ alkyl radical, optionally interrupted by one or more heteroatoms and / or by one or more groups comprising at least one heteroatom preferably chosen from oxygen, nitrogen, sulfur, CO,

SO ₁ SO ₂ or combinations thereof; the alkyl radical having no nitro, nitroso, peroxo or diazo function, an alkoxyaryl radical (-Ph-OR) in which the radical R represents a C ₁ -C ₄ alkyl radical or a (di-) (alkyl) aminoaryl radical ( -Ph-N (R) ₂ ) in which the radicals R independently of one another represent a C ₁ -C ₄ alkyl radical optionally substituted by a hydroxyl or an alkylsulfonyl radical (RSO ₂ -) in which the radical R represents an alkyl radical in C ₁ -C ₄ aminocarbonyl radical, a (di) alkyl (Ci-C ₄₎ aminocarbonyl optionally a CH ₃ CO- radical - optionally substituted phenyl, optionally substituted benzyl

^* n is an integer between 0 and 4, when n is less than 4, the unsubstituted carbon atom (s) carries (s) a hydrogen atom ^* n 'is an integer between 0 and 2, when n' is less than 2, the unsubstituted carbon atom (s) carries (s) a hydrogen atom

^* The electrical neutrality of the compounds of formula (I) being provided with one or more cosmetically acceptable anions, identical or not.

2. Compounds according to the preceding claim, characterized in that the radical R 1 represents: a hydrogen, an alkyl radical in dC ₆ , optionally substituted with at least one hydroxyl group, with at least one C ₁ -C ₂ alkoxy group, with less one group a hydroxycarbonyl group, optionally by at least one amino group substituted or not by one or two identical or different alkyl radicals dC ₂ a phenyl radical optionally substituted by at least one halogen atom such as chlorine, bromine, iodine or fluorine; by at least one hydroxyl and / or amino group. a benzyl radical optionally substituted with at least one hydroxyl and / or amino group. an alkyl radical (dC ₄₎ alkyl carbonyl radical (-C ₄₎ alkylsulfonyl.

3. Compounds according to one of the preceding claims, characterized in that the radical R ₁ represents a hydrogen atom; a methyl radical, a 2-hydroxyethyl radical, a 3-methoxypropyl radical, a (di-) (methyl) aminoethyl radical, a CH ₃ CO- radical, a CH ₃ SO ₂ - radical, a phenyl radical or a benzyl radical; substituted with one or two hydroxy, amino groups or combinations thereof.

4. Compounds according to one of the preceding claims, characterized in that the radicals R ₅ , which may be identical or different, represent an optionally substituted C ₁ -C ₆ alkyl radical, optionally interrupted by one or more heteroatoms and / or by one or more groups. comprising at least one heteroatom, preferably selected from oxygen, nitrogen, sulfur, CO, SO, SO ₂ or combinations thereof; the alkyl radical having no nitro, nitroso, peroxo or diazo function.

A trimethylsilylalkyl radical C ₁ -C ₄ a phenyl radical optionally substituted an optionally substituted benzyl radical.

5. Compounds according to one of the preceding claims, characterized in that the radicals R ₅ , which are identical or different, represent a methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, 2-hydroxyethyl or 3-hydroxypropyl radical. 6-hydroxyhexyl, 2-methoxyethyl, 3-methoxypropyl, 3-trimethylsilylpropyl, 2 - ((di-) methyl) aminopropyl, 3 - ((di-) methyl) aminopropyl, phenyl, 4-chlorophenyl, benzyl, 4,6 - dihydroxybenzyl.

6. Compounds according to one of the preceding claims, characterized in that the radicals R ₂ , R ₃ , identical or different, represent: - a halogen atom selected from bromine, chlorine, fluorine, iodine. alkyl CRCI _{6 alkyl} optionally substituted, optionally interrupted by one or more heteroatoms and / or by one or more groups comprising at least one heteroatom preferably selected from oxygen, nitrogen, sulfur, CO, SO, SO ₂ or their combinations; the alkyl radical having no nitro, nitroso, peroxo or diazo function a hydroxyl radical a C ₁ -C ₄ alkoxy radical; a (poly) hydroxyalkoxy, C ₂ -C ₄ alkoxy (Ci-C ₄₎ alkoxycarbonyl radical alky ^ d ^^ arbonyloxy an optionally substituted aryloxy radical - an amino radical optionally substituted by one or two alkyl radicals -C ₄ identical or different, optionally bearing at least one hydroxyl group or C ₁ -C ₂ alkoxy, said alkyl radicals possibly being able to form, with the nitrogen atom to which they are attached, a 5- or 7-membered, saturated or unsaturated, optionally substituted heterocycle optionally aromatic, optionally comprising another heteroatom identical to or different from nitrogen; with one or two phenyl, aminophenyl, N, N-diethylaminophenyl methoxyphenyl or a radical alkyl (Ci-C ₄₎ alkoxycarbonylamino wherein the amino function is unsubstituted or substituted with alkyl C ₁ -C ₄ aminocarbonyl radical, (di) alkyl (Ci-C ₄ ) aminocarbonyl group - a ureido radical substituted or not by one or more C ₁ -C ₄ alkyl radicals an aminosulfonyl radical, (di) alkyl (C ₁ -C ₄ ) aminosulfonyl radical an alkyl radical (CrC ₄₎ thio an alkyl (Ci-C ₄₎ sulfonylamino wherein the amino function is unsubstituted or substituted with alkyl C ₁ -C ₄ to ₁ a cyano radical a phenyl radical thiophene imidazole radical a radical trimethylsilylalkyl (Ci-C ₄₎ - nitro trifluoromethyl thio radical an alkyl radical (C ₁ -C ₄₎ alkyl sulfinyl radical (-C ₄₎ alkylsulfonyl.

7. Compounds according to one of the preceding claims, characterized in that the radicals R ₂ , R 3, which may be identical or different, represent: a halogen atom chosen from chlorine and fluorine. a C ₁ -C ₈ alkyl radical optionally substituted by one or more hydroxy or ((di-) alkyl) amino or sulphonylamino, optionally interrupted by one or more heteroatoms and / or by one or more groups comprising at least one heteroatom preferably selected from oxygen, sulfur, SO, SO ₂ or combinations thereof; the alkyl radical having no nitro, nitroso, peroxo or diazo function; a hydroxyl radical; a dC ₄ alkoxy radical; a (C 1 -C ₄ ) alkoxycarbonyl radical; an optionally substituted aryloxy radical; an optionally substituted amino radical:

• by one or two phenyl, aminophenyl N, N-diethylaminophenyl, methoxyphenyl or a radical alkyl (Ci-C ₄₎ alkoxycarbonylamino wherein the amino function is unsubstituted or substituted with alkyl C ₁ -C ₄ to ₁ aminocarbonyl radical an aminosulphonyl, (di) alkyl (C 1 -C ₄ ) aminosulphonyl radical, a (C ₁ -C ₄ ) alkyl radical, a phenyl radical, a trimethylsilylalkyl (C ₁ -C ₄ ) radical, a trifluoromethyl radical or a thio radical.

8. Compounds according to one of the preceding claims, characterized in that two adjacent radicals R ₂ form between them and with the carbon atoms to which they are connected, a cyclic radical, optionally aromatic, comprising 5 or 6 members, substituted or unsubstituted.

9. Compounds according to one of the preceding claims, characterized in that two adjacent radicals R ₃ form between them and with the carbon atoms to which they are attached, a 6-membered aromatic ring, substituted or unsubstituted.

10. Compounds to any of the preceding claims, characterized in that the radical R ₄ represents: a hydrogen atom - an alkyl radical in C ₁ -Cs optionally substituted hydroxycarbonyl radical alkoxycarbonyl C ₁ -C ₂ a phenyl radical a benzyl radical optionally substituted with one or two hydroxyl groups, amino groups or their combination.

1. Compounds according to one of the preceding claims, characterized in that the radical R ₄ represents a hydrogen atom, a methyl radical, optionally a hydroxycarbonyl radical, a methoxyethyl radical, an ethoxyethyl radical, a phenyl radical or a benzyl radical. .

12. Compounds according to one of the preceding claims, characterized in that the radicals R ₆ or R ₇ , identical or different, represent: a hydrogen atom an optionally substituted C ₁ -C ₈ alkyl radical, optionally interrupted by a or more heteroatoms and / or one or more groups comprising at least one heteroatom preferably selected from oxygen, nitrogen, sulfur, CO, SO, SO ₂ or combinations thereof; the alkyl group having not any nitro, nitroso, peroxo or diazo phenyl optionally substituted by one or more alkoxy radicals C ₁ -C ₄ alkyl and / or by one or more radicals (di -) (alkyl (Ci-C ₄ ) -) amino. a benzyl optionally substituted by one or more hydroxyl and / or amino, an aminocarbonyl radical, a (di) alkyl (CrC ₄ ) aminocarbonyl radical, optionally a CH ₃ CO- group.

13. Compounds according to one of the preceding claims, characterized in that the radicals R ₆ or R ₇ , which may be identical or different, represent:

A hydrogen atom

Methyl, ethyl, 2-hydroxyethyl, 3-hydroxypropyl, 3-methoxypropyl

Phenyl - A benzyl

2,4-dihydroxybenzyl

A methoxyphenyl

Aminophenyl

Diethylaminophenyl - optionally a CH ₃ CO- group.

14. Compounds according to any one of the preceding claims, characterized in that the radicals R ₆ and R ₇ , in the case of alkyl radicals as defined above, form, with the nitrogen atom to which they are attached, a heterocycle. 5, 6 or 7-membered, preferably saturated, optionally comprising another heteroatom identical to or different from nitrogen.

15. Compounds according to any one of claims 1 to 14, characterized in that one of the radicals R ₆ or R ₇ can form with the nitrogen atom to which it is attached and with a radical R ₂ located in ortho of the group NR ₆ R ₇ , a saturated or unsaturated heterocycle at 5 or

6-membered substituted or not.

16. Compounds according to any one of the preceding claims, characterized in that the cosmetically acceptable An anion is selected from halides, such as chlorides, bromides; hydroxides; sulphates; hydrogen sulphates; carbonates, hydrogen carbonates; perchlorates; the carboxylic acid salts like acetates; citrates; tartrates; alkyl sulphates for which the linear or branched alkyl part is C ₁ -C ₆ , such as methosulphate or ethosulphate ions; alkylsulphonates for which the linear or branched alkyl part is C ₁ -C ₆ ; arylsulfonates for which the aryl part, preferably phenyl, is optionally substituted by one or more alkyl radicals in dC ₄ .

17. Compounds according to any one of the preceding claims, characterized in that they correspond to the following formulas, as well as their resonant forms and / or their addition salts with an acid and / or their solvates:

Year

Year

Year in which the radicals R 1, R ₄ , R ₅ , An are as defined above.

18. Dyeing composition comprising in a medium suitable for dyeing keratin fibers, as direct dye, at least one compound of formula (I) according to any one of the preceding claims, as well as its mesomeric forms, its salts of additions with an acid and its solvates.

19. Composition according to the preceding claim, characterized in that the content of compound of formula (I) or in each of the compounds of formula (I) varies between 0.001 and 20% by weight relative to the total weight of the dyeing composition, plus particularly between 0.01 to 10% by weight ,.

20. Composition according to any one of claims 18 or 19, characterized in that it comprises at least one additional direct dye, at least one oxidation base optionally associated with at least one coupler, or mixtures thereof.

21. Composition according to the preceding claim, characterized in that the additional direct dye is a cationic or nonionic dye selected from nitrobenzene dyes, azo, azomethine, methine, tetraazapenthamethine, anthraquinone, naphthoquinone, benzoquinone, phenotiazine indigo, xanthene dyes, phenanthridines, phthalocyanines, those derived from triarylmethane, natural dyes, alone or in mixtures.

22. Composition according to Claim 20, characterized in that the oxidation base is chosen from o-phenylenediamines, p-phenylenediamines, double bases, o-aminophenols, p-aminophenols, heterocyclic bases, and their salts. addition with an acid, and mixtures thereof.

23. A composition according to claim 20, characterized in that the coupler is chosen from m-aminophenols, m-phenylenediamines, m-diphenols, naphthols, heterocyclic couplers, their addition salts with an acid, as well as their mixtures.

24. Composition according to any one of claims 18 to 23, characterized in that it comprises at least one oxidizing agent.

25. A process for dyeing keratinous fibers comprising contacting a composition according to any one of claims 18 to 23 with said fibers, dry or wet, for a time sufficient to obtain the desired effect.

26. Multi-compartment device in which a first compartment contains the composition according to any one of claims 18 to 24 and a second compartment containing an oxidizing composition.

27. Process for the preparation of compounds of formula (I) according to one of claims 1 to 17, wherein the following steps are carried out: (a) Condensation of an aldehyde with a derivative of hydrazine

(b) Quaternization of the heterocyclic nucleus

28. Process for the preparation of the compounds of formula (I) according to one of claims 1 to 17, in which the following steps are carried out:

(a) Condensation of an aldehyde with a hydrazine derivative

(b) Alkylation of the heterocyclic skeleton

(c) Amination reaction of the aromatic ring

(IX) (VIII) x = 1, Br, Cl

(d) Alkylation reaction of one of the nitrogen atoms of the hydrazone function:

(IX)

29. Process for the preparation of the compounds of formula (I) according to one of claims 1 to 17, wherein the following steps are carried out: (a) quaternization reaction of the heterocyclic nucleus:

b) Copulation reaction of a diazonium salt on an activated system.

(c) alkylation reaction