2
CATIONIC AZO DYES WITH JULOLIDINE UNITS, DYEING COMPOSITION CONTAINING THEM, METHOD OF
DYEING
The present application relates to the use for the dyeing of keratin fibres, in particular human keratin fibres, such as the hair, of cationic azo compounds with julolidine units as direct dyes, a dyeing composition containing these particular azo compounds, a method of dyeing of said fibres employing them, a kit with compartments and novel cationic azo compounds with julolidine units.
The dyeing of keratin fibres and in particular human hair with dyeing compositions containing oxidation dye precursors, generally called oxidation bases, such as ortho- or para-phenylenediamines, ortho-or para-aminophenols and heterocyclic compounds, is known. These oxidation bases are colourless or weakly coloured compounds which, when combined with oxidizing products, can give rise by a process of oxidative condensation to coloured compounds.
It is also known that it is possible to vary the shades obtained with these oxidation bases by combining them with dyeing coupling agents or modifiers, the latter being selected notably from the aromatic meta-diamines, the meta-aminophenols, the meta-diphenols and certain heterocyclic compounds, such as indole compounds.
The wide range of molecules employed for the oxidation bases and the coupling agents gives a rich palette of colours.
The so-called "permanent" dyeing obtained using these oxidation dyes must, moreover, meet a certain number of requirements. Thus, it must not cause any problems in toxicological terms, it must make it possible to obtain shades of the desired intensity and display

2A
good resistance to external agents, such as light, weather, washing, permanent waving, sweating and rubbing.
The dyes must also provide coverage of white hair, and must finally have minimum selectivity, i.e. they must give the smallest possible differences in coloration all the way along one and the same keratin fibre, which is generally sensitized (i.e. damaged) to a different degree between its tip and its root.
The dyeing of keratin fibres by direct or semi-permanent dyeing is also known. The method traditionally used in direct dyeing comprises applying direct dyes, which are coloured and colouring molecules with affinity for the fibres, to the keratin fibres, waiting for a time to allow the coloured molecules to penetrate, by diffusion, to the interior of the hairs, and then rinsing the fibres.
In contrast to the compositions for oxidation dyeing, the direct or semi-permanent dyeing compositions are used without the obligatory presence of an oxidizing agent. This dyeing can be carried out repeatedly without degrading the keratin fibre.
For example, the use of nitro benzene, anthraquinone, nitropyridine, azo, xanthene, acridine, azine or triarylmethane direct dyes is known.
The resulting coloration is often chromatic, but is however temporary or semi-permanent owing to the nature of the bonds between the direct dyes and the keratin fibres. These interactions mean that the dyes are readily desorbed from the surface and/or the core of the fibre. The coloration generally has poor resistance to washing or to sweating.
There is a real need for dyes with better performance, giving improvements in terms of uniformity of colouring, in relation to the quality of the hair that is dyed, shampoo and after-shampoo resistance

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(tenacity), restriction of scouring which leads to risks of patchiness, colour change over time when chromatic dyes are combined which have different respective tenacity.
Furthermore, the use of known cationic direct dyes makes it possible to obtain rich chromatic shades, which are however restricted to one colour range (yellow, orange, red). Thus, there is a need for dyes outside of the known colour range.
The applicant has now discovered, surprisingly and advantageously, that a class of cationic direct azo dyes with a so-called "julolidine" unit can provide these improvements.
Cationic dyes with the so-called "julolidine" unit are described in US patent 4,341,853 as a photosensitizer in electrophotography.
These azo compounds give dyes that are resistant to external factors (sun, weather) as well as to shampooing and sweating. These compositions have a good toxicological profile. In addition, these dyes can produce strong highlights, notably in the blue and violet shades. Whether alone or in combination with other traditional direct dyes or oxidation dyes, they make it possible to extend the colour range.
A first object of the present invention relates to the use of cationic azo compounds with a julolidine unit as direct dyes for keratin fibres, in particular human keratin fibres, such as the hair.
A second object of the present invention comprises a dyeing composition for the dyeing of keratin fibres, in particular human keratin fibres, such as the hair, containing at least one cationic azo compound with a julolidine unit according to the invention, in a dyeing medium suitable for dyeing.
The invention also relates to a method of dyeing of keratin fibres, in particular human keratin fibres, such as the hair, employing the dyeing composition according to the invention.

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Another object of the present invention is the use of said composition for the dyeing of keratin fibres, in particular human keratin fibres, such as the hair.
The invention further relates to a kit with compartments containing the dyeing composition according to the present invention.
Finally, a last object of the invention relates to particular cationic azo compounds with a julolidine unit.
Other characteristics, aspects, objects and advantages of the invention will become clearer on reading the description and the examples which follow.
It should be noted that in what follows, and unless stated otherwise, the limits of a range of values are included in that range.
The cationic azo compounds with a julolidine unit according to the present invention correspond to the compound of the following formula (I):

in which
A represents a cationic aromatic heterocycle selected from the
compounds of the following general formulae:

5
R1 represents independently of one another:
• a linear or branched, saturated or unsaturated C1-C16 hydrocarbon
chain, which can form one or more carbon rings with 3 to 7 ring
members, optionally condensed with the aromatic ring, optionally
substituted, optionally interrupted by one or more groups selected from
heteroatoms such as oxygen, nitrogen or sulphur, and the carbonyl
group; Rj not containing a nitro, nitroso, peroxide and diazo bond; Ri
being directly attached to the nitrogen atom, quaternized or not, of the
heteroaromatic ring A by means of a carbon atom.
R2 represents independently of one another:
• a linear or branched, saturated or unsaturated Cj-Ci6
hydrocarbon chain, which can form one or more aromatic or non-
aromatic carbon rings, with 3 to 6 ring members, optionally substituted,
optionally interrupted by one or more heteroatoms or by one or more
groups bearing at least one heteroatom, preferably selected from oxygen
and nitrogen;
• a hydroxyl group,
• a C1-C4 alkoxy group,
a C2-C4 (poly)hydroxyalkoxy group;
an alkoxycarbonyl group (R11O-CO-) in which R11 represents a C1-C4 alkyl radical;
• an alkylcarbonyloxy radical (R12CO-O-) in which R12 represents
a C1-C4 alkyl radical;
• an amino group, an amino group substituted with one or two Cj-
C4 alkyl radicals, which may be identical or different, optionally bearing
at least one hydroxyl group, where the two alkyl radicals can optionally
form, with the nitrogen atom to which they are attached, a heterocycle
with 5 or 6 ring members optionally bearing another heteroatom
identical to or different from nitrogen, for example oxygen, sulphur;

6
• an alkylcarbonylamino group (R13CO-NR13-) and/or (R13CO-NH)
in which the radicals R13 independently of one another, represent a Ci-
C4 alkyl radical;
• a carbamoyl group ((R14)2N-CO) in which the radicals R14
independently of one another, which may be identical or different,
represent a hydrogen atom, a C1-C4 alkyl radical;
a ureido group ((R15)2N-CO-NR16-) in which the radicals R15 and R16, independently of one another, represent a hydrogen atom, a C1-C4 alkyl radical;
• a sulphonamide group ((R17)2N-SO2-) in which the radicals R17,
independently of one another, represent a hydrogen atom, a C1-C4 alkyl
radical;
• an alkylsulphonylamino group (R18SO2-NR19-) in which the
radicals Rjs, R]9, independently of one another, represent a hydrogen
atom, a C1-C4 alkyl radical;
a guanidinium group ((R2o)2N-C(=NH2+)-NR2i-) in which the radicals R20 and R21, independently of one another, represent a hydrogen atom, a C1-C4 alkyl radical;
a nitro group;
• a cyano group;
a halogen atom, preferably chlorine, fluorine;
two radicals R2, carried by adjacent carbon atoms can form, together with the carbon atom to which each is attached, an aromatic or non-aromatic condensed ring; m represents an integer between 0 and 4; e is an integer between 0 and 2; p is an integer between 0 and 1; D represents a group CR2 or a nitrogen atom Q represents a group NRi, or an atom of oxygen or of sulphur;

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bond a arising from formulae (Ila), (lib) or (lie), joins group A to the
azo group;
in the case of formulae (Ila), (lib) or (He) and when two radicals R2
carried by two adjacent carbon atoms form an aromatic ring, bond a can
join group A to the azo group via said aromatic ring;
the electroneutrality of the compounds being provided by one or more
anions An", which may be identical or different, cosmetically
acceptable, including chloride, methylsulphate, methosulphate, tosylate,
acetate;
X, Y and Z are defined as possibilities of substitutions respectively on
the alkyl and aryl rings of the three-ring nucleus;
x is between 0 and 2, y is between 0 and 6, and z is between 0 and 6, x,
y and z being integers;
or their salts of addition or their solvates,
with the exception of
2-(9-julolidylazo)-3-methylbenzothiazolium perchlorate
2-(9-julolidylazo)-3-ethylthiazolium perchlorate, which are known
sensitizers in electrophotography.
In what follows, and unless stated otherwise:
When an alkyl radical or the alkyl part of a radical is said to be "substituted", it contains at least one substituent selected from the groups:
• hydroxyl,
• C1-C4 alkoxy, C2-C4 (poly)hydroxyalkoxy,
• amino, amino substituted with one or more C1-C4 alkyl groups
which may be identical or different, optionally bearing at least one
hydroxyl group, said alkyl radicals, which can form, with the nitrogen
atom to which they are attached, a heterocycle with 5 or 6 ring members,

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optionally containing at least one other heteroatom which may or may not be nitrogen.
When an aryl or heteroarvl radical or the aryl or heteroaryl part of a radical is said to be "substituted", such as the substituent X on the aromatic ring of the three-ring nucleus, it then comprises at least one substituent carried by a carbon atom, selected from:
• a C1-C16, preferably Ci-Cs, alkyl radical, optionally substituted with
one or more radicals selected from the radicals hydroxy, C1-C2 alkoxy,
C2-C4 (poly)-hydroxyalkoxy, acylamino, amino substituted with one or
two C1-C4 alkyl radicals, which may be identical or different, optionally
bearing at least one hydroxyl group or the two radicals which can form,
with the nitrogen atom to which they are attached, a heterocycle with 5
or 7 ring members, preferably 5 or 6 ring members, optionally
containing another heteroatom identical to or different from nitrogen;
• a halogen atom such as chlorine, fluorine or bromine;
• a hydroxyl group;
a C1-C2 alkoxy radical;
a C2-C4 (poly)-hydroxyalkoxy radical;
• an amino radical;
an amino radical substituted with one or two C1-C4 alkyl radicals, which may be identical or different, optionally bearing at least one hydroxyl group;
• an acylamino radical (-NR31-COR32) in which the radical R31 is a
hydrogen atom, a C1-C4 alkyl radical optionally bearing at least one
hydroxyl group and the radical R32 is a C1-C2 alkyl radical;
• a carbamoyl radical ((R33)2N-CO-) in which the radicals R33, which
may be identical or different, represent a hydrogen atom, a CJ-C4 alkyl
radical optionally bearing at least one hydroxyl group;

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• an alkylsulphonylamino radical (R34SO2-NR35-) in which the radical
R34 represents a hydrogen atom, a C1-C4 alkyl radical optionally bearing
at least one hydroxyl group and the radical R35 represents a C1-C4 alkyl
radical, a phenyl radical;
an aminosulphonyl radical ((Rj6)2N-SO2-) in which the radicals R36, which may be identical or different, represent a hydrogen atom, a C1-C4 alkyl radical optionally bearing at least one hydroxyl group.
When the cyclic or heterocyclic part of a non-aromatic radical is said to be "substituted", such as the substituents Y and Z of the aliphatic heterocycles of the three-ring nucleus, it then comprises at least one substituent carried by a carbon atom selected from the groups:
• hydroxyl,
C1-C4 alkoxy, C2-C4 (poly)hydroxyalkoxy,
alkylcarbonylamino ((R41CO-NR42-) in which the radical R42 is a hydrogen atom, a C1-C4 alkyl radical optionally bearing at least one hydroxyl group and the radical R41 is a C1-C2 alkyl radical, amino substituted with two C1-C4 alkyl groups which may be identical or different optionally bearing at least one hydroxyl group, said alkyl radicals which can form, with the nitrogen atom to which they are attached, a heterocycle with 5 or 6 ring members, optionally containing at least one other heteroatom which may or may not be nitrogen.
-When a ring does not carry the maximum number of substituents, the unsubstituted position or positions then carry a hydrogen atom.
Preferably, Ri represents a Ci-Cg alkyl or hydroxyalkyl group.
According to a first variant, formulae (Ila), (lib) and (lie) are such that they contain two radicals R2 carried by adjacent carbon atoms, said radicals then forming, together with the carbon atom to which each is attached, an aromatic condensed ring, optionally substituted.

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According to a second variant, e, m and p have a value of 0.
Preferably, x has a value of 0 or 1 with X representing an alkyl, hydroxyl, hydroxyalkyl, alkoxy, amino, alkylamino, dialkylamino, acylamino group; alkyl denoting a Cy-Cf, chain, optionally substituted, and acyl denoting alkylcarbonyl.
The following compounds may be mentioned as examples of compounds of formula (I) that can be used according to the invention:


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The dyes corresponding to the formula can be obtained, for example, by four different routes of synthesis, hereinafter called respectively route A, route B, route C and route D:
In the following schemes, the definition of B, non-cationic precursor of A, corresponds to the following 3 formulae:

Hereinafter, HAL denotes a halogen group joined to Ri by one of its carbon atoms, preferably a chloro, bromo or iodo group, or alternatively an alkylsulphato group, preferably methylsulphato or ethylsulphato or alternatively methylsulphonato (mesylate) or arylsulphonato (tosylate).
I/Route of synthesis A
The compound of formula (I) is obtained in three successive stages according to the following scheme:

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The diazonium salt 2. of the heteroaromatic amine BNH2 j_ is prepared by classical methods (H Zollinger, Color Chemistry, Wiley VCH Ed 2003 and The Chemistry of synthetic dyes, Academic Press, London, vol II, 1952). Then the diazonium salt 2_ is reacted with a compound 3. (an aromatic amine with a julolidine unit) to form compound 4_. This type of coupling is well known in the literature cited above.
The third stage comprises reacting compound 4. with an alkylating agent, such as an alkyl sulphate, an alkyl halide, an alkyl alkylsulphonate or an alkyl arylsulphonate, to form compound 5.: a cationic direct azo dye with a julolidine unit.
The alkylation reaction is carried out for example in a halogenated solvent (dichloromettiane) or ester (ethyl acetate), at a temperature below 150°C, preferably with solvent reflux. These conditions are notably described in the literature. As reference to this type of reaction, we may mention for example Advanced Organic Synthesis 5th Ed M. Smith and J. March John Wiley & Sons Ed, 2001 and the international application WO 03/060015.

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2/Route of synthesis B
The compound of formula (I) can be obtained by diazotation of the para-aminated derivative of an aromatic amine with a julolidine unit 6., then coupling of the diazonium salt 7. obtained with a heterocycle to give compound 8., then alkylation of the heterocyclic function to give compound 9. (the cationic direct azo dye with a julolidine unit) according to the following scheme:

All the stages of synthesis are described in the literature and the references for route 1 are also applicable.
More particularly, the second stage comprises reacting the diazonium salt 1_ obtained beforehand with a heterocycle B-H (following the previous definition of B and H representing a hydrogen atom bound to B on the position which will then be that of the azo group).
3/Route of synthesis C
The compound of formula (I) can also be obtained in two stages of synthesis: nucleophilic attack on a carbon atom of a cationic heterocycle [11] by a para-hydrazino compound of an aromatic amine

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with a julolidine unit j_0 then oxidation of the compound j_2 obtained to give compound \3_ (a cationic direct azo dye with a julolidine unit). These reactions are exemplified below with a cationic heterocycle of the pyridinium type and more specifically with compound JJ_ according to the following scheme:

The reaction for forming compound 12. can be carried out in a polar solvent, preferably an alcohol or DMF, at a temperature below 150cC, in the presence if necessary of a base less nucleophilic than the hydrazine selected (/. Med. Chem. 1996, 39 (2), 570-581). Oxidation can be carried out by means of the usual oxidizing agents: N-bromosuccinimide, ferric chloride, manganese oxide, chromium oxides, hydrogen peroxide, peracids, preferably in an acid environment and at a temperature below 100°C for less than twenty-four hours.
4/Route of synthesis D
The compound of formula (I) can also be obtained by oxidative coupling. This route is described in the literature. For reference to this

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type of reaction, we may mention for example Angew. Chem. 1958, 70,215; Angew. Chem., Int. Ed., 1962,1,640 and H Zollinger, Color Chemistry 3rd Ed, VCH Wiley, 2003. The route is exemplified by the following scheme, using pyridinium to illustrate the heterocycle, and more specifically compound j_4 to give compound 1_7_ (a cationic direct azo dye with a julolidine unit):

The starting reactants are commercially available or are obtained by methods known by a person skilled in the art, advantageously starting from commercially available compounds.
The invention also relates to the use of cationic azo compounds with a julolidine unit corresponding to the compound of the following formula (I):

in which
A represents a cationic aromatic heterocycle selected from the
compounds of the following general formulae:

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Ri represents independently of one another:
• a linear or branched, saturated or unsaturated C1-C16 hydrocarbon
chain, which can form one or more carbon rings with 3 to 7 ring
members, optionally condensed with the aromatic ring, optionally
substituted, optionally interrupted by one or more groups selected from
heteroatoms such as oxygen, nitrogen or sulphur, and the carbonyl
group; Ri not containing a nitro, nitroso, peroxide and diazo bond; Rbeing directly attached to the nitrogen atom, quaternized or not, of the
heteroaromatic ring A by means of a carbon atom.
R2 represents independently of one another:
• a linear or branched, saturated or unsaturated Ci-Cj6
hydrocarbon chain, which can form one or more aromatic or non-
aromatic carbon rings, with 3 to 6 ring members, optionally substituted,
optionally interrupted by one or more heteroatoms or by one or more
groups bearing at least one heteroatom, preferably selected from oxygen,
nitrogen;
• a hydroxyl group,
a C1-C4 alkoxy group,
a C2-C4 (poly)hydroxyalkoxy group;
an alkoxycarbonyl group (RnO-CO-) in which Rn represents a C1-C4 alkyl radical;
an alkylcarbonyloxy radical (R12CO-O-) in which R12 represents a C1-C4 alkyl radical;

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• an amino group, an amino group substituted with one or two Ci-
C4 alkyl radicals, which may be identical or different, optionally bearing
at least one hydroxyl group, where the two alkyl radicals can optionally
form, with the nitrogen atom to which they are attached, a heterocycle
with 5 or 6 ring members optionally bearing another heteroatom
identical to or different from nitrogen, for example oxygen, sulphur;
an alkylcarbonylamino group (R13CO-NR.J3-) and/or (R13CO-NH) in which the radicals R13 independently of one another, represent a Ci-C4 alkyl radical;
• a carbamoyl group ((Ri^N-CO) in which the radicals R14
independently of one another, which may be identical or different,
represent a hydrogen atom, a C1-C4 alkyl radical;
• a ureido group ((Ri5)2N-CO-NRi6-) in which the radicals R]5 and
Rj6, independently of one another, represent a hydrogen atom, a C1-C4
alkyl radical;
• a sulphonamide group ((Ri7)2N-SO2-) in which the radicals R17,
independently of one another, represent a hydrogen atom, a C1-C4 alkyl
radical;
an alkylsulphonylamino group (R18SO2-NR19-) in which the radicals Ris, R19, independently of one another, represent a hydrogen atom, a C1-C4 alkyl radical;
a guanidinium group ((R2o)2N-C(=NH2+)-NR2i-) in which the radicals R20 and R21, independently of one another, represent a hydrogen atom, a C1-C4 alkyl radical;
• a nitro group;
• a cyano group;
a halogen atom, preferably chlorine, fluorine;

two radicals R2, carried by adjacent carbon atoms, can form, together with the carbon atom to which each is attached, an aromatic or non-aromatic condensed ring; m represents an integer between 0 and 4; e is an integer between 0 and 2; p is an integer between 0 and 1; D represents a group CR2 or a nitrogen atom Q represents a group NRi, or an atom of oxygen or of sulphur; the bond a from formulae (Ha), (lib) or (lie), joins group A to the azo group;
in the case of formulae (Ila), (lib) or (lie) and when two radicals R2 carried by two adjacent carbon atoms form an aromatic ring, bond a can join group A to the azo group via said aromatic ring;
the electroneutrality of the compounds being provided by one or more anions An~, which may be identical or different, cosmetically acceptable, including chloride, methylsulphate, methosulphate, tosylate, acetate;
X, Y and Z are defined as possibilities of substitutions respectively on the alkyl and aryl rings of the three-ring nucleus;
x is between 0 and 2, y is between 0 and 6, and z is between 0 and 6, x, y and z being integers; or their salts of addition or their solvates In what follows, and unless stated otherwise:
When an alkyl radical or the alkyl part of a radical is said to be
"substituted", it contains at least one substituent selected from the
groups:
• hydroxyl,
C1-C4 alkoxy, C2-C4 (poly)hydroxyalkoxy,

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amino, amino substituted with one or more C1-C4 alkyl groups which may be identical or different optionally bearing at least one hydroxyl group, and said alkyl radicals can form, with the nitrogen atom to which they are attached, a heterocycle with 5 or 6 ring members, optionally containing at least one other heteroatom which may or may not be nitrogen.
When an arvl or heteroarvl radical or the arvl or heteroarvl part of a radical is said to be "substituted", such as the substituent X on the aromatic ring of the three-ring nucleus, it then comprises at least one substituent carried by a carbon atom, selected from:
a C1-C16, preferably Ci-Cg, alkyl radical, optionally substituted with one or more radicals selected from the radicals hydroxy, C1-C2 alkoxy, C2-C4 (poly)-hydroxyalkoxy, acylamino, amino substituted with one or two C1-C4 alkyl radicals, which may be identical or different, optionally bearing at least one hydroxyl group or where the two radicals can form, with the nitrogen atom to which they are attached, a heterocycle with 5 or 7 ring members, preferably 5 or 6 ring members, optionally containing another heteroatom identical to or different from nitrogen;
• a halogen atom such as chlorine, fluorine or bromine;
a hydroxyl group;
a C1-C2 alkoxy radical;
• a C2-C4 (poly)-hydroxyalkoxy radical;
• an amino radical;
• an amino radical substituted with one or two C1-C4 alkyl radicals,
which may be identical or different, optionally bearing at least one
hydroxyl group;
an acylamino radical (-NR.3j-COR.32) in which the radical R31 is a hydrogen atom, a C1-C4 alkyl radical optionally bearing at least one hydroxyl group and the radical R32 is a C1-C2 alkyl radical;

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• a carbamoyl radical ((R.33)2N-CO-) in which the radicals R33, which
may be identical or different, represent a hydrogen atom, a C1-C4 alkyl
radical optionally bearing at least one hydroxyl group;
• an alkylsulphonylamino radical (R34SO2-NR35-) in which the radical
R34 represents a hydrogen atom, a C1-C4 alkyl radical optionally bearing
at least one hydroxyl group and the radical R35 represents a C1-C4 alkyl
radical, a phenyl radical;
an aminosulphonyl radical ((R36)2N-SO2-) in which the radicals R36, which may be identical or different, represent a hydrogen atom, a C1-C4 alkyl radical optionally bearing at least one hydroxyl group.
When the cyclic or heterocyclic part of a non-aromatic radical is said to be "substituted", for example the substituents Y and Z of the aliphatic heterocycles of the three-ring nucleus, it then comprises at least one substituent carried by a carbon atom selected from the groups:
• hydroxyl,
C1-C4 alkoxy, C2-C4 (poly)hydroxyalkoxy,
• alkylcarbonylamino ((R41CO-NR42-) in which the radical R42 is a
hydrogen atom, a C1-C4 alkyl radical optionally bearing at least one
hydroxyl group and the radical R41 is a C1-C2 alkyl radical, amino
radical substituted with two C1-C4 alkyl groups which may be identical
or different optionally bearing at least one hydroxyl group, said alkyl
radicals which can form, with the nitrogen atom to which they are
attached, a heterocycle with 5 or 6 ring members, optionally containing
at least one other heteroatom which may or may not be nitrogen.
-When a ring does not carry the maximum number of substituents, the unsubstituted position or positions then carry a hydrogen atom.
Preferably, Ri represents a Ci-Cg alkyl or hydroxyalkyl group.

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According to a first variant, formulae (Ila), (lib) and (He) are such that they contain two radicals R2 carried by adjacent carbon atoms, said radicals then forming, together with the carbon atom to which each is attached, an aromatic condensed ring, optionally substituted.
According to a second variant, e, m and p have the value 0.
Preferably, x has a value of 0 or 1 with X being an alkyl, hydroxyl, hydroxyalkyl, alkoxy, amino, alkylamino, dialkylamino, acylamino group; alkyl denotes a C1-C6 chain optionally substituted, acyl denotes alkylcarbonyl.
The following compounds may be mentioned as examples of compounds of formula (I) that can be used according to the invention:


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The invention also relates to a dyeing composition for the dyeing of keratin fibres, in particular of human keratin fibres, such as the hair, containing, in a suitable dyeing medium, at least one cationic azo compound as defined above for use as a direct dye.
The dyeing composition according to the present invention can contain from 0.001 to 20 wt.%, preferably from 0.01 to 10 wt.% of cationic direct azo dye of formula (I) relative to the total weight of the composition.
The composition of the present invention can include in addition at least one oxidation base.
For example, the oxidation bases are selected from phenylenediamines, bis-phenylalkylenediamines, para-aminophenols, ortho-aminophenols, heterocyclic bases and their salts of addition.
Among the paraphenylenediamines, the following may be
mentioned as examples: paraphenylenediamine, paratoluylenediamine,
2-chloro paraphenylenediamine, 2,3-dimethyl paraphenylenediamine,
2,6-dimethyl paraphenylenediamine, 2,6-diethyl
paraphenylenediamine, 2,5-dimethyl paraphenylenediamine, N,N-dimethyl paraphenylenediamine, N,N-diethyl paraphenylenediamine, N,N-dipropyl paraphenylenediamine, 4-amino N,N-diethyl 3-methyl

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aniline, N,N-bis-(P-hydroxyethyl) paraphenylenediamine, 4-N,N-bis-((3-hydroxyethyl)amino-2-methylaniline,
4-N,N-bis-((3-hydroxyethyl)amino-2-chloro aniline, 2-(3-hydroxyethyl
paraphenylenediamine, 2-fluoro paraphenylenediamine, 2-isopropyl
paraphenylenediamine, N-(P-hydroxypropyl)
paraphenylenediamine, 2-hydroxymethyl paraphenylenediamine,
N,N-dimethyl 3-methyl paraphenylenediamine, N,N-(ethyl, p-
hydroxyethyl) paraphenylenediamine, N-(P,y-dihydroxypropyl)
paraphenylenediamine, N-(4'-aminophenyl) paraphenylenediamine,
N-phenyl paraphenylenediamine, 2-P-hydroxyethyloxy
paraphenylenediamine, 2-P-acetylaminoethyloxy
paraphenylenediamine, N-(P-methoxyethyl) paraphenylenediamine, 4-
aminophenylpyrrolidine, 2-thienyl paraphenylenediamine, 2-P
hydroxyethylamino 5-amino toluene, 3-hydroxy l-(4'-
aminophenyl)pyrrolidine and their salts of addition with an acid.
Among the paraphenylenediamines mentioned above,
paraphenylenediamine, paratoluylenediamine, 2-isopropyl
paraphenylenediamine, 2-p-hydroxyethyl paraphenylenediamine,
2-P-hydroxyethyloxy paraphenylenediamine, 2,6-dimethyl
paraphenylenediamine, 2,6-diethy] paraphenylenediamine, 2,3-dimethyl
paraphenylenediamine, N,N-bis-(P-hydroxyethyl) paraphenylenediamine,
2-chloro paraphenylenediamine, 2-P-acetylaminoethyloxy
paraphenylenediamine, and their salts of addition with an acid are especially preferred.
Among the bis-phenylalkylenediamines, the following may be
mentioned as examples: N,N'-bis-(P-hydroxyethyl) N,N'-bis-(4'-
aminophenyl) 1,3-diamino propanol, N,N'-bis-(p-hydroxyethyl) N,N'-bis-
(4'-aminophenyl) ethylenediamine, N,N'-bis-(4-aminophenyl)

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tetramethylenediamine, N,N'-bis-(P-hydroxyethyl) N,N'-bis-(4-
aminophenyl) tetramethylenediamine, N,N'-bis-(4-methyl-aminophenyl)
tetramethylenediamine, N,N'-bis-(ethyl) N,N'-bis-(4'-amino,
3'-methylphenyl) ethylenediamine, l,8-bis-(2,5-diamino phenoxy)-3,6-dioxaoctane, and their salts of addition.
Among the para-aminophenols, the following may be mentioned as examples: para-aminophenol, 4-amino 3-methyl phenol, 4-amino 3-fluoro phenol, 4-amino-3-chlorophenol, 4-amino 3-hydroxymethyl phenol, 4-amino 2-methyl phenol, 4-amino 2-hydroxymethyl phenol, 4-amino 2-methoxymethyl phenol, 4-amino 2-aminomethyl phenol, 4-amino 2-((3-hydroxyethyl aminomethyl) phenol, 4-amino 2-fluoro phenol, and their salts of addition with an acid.
Among the ortho-aminophenols, the following may be mentioned as examples: 2-amino phenol, 2-amino 5-methyl phenol, 2-amino 6-methyl phenol, 5-acetamido 2-amino phenol, and their salts of addition.
Among the heterocyclic bases, the following may be mentioned as examples: pyridine derivatives, pyrimidine derivatives and pyrazole derivatives.
Among the pyridine derivatives, we may mention the compounds described for example in patents GB 1 026 978 and GB 1 153 196, such as 2,5-diamino pyridine, 2-(4-methoxyphenyl)amino 3-amino pyridine, 3,4-diamino pyridine, and their salts of addition.
Other pyridine oxidation bases that can be used in the present
invention are the 3-amino pyrazolo-[l,5-a]-pyridine oxidation bases or
their salts of addition described for example in patent application FR
2801308. As examples, we may mention pyrazolo[l,5-a]pyridin-3-
ylamine; 2-acetylamino pyrazolo-[l,5-a] pyridin-3-ylamine; 2-
morpholin-4-yl-pyrazolo[l,5-a]pyridin-3-ylamine; 3-amino-

25
pyraz,olo[l,5-a]pyridine-2-carboxylic acid; 2-methoxy-pyrazolo[l,5-
a]pyridin-3-ylamino; (3-amino-pyrazolo[l,5-a]pyridin-7-yl)-methanol;
2-(3-amino-pyrazolo[l,5-a]pyridin-5-yl)-ethanol; 2-(3-amino-
pyrazolo[l,5-a]pyridin-7-yl)-ethanol; (3-amino-pyrazolo[l,5-a]pyridin-
2-yl)~methanol; 3,6-diamino-pyrazolo[l,5-a]pyridine; 3,4-diamino-
pyrazolo[l,5-a]pyridine; pyrazolo[l,5-a]pyridine-3,7-diamine; 7-
morpholin-4-yl-pyrazolo[l,5-a]pyridin-3-ylamine; pyrazolo[l,5-
a]pyridine-3,5-diamine; 5-morpholin-4-yl-pyrazolo[l,5-a]pyridin-3-
ylamine; 2-[(3-amino-pyrazolo[l,5-a]pyridin-5-yl)-(2-hydroxyethyl)-
amino]-ethanol; 2-[(3-amino-pyrazolo[l,5-a]pyridin-7-yl)-(2-
hydroxyethyl)-amino]-ethanol; 3-amino-pyrazolo[l,5-a]pyridin-5-ol; 3-amino-pyrazolo[l,5-a]pyridin-4-ol; 3-amino-pyrazolo[l,5-a]pyridin-6-ol; 3-amino-pyrazolo[l,5-a]pyridin-7-ol; as well as their salts of addition.
Among the pyrimidine derivatives, we may mention the
compounds described for example in patents DE 2359399; JP 88-169571;
JP 05-63124; EP 0770375 or patent application WO 96/15765 such as
2,4,5,6-tetra-aminopyrimidine, 4-hydroxy 2,5,6-triaminopyrimidine,
2-hydroxy 4,5,6-triaminopyrimidine, 2,4-dihydroxy 5,6-
diaminopyrimidine, 2,5,6-triaminopyrimidine and their salts of addition and their tautomeric forms, when a tautomeric equilibrium exists.
Among the pyrazole derivatives, we may mention the compounds described in patents DE 3843892, DE 4133957 and patent applications WO 94/08969, WO 94/08970, FR-A-2 733 749 and DE 195 43 988 such as 4,5-diamino 1-methyl pyrazole, 4,5-diamino l-(p-hydroxyethyl) pyrazole, 3,4-diamino pyrazole, 4,5-diamino l-(4'-chlorobenzyl) pyrazole, 4,5-diamino 1,3-dimethyl pyrazole, 4,5-diamino 3-methyl 1-phenyl pyrazole, 4,5-diamino 1-methyl 3-phenyl pyrazole, 4-amino 1,3-dimethyl 5-hydrazino pyrazole, 1-benzyl 4,5-diamino 3-methyl pyrazole,

26
4,5-diamino 3-tert-butyl 1-methyl pyrazole, 4,5-diamino 1-tert-butyl 3-methyl pyrazole, 4,5-diamino l-(P-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-diamino 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-(P-hydroxyethyl)amino 1-methyl pyrazole, and their salts of addition. It is also possible to use 4,5-diamino l-(p-methoxyethyl)pyrazole.
The oxidation base or bases present in the composition of the invention are generally present in an amount ranging from approx. 0.001 to 20 wt.% of the total weight of the dyeing composition, preferably ranging from 0.005 to 6%.
If the composition contains at least one oxidation base, the composition according to the invention preferably contains one or more coupling agents used conventionally for the dyeing of keratin fibres. Among these coupling agents, we may notably mention the meta-phenylenediamines, meta-aminophenols, meta-diphenols, naphthalenic coupling agents, and heterocyclic coupling agents, as well as their salts of addition.
As examples, we may mention 1,3-dihydroxy benzene, 1,3-
dihydroxy 2-methyl benzene, 4-chloro 1,3-dihydroxy benzene, 2,4-
diamino l-(P-hydroxyethyloxy) benzene, 2-amino 4-(P-
hydroxyethylamino) 1-methoxybenzene, 1,3-diamino benzene, 1,3-bis-(2,4-diaminophenoxy) propane, 3-ureido aniline, 3-ureido 1-dimethylamino benzene, sesamol, l-P-hydroxyethylamino-3,4-methylenedioxybenzene, oc-naphthol, 2 methyl-1-naphthol, 6-hydroxy

27
indole, 4-hydroxy indole, 4-hydroxy N-methyl indole, 2-amino-3-
hydroxy pyridine, 6-hydroxy benzomorpholine, 3,5-diamino-2,6-
dimelhoxypyridine, l-N-(P-hydroxyethyl)amino-3,4-methylene
dioxvbenzene, 2,6-bis-(P-hydroxyethylamino)toluene and their salts of addition.
In the composition of the present invention, the coupling agent or agents are generally present in an amount ranging from approx. 0.001 to 20 wt.% of the total weight of the dyeing composition, preferably ranging from 0.005 to 6%.
Generally speaking, the salts of addition of the oxidation bases and of the coupling agents that can be used within the scope of the invention are notably selected from the salts of addition with an acid such as hydrochlorides, hydrobromides, sulphates, citrates, succinates, tartrates, lactates, tosylates, benzenesulphonates, phosphates and acetates and salts of addition with a base such as soda, potash, ammonia, amines or alkanolamines.
The dyeing composition according to the invention can moreover contain one or more additional direct dyes other than the cationic azo direct dyes of formula (I) according to the invention, which can notably be selected from the nitro dyes of the neutral, acid or cationic benzene series, the neutral, acid or cationic azo direct dyes, the quinone direct dyes and in particular neutral, acid or cationic anthraquinone direct dyes, azine direct dyes, triarylmethane direct dyes, indoamino direct dyes and natural direct dyes. As non-limiting examples, we may mention benzene nitro dyes, the azo, azometrune, methine, tetraazapentamethine, anthraquinone, naphthoquinone, benzoquinone, phenothiazine indigoid, xanthene, phenanthridine, and phthalocyanine dyes, those derived from triarylmethane and the natural dyes, alone or in mixtures.

28
Among the benzene direct dyes that can be used according to the invention, we may mention non-limitatively the following compounds:
- 1.4-diamino-2-nitrobenzene,
- l-amino-2 nitro-4-(3- hydroxyelhylaminobenzene
- l-amino-2 nitro-4-bis()3-hydi"oxyethyl)-aminobenzene
- 1,4-bis(P-hydroxyethylamino)-2-nitrobenzene
- 1- P-hydroxyethylamino-2-nitro-4-bis-(|3-hydroxyethylamino)-
benzene
- l-P-hydroxyethylamino-2-nitro-4-aminobenzene
- l-(3-hydroxyethylamino-2-nitro-4-(ethyl)(p-hydroxyethyl)-
aminobenzene
- l-amino-3-methyl-4-p-hydroxyethylamino-6-nitrobenzene
- l-amino-2-nitro-4-P-hydroxyethylamino-5-chlorobenzene
- l,2-diamino-4-nitrobenzene
- l-amino-2-P-hydroxyethylamino-5-nitrobenzene
- 1,2-bis-(P-hydroxyethylamino)-4-nitrobenzene
- l-amino-2-tris-(hydroxymethyl)-methylamino-5-nitrobenzene
- l-hydroxy-2-amino-5-nitrobenzene
- l-hydroxy-2-amino-4-nitrobenzene
- l-hydroxy-3-nitro-4-aminobenzene
- l-hydroxy-2-amino-4,6-dinitrobenzene
- l-P-hydroxyethyloxy-2-P-hydroxyethylamino-5-nitrobenzene
- 1 -me thoxy-2-P-hydroxyethy lamino-5 -nitrobenzene
- l-P-hydroxyethyloxy-3-methylamino-4-nitrobenzene
- 1- p,y-dihydroxypropyloxy-3-methylamino-4-nitrobenzene
- l-P-hydroxyethylamino-4-p,7-dihydroxypropyloxy-2-nitrobenzene
- l-P,y-dihydroxypropylamino-4-trifluoromethyl-2-nitrobenzene
- l-P-hydroxyethylamino-4-trifluoromethyl-2-nitrobenzene
- l-P-hydroxyethylamino-3-methyl-2-nitrobenzene

29
- l-P-aminoethylamino-5-methoxy-2-nitrobenzene
- l-hydroxy-2-chloro-6-ethylamino-4-nitrobenzene
- l-hydroxy-2-chloro-6-amino-4-nitrobenzene
- l-hydroxy-6-bis-(|3-hydroxyethyl)-amino-3-nitrobenzene
- l-(3-hydroxyethylamino-2-nitro benzene
- l-hydroxy-4-[3-hydroxyethylamino-3-nitrobenzene.
Among the direct azo dyes that can be used according to the invention we may mention the cationic azo dyes described in patent applications WO 95/15144, WO-95/01772 and EP-714954 the contents of which form an integral part of the invention.
Among these compounds, we may mention quite particularly the following dyes:
l,3-dimethyl-2-[[4-(dimethylamino)phenyl]azo]-lH-imidazolium chloride,
l,3-dimethyl-2-[(4-aminophenyl)azo]-lH-imidazolium chloride, l-methyl-4-[(methylphenylhydrazono)methyl]-pyridinium methyls ulphate.
Among the direct azo dyes, we may also mention the following dyes, described in COLOUR 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

30
- Acid Red 35
- Basic Brown 17
- Acid Yellow 23
- Acid Orange 24
- Disperse Black 9.
We may also mention l-(4'-aminodiphenylazo)-2-methyl-4-bis-
(|3-hydroxyethyl) aminobenzene and 4-hydroxy-3-(2-
methoxyphenylazo)-l-naphthalene sulphonic acid.
Among the direct quinone dyes, we may mention the following dyes:
- Disperse Red 15
- Solvent Violet 13
- Acid Violet 43
- Disperse Violet 1
- Disperse Violet 4
- Disperse Blue 1
- Disperse Violet 8
- Disperse Blue 3
- Disperse Red 11
- Acid Blue 62
- Disperse Blue 7
- Basic Blue 22
- Disperse Violet 15
- Basic Blue 99
as well as the following compounds:
- l-N-methylmorpholiniumpropylamino-4-hydroxyanthraquinone
- l-aminopropylamino-4-methylaminoanthraquinone
- 1-aminopropylaminoanthraquinone
- 5-(3-hydroxyethyl-1,4-diaminoanthraquinone

31
- 2-aminoethylaminoanthraquinone
- 1,4-bis-(P,y-dihydroxypropylamino)-anthraquinone.
Among the azine dyes, we may mention the following compounds:
- Basic Blue 17
- Basic Red 2.
Among the triarylmethane dyes that can be used according to the invention, we may mention 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 indoamino dyes that can be used according to the invention, we may mention the following compounds:
2-p-hydroxyethylamino-5-[bis-(P-4'-hydroxyethyl)amino]anilino-1,4-benzoquinone
2-P-hydroxyethylamino-5-(2'-methoxy-4'-amino)anilino-l,4-benzoquinone
3-N(2'-chloro-4'-hydroxy)phenyl-acetylarnino-6-methoxy-1,4-benzoquinone imine
3-N(3'-chloro-4'-methylamino)phenyl-ureido-6-methyl-l,4-benzoquinone imine
3-[4'-N-(ethyl,carbamylmethyl)-amino]-phenyl-ureido-6-methyl-l,4-benzoquinone imine.

32
Among the dyes of the tetraazapentamethine type that can be used according to the invention, we may mention the following compounds shown in the following table, An being defined as previously:

Among the natural direct dyes that can be used according to the invention, we may mention lawsone, juglone, alizarin, purpurin, carminic acid, kermesic acid, purpurogallin, protocatechaldehyde, indigo, isatin, curcumine, spinulosine, apigenidine. It is also possible to

33
use extracts or decoctions containing these natural dyes and notably henna-based cataplasms or extracts.
The direct dye or dyes different from those of formula (I) preferably represent from approx. 0.001 to 20 wt.% of the total weight of the composition, and even more preferably from approx. 0.005 to 10 wt.%.
The composition according to the invention can also contain at least one oxidizing agent conventionally used for the oxidation dyeing of keratin fibres, such as hydrogen peroxide, urea peroxide, alkali metal bromates, persalts such as perborates and persulphates, peracids and oxidase enzymes among which we may mention peroxidases, 2-electron oxido-reductases such as uricases and 4-electron oxygenases such as laccases. Hydrogen peroxide is particularly preferred.
The medium suitable for dyeing, also called dyeing support, is a cosmetic medium generally comprising water or a mixture of water and at least one organic solvent for dissolving the compounds that would not be sufficiently soluble in water. As examples of organic solvent we may mention C1-C4 lower alkanols, such as ethanol and isopropanol; polyols and ethers of polyols such as 2-butoxyethanol, propyleneglycol, glycerol, monomethylether of propyleneglycol, monoethylether and monomethylether of diethyleneglycol, as well as aromatic alcohols such as benzyl alcohol or phenoxyethanol, and mixtures thereof.
The solvents are, preferably, present in proportions preferably between about 1 and 40 wt.% relative to the total weight of the dyeing composition, and even more preferably between about 5 and 30 wt.%.
The dyeing composition according to the invention can also contain various additives used conventionally in hair-dyeing compositions, such as anionic, cationic, non-ionic, amphoteric,

34
zwitterionic surfactants or mixtures thereof, anionic, cationic, non-ionic, amphoteric, zwitterionic polymers or mixtures thereof, mineral or organic thickening agents, and in particular anionic, cationic, non-ionic and amphoteric associative thickening agents, antioxidizing agents, penetrating agents, sequestering agents, perfumes, buffers, dispersants, conditioners such as volatile or nonvolatile, modified or unmodified silicones, film-forming agents, ceramides, preservatives and opacifiers.
The above additives are generally present in an amount for each of them between 0.01 and 20 wt.% relative to the weight of the composition.
Of course, a person skilled in the art will ensure that any additional compound or compounds selected are such that the advantageous properties intrinsic to the dyeing composition according to the invention will not be adversely affected, or not substantially so, by any additions envisaged.
The pH of the dyeing composition according to the invention is generally between 3 and 12, preferably between 5 and 11, and even more particularly from 6 to 10.5. It can be adjusted to the desired value by means of acidifying or alkalizing agents usually employed in the dyeing of keratin fibres or alternatively by means of conventional buffer systems.
Among the acidifying agents, we may mention the following examples: mineral or organic acids such as hydrochloric acid, orthophosphoric acid, sulphuric acid, carboxylic acids such as acetic acid, tartaric acid, citric acid, lactic acid, sulphonic acids.
Among the alkalizing agents, we may mention the following examples: ammonia, alkaline carbonates, alkanolamines, such as mono-, di- and triethanolamines as well as their derivatives,

35
hydroxides of sodium or of potassium and compounds of the following formula (II):

in which W is a propylene residue optionally substituted with a hydroxyl group or a C1-C4 alkyl radical; Ra, Rb, Rc and Rd, which may be identical or different, represent a hydrogen atom, a C1-C4 alkyl radical or C[-C4 hydroxyalkyl radical.
The dyeing composition according to the invention can be in various forms, such as in the form of liquids, creams, gels, or in any other suitable form for carrying out the dyeing of keratin fibres, and notably of the human hair.
The method of the present invention is a method in which the composition according to the present invention as defined previously is applied to the fibres, then said fibres are rinsed.
According to a particular embodiment, the composition of the invention is applied to keratin fibres in the presence of an oxidizing agent, and in this case it is called a highlighting dyeing. The oxidizing agent can be added to the composition of the invention at the moment of use or it can be provided by an oxidizing composition containing it, applied simultaneously or sequentially with the composition of the invention.
Preferably, in this particular embodiment, the composition of the invention contains at least one oxidation base.
The compositions with or without oxidizing agent are applied to the keratin materials and after a waiting time of about 3 minutes to

36
1 hour, preferably about 15 minutes to 45 minutes, the keratin fibres are rinsed, washed with shampoo, rinsed again and then dried.
The oxidizing composition can also contain various additives used conventionally in hair-dyeing compositions and as defined previously.
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 keratin fibres preferably varies between about 3 and 12, even more preferably between 5 and 11 and even more particularly between 6 and 10.5. It can be adjusted to the desired value by means of acidifying or alkalizing agents usually employed in the dyeing of keratin fibres and as defined previously.
The ready-to-use composition which is finally applied to the keratin fibres can be in various forms, such as in the form of liquids, creams, gels or in any other form suitable for carrying out the dyeing of keratin fibres, and notably of the human hair.
The invention also relates to the use of the dyeing composition according to the invention for the dyeing of keratin fibres.
The invention also relates to a kit with several compartments or "dyeing kit", in which a first compartment contains the dyeing composition according to the invention and a second compartment contains an oxidizing agent. This kit can be equipped with means for supplying the desired mixture onto the hair, such as the kits described in patent FR-2 586 913 in the name of the applicant.
The following examples serve to illustrate the invention but without limiting it.
Examples of preparations of compounds according to the invention:

37 1) Example 1 by route A

100 mL of anhydrous acetic acid and 500 mL of anhydrous propionic acid are added to 200 g of solution at 40% w/v of nitrosylsulphuric acid in sulphuric acid, the mixture is then cooled to below 5°C, and 50 g of 4-aminopyridine is added gradually. The mixture thus obtained is diluted by adding 200 mL of propionic acid and 40 mL of acetic acid, then a solution of 50 g of julolidine in 200 mL of methanol is added dropwise, keeping the temperature below 10°C. The reaction mixture is neutralized after 16 h of reaction at a temperature below 5°C by introduction of 500 mL of water, 300 g of ice then 500 mL of 30% soda. The product (A) is extracted with ethyl acetate, and purified by chromatography on silica gel.
5 mL of dimethylsulphate iis added to 5 g of pure product (A), diluted in 50 mL of dichloromethane, then the reaction mixture is stirred for 2 h. The mixture is concentrated by distillation of the solvents under vacuum, then the residue obtained is purified by dissolution in methyl ethyl ketone followed by precipitation with heptane. 7.12 g of a blue powder is obtained. Analyses indicate that it corresponds to the expected compound [i].

38 2) Example 2 by route A

30 mL of 35% hydrochloric acid is added to 13.21 g of suspension of aminoimidazole in 100 mL of water, the mixture is cooled to -5°C then a solution of 7 g of sodium nitrite in 10 mL of water is added dropwise, keeping the temperature below 0°C. Then 5 g of sulphanilic acid is added, the mixture is poured into an acid solution of julolidine obtained beforehand by mixing 8.75 g of julolidine, 175 mL of water and 225 mL of acetic acid and 40 g of sodium acetate, maintained at 0°C. After 2 h at 5°C, the reaction mixture is diluted, and adjusted to pH 8 with soda. The precipitated product (B) is filtered and washed with water.
5 g of (B) is dissolved in 50 mL of dichloromethane, and 5 mL of dimethylsulphate and 1.53 g of sodium acetate are added successively. After stirring for 2 h, the mixture is concentrated under vacuum, taken up in 100 mL of methyl ethyl ketone and then 100 mL of heptane is added. The precipitate obtained is washed with heptane, and 4.5 g of violet-black powder is obtained. After treatment with ion-exchange resin, the expected product [ii] is obtained in the form of hydrochloride

39
(2.56 g). Analyses indicate that it corresponds to the expected compound [ii].
3) Example 3 by route A

6.3 g of 3-aminopyridine, 17 mL of 35% hydrochloric acid and 65 g of ice are mixed in a 500-mL three-necked flask. A solution of 5.08 g of sodium nitrite in 20 mL of water is added dropwise, keeping the temperature of the mixture at 0°C. On completion of addition, the mixture is stirred for 20 min at 0°C then a solution of 400 mg of urea in 10 mL of water is added. A solution of 11.6 g of julolidine in a mixture of ethanol (25 mL), 35% hydrochloric acid (16 mL) and ice (22 g) is added dropwise, keeping the temperature below 10°C. After 3 h at 5°C, the reaction mixture is neutralized by adding ammonia, until the pH is 9.5. The paste thus obtained is extracted with ethyl acetate with addition of water. The organic phase is dried and concentrated under vacuum; the product thus obtained is purified by chromatography (silica gel, eluent heptane/ethyl acetate) and a pure fraction of a powder of a deep red colour is collected (4.3 g), corresponding to the expected compound (product (C)).
The product obtained in the above stage (127 mg) is dissolved in toluene (5 mL), 86 (iL of dimethylsulphate is added and the reaction

40
mixture is stirred for 72 h. The toluene is removed under vacuum, the product obtained is treated with water for 4 h at room temperature then dried under vacuum, obtaining a deep violet solid (170 mg). Analyses indicate that it corresponds to the expected compound [iii].

10 g of 2-amino-l-methyl benzimidazole is dissolved in a hot mixture of 60 ml of orthophosphoric acid and 20 ml of acetic acid.
26 g of nitrosylsulphuric acid (at 40% in sulphuric acid) is diluted in 25 mL of 98% phosphoric acid at 10°C in a 250-mL three-necked flask equipped with a thermometer and an argon supply.
The first solution is poured dropwise into the second, maintaining the temperature between 2 and 5°C, in 30 min. The mixture is stirred for 15 min. 3.3 g of sulphamic acid is added and the mixture is stirred for 15 min.
13 g of julolidine, previously melted, is dissolved in 25 mL of DMF and 9 g of acetic acid.
The diazonium salt obtained in the preceding operation is poured dropwise into this solution, keeping the temperature below 10°C. The

41
reaction mixture is diluted with 50 mL of water then kept at 0°C for 18 h. 500 g of ice is added, then 100 mL of 30% soda; once more 500 g of ice and 150 mL of 30% soda. The mixture thus obtained is further diluted with 2 L of water then adjusted to pH 7 by adding sodium hydrogencarbonate (190 g).
The precipitate obtained is filtered (9.6 g) and dried. 1 g is purified by chromatography (silica, eluent dichloromethane/methanol). 100 mg of a red powder is obtained. Analyses indicate that it corresponds to the expected compound (D).
100 mg of D is dissolved in 20 mL of dichloromethane, and 500 ul of dimethyl sulphate is added dropwise to this mixture at room temperature. The solution is stirred for 5 min, then poured into 250 mL of ethyl ether. The precipitate is filtered and washed with 4 x 50 mL of ethyl ether. After drying, 50 mg of a black paste is recovered. Analyses indicate that it corresponds to the expected compound [iv].

11.8 g of julolidine is dissolved at 40°C in 100 mL of water to which 5.7 mL of 35% hydrochloric acid has been added. 10 g of

42
pyridine-2-amine 1-oxide (prepared according to the methods described in Synth. Commun. 1977, 509-514) is dissolved in 100 mL of water to which 17.4 mL of 35% hydrochloric acid has been added. A solution of 4.7 g of sodium nitrite dissolved in 10 mL of water is added, maintaining the temperature of the mixture at 0°C. The mixture is stirred for 30 min at 0°C. It is then poured into the acidic solution of julolidine, keeping the temperature below 10°C. The mixture is returned to room temperature in two hours. Addition of 70 g of sodium acetate brings the pH of the mixture to 4.2. After extraction with dichloromethane, rinsing with water, drying over sodium sulphate, filtration, concentration under vacuum, trituration in ether, filtration of the powder obtained and drying under vacuum, 10 g of dark violet powder is collected. Analyses show that it corresponds to the expected product (E), with minor impurities.
5 g of (E) is dissolved in 20 mL of N-methylpyrrolidinone (NMP) and the solution is heated to 60°C. 4.05 g of dimethylsulphate is added to the mixture. After 2 h 30 min the solution is cooled to room temperature. 50 mL of 20% ammonia solution is added. After 15 h at room temperature, the mixture is extracted with dichloromethane (2 x 100 mL), washed with water, dried and concentrated under vacuum. The dark blue oil obtained is washed twice with isopropyl ether, then triturated in a third fraction. After filtration, rinsing with ether and drying under vacuum, 2 g of brown powder is collected. Analyses show that it corresponds to the expected product [v].
Examples of dyeing (non-highlighting conditions):

43
The dyeing compositions are prepared in the following proportions:
Solution 1

Hydroxyethylcellulose Natrosol 250MR 0.72 g
Alkyl C8/C10 (50:50) hydroxyethylcellulose CGI 10 5g
Benzyl alcohol 4g
Polyethylene glycol 400 4g
Water qs 100 g
Solution 2: BUFFER pH 9.5

Ammonium chloride (NH4C1) 5.4 g
Ammonia in sol. at 20% qs pH 9.5 (approx. 4 mL)
Demineralized water qs 100 mL
Solution 3: BUFFER pH 7

KH2PO4 0.026 mol/L
Na2PO4 0.041 mol/L
Demineralized water qs 500 mL
The dyeing compositions are obtained by dissolving the dye stated below (5xl0"3mol/L) in solution 1, then adding an equivalent volume of buffer solution 2 or 3 (pH 7 or 9.5).
Each composition is applied to grey hair with 90% white, (1 g of hair to 6 g of solution). After a waiting time of 30 min, the locks of hair are rinsed, washed with a standard shampoo, rinsed again and then dried.
The following results of dyeing were obtained:

pH 7 pH 9.5

44

Dye [i] Vivid chromatic blue Vivid chromatic blue
Dye [ii] Vivid chromatic violet Vivid chromatic violet
Dye [iii] Vivid chromatic fuchsia Vivid chromatic fuchsia
Dye [iv] Vivid chromatic blue Vivid chromatic blue
Dye [v] Vivid Blue-violet Vivid Blue-violet
Examples of dyeing (highlighting conditions):
The dyeing compositions were prepared in the following proportions:

Dye 0.25 g
Hydroxyethylcellulose Natrosol 250MR 0.72 g
Alkyl C8/C10 (50:50) hydroxyethylcellulose CGI 10 5g
Benzyl alcohol 4g
Polyethylene glycol 400 4g
Ammonium hydroxide 13 g
Water qs 100 g
At the moment of use, this formulation is mixed weight for weight with 40 vol.% hydrogen peroxide solution then applied to locks of hair NW (Natural White) and PW (Permanent White) - 1 g of hair to 6 g of solution. After waiting 30 min, the locks of hair are rinsed, washed with a standard shampoo, rinsed again and then dried.

45
The following results of dyeing were obtained

NW PW
Dye [i] Vivid chromatic blue Vivid chromatic blue
Dye [ii] Vivid chromatic violet Vivid chromatic violet
The dyed locks of hair are tested for resistance to washing, by carrying out 12 shampooings (with a standard shampoo) and assessing the colour after these 12 shampooings. After 12 shampooings, the locks of hair are still coloured.

46 CLAIMS
1. Use of at least one cationic azo compound with a julolidine unit of formula (I):
(X)x / \Z^Z
A—N V ' \_/ A
N\ P\ /
N—(f y—N
(Y)y
(I) in which
A represents a cationic aromatic heterocycle selected from the compounds of the following general formulae:

in which:
Ri represent independently of one another:
• a linear or branched, saturated or unsaturated Cj-Ci6 hydrocarbon chain, which can form one or more carbon rings with 3 to 7 ring members, optionally condensed with the aromatic ring, optionally substituted, optionally interrupted by one or more groups selected from the heteroatoms such as oxygen, nitrogen or sulphur, and the carbonyl group; Ri not containing a nitro, nitroso, peroxide and diazo bond; Ri

47
being directly attached to the nitrogen atom, quaternized or not, of the heteroaromatic ring A by means of a carbon atom. R2 represents independently of one another:
• a linear or branched, saturated or unsaturated C1-C16
hydrocarbon chain, which can form one or more aromatic or non-
aromatic carbon rings, with 3 to 6 ring members, optionally substituted,
optionally interrupted by one or more heteroatoms or by one or more
groups bearing at least one heteroatom, preferably selected from oxygen,
nitrogen;
a hydroxyl group,
• a C1-C4 alkoxy group,
a C2-C4 (poly)hydroxyalkoxy group;
• an alkoxycarbonyl group (RnO-CO-) in which Rn represents a
C1-C4 alkyl radical,
an alkylcarbonyloxy radical (R12CO-O-) in which Rn represents a C1-C4 alkyl radical;
• an amino group, an amino group substituted with one or two Ci-
C4 alkyl radicals, which may be identical or different, optionally bearing
at least one hydroxyl group, where the two alkyl radicals can optionally
form, with the nitrogen atom to which they are attached, a heterocycle
with 5 or 6 ring members optionally bearing another heteroatom
identical to or different from nitrogen, for example oxygen, sulphur;
an alkylcarbonylamino group (R^CO-NRn-) and/or (R13CO-NH-) in which the radicals R13 independently of one another, represent a C1-C4 alkyl radical;
a carbamoyl group ((Ri4)2N-CO) in which the radicals R14 independently of one another, which may be identical or different, represent a hydrogen atom, a C1-C4 alkyl radical;

48
• a ureido group ((Ri5)2N-CO-NRi6-) in which the radicals R15 and
Rj6, independently of one another, represent a hydrogen atom, a C1-C4
alkyl radical;
• a sulphonamide group ((Rn^N-SC^-) in which the radicals R17,
independently of one another, represent a hydrogen atom, a C1-C4 alkyl
radical;
an alkylsulphonylamino group (R18SO2-NR19-) in which the radicals Ris, R19, independently of one another, represent a hydrogen atom, a C1-C4 alkyl radical;
a guanidinium group ((R2o)2N-C(=NH2+)-NR2i-) in which the radicals R2o and R21, independently of one another, represent a hydrogen atom, a C1-C4 alkyl radical;
a nitro group;
• a cyano group;
• a halogen atom, preferably chlorine, fluorine;
two radicals R2, carried by adjacent carbon atoms can form, together with (he carbon atom to which each is attached, an aromatic or non-aromatic condensed ring; m represents an integer between 0 and 4; e is an integer between 0 and 2; p is an integer between 0 and 1; D represents a group CR2 or a nitrogen atom; Q represents a group NRi, or an atom of oxygen or of sulphur; bond a from formulae (Ha), (lib) or (lie), joins group A to the azo group;
in the case of formulae (Ha), (lib) or (lie) and when two radicals R2 carried by two adjacent carbon atoms form an aromatic ring, bond a can join group A to the azo group via said aromatic ring;

49
the electroneutrality of the compounds being provided by one or more
anions An", which may be identical or different, cosmetically
acceptable;
X, Y and Z are defined as possibilities of substitutions respectively on
the aikyl and aryl rings of the three-ring nucleus;
x is between 0 and 2, y is between 0 and 6, and z is between 0 and 6, x,
y and z being integers;
or their salts of addition or their solvates,
when an alkyl radical or the alkyl part of a radical is said to be
"substituted", it contains at least one substituent selected from the
groups:
• hydroxyl,
• C1-C4 alkoxy, C2-C4 (poly)hydroxyalkoxy,
• amino, amino substituted with one or more C1-C4 alkyl groups
which may be identical or different, optionally bearing at least one
hydroxyl group, and said alkyl radicals can form, with the nitrogen atom
to which they are attached, a helerocycle with 5 or 6 ring members,
optionally containing at least one other heteroatom which may or may
not be nitrogen;
when an aryl or heteroaryl radical or the aryl or heteroaryl part of a radical is said to be "substituted", such as the substituent X on the aromatic ring of the three-ring nucleus, it then comprises at least one substituent carried by a carbon atom, selected from:
a C1-C16, preferably Ci-Cs, alkyl radical, optionally substituted with one or more radicals selected from the radicals hydroxy, Ci-C2 alkoxy, C2-C4 (poly)-hydroxyalkoxy, acylamino, amino substituted with one or two C1-C4 alkyl radicals, which may be identical or different, optionally bearing at least one hydroxyl group or where the two radicals can form, with the nitrogen atom to which they are attached, a heterocycle with 5

50
or 7 ring members, preferably 5 or 6 ring members, optionally containing another heteroatom identical to or different from nitrogen;
• a halogen atom such as chlorine, fluorine or bromine;
• a tiydroxyl group;
a C1-C2 alkoxy radical;
• a C2-C4 (poly)-hydroxyalkoxy radical;
• an amino radical;
• an amino radical substituted with one or two C1-C4 alkyl radicals,
which may be identical or different, optionally bearing at least one
hydroxyl group;
• an acylamino radical (-NR31-COR32) in which the radical R31 is a
hydrogen atom, a C1-C4 alkyl radical optionally bearing at least one
hydroxyl group and the radical R32 is a C1-C2 alkyl radical;
• a carbamoyl radical ((R33)2N-CO-) in which the radicals R33, which
may be identical or different, represent a hydrogen atom, a C]-C4 alkyl
radical optionally bearing at least one hydroxyl group;
an alkylsulphonylamino radical (R34SO2-NR35-) in which the radical R34 represents a hydrogen atom, a C1-C4 alkyl radical optionally bearing at least one hydroxyl group and the radical R35 represents a C1-C4 alkyl radical, a phenyl radical;
an aminosulphonyl radical ((R36)2N-SC>2-) in which the radicals R36, which may be identical or different, represent a hydrogen atom, a C1-C4 alkyl radical optionally bearing at least one hydroxyl group; when the cyclic or heterocyclic part of a non-aromatic radical is said to be "substituted", such as the substituents Y and Z of the aliphatic heterocycles of the three-ring nucleus, it then comprises at least one substituent carried by a carbon atom selected from the groups:
• hydroxyl,
C1-C4 alkoxy, C2-C4 (poly)hydroxyalkoxy,

51
• alkylcarbonylamino ((R41CO-NR42-) in which the radical R42 is a hydrogen atom, a C1-C4 alkyl radical optionally bearing at least one hydroxyl group and the radical R4] is a Cj-C2 alkyl radical, amino substituted with two C1-C4 alkyl groups which may be identical or different optionally bearing at least one hydroxyl group, and said alkyl radicals can form, with the nitrogen atom to which they are attached, a heterocycle with 5 or 6 ring members, optionally containing at least one other heteroatom which may or may not be nitrogen;
when a ring does not carry the maximum number of substituents, the unsubstituted position or positions then carry a hydrogen atom; as direct dye for keratin fibres, in particular human keratin fibres, such as the hair.
2. Use according to Claim 1, characterized in that Ri represents a
Ci-Cg alkyl or hydroxyalkyl group.
3. Use according to Claim 1 or 2, characterized in that formulae
(Ha), (lib) and (lie) are such that they contain two radicals R2 carried
by adjacent carbon atoms, said radicals then forming, together with the
carbon atom to which each is attached, an aromatic condensed ring,
optionally substituted.
4. Use according to any one of the Claims 1 to 3, characterized in
that e, m and p have the value 0.
5. Use according to any one of the Claims 1 to 4, characterized
in that x is 0 or x is 1 with X representing an alkyl, hydroxyl,
hydroxyalkyl, alkoxy, amino, alkylamino, dialkylamino, or acylamino
group.
6. Use according to any one of the Claims 1 to 5, characterized in
that the compound of formula (I) has one of the following structures:

52

7. Dyeing composition for the dyeing of keratin fibres, in particular human keratin fibres such as the hair, comprising, in a suitable dyeing medium, at least one cationic azo compound as defined in any one of the Claims 1 to 6.

53
8. Composition according to Claim 7, characterized in that it
contains from 0.001 to 20%, preferably from 0.01 to 10% of direct
dye(s) of formula (I) relative to the total weight of the composition.
9. Composition according to Claim 7 or 8, characterized in that it
contains an oxidation base selected from para-phenylenediamines, bis-
phenylalkylenediamines, para-aminophenols, ortho-aminophenols,
heterocyclic bases and their salts of addition.

10. Composition according to any one of the Claims 7 to 9,
characterized in that it contains an amount between 0.001 and 20 wt.%
and preferably between 0.005 and 6 wt.% of oxidation bases relative to
the total weight of the composition.
11. Dyeing composition according to one of the Claims 7 to 10,
characterized in that it contains in addition a coupling agent selected
from meta-phenylenediamines, meta-aminophenols, meta-diphenols,
naphthalenic coupling agents, heterocyclic coupling agents and their
salts of addition.
12. Composition according to Claim 11, characterized in that the
coupling agent is selected from 1,3-dihydroxy benzene, 1,3-dihydroxy 2-
methyl benzene, 4-chloro 1,3-dihydroxy benzene, 2,4-diamino l-(fi-
hydroxyethyloxy) benzene, 2-amino 4-(P-hydroxyethylamino) 1-
methoxybenzene, 1,3-diamino benzene, l,3-bis-(2,4-diaminophenoxy)
propane, 3-ureido aniline, 3-ureido 1-dimethylamino benzene, sesamol,
l-P-hydroxyethylamino-3,4-methylenedioxybenzene, a-naphthol, 2-
methyl-1-naphthol, 6-hydroxy indole, 4-hydroxy indole, 4-hydroxy N-
methyl indole, 2-amino-3-hydroxy pyridine, 6-hydroxy benzomorpholine,
3,5-diamino-2,6-dimethoxypyridine, l-N-(p-hydroxyethyl)amino-3,4-
methylene dioxybenzene, 2,6-bis-(P-hydroxyethylamino)toluene and
their salts of addition.
13. Composition according to Claim 11 or 12, characterized in
that the coupling agent or agents are present in an amount between 0.001

54
and 20 wt.%, preferably between 0.005 and 6 wt.% relative to the total weight of the composition.
14. Composition according to one of the Claims 7 to 13, characterized in that it contains one or more additional direct dyes different from the compounds of formula (I), selected from the nitro dyes of the neutral, acid or cationic benzene series, the neutral, acid or cationic direct azo dyes, the quinone direct dyes and in particular neutral, acid or cationic anthraquinone direct dyes, the azine direct dyes, the triarylmethane direct dyes, the tetraazapentamethine direct dyes, the indoamino direct dyes and the natural direct dyes.
15. Composition according to Claim 16, characterized in that
the additional direct dye or dyes are present in an amount between 0.001
and 20 wt.% and preferably between 0.005 and 10 wt.% relative to the
total weight of the composition.
16. Composition according to any one of the Claims 7 to 15,
characterized in that it contains at least one oxidizing agent selected
from hydrogen peroxide, urea peroxide, alkali metal bromates, persalts,
peracids and oxidase enzymes, and preferably hydrogen peroxide.
17. Composition according to any one of the Claims 7 to 16,
characterized in that it contains at least one hydroxylated solvent, such
as ethanol, propylene glycol, glycerol, mono ethers of polyols.
18. Composition according to any one of the Claims 7 to 17,
characterized in that it contains at least one additive selected from the
anionic, cationic, non-ionic, amphoteric, zwitterionic surfactants or
mixtures thereof, the anionic, cationic, non-ionic, amphoteric,
zwitterionic polymers or mixtures thereof, mineral and organic
thickening agents, and in particular anionic, cationic, non-ionic and
amphoteric associative polymeric thickening agents, antioxidizing
agents, penetrating agents, sequestering agents, perfumes, buffers,
dispersants, conditioners such as volatile or non-volatile, modified or

55
unmodified silicones, film-forming agents, ceramides, preservatives, opacifiers.
19. Method of dyeing of keratin fibres, characterized in that it comprises the following stages:
- the dyeing composition according to one of the Claims 7 to
18 is applied to the keratin fibres,
- it is left for a waiting time between 3 minutes and 1 hour
and preferably between 15 minutes and 45 minutes, then
- said fibres are rinsed.
20. Use of a composition according to one of the Claims 7 to
18 for the dyeing of keratin fibres.
21. Kit with several compartments or "dyeing kit",
characterized in that it comprises a first compartment containing a
composition as defined according to one of the Claims 7 to 18 and a
second compartment containing a composition that includes an
oxidizing agent.
22. Cationic azo compound with a julolidine unit of formula
(I):

in which
A represents a cationic aromatic heterocycle selected from the
compounds of the following general formulae:

56

in which:
Ri represent independently of one another:
• a linear or branched, saturated or unsaturated C]-Cj6 hydrocarbon
chain, which can form one or more carbon rings with 3 to 7 ring
members, optionally condensed with the aromatic ring, optionally
substituted, optionally interrupted by one or more groups selected from
the heteroatoms such as oxygen, nitrogen or sulphur, and the carbonyl
group; Ri not containing a nitro, nitroso, peroxide and diazo bond; Rj
being directly attached to the nitrogen atom, quaternized or not, of the
heteroaromatic ring A by means of a carbon atom.
R2 represents independently of one another:
• a linear or branched, saturated or unsaturated C1-C16
hydrocarbon chain, which can form one or more aromatic or non-
aromatic carbon rings, with 3 to 6 ring members, optionally substituted,
optionally interrupted by one or more heteroatoms or by one or more
groups bearing at least one heteroatom, preferably selected from oxygen,
nitrogen;
• a hydroxyl group,
• a C1-C4 alkoxy group,
• a C2-C4 (poly)hydroxyalkoxy group;
an alkoxycarbonyl group (RuO-CO-) in which Rn represents a C1-C4 alkyl radical,
• an alkylcarbonyloxy radical (R12CO-O-) in which R12 represents
a C1-C4 alkyl radical;

57
an amino group, an amino group substituted with one or two Cj-C4 alkyl radicals, which may be identical or different, optionally bearing at least one hydroxyl group, where the two alkyl radicals can optionally form, with the nitrogen atom to which they are attached, a heterocycle with 5 or 6 ring members optionally bearing another heteroatom identical to or different from nitrogen, for example oxygen, sulphur;
an alkylcarbonylamino group (R13CO-NR13-) and/or (RnCO-NH-) in which the radicals R13 independently of one another, represent a C1-C4 alkyl radical;
a carbamoyl group ((Ri4)2N-CO) in which the radicals R14 independently of one another, which may be identical or different, represent a hydrogen atom, a C1-C4. alkyl radical;
a ureido group ((Ri5)2N-CO'-NRi6-) in which the radicals R15 and Rj6, independently of one another, represent a hydrogen atom, a C1-C4 alkyl radical;
a sulphonamide group ((Rn)2N-SO2-) in which the radicals Rn, independently of one another, represent a hydrogen atom, a C1-C4 alkyl radical;
• an alkylsulphonylamino group (R18SO2-NR19-) in which the
radicals Rjg, R19, independently of one another, represent a hydrogen
atom, a C1-C4 alkyl radical;
a guanidinium group ((R2o)2N-C(=NH2+)-NR2i-) in which the radicals R20 and R21, independently of one another, represent a hydrogen atom, a C1-C4 alkyl radical;
• a nitro group;
• a cyano group;
• a halogen atom, preferably chlorine, fluorine;
two radicals R2, carried by adjacent carbon atoms can form, together with the carbon atom to which each is attached, an aromatic or non-aromatic condensed ring;

58
m represents an integer between 0 and 4;
e is an integer between 0 and 2;
p is an integer between 0 and 1;
D represents a group CR2 or a nitrogen atom;
Q represents a group NRi, or an atom of oxygen or of sulphur;
bond a from formulae (Ha), (lib) or (He), joins group A to the azo
group;
in the case of formulae (Ha), (lib) or (He) and when two radicals R2
carried by two adjacent carbon atoms form an aromatic ring, bond a can
join group A to the azo group via said aromatic ring;
the electroneutrality of the compounds being provided by one or more
anions An", which may be identical or different, cosmetically
acceptable;
X, Y and Z are defined as possibilities of substitutions respectively on
the alkyl and aryl rings of the three-ring nucleus;
x is between 0 and 2, y is between 0 and 6, and z is between 0 and 6, x,
y and z being integers;
or their salts of addition or their solvates;
when an alkyl radical or the alkyl part of a radical is said to be
"substituted", it contains at least one substituent selected from the
groups:
hydroxyl,
C1-C4 alkoxy, C2-C4 (poly)hydroxyalkoxy,
• amino, amino substituted v/ith one or more C1-C4 alkyl groups
which may be identical or different optionally bearing at least one hydroxyl group, where said alkyl radicals can form, with the nitrogen atom to which they are attached, a heterocycle with 5 or 6 ring members, optionally containing at least one other heteroatom which may or may not be nitrogen;

59
when an aryl or heteroaryl radical or the aryl or heteroaryl part of a radical is said to be "substituted", such as the substituent X on the aromatic ring of the three-ring nucleus, it then comprises at least one substituent carried by a carbon atom, selected from:
a Cj-Cj6, preferably C]-C8, alkyl radical, optionally substituted with one or more radicals selected from the radicals hydroxy, C1-C2 alkoxy, C2-C4 (poly)-hydroxyalkoxy, acylamino, amino substituted with one or two C1-C4 alkyl radicals, which may be identical or different, optionally bearing at least one hydroxyl group or the two radicals which can form with the nitrogen atom to which they are attached, a heterocycle with 5 or 7 ring members, preferably 5 or 6 ring members, optionally containing another heteroatom identical to or different from nitrogen;
a halogen atom such as chlorine, fluorine or bromine;
a hydroxyl group;
• a C1-C2 alkoxy radical;
• a C2-C4 (poly)-hydroxyalkoxy radical;
an amino radical;
an amino radical substituted with one or two C1-C4 alkyl radicals, which may be identical or different, optionally bearing at least one hydroxyl group;
• an acylamino radical (-NR31-COR32) in which the radical R31 is a
hydrogen atom, a C1-C4 alkyl radical optionally bearing at least one
hydroxyl group and the radical R32 is a C1-C2 alkyl radical;
a carbamoyl radical ((R33)2N-CO-) in which the radicals R33, which may be identical or different, represent a hydrogen atom, a C1-C4 alkyl radical optionally bearing at least one hydroxyl group;
an alkylsulphonylamino radical (R34SO2-NR35-) in which the radical R34 represents a hydrogen atom, a C1-C4 alkyl radical optionally bearing at least one hydroxyl group and the radical R35 represents a C1-C4 alkyl radical, a phenyl radical;

60
an aminosulphonyl radical ((R36)2N-SO2-) in which the radicals R36, which may be identical or different, represent a hydrogen atom, a C1-C4 alkyl radical optionally bearing at least one hydroxyl group, when the cyclic or heterocyclic part of a non-aromatic radical is said to be "substituted", such as the substituents Y and Z of the aliphatic heterocycles of the three-ring nucleus, it then comprises at least one substituent carried by a carbon atom selected from the groups:
hydroxyl,
• C1-C4 alkoxy, C2-C4 (poly)hydroxyalkoxy,
• alkylcarbonylamino ((R41CO-NR42-) in which the radical R42 is a
hydrogen atom, a C1-C4 alkyl radical optionally bearing at least one
hydroxyl group and the radical R.41 is a C1-C2 alkyl radical, amino
substituted with two C1-C4 alkyl groups which may be identical or
different optionally bearing at least one hydroxyl group, and said alkyl
radicals can form, with the nitrogen atom to which they are attached, a
heterocycle with 5 or 6 ring members, optionally containing at least one
other heteroatom which may or may not be nitrogen;
when a ring does not carry the maximum number of substituents, the unsubstituted position or positions then carry a hydrogen atom; with the exception of
2-(9-julolidylazo)-3-methylbenzothiazolium perchlorate 2-(9-julolidylazo)-3-ethylthiazolium perchlorate.
23. Compound according to Claim 22, characterized in that Ri
represents a Ci-Cg alkyl or hydroxyalkyl group.
24. Compound according to Claim 22 or 23, characterized in that
the formulae (Ha), (lib) and (lie) are such that they contain two radicals
R2 carried by adjacent carbon atoms, said radicals then forming,
together with the carbon atom to which each is attached, an aromatic
condensed ring, optionally substituted.

61
25. Compound according to any one of the Claims 22 to 24,
characterized in that e, m and p have the value 0.
26. Compound according to any one of the Claims 22 to 25,
characterized in that x is 0 or x is 1 with X representing an alkyl,
hydroxyl, hydroxyalkyl, alkoxy, amino, alkylamino, dialkylamino, or
acylamino group.
27. Compound according to any one of the Claims 22 to 26,
characterized in that the compound of formula (I) has one of the
following structures:


62

The present application relates to the use of cationic azo compounds with julolidine units as; direct dyes, for the dyeing of keratin fibres, in particular human keratin fibres, such as the hair.
The present application also relates to a dyeing composition for the dyeing of keratin fibres, in particular human keratin fibres such as the hair, containing at least one cationic direct azo dye with julolidine units, in a suitable dyeing medium.
The present application also relates to a method of dyeing of keratin fibres, in particular human keratin fibres such as the hair, employing the dyeing composition according to the invention.
The present application also relates to certain particular cationic azo compounds with julolidine units.