WO2014202150A1

WO2014202150A1 - New cationic dyes, kits and compositions thereof, and process for dyeing keratin fibers

Info

Publication number: WO2014202150A1
Application number: PCT/EP2013/062983
Authority: WO
Inventors: Otto Goettel; Johann Aeby
Original assignee: Alfa Parf Group S.P.A.
Priority date: 2013-06-21
Filing date: 2013-06-21
Publication date: 2014-12-24

Abstract

The present invention relates to new cationic dyes of general formula (I) and (II): The invention also relates to kits and compositions for dyeing keratin fibers, which contain at least one of these dyes as well as to a process for dyeing keratin fibers using at least one of these dyes.

Description

NEW CATIONIC DYES, KITS AND COMPOSITIONS THEREOF, AND

PROCESS FOR DYEING KERATIN FIBERS

Technical field of the invention

The present invention relates to new cationic dyes, kits and compositions for dyeing keratin fibers, which contain at least one of these dyes. The present invention also relates to a process for dyeing keratin fibers.

Background of the invention

Throughout the years, there has been a desire to alter the color of synthetic and natural fibers. In particular, coloring of human hair has been sought in view of changing styles and fashion.

The coloring of hair is currently subject to the most varied trends. Whereas in the past hair was colored primarily to cover gray hair, today there is an increasing demand for integrating the hair color into current fashion as an expression of personality .

Now as before, two established methods of hair coloring are broadly applied. One is the semi-permanent system which consists of the possibility of coloring hair with colorants containing direct dyes (often referred to as toners).

The majority of such dyes belong to the family of nitro dyes. These dyes which are derivatives of p-aminophenol and p-phenylenediamine have the drawback that they produce irregularities, when used on hair that has been damaged to different degrees, and leads to quite uneven colorations; further, endurance is insufficient, i.e. fastness, in particular with respect to shampoos, after each washing the color result becomes weaker so that the natural hair color is re- obtained after five to ten washes, depending on the individual hair type.

Besides the semi-permanent system, oxidation dyes have attained substantial cosmetic significance in the field of conventional hair dyeing. Keratin fibers, and in particular human hair, are dyed with dye compositions containing dye precursors, generally referred to as oxidation dyes, the so called primary intermediates and couplers. The color is obtained by reaction of primary intermediates with couplers in an oxidating environment.

Primary intermediates are in particular para-phenylenediamines, para-aminophenols and 4,5-diaminopyrazoles, which are generally referred to as oxidation bases.

Couplers are selected in particular from meta-dihydroxybenzenes, meta- aminophenols meta-phenylenediamines, and certain heterocyclic compounds.

Oxidation dye precursors are normally colorless or weakly colored compounds which, when combined with oxidizing products, can give rise to colored compounds and dyes by a process of oxidative condensation.

It is possible, by a combination of suitable primary intermediates and couplers, to produce a wide range of different color nuances. At any rate, such hair colorations must remain stable for at least four to six weeks under normal everyday conditions.

It is common practice that specific direct dyes are added to the oxidative colorants to obtain particular nuances.

Direct dyes which are used in combination with oxidative colorants have to fulfill a number of technical requirements. Besides providing the appropriate colors, the dye uptake must be even from the roots to the tips, the direct dyes must be stable to hydrogen peroxide and they should also be stable to reducing conditions present in oxidative colorants. Further, fading must be on a very low level to avoid discoloration after several washes. Finally, in addition to the technical properties, the dyes must be safe from a toxicological and dermatological point of view.

However, hair coloring compositions currently available are not entirely satisfactory, in particular from the point of view of resistance of colorations obtained to the various attacking factors to which the hair may be subjected and, in particular, to shampoos. Therefore there is still strong need for dyes which fulfill these requirements.

Summary of the invention

The present invention relates to new cationic dyes of general formula (I) and

i^{+ X"} i⁺

(I) (II)

wherein the substituents are as defined below.

A further object of the invention is a ready- to use composition for dyeing keratin fibers comprising in a medium suitable for dyeing:

- at least one cationic dye of general formula (I) or (II),

- at least one oxidation dye;

- at least one oxidizing agent,

as well as a process for dyeing keratin fibers using said ready-to-use composition.

Finally, another object of the invention is a multi-compartment dyeing kit or device or any other multi-compartment packaging system comprising at least one cationic direct dye of formula (I) or (II).

Detailed description of the invention

One subject of the invention are cationic dyes of general formula (I) and (II):

wherein

l is hydrogen, a straight-chain or branched (C 1 -C6)-alkyl group, a (Cl- C4)-hydroxyalkyl group, a (C 1 -C4)-aminoalkyl group, a (Cl-C8)-alkylamino group, a di-(Cl-C8)-alkylamino group, a (C1-C4)- alkylamino-(Cl-C4)-alkyl group or a di(C 1 -C4)-alkylamino-(C 1 -C4)-alkyl group, a benzyl group, an aryl group or a heteroaryl group;

R2 to R6 are, equal or different independently from each other, selected from hydrogen, a straight-chain or branched (C 1 -C6)-alkyl or -alkoxy group, a (Cl-C4)-hydroxyalkyl or -hydroxyalkoxy group, a methoxymethyl group, a nitro group, a halogen atom selected from chlorine, bromine, iodine and fluorine, a trifluoromethyl group, a cyano group, an acetylamino or an amino group;

R7 is a hydrogen atom, a methyl or an ethyl group, a hydroxy group, an amino group, a hydroxy-(C2-C3)-alkylamino group or a methoxy group;

R8 is a hydrogen atom, a halogen atom selected from chlorine, bromine, iodine and fluorine or a methyl group;

R9 is a hydrogen atom, an amino group, a (C 1 -C6)-alkyl group, a (Cl-C6)-alkoxy group or a (C2-C3)-hydroxyalkoxy group;

Y is an oxygen atom or an NR group wherein R is (C 1 -C4)-alkyl, (C2-C4)- hydroxyalkyl; or the NR group is bonded to R9 to form a benzoxazine system;

L is a bridging group between the pyrazole ring and the quaternary group and consists of a phenylene diradical or a (Cl-C3)-alkylene diradical;

Q⁺ is a saturated cationic group selected from formula (a) or an unsaturated or aromatic cationic group selected from formula (b) to (g):

wherein

RIO to R12 are, equal or different and independently of each other, selected from a straight-chain or branched (Cl-C6)-alkyl group, a (C2-C4)-hydroxyalkyl group, a (C3-C6)-dihydroxyalkyl group, a (C3-C6)-polyhydroxyalkyl group or a (Cl-C6)-alkoxy-(Cl-C4)-alkyl group; or two of the groups RIO to R12 together with the nitrogen atom to which they are linked form a five-membered or six- membered heterocycle optionally containing one or more other heteroatoms (for example O, N, S) and other substituents [for example F, CI, Br, I, OH, NH2 or a straight- chain or branched (C 1 -C6)-alkyl group, a straight-chain or branched (Cl- C6)-alkoxy group, a (Cl-C6)-alkoxy-(Cl-C4)-alkyl group or a hydroxyethyl group];

R13 is a straight-chain or branched (Cl-C8)-alkyl group, a hydroxyethyl group or a benzyl group;

R14 is hydrogen, a straight-chain or branched (C 1 -C9)-alkyl group, an amino group, a mono-(Cl-C6)-alkylamino group, a di-(C 1 -C6)-alkylamino group or a pyrrolidino group;

R15 is a (Cl-C4)-alkyl radical, which may be substituted with a hydroxy radical;

X is a monovalent or polyvalent anion, which may be selected from the group comprising chloride, bromide, methylsulfonate or methylsulfate, arylsulfonate, hydrogen sulfate, sulfate, phosphate, acetate or hydroxysuccinate ion.

The dyes may also be isolated as adduct with and acid, in particular with an inorganic acid such as hydrochloric acid or hydrobromic acid.

Preferred are cationic dyes of general formula (I) or (II) wherein:

l is hydrogen;

R2 to R6 are, equal or different independently from each other, selected from hydrogen, a methyl or methoxy group, a (C 1 -C2)-hydroxyalkyl group, a (C2-C3)-hydroxyalkoxy group, a methoxymethyl group, a nitro group, a chloro atom, or a trifluoromethyl group;

R7 is a hydroxy group, an amino group, a hydroxyethylamino group or a methoxy group;

R8 is a hydrogen atom, a chloro atom or a methyl group;

R9 is a methyl group, a methoxy group or a hydroxyethoxy group;

RIO to R12 are, equal or different and independently of each other, selected from a methyl group, ethyl group or hydroxy ethyl group; or two of the RIO to Rl 2 groups together with the nitrogen atom to which they are linked form a pyrrolidino group, morpholino group or N-methylpiperazino group;

R13 is a methyl group or a hydroxyethyl group;

R14 is hydrogen, a methyl group, p-dimethylamino group or p-pyrrolidino group;

R15 is a methyl, ethyl or hydroxyethyl group;

Y is O or NH;

X is a chloride, bromide or methylsulfate;

L is a (Cl-C3)-diradical;

Q⁺ is a (C3-C9)-trialkylammonium radical, a N-methylimidazolium radical or a N-methylpyridinium radical. Most preferred are the cationic dyes of general formula (I) or (II) wherein: l is hydrogen;

R2-R6 are, equal or different independently from each other, selected from hydrogen, a methyl or methoxy group, a (C 1 -C2)-hydroxyalkyl group, a hydroxyethoxy group, a methoxymethyl group, a nitro group, or a chloro atom;

R7 is a hydroxy group, an amino group or a hydroxyethylamino group;

R8 is a hydrogen atom or a methyl group;

R9 is a methyl group, a methoxy group or a hydroxyethoxy group;

RIO to R12 are, equal or different and independently of each other, selected from a methyl group, ethyl group or hydroxyethyl group; or two of the RIO to R12 groups together with the nitrogen atom to which they are linked form a pyrrolidino group, a morpholino group or a N-methylpiperazino group;

R13 is a methyl group;

R14 is hydrogen, a methyl group, a p-dimethylamino group or a p- pyrrolidino group;

R15 is a methyl, ethyl or hydroxyethyl group;

Y is O or NH;

X is chloride, bromide or methylsulfate;

L is a methylene diradical;

Q is N-methylpyridinium moiety.

Manufacturing of the cationic direct dyes of the present invention is based on commonly known chemical methods. As an example, the synthesis of a set of inventive dyes is illustrated in the following part. Selected was a starting pyrazole, substituted at the pyrazole-Nl atom with a pyridine-3-yl-methyl radical, which leads to dyes containing the substitution pattern (d).

The synthesis of numerous 5-amino pyrazoles, useful for synthesis of the cationic dyes of the current invention, was described by H. Hohn, Z. Chem., 10, 386 (1970). Selected from this literature was for illustration of the current invention l-(pyridin-3-ylmethyl)-lH-pyrazol-5-amine (III). Synthesizing the dyes of the invention is especially economical if the same 5-amino-pyrazole intermediate is used for manufacturing dyes of formula (I) and formula (II).

As shown by Scheme 1 , diazotation of an aromatic amine (IV) and coupling with the 5-aminopyrazole (III) gives the azo compound (V) which in the following is quaternized to give the cationic dyes of formula (Id).

A huge number of aromatic amines of structure (IV) are commercially available and can be used for preparing the dyes of general formula (I). Therefore, the examples given in the following represent a few samples of a wide range of possible products.

The diazo process is carried out according to known methods, which are for instance described in "Methoden der Organischen Chemie (Houben Weyl)", Band X/3, Georg Thieme Verlag, Stuttgart, 1965, pp. 1-212 for the diazotation of aromatic amines, and pp. 213ff for the azo coupling.

Scheme 1; Synthesis of cationic dyes of formula (I) starting from 1-

(Pyridin-3 -ylmethyl)- 1 H-pyrazol-5 -amine

(III) (TV) (V) (Id)

Some of the cationic dyes of formula (Id) are appropriate intermediates to be converted into the cationic dyes of formula (lid). In this case preferred are dyes in which the groups 2 to R6 are sufficiently inert to the treatments described in the following.

By cleaving the azo group of cationic dyes of formula (I), selected for illustration was formula (Id), preferentially by catalytic hydrogenation, the aniline (IV) is split off and the 4,5-diaminopyrazole intermediate (VId) is obtained. Isolation of the pyrazole is not required; preferentially the pyrazole is generated in situ and directly reacted with common hair dye couplers (VII) or other meta-di- donor substituted benzenes in presence of an oxidant whereby cationic dyes of the general formula (lid) are obtained. Chemistry of the dye transformation process is illustrated in Scheme 2a.

Scheme 2a: Transformation of dyes of formula (Id) into dyes of formula

(lid)

(Id) (IV) (VId) (VII) (lid)

Cationic pyrazole dyes of the general formula (II) can also be obtained by oxidative coupling of the isolated quaternized 4,5-diaminopyrazole; in this regard reference is expressly made to US7462204B2 where the synthesis and the isolation of quaternized 4,5-diaminopyrazoles is reported.

Scheme 2b: Coupling of quaternized 4,5-diaminopyrazoles (VI) and formation of cationic dyes of general formula (II)

(VI) (VII) (II)

By using coupling components of structure (VII) the cationic dye general formula (II) are obtained, which are brilliant orange to deep violet. The cationic chromophores can be combined with various anions. The type of anion is normally the result of the selected reagents used in the process, such as the alkylating agents or agents added to the dye in order to exchange the anion. The latter can be necessary for practical reasons, for instance to improve the crystallization properties of the dyes.

In some cases it can be favorable to isolate the dyes as adduct with an acid, for instance as a 1 : 1 adduct with hydrochloric acid or with hydrobromic acid.

Furthermore, some of the dyes can contain crystal water.

According to a preferred embodiment of the present invention, the pyrazole azo dyes of general formula (I), which can be used, for example, in the compositions in accordance with the invention, may be selected from the group comprising:

3- { [5-Amino-4-(phenyldiazenyl)- lH-pyrazol- 1 -yljmethyl} - 1 - methylpyridinium chloride;

3-( {5-Amino-4-[(4-methylphenyl)diazenyl] - lH-pyrazol- 1 -yl} methyl)- 1 - methylpyridinium chloride;

3-( {5-Amino-4-[(4-methylphenyl)diazenyl] - lH-pyrazol- 1 -yl} methyl)- 1 - methylpyridinium bromide;

3-( {5-Amino-4-[(3-methylphenyl)diazenyl] - lH-pyrazol- 1 -yl} methyl)- 1 - methylpyridinium chloride;

3-( {5-Amino-4-[(2-methylphenyl)diazenyl] - lH-pyrazol- 1 -yl} methyl)- 1 - methylpyridinium chloride;

3-[(5-Amino-4- { [4-(hydroxymethyl)phenyl]diazenyl} - lH-pyrazol- 1 - yl)methyl]- 1 -methylpyridinium bromide;

3-[(5-Amino-4- { [3-(hydroxymethyl)phenyl]diazenyl} - lH-pyrazol- 1 - yl)methyl]- 1 -methylpyridinium bromide;

3-[(5-Amino-4- { [2-(hydroxymethyl)phenyl]diazenyl} - lH-pyrazol- 1 - yl)methyl]- 1 -methylpyridinium bromide; 3-( {5-Amino-4-[(4-nitrophenyl)diazenyl] - IH-pyrazol- 1 -yl} methyl)- 1 - methylpyridinium chloride;

3-( {5-Amino-4-[(2-methyl-4-nitrophenyl)diazenyl] - IH-pyrazol- 1 - yl} methyl)- 1 -methylpyridinium methyl sulfate;

3-( {5-Amino-4-[(2-methyl-3-nitrophenyl)diazenyl] - IH-pyrazol- 1 - yl} methyl)- 1 -methylpyridinium chloride;

3-( {5-Amino-4-[(4-methyl-2-nitrophenyl)diazenyl] - IH-pyrazol- 1 - yl} methyl)- 1 -methylpyridinium chloride;

3-[(5-Amino-4- { [2-(methoxymethyl)-4-nitrophenyl]diazenyl} - lH-pyrazol- l-yl)methyl]-l -methylpyridinium methyl sulfate;

3-[(5-Amino-4- { [4-(trifluoromethyl)phenyl]diazenyl} - IH-pyrazol- 1 - yl)methyl]- 1 -methylpyridinium chloride;

3-[(5-Amino-4- { [3-(trifluoromethyl)phenyl]diazenyl} - IH-pyrazol- 1 - yl)methyl]- 1 -methylpyridinium chloride;

3-[(5-Amino-4- { [2-(trifluoromethyl)phenyl]diazenyl} - IH-pyrazol- 1 - yl)methyl]- 1 -methylpyridinium chloride;

3-( {5-Amino-4-[(4-methoxyphenyl)diazenyl]- IH-pyrazol- 1 -yl} methyl)- 1 - methylpyridinium chloride;

3-( {5-Amino-4-[(3-methoxyphenyl)diazenyl]- IH-pyrazol- 1 -yl} methyl)- 1 - methylpyridinium chloride;

3-( {5-Amino-4-[(2-methoxyphenyl)diazenyl]- IH-pyrazol- 1 -yl} methyl)- 1 - methylpyridinium chloride;

3-( {5-Amino-4-[(4-chlorophenyl)diazenyl] - IH-pyrazol- 1 -yl} methyl)- 1 - methylpyridinium chloride;

3-( {5-Amino-4-[(3-chlorophenyl)diazenyl] - IH-pyrazol- 1 -yl} methyl)- 1 - methylpyridinium chloride;

3-( {5-Amino-4-[(2-chlorophenyl)diazenyl] - IH-pyrazol- 1 -yl} methyl)- 1 - methylpyridinium chloride; 3-( {5-Amino-4-[(2-chloro-4-methylphenyl)diazenyl] - IH-pyrazol- 1 - yl} methyl)- 1 -methylpyridinium chloride;

3-( {5-Amino-4-[(5-chloro-2-methylphenyl)diazenyl] - IH-pyrazol- 1 - yl} methyl)- 1 -methylpyridinium chloride;

3-( {5-Amino-4-[(4-chloro-2-methylphenyl)diazenyl] - IH-pyrazol- 1 - yl } methyl)- 1 -methylpyridinium chloride ;

3-( {5-Amino-4-[(5-chloro-2-methoxyphenyl)diazenyl] - IH-pyrazol- 1 - yl} methyl)- 1 -methylpyridinium chloride;

3-( {5-Amino-4-[(3-chloro-4-fluorophenyl)diazenyl] - IH-pyrazol- 1 - yl} methyl)- 1 -methylpyridinium chloride;

3-( {5-Amino-4-[(2-chloro-4-nitrophenyl)diazenyl] - IH-pyrazol- 1 - yl} methyl)- 1 -methylpyridinium chloride;

3-( {5-Amino-4-[(2-chloro-5-nitrophenyl)diazenyl] - IH-pyrazol- 1 - yl} methyl)- 1 -methylpyridinium chloride;

3-( {5-Amino-4-[(4-chloro-2-nitrophenyl)diazenyl] - IH-pyrazol- 1 - yl} methyl)- 1 -methylpyridinium chloride;

3-( {5-Amino-4-[(4-chloro-3-nitrophenyl)diazenyl] - IH-pyrazol- 1 - yl} methyl)- 1 -methylpyridinium chloride;

3-( {5-Amino-4-[(5-chloro-2-nitrophenyl)diazenyl] - IH-pyrazol- 1 - yl} methyl)- 1 -methylpyridinium chloride;

3-( {5-Amino-4-[(2-cyano-4-nitrophenyl)diazenyl] - IH-pyrazol- 1 - yl} methyl)- 1 -methylpyridinium chloride;

3-( {5-Amino-4-[(2,4-dichlorophenyl)diazenyl]- IH-pyrazol- 1 -yl} methyl)- 1 - methylpyridinium chloride;

3-( {5-Amino-4-[(2,5-dichlorophenyl)diazenyl]- IH-pyrazol- 1 -yl} methyl)- 1 - methylpyridinium chloride;

3-( {5-Amino-4-[(2,4-dimethylphenyl)diazenyl] - IH-pyrazol- 1 -yl} methyl)- 1 - methylpyridinium chloride; 3-( {5-Amino-4-[(2,5-dimethylphenyl)diazenyl] - 1 H-pyrazol- 1 -yl} methyl)- 1 - methylpyridinium chloride;

3- ( {5-Amino-4-[(4-(methoxycarbonyl)phenyl)diazenyl] - 1 H-pyrazol- 1 - yl} methyl)- 1 -methylpyridinium methyl sulfate;

4- { [5-Amino-4-(phenyldiazenyl)- IH-pyrazol- 1 -yljmethyl} - 1 - methylpyridinium chloride;

4- { [5 -Amino-4- [(4-methylphenyl)diazenyl] - 1 H-pyrazol- 1 -yl} methyl)- 1 - methylpyridinium chloride;

4- { [5 -Amino-4- [(3 -methylphenyl)diazenyl] - 1 H-pyrazol- 1 -yl} methyl)- 1 - methylpyridinium chloride;

4- { [5 -Amino-4- [(2-methylphenyl)diazenyl] - 1 H-pyrazol- 1 -yl} methyl)- 1 - methylpyridinium chloride;

4- [(5 -Amino-4- { [4-(hydroxymethyl)phenyl]diazenyl} - 1 H-pyrazol- 1 - yl)methyl]- 1 -methylpyridinium bromide;

4- [(5 -Amino-4- { [3-(hydroxymethyl)phenyl]diazenyl} - 1 H-pyrazol- 1 - yl)methyl]- 1 -methylpyridinium bromide;

4- [(5 -Amino-4- { [2-(hydroxymethyl)phenyl]diazenyl} - 1 H-pyrazol- 1 - yl)methyl]- 1 -methylpyridinium bromide;

4- { [5-Amino-4-[(4-nitrophenyl)diazenyl]- IH-pyrazol- 1 -yl} methyl)- 1 - methylpyridinium chloride;

4- { [5 -Amino-4- [(2-methyl-4-nitrophenyl)diazenyl] - 1 H-pyrazol- 1 - yl} methyl)- 1 -methylpyridinium chloride;

4- { [5-Amino-4-[(2-methyl-3-nitrophenyl)diazenyl]- IH-pyrazol- 1 - yl} methyl)- 1 -methylpyridinium chloride;

4- { [5 -Amino-4- [(4-methyl-2-nitrophenyl)diazenyl] - 1 H-pyrazol- 1 - yl} methyl)- 1 -methylpyridinium chloride;

4- [(5 -Amino-4- { [2-(methoxymethyl)-4-nitrophenyl]diazenyl} - lH-pyrazol- l-yl)methyl]-l -methylpyridinium methyl sulfate; 4-[(5-Amino-4- { [4-(trifluoromethyl)phenyl]diazenyl} - IH-pyrazol- 1 - yl)methyl]- 1 -methylpyridinium chloride;

4-[(5-Amino-4- { [3-(trifluoromethyl)phenyl]diazenyl} - IH-pyrazol- 1 - yl)methyl]- 1 -methylpyridinium chloride;

4-[(5-Amino-4- { [2-(trifluoromethyl)phenyl]diazenyl} - IH-pyrazol- 1 - yl)methyl]- 1 -methylpyridinium chloride;

4- { [5-Amino-4-[(4-methoxyphenyl)diazenyl]- IH-pyrazol- 1 -yl} methyl)- 1 - methylpyridinium chloride;

4- { [5-Amino-4-[(3-methoxyphenyl)diazenyl]- IH-pyrazol- 1 -yl} methyl)- 1 - methylpyridinium chloride;

4- { [5-Amino-4-[(2-methoxyphenyl)diazenyl]- IH-pyrazol- 1 -yl} methyl)- 1 - methylpyridinium chloride;

4- { [5-Amino-4-[(4-chlorophenyl)diazenyl]- IH-pyrazol- 1 -yl} methyl)- 1 - methylpyridinium chloride;

4- { [5-Amino-4-[(3-chlorophenyl)diazenyl]- IH-pyrazol- 1 -yl} methyl)- 1 - methylpyridinium chloride;

4- { [5-Amino-4-[(2-chlorophenyl)diazenyl]- IH-pyrazol- 1 -yl} methyl)- 1 - methylpyridinium chloride;

4- { [5-Amino-4-[(2-chloro-4-methylphenyl)diazenyl]- IH-pyrazol- 1 - yl} methyl)- 1 -methylpyridinium chloride;

4- { [5-Amino-4-[(5-chloro-2-methylphenyl)diazenyl]- IH-pyrazol- 1 - yl} methyl)- 1 -methylpyridinium chloride;

4- { [5-Amino-4-[(4-chloro-2-methylphenyl)diazenyl]- IH-pyrazol- 1 - yl} methyl)- 1 -methylpyridinium chloride;

4- { [5-Amino-4-[(5-chloro-2-methoxyphenyl)diazenyl]- IH-pyrazol- 1 - yl} methyl)- 1 -methylpyridinium chloride;

4- { [5-Amino-4-[(3-chloro-4-fluorophenyl)diazenyl]- IH-pyrazol- 1 - yl} methyl)- 1 -methylpyridinium chloride; 4- { [5-Amino-4-[(2-chloro-4-nitrophenyl)diazenyl]- lH-pyrazol- 1 - yl} methyl)- 1 -methylpyridinium chloride;

4- { [5-Amino-4-[(2-chloro-5-nitrophenyl)diazenyl]- lH-pyrazol- 1 - yl} methyl)- 1 -methylpyridinium chloride;

4- { [5-Amino-4-[(4-chloro-2-nitrophenyl)diazenyl]- lH-pyrazol- 1 - yl} methyl)- 1 -methylpyridinium chloride;

4- { [5-Amino-4-[(4-chloro-3-nitrophenyl)diazenyl]- lH-pyrazol- 1 - yl} methyl)- 1 -methylpyridinium chloride;

4- { [5-Amino-4-[(5-chloro-2-nitrophenyl)diazenyl]- lH-pyrazol- 1 - yl} methyl)- 1 -methylpyridinium chloride;

4- { [5-Amino-4-[(2-cyano-4-nitrophenyl)diazenyl]- lH-pyrazol- 1 - yl} methyl)- 1 -methylpyridinium chloride;

4- { [5-Amino-4-[(2,4-dichlorophenyl)diazenyl]- lH-pyrazol- 1 -yl} methyl)- 1 - methylpyridinium chloride;

4- { [5-Amino-4-[(2,5-dichlorophenyl)diazenyl]- lH-pyrazol- 1 -yl} methyl)- 1 - methylpyridinium chloride;

4- { [5-Amino-4-[(2,4-dimethylphenyl)diazenyl]- lH-pyrazol- 1 -yl} methyl)- 1 - methylpyridinium chloride;

4- { [5-Amino-4-[(2,5-dimethylphenyl)diazenyl]- lH-pyrazol- 1 -yl} methyl)- 1 - methylpyridinium chloride;

4-( {5-Amino-4-[(4-(methoxycarbonyl)phenyl)diazenyl] - 1 H-pyrazol- 1 - yl} methyl)- 1 -methylpyridinium methyl sulfate.

According to another preferred embodiment of the present invention, the pyrazole dyes of general formula (II), which can be used, for example, in the compositions in accordance with the invention, may be selected from the group comprising:

3 -( { 5 - Amino-4- [(2-amino-3 , 5 -dimethyl-4-oxocyclohexa-2, 5 -dien- 1 - ylidene)amino]- 1 H-pyrazol- 1 -yl} methyl)- 1 -methylpyridinium chloride; 3 - { [5 - Amino-4-( {2- [(2-hydroxyethyl)amino] - 5 -methyl-4-oxocyclohexa-2, 5 - dien- 1 -ylidene} amino)- IH-pyrazol- 1 -yl] methyl} - 1 -methylpyridinium chloride;

3 -( { 5 - Amino-4- [(2-amino-4-imino-5 -methylcyclohexa-2, 5 -dien- 1 - ylidene)amino]- IH-pyrazol- 1 -yl} methyl)- 1 -methylpyridinium chloride;

3 -( { 5 - Amino-4- [(2-amino-4-imino-5 -methoxycyclohexa-2, 5 -dien- 1 - ylidene)amino]- IH-pyrazol- 1 -yl} methyl)- 1 -methylpyridinium chloride;

3 - { [5 -amino-4-( {2- [(2-hydroxyethyl)amino] -4-imino- 5 -methoxycyclohexa- 2,5-dien- 1 -ylidene} amino)- IH-pyrazol- 1 -yljmethyl} - 1 -methylpyridinium chloride;

3 - [(5 - Amino-4- { [2-amino- 5 -(2-hydroxyethoxy)-4-iminocyclohexa-2, 5 -dien- 1 -ylidene] amino } - 1 H-pyrazol- 1 -yl)methyl] - 1 -methylpyridinium chloride ;

3 -( { 5 -amino-4- [(5 -hexyl-2-hydroxy-4-oxocyclohexa-2, 5 -dien- 1 - ylidene)amino]- 1 H-pyrazol- 1 -yl} methyl)- 1 -methylpyridinium chloride;

4-( { 5 - Amino-4- [(2-amino-3 , 5 -dimethyl-4-oxocyclohexa-2, 5 -dien- 1 - ylidene)amino]- 1 H-pyrazol- 1 -yl} methyl)- 1 -methylpyridinium chloride;

4- { [5 - Amino-4-( {2- [(2-hydroxyethyl)amino] - 5 -methyl-4-oxocyclohexa-2, 5 - dien- 1 -ylidene} amino)- 1 H-pyrazol- 1 -yljmethyl} - 1 -methylpyridinium chloride;

4-( { 5 - Amino-4- [(2-amino-4-imino-5 -methylcyclohexa-2, 5 -dien- 1 - ylidene)amino]- 1 H-pyrazol- 1 -yl} methyl)- 1 -methylpyridinium chloride;

4-( { 5 - Amino-4- [(2-amino-4-imino-5 -methoxycyclohexa-2, 5 -dien- 1 - ylidene)amino]- 1 H-pyrazol- 1 -yl} methyl)- 1 -methylpyridinium chloride;

4- { [5 -amino-4-( {2- [(2-hydroxyethyl)amino] -4-imino- 5 -methoxycyclohexa- 2,5-dien- 1 -ylidene} amino)- 1 H-pyrazol- 1 -yljmethyl} - 1 -methylpyridinium chloride;

4- [(5 - Amino-4- { [2-amino- 5 -(2-hydroxyethoxy)-4-iminocyclohexa-2, 5 -dien- 1 -ylidene] amino } - 1 H-pyrazol- 1 -yl)methyl] - 1 -methylpyridinium chloride .

The dyes may also exist in one or more tautomeric forms.

Most preferred cationic dyes of general formula (I) or (II), in the following case obtained from the pyrazole intermediate (III), may be selected from the group comprising: 3- { [5-Amino-4-(phenyldiazenyl)- IH-pyrazol- 1 -yljmethyl} - 1^■

methylpyridinium chloride hydrochloride (1-1)

(i-i);

3-[(5-Amino-4- { [2-(h droxymethyl)phenyl]diazenyl} - IH-pyrazol- 1 - yl)methyl]-l -methylpyridin

3-( {5-Amino-4-[(4-methylphenyl)diazenyl] - IH-pyrazol- 1 -yl} methyl)- 1 -(2- hydroxyethyl)pyridinium bromide hydrobromide (1-3)

(1-3);

3-[(5-Amino-4- { [2- methoxymethyl)-4-nitrophenyl]diazenyl} - lH-pyrazol- l-yl)methyl]-l -methylpyri

3 -( { 5 - Amino-4- [(2-amino-3 , 5 -dimethyl-4-oxocyclohexa-2, 5 -dien- 1 - ene)amino]- 1 H-pyrazol- 1 -yl} methyl)- 1 -methylpyridinium chloride (II-l)

(ii-i);

3- { [5-Amino-4-( {2-[(2-hydroxyethyl)amino]-5-methyl-4-oxocyclohexa-2,5- dien- 1 -ylidene } amino)- 1 H-pyrazol- 1 -yl] methyl} - 1 -methylpyridinium chloride (Π-2)

3 -( { 5 - Amino-4- [(2-amino-4-imino-5 -methylcyclohexa-2, 5 -dien- 1 - ene)amino]- 1 H-pyrazol- 1 -yl} methyl)- 1 -methylpyridinium chloride (II-3)

(II-3);

3 - [(5 - Amino-4- { [2-amino- 5 -(2-hydroxyethoxy)-4-iminocyclohexa-2, 5 -dien- 1 -ylidene] amino } - 1 H-pyrazol- 1 -yl)methyl] - 1 -methylpyridinium chloride (II-4)

(II-4). Another versatile method useful for the preparation of broad spectrum of 4,5-diaminopyrazoles is for instance described in DE4234885 starting from 3,5- dibromo-4-nitropyrazole. US7091350B2 further illustrates the potential of this intermediate leading to a variety of useful intermediates containing quaternizable groups in the pyrazole-Nl-substituent.

It is possible to obtain compositions for dyeing keratin fibers, in particular human hair, comprising the direct cationic dyes of general formula (I) or (II), which don't have the inconveniences of the known compositions.

The compositions according to present invention allow obtaining colorations which have good endurance and which are rich of shine and brilliant reflexes.

Another subject of the invention is thus a ready-to-use composition for dyeing of keratin fibers, such as hair in particular human hair.

The ready-to-use compositions comprise, in a medium which is suitable for dyeing:

at least one cationic direct dye of formula (I) or (II) according to the present invention,

in combination with

at least one oxidation dye, and

- at least one oxidizing agent.

The cationic direct dye(s) of formulae (I) and/or (II) in accordance with the invention are preferably present in a concentration ranging from approximately 0.001 to approximately 10% by weight relative to the total weight of the composition, and even more preferably from approximately 0.05 to approximately 2% by weight relative to the total weight of the composition.

Besides the cationic dyes of formula (I) and/or (II) the cosmetic composition comprises at least one oxidation base.

Suitable oxidation bases, also called primary intermediates, which can be used in accordance with the invention are preferably selected from para-phenylenediamines, bis(phenyl)alkylenediamines, para-aminophenols, ortho- aminophenols and heterocyclic oxidation dyes.

The para-phenylenediamines may be selected, for example, from 1,4- Diamino-benzene; l,4-Diamino-2-methyl-benzene; 1 ,4-Diamino-2-(2- hydroxyethyl)-benzene; 1 ,4-Diamino-2,3-dimethyl-benzene; 1 ,4-Diamino-2,6- dimethyl-benzene; 1 ,4-Diamino-2-methoxymethyl-benzene; 1 ,4-Diamino-2- chloro-benzene; 4- [Di(2-hydroxyethyl)amino] -aniline; 2,2'-({2-[(4-

Aminophenyl)amino] ethyl} imino)diethanol; (4-Aminophenyl)-(3-(imidazol- 1 - yl)propyl)amine; N,N'-bis( -hydroxyethyl)-N,N'-bis(4'-aminophenyl)- 1 ,3- diaminopropanol.

The para-aminophenols may be selected, for example, from 4-aminophenol; 4-(methylamino)phenol, 4-Amino-3-methylphenol; 2-Aminomethyl-4- aminophenol; Bis(5-amino-2-hydroxyphenyl)methane.

The ortho-aminophenols may be, for example, 2-Amino-5-ethylphenol or 2-

Amino- 5 -methoxymethylphenol.

The heterocyclic oxidation bases may be selected, for example, from 4,5- Diamino- 1 -(2-hydroxyethyl)- 1 H-pyrazole; 4,5-Diamino-4-methylbenzyl- 1 H- pyrazole; 2,3-Diaminodihydroxypyrazolo pyrazolone dime tho sulfonate; 2,5- Diaminopyridine; 2,4,5,6-Tetraaminopyrimidine.

The coupler components that may be used are, for example, m- phenylenediamine derivatives, resorcinol and resorcinol derivatives, m-amino- phenol and m-amino-phenol derivatives, naphthols as well as heterocyclic couplers, such as pyridines, pyrazolones, indoles.

Suitable coupler substances of the resorcinol type may be for instance:

1 ,3-Dihydroxybenzene; 4-Chloro- 1 ,3-dihydroxybenzene;

1 ,3-Dihydroxy-2-methylbenzene.

Suitable coupler substances may be m-aminophenol and derivatives thereof, such as 3-Aminophenol; 5-Amino-2-methylphenol; 5-Amino-4-chloro-2- methylphenol; 3-Amino-2,6-dimethylphenol; 2-Methyl-5- hydroxyethylaminophenol; 3-Amino-2,4-dichlorophenol; 3,4-Dihydro-2H- 1 ,4- benzoxazin-6-ol; Hydroxyethyl-3,4-methylenedioxyaniline; 3,4-Dihydro-6- hydroxy-2H- 1 ,4-benzoxazine; 6-Amino-3,4-dihydro-2H- 1 ,4-benzoxazine.

Suitable coupler substances of the m-phenylenediamine type may be for instance:

2,4-Diamino- 1 -(2-hydroxyethoxy)benzene; 2-Amino-4-[(2- hydroxyethyl)amino]anisole; 1 ,3-Bis(2,4-diaminophenoxy)propane; 1 -Methyl-2,6- bis-(2-hydroxyethylamino)-benzene.

Suitable coupler substances of the naphthol type may be for example:

1-Naphthol; 2-Methyl-l -naphthol; 1,5-Naphthalenediol;

2,7-Naphthalenediol

Suitable heterocyclic coupler substances may be for example:

2,6-Diaminopyridine; 2,6-Dihydroxy-3,4-dimethylpyridine;

3 , 5 -Diamino-2,6-dimethoxypyridine ; 2- Amino-3 -hydroxypyridine ; 6-Methoxy-2- methylamino-3-aminopyridine; 3-Methyl- 1 -phenyl-5-pyrazolone;

and the indole derivatives:

6-Hydroxyindole; 5,6-Dihydroxyindole; 5,6-Dihydroxyindoline.

Oxidation bases and couplers containing unsubstituted or substituted amino groups may be used as free bases or in form of their acid-addition salts. The acid- addition salts may be selected in particular from the hydrochlorides, hydrobromides, sulphates, phosphates and hydroxysuccinates.

The oxidation dye(s) are preferably present in a concentration ranging from approximately 0.0001 to approximately 10% by weight relative to the total weight of the composition, and even more preferably from approximately 0.001 to approximately 5% by weight relative to the total weight of the composition.

The composition, besides the cationic dyes of formula (I) and/or (II), primary intermediates and couplers, comprises at least one oxidizing agent.

The oxidizing agent present in the dye composition may be selected from oxidizing agents used conventionally in oxidation dyeing and preferably from hydrogen peroxide, urea peroxide, alkali or ammonium persulphates or alkali perborates. Hydrogen peroxide is particularly preferred.

The pH of the composition generally ranges from approximately 5 to approximately 12. The preferred range is from 6.5 to 1 1.5. It can be adjusted to the desired value using acidifying or basifying agents usually used in hair color technology.

The acidifying agents may be, for example, inorganic or organic acids, such as hydrochloric acid, sulphuric acid, orthophosphoric acid and carboxylic acids, such as hydroxysuccinic acid, citric acid or lactic acid.

The basifying agents may be , for example, aqueous ammonia, alkaline carbonates, alkanolamines, such as monoethanolamine (MEA), l-amino-2- propanol, 2-amino-2-methyl-propanol (AMP), 2-amino-2-methyl-l,3-propanediol, 2-amino-2-ethyl- 1 ,3-propanediol and tris(hydroxymethyl)-aminomethane (Tromethamine, Tris).

Further, the composition may contain amino acids, preferably a-amino acids such as Arginine, Glycine, Ornithine, Lysine Serine and Histidine; most preferred are Arginine and Glycine.

The compositions in accordance with the current invention make it possible to obtain colorations in brilliant shades which exhibit excellent stability to everyday conditions, in particular to shampoos.

The medium which is suitable for dyeing (or the support) for the composition in accordance with the invention generally comprises water or a mixture of water and at least one organic solvent in order to dissolve the compounds which would not be sufficiently soluble in water. The organic solvent may be, for example, Q -C₄ lower alkanols such as ethanol and isopropanol; glycerol; glycols and glycol ethers such as 2-butoxy-ethanol, propylene glycol, propylene glycol monomethyl ether, diethylene glycol monoethyl ether and monomethyl ether; and aromatic alcohols such as benzyl alcohol or phenoxyethanol; and mixtures thereof.

The organic solvent(s) can be present in a concentration preferably ranging from approximately 1 to approximately 40% by weight relative to the total weight of the dye composition, and even more preferably from approximately 5 to approximately 30% by weight relative to the total weight of the dye composition.

The compositions in accordance with the invention can also contain various adjuvants used conventionally in compositions for dyeing the hair, such as anionic, cationic, nonionic or amphoteric surfactants or mixtures thereof; anionic, cationic, nonionic or amphoteric polymers or mixtures thereof; inorganic or organic thickeners; antioxidants; penetration agents; sequestering agents; fragrances; buffers; dispersing agents; packaging agents; film-forming agents; preserving agents and opacifiers.

Surfactants that may be used in hair colorants of the current invention may be from the classes of anionic, cationic, amphoteric (including zwitterionic surfactants) or nonionic surfactant. Suitable surfactants, other than cationic surfactants, include fatty alcohol sulfates, ethoxylated fatty alcohol sulfates, alkylsulfonates, alkylbenzenesulfonates, alkyltrimethylammonium salts, alkylbetaines, ethoxylated fatty alcohols, ethoxylated fatty acids, ethoxylated alkylphenols, block polymers of ethylene and/or propylene glycol, glycerol esters, phosphate esters, fatty acid alkanol amides and ethoxylated fatty acid esters, alkyl sulfates, ethoxylated alkyl sulfates, alkyl glyceryl ether sulfonates, methyl acyl taurates, acyl isethionates, alkyl ethoxy carboxylates, fatty acid mono- and diethanolamides. Especially useful are sodium and ammonium alkyl sulfates, sodium and ammonium ether sulfates having 1 to 3 ethylene oxide groups and nonionic surfactants sold as Tergitols, e.g., C1 1-C15 Pareth-9 and Neodols, e.g. C12-C15 Pareth-3. They may be included for various reasons, e.g. to assist in thickening, for forming emulsions, to help in wetting hair during application of the hair dye product composition, etc. Amphoteric surfactants include, for example, the asparagine derivatives as well as betaines, sultaines, glycinates and propionates having an alkyl or alkylamido group of from about 10 to about 20 carbon atoms. Typical amphoteric surfactants suitable for use in this invention include lauryl betaine, lauroamphoglycinate, lauroamphopropionate, lauryl sultaine, myristamidopropyl betaine, myristyl betaine, stearoamphopropylsulfonate, cocamidoethyl betaine, cocamidopropyl betaine, cocoamphoglycinate, cocoamphocarboxypropionate, cocoamphocarboxyglycinate, cocobetaine, and cocoamphopropionate.

Suitable conditioning materials include silicones and silicone derivatives; hydrocarbon oils; monomeric quaternary compounds and quaternized polymers.

Monomeric quaternary compounds are typically cationic compounds, but may also include betaines and other amphoteric and zwitterionic materials that provide a conditioning effect. Suitable monomeric quaternary compounds include behentrialkonium chloride, behentrimonium chloride, benzalkonium bromide or chloride, benzyl triethyl ammonium chloride, bis-hydroxyethyl tallowmonium chloride, CI 2- 18 dialkyldimonium chloride, cetalkonium chloride, ceteartrimonium bromide and chloride, cetrimonium bromide, chloride and methosulfate, cetylpyridonium chloride, cocamidoproypl ethyldimonium ethosulfate, cocamidopropyl ethosulfate, cocoethyldimonium ethosulfate, cocotrimonium chloride and ethosulfate, dibehenyl dimonium chloride, dicetyldimonium chloride, dicocodimonium chloride, dilauryl dimonium chloride, disoydimonium chloride, ditallowdimonium chloride, hydrogenated tallow trimonium chloride, hydroxyethyl cetyl dimonium chloride, myristalkonium chloride, olealkonium chloride, soyethomonium ethosulfate, soytrimonium chloride, stearalkonium chloride, and many other compounds as disclosed for example in WO98/27941.

Quaternized polymers are typically cationic polymers, but may also include amphoteric and zwitterionic polymers. Useful polymers are exemplified by polyquaternium-4, polyquaternium-6, polyquaternium-7, polyquaternium-8, polyquaternium-9, polyquaternium-10, polyquaternium-22, polyquaternium-32, polyquaternium-39, polyquaternium-44 and polyquaternium-47. Silicones suitable to condition hair are dimethicone, amodimethicone, dimethicone copolyol and dimethiconol.

Suitable silicones are also disclosed in WO99/34770.

The compositions of the present invention may also contain at least one silicone quaternary compound selected from silicone quaternium- 1 , silicone quaternium-2, silicone quaternium-2 panthenol succinate, silicone quaternium-3, silicone quaternium-4, silicone quaternium-5, silicone quaternium-6, silicone quaternium-7, silicone quaternium-8, silicone quaternium-9, silicone quaternium- 10, silicone quaternium- 1 1 , silicone quaternium- 12, silicone quaternium- 15, silicone quaternium- 16, silicone quaternium- 16/glycidoxy dimethicone crosspolymer, silicone quaternium- 17, silicone quaternium- 18, silicone quaternium-20 and silicone quaternium-21.

Concentration of the polyquaternium or silicone quaternary compound may vary in the range of 0.01 to 10%, preferably 0.05 to 7.5%, more preferably 0.1 to 5% and most preferably 0.1 to 3% by weight calculated to the weight of the composition.

Suitable thickeners may be for example higher fatty alcohols, starches, cellulose derivatives, petrolatum, paraffin oil, fatty acids and anionic and nonionic polymeric thickeners based on polyacrylic and polyurethane polymers. Examples are cellulose derivatives, such as hydroxyalkylcelluloses, preferentially hydroxymethyl and hydroxyethylcellulose; carboxyalkylcellulose, such as carboxymethylcellulose; hydrophobically modified anionic polymers and nonionic polymers, particularly such polymers having both hydrophilic and hydrophobic moieties (i.e. amphiphilic polymers). Useful nonionic polymers include polyurethane derivatives such as PEG-150/stearyl alcohol/SDMI copolymer. Suitable polyether urethanes are Aculyn® 22, Aculyn® 44, and Aculyn® 46 polymers sold by Rohm & Haas. Other useful amphiphilic polymers are disclosed in US6010541. Examples of anionic polymers that can be used as thickeners are acrylates copolymer, acrylates/ceteth-20 methacrylates copolymer, acrylates/ceteth-20 itaconate copolymer, and acrylates/beheneth-25 acrylates copolymers. In the case of the associative type of thickeners, e.g. Aculyns 22, 44 and 46, the polymer may be included in one of either the hair dye composition or the developer composition of the hair dye product and the surfactant material in the other. Thus, upon mixing of the hair dye and developer compositions, the requisite viscosity is obtained.

The thickeners are provided in an amount to provide a suitably thick product as it is applied to the hair. Such products generally have a viscosity of from 1000 to 100000 cps, and often have a thixotropic rheology.

Another subject of the invention is a multi-compartment dyeing "kit- 1 " or device or any other multi-compartment packaging system, comprising:

- a first compartment which contains, in a medium suitable for dyeing, at least one primary intermediate, at least one coupler and at least one cationic direct dye selected from the compounds of formulae (I) or (II), and

- a second compartment which contains, in a medium suitable for dyeing, the oxidizing composition.

Another subject of the invention is a multi-compartment dyeing "kit-2" or device or any other multi-compartment packaging system, comprising:

- a first compartment which contains, in a medium suitable for dyeing, at least one primary intermediate and at least one coupler,

- a second compartment which contains, in a medium suitable for dyeing, at least one cationic direct dye selected from compounds of formulae (I) or (II), and

- a third compartment which contains, in a medium suitable for dyeing, the oxidizing composition.

The compositions in accordance with the invention can be in various forms, such as in the form of liquids, creams, gels or foams or in any other form which is appropriate for dyeing keratin fibers, and in particular human hair.

Another subject of the invention is a process for dyeing keratin fibers, and in particular human keratin fibers such as the hair, using at least one cationic dye of general formula (I) or (II) as defined above.

The process for dyeing keratin fibers comprises:

- preparing a composition comprising, in a medium suitable for dyeing, at least one cationic dye of general formula (I) or (II) as defined above, at least one primary intermediate and optionally at least one coupler,

- separately preparing a developer composition comprising, in a medium suitable for dyeing, at least one oxidizing agent,

- mixing both compositions to obtain the composition for dyeing keratin fibers,

- applying said composition to said keratin fibers,

- leaving the composition on said keratin fibers for a time ranging from 5 to 45 minutes,

- keratin fibers are then rinsed, optionally washed with shampoo, rinsed again and dried.

Alternatively, a process for dyeing keratin fibers comprises:

- preparing a composition comprising, in a medium suitable for dyeing, at least one cationic dye of general formula (I) or (II) as defined above,

- preparing a composition comprising at least one primary intermediate and optionally at least one coupler, - separately preparing a developer composition comprising, in a medium suitable for dyeing, at least one oxidizing agent,

- mixing the three separately prepared compositions to obtain the composition for dyeing keratin fibers,

- applying said composition to said keratin fibers,

According to this process, the ready-to-use composition for dyeing keratin fibers is obtained by mixing together the components, for example the components of the kits as defined above.

The cosmetic composition thus obtained is applied to the keratin fibers and is left on them for an exposure time preferably ranging from approximately 5 to approximately 45 minutes, more preferably from approximately 10 to approximately 30 minutes, after which the fibers are rinsed, optionally washed with shampoo, rinsed again and dried.

The following examples further illustrate the present invention.

EXAMPLES

Example 1; Preparation of {[5-amino-4-(aryldiazenyl)-l -pyrazol-l- yl] methyl}-l-methylpyridinium salts

Step 1: General procedure for the preparation of 4-(aryldiazenyl)-l - pyrazol-5-amines

100 mmol of the corresponding arylamine is added to 50 ml at 1 : 1 (v/v) mixture of water and hydrochloric acid 35%. The mixture is stirred for 15 min at room temperature to obtain a solution or a fine suspension, respectively. Then the mixture is cooled in an ice bath and at 0-5°C a solution of 7.25 g (105 mmol) of sodium nitrite in 20 ml water is added within 30 min; stirring is continued for 1 hour. The obtained diazonium salt solution is then added to a mechanically stirred solution of the corresponding 5-amino-lH-pyrazole (100 mmol) and 20.5g (250 mmol) sodium acetate dissolved in 150 ml water/methanol 2: 1 (v/v). The spontaneously obtained orange-yellow, paste-like dye suspension is stirred for lh; then the product is filtered off, washed with water and dried.

According to the general procedure the following compounds were obtained from 1 -(pyridin-3-ylmethyl)- lH-pyrazol-5-amine:

Example la: 4-(Phenyldiazenyl)-l-(pyridin-3-ylmethyl)-l -pyrazol-5- amine

Arylamine: aniline

Yield: 91%

m.p.: 164°C

CHN Analysis (C15H14N6; MW = 278.32):

Example lb : 4- [(4-methylphenyl)diazenyl] -l-(pyridin-3-ylmethyl)-l - pyrazol-5-amine

Arylamine: p-toluidine

Yield: 98%

m.p.: 163-164°C

Example lc: Methyl 4-{[5-amino-l-(pyridin-3-ylmethyl)-l -pyrazol-4- yl]diazenyl}benzoate

Arylamine: methyl p-aminobenzoate

Yield: 96%

m.p.: 158°C Example Id: 4-[(2-methyl-4-nitrophenyl)diazenyl]-l-(pyridin-3- ylmethyi)-l//-pyrazol-5-amine

Arylamine : 2-methyl-4-nitroaniline

Yield: 96%

m.p.: 198-199°C

Example le: 4-{[2-(methoxymethyl)-4-nitrophenyl]diazenyl}-l-(pyridin- 3-ylmethyi)-l//-pyrazol-5-amine

Arylamine : 2-methoxymethyl-4-nitroaniline

Yield: 88%

m.p.: 187-189°C (dec.)

Example If: (2-{[5-amino-l-(pyridin-3-ylmethyl)-l//-pyrazol-4- yl]diazenyl}phenyl)methanol

Arylamine: 2-aminobenzylalkohol

Yield: 77%

m.p.: 158°C

By the same procedure is obtained from l-(pyridin-4-ylmethyl)-lH-pyrazol- 5 -amine:

Example lg: (2-{[5-amino-l-(pyridin-4-ylmethyl)-l//-pyrazol-4- yl] diazenyl}phenyl)methanol

Arylamine: 2-aminobenzylalkohol

Yield: 82%

m.p.: 180-182°C

Step 2: Quaternization of the Intermediates from Step 1

Example 2a: 3-{[5-Amino-4-(phenyldiazenyl)-l//-pyrazol-l-yl]methyl}- 1-methylpyridinium chloride hydrochloride

4-(Phenyldiazenyl)- 1 -(pyridin-3-ylmethyl)- lH-pyrazol-5-amine (example la, 20 mmol, 5.57 g) is heated to reflux in acetonitrile (50 ml) whereby an orange- red solution is obtained. Then dimethylsulfate (22 mmol, 2.77 g) is added and heating is continued. After approximately 4 hours the reaction mixture is allowed to cool. At room temperature hydrochloric acid is added with stirring whereby the product precipitates out. Stirring is continued for lh; then the product is filtered off and dried to give 6.63g (86.5% of th.) orange, fine powdery solid.

The dye crystallizes out as hydrochloride and contains one equivalent of crystal water.

CHN Analysis (C16H17N6.C1 x HC1 x H₂O, MW = 383.28)

Example 2b : 3-({5-Amino-4- [(4-methylphenyl)diazenyl] -l//-pyrazol-l- yl}methyl)-l-methylpyridinium bromide hydrobromide

4-[(4-Methylphenyl)diazenyl]- 1 -(pyridin-3-ylmethyl)- lH-pyrazol-5-amine (example lb, 120 mmol, 35.08 g) is heated to reflux in 350ml acetone. Then dimethylsulfate (126 mmol, 15.89 g) is added over a 30min period and heating is continued for a further 3h. The reaction mixture is evaporated, then the residue is dissolved in 150 ml ethanol and 25 ml of an ammonium bromide solution (180 mmol, 17.63 g) is added followed by the addition of a solution of hydrobromic acid with external cooling (33% in acetic acid, 132 mmol, 32.37 g). Precipitation occurs and a thick suspension is obtained. The mixture is diluted with 50 ml ethanol and stirring is continued at room temperature for a further hour. The solid is filtered off and recrystallized from 450 ml ethanol/water 9: 1 (v/v). Filtration and drying gives 34.72 g (57.4% of th.) orange needles.

The dye crystallizes out as hydrobromide and contains two equivalents of crystal water. CHN Analysis (C17H19N6.Br x HBr x 2H₂O, MW = 504.22)

Example 2c: 3-({5-Amino-4-[(4-(methoxycarbonyl)phenyl)diazenyl]-lH- pyrazol-l-yl}methyl)-l-methylpyridinium methyl sulfate

Methyl 4-{[5-amino-l-(pyridin-3-ylmethyl)-lH-pyrazol-4- yl]diazenyl}benzoate (example lc, 6.6 g, 19.6 mmol) is suspended in 100 ml 3- methoxypropionitrile and heated to 100°C. Dimethylsulfate (2.6 g, 20.6 mmol) is added over a 15 min period whereby a red solution is obtained. Stirring is continued for an additional hour; then the reaction mixture is allowed to cool to room temperature. The solution is concentrated to a volume of 20-30 ml, then an identical volume of isopropanol is added to precipitate the dye. After stirring for 30 min the dye is filtered off, washed with isopropanol and dried to give 7.8g (86% of th.) mustard-yellow solid.

1H-NM (DMSO-d₆): δ = 8.95 (signal overlap, 2H); 8.38 (d, ³J = 8.1 Hz, 1H); 8.14 (dd, ³J = 8.1 Hz, ³J = 6.1 Hz, 1H); 8.05 (d, ³J = 8.8 Hz, 2H); 7.97 (s, 1H); 7.84 (d, ³J = 8.8 Hz, 2H); 7.62 (s, 2H); 5.49 (s, 2H); 4.38 (s, 3H); 3.87 (s, 3H); 3.38 ppm (s, 3H).

Example 2d: 3-({5-Amino-4- [(2-methyl-4-nitrophenyl)diazenyl] -1H- pyrazol-l-yl}methyl)-l-methylpyridinium methyl sulfate

4-[(2-methyl-4-nitrophenyl)diazenyl]- 1 -(pyridin-3-ylmethyl)- lH-pyrazol-5- amine (example Id, 37.1 g, 1 10 mmol) is heated in 330 ml 3-methoxypropionitrile to 75°C; a thick suspension is obtained. At this temperature dimethylsulfate (14.5 g, 1 15 mmol) is added and stirring is continued for 2 hours whereby an easily stirrable suspension is obtained. The heating bath is removed, then at 50°C 100 ml acetone is added and stirring is continued for an additional hour. Filtration of the dye and drying gives 46.9 g (92% of th.) bright orange solid. 1H-NM (DMSO-d₆): δ = 8.97 (signal overlap, 2H); 8.41 (d, ³J = 8.1 Hz, 1H); 8.22 (d, ⁴J = 2.6 Hz, 1H); 8.15 (dd, ³J = 8.1 Hz, ³J = 6.5 Hz, 1H); 8.10 (dd, ³J = 8.7 Hz, ⁴J = 2.6 Hz, 1H); 8.03 (s, 1H); 7.75 (s, 2H); 7.70 (d, ³J = 8.7 Hz, 1H); 5.50 (s, 2H); 4.39 (s, 3H); 3.38 (s, 3H); 2.61 ppm (s, 3H).

Example 2e: 3-[(5-Amino-4-{[2-(methoxymethyl)-4- nitrophenyl]diazenyl}-l -pyrazol-l-yl)methyl]-l-methylpyridinium methyl sulfate

4- { [2-(Methoxymethyl)-4-nitrophenyl]diazenyl} - 1 -(pyridin-3-ylmethyl)- lH-pyrazol-5-amine (140 mmol, 51.43 g) is dissolved in N-methyl-2-pyrolidone (150 ml) and heated to 60°C. Then dimethylsulfate (154 mmol, 19.42 g) is added within 10 min. The mixture is stirred at 60°C for 1 h; then temperature is increased to 80°C. After 2 h further dimethylsulfate (15.4 mmol, 1.94g) is added to complete the reaction. After a further 3 h temperature is raised to 100°C for an additional hour. Heating is stopped, and the mixture is diluted with N-methyl-2-pyrolidone (50 ml). The solution is filtered warm, then at approximately 60°C, acetone (250 ml) is carefully added whereas the dye precipitates out and a fine suspension is formed. After stirring for 30 min the suspension is cooled in an ice bath and the solid is filtered off. The dye is washed with acetone and dried. Yield: 48.87 g orange solid (70.7% of th.).

1H-NMR (DMSO-d₆): δ = 8.95 (signal overlap, 2H); 8.41 (d, ³J = 8.1 Hz,

1H); 8.34 (d, ³J = 2.6 Hz, 1H); 8.22 (dd, ³J = 8.9 Hz, ³J = 2.6 Hz, 1H); 8.14 (dd, ³J = 8.1 Hz, ³J = 6.5 Hz, 1H); 8.05 (s, 1H); 7.82 (s, broad, 2H); 7.76 (d, ³J = 8.9 Hz, 1H); 5.48 (s, 2H); 4.86 (s, 2H); 4.37 (s, 3H); 3.41 (s, 3H); 3.5-3.3 ppm (signal overlap, 3H and water).

Example 2f: 3-[(5-Amino-4-{[2-(hydroxymethyl)phenyl]diazenyl}-lH- pyrazol-l-yl)methyl]-l-methylpyridinium bromide

(2- { [5 -Amino- 1 -(pyridin-3-ylmethyl)- lH-pyrazol-4- yl]diazenyl}phenyl)methanol (70 mmol, 21.58 g) is stirred in 3-methoxypropionitrile (100 ml) and heated to 60°C. At this temperature dimethylsulfate (73.5 mmol, 9.27 g) is added within 30 min. A clear red solution is obtained after the addition was complete. Stirring is continued for a further 30 min. The reaction mixture is allowed to cool to room temperature, then the solvent is evaporated. The viscous residue is dissolved in water(80 ml), then ammonium bromide solution (73.5 mmol, 7.2 g dissolved in 30 ml water) is added and stirring at room temperature is continued. Shortly after the addition the dye precipitates out. The solid is filtered off and recrystallized from water (60 ml). After filtration and drying 15.88 g (56.3% of th.) yellow solid is obtained.

CHN Analysis (C17H19N6O.Br; MW = 403.28)

1H-NM (DMSO-d₆): δ = 8.95 (signal overlap, 2H); 8.38 (d, ³J = 8.1 Hz, 1H); 8.15 (dd, ³J = 8.9 Hz, ³J = 2.6 Hz, 1H); 7.97 (s, 1H); 7.54 (m, 2H); 7.44 (s, broad, 2H); 7.32 (m, 2H); 5.48 (s, 2H); 5.21 (s, broad, 1H); 4.86 (s, 2H); 4.37 ppm (s, 3H).

Example 2g: 4- [(5-amino-4-{ [2-(hydroxymethyl)phenyl] diazenyl}-l - pyrazol-l-yl)methyl]-l-methylpyridinium methyl sulfate

To a stirred suspension of (2-{[5-amino-l-(pyridin-4-ylmethyl)-lH-pyrazol- 4-yl]diazenyl}phenyl)methanol (3.08 g , 10 mmol) in 3-methoxypropionitrile (30 ml) dimethylsulfate is added (1.32 g, 10.5 mmol). The mixture is heated to 60°C and a clear solution is obtained. After 2 hours the reaction mixture is allowed to cool whereby the product crystallizes out. Filtration and drying gives 3.87 g (89.1 % of th.) orange-yellow product.

The product on TLC is uniform and shows the expected characteristics of a cationic dye. TLC (silica 0.25 mm), isopropanol (4)/water (5.5)/acetic acid (0.5): R_f starting material = 0.81 ; R cationic dye = 0.58.

Example 3: Synthesis of Cationic Dyes of formula (II): general synthesis method

In a flask are placed 35ml ethanol and 5ml water. With stirring, 3-[(4,5- diamino- lH-pyrazol- 1 -yl)methyl]- 1 -methylpyridinium methylsulfate dihydrochloride (lOmmol, 3.88g) and the corresponding coupler (l lmmol) are added and the pH of the mixture is adjusted to 9 by the addition of ammonium hydroxide 28%. Then aqueous hydrogen peroxide solution of 9% strength (30mmol, 1 1.34g) is added; within a few minutes the color of the reaction mixture changes to deep red. After stirring for 16h at room temperature a red-brown dye suspension is obtained. The solid is filtered off, washed with ethanol and dried.

Example 3a: 3-({5-Amino-4-[(2-amino-3,5-dimethyl-4-oxocyclohexa-2,5- dien-l-ylidene)amino]-l -pyrazol-l-yl}methyl)-l-methylpyridinium chloride is obtained from 3-amino-2,6-dimethylphenol (3.34g, 89% yield).

1H-NMR (DMSO-d₆): δ = 8.98 (s, 1H); 8.95 (d, ³J = 6.1 Hz, 1H); 8.35 (d, ³J = 8.0 Hz, 1H); 8.13 (dd, ³J = 8.0 Hz, ³J = 6.1 Hz, 1H); 7.85 (s, 1H); 7.17 (d, ⁴J = 1.2 Hz, 1H); 7.02 (s, 2H); 6.32 (s, broad, 2H); 5.48 (s, 2H); 4.37 (s, 3H); 1.93 (d, ⁴J=1.2 Hz, 3H); 1.76 ppm (s, 3H). Example 3b : 3-{ [5-Amino-4-({2- [(2-hy droxyethyl)amino] -5-methyl-4- oxocyclohexa-2,5-dien-l-ylidene}amino)-l -pyrazol-l-yl]methyl}-l- methylpyridinium chloride is obtained from 2-methyl-5- hydroxyethylaminophenol (1.59g, 39.5% yield).

1H-NM (DMSO-d₆): δ = 9.01 (s, 1H); 8.96 (d, ³J = 5.9 Hz, 1H); 8.35 (d, ³J = 8.1 Hz, 1H); 8.13 (dd, ³J = 8.1 Hz, ³J = 5.9 Hz 1H); 7.88 (s, 1H); 7.36 (t, ³J = 6.2 Hz, 1H); 7.22 (d, ⁴J = 1.3 Hz, 1H); 7.18 (s, 1H); 5.51 (s, 2H); 5.26 (s, 2H); 4.37 (m, signal overlap, 4H); 3.53 (t, ³J = 6.2 Hz, 2H); 3.18 (dt, ³J = 6.3 Hz, ³J = 6.2 Hz, 2H); 1.92 ppm (d, ⁴J = 1.3 Hz, 3H).

Example 3c: 3-({5-Amino-4-[(2-amino-4-imino-5-methylcyclohexa-2,5- dien-l-ylidene)amino]-l -pyrazol-l-yl}methyl)-l-methylpyridinium chloride is obtained from 2,4-diaminotoluene (3.28g, 92% yield).

1H-NMR (DMSO-d₆): δ = 9.08 (s, 1H); 8.98 (d, ³J = 6.0 Hz, 1H); 8.45 (d, ³J = 8.1 Hz, 1H); 8.19 (s, 1H); 8.14 (dd, ³J = 8.1 Hz, ³J = 6.0 Hz, 1H); 8.07 (s, broad, 5H); 7.27 (d, ³J = 0.9 Hz, 1H); 5.88 (s, 1H); 5.57 (s, 2H); 4.37 (s, 3H); 2.13 ppm (d, ³J = 0.9 Hz, 3H). Example 3d: 3-({5-Amino-4-[(2-amino-4-imino-5-methoxycyclohexa- 2,5-dien-l-ylidene)amino]-l -pyrazol-l-yl}methyl)-l-methylpyridinium chloride is obtained from 2,4-diaminoanisole sulfate (3.29g, 88% yield).

1H-NM (DMSO-d₆): δ = 9.08 (s, IH); 9.0-8.8 (s, broad, IH); 8.98 (d, ³J = 6.0 Hz, IH); 8.45 (s, broad, 2H); 8.42 (d, ³J = 8.2 Hz, IH); 8.14 (dd, ³J = 8.2 Hz, ³J = 6.0 Hz, IH); 8.00 (s, IH); 7.93 (s, broad, 2H); 6.38 (s, IH); 5.92 (s, IH); 5.56 (s, 2H); 4.37 (s, 3H); 3.91 ppm (s, 3H).

Example 3e: 3-{ [5-amino-4-({2- [(2-hy droxyethyl)amino] -4-imino-5- methoxycyclohexa-2,5-dien-l-ylidene}amino)-l -pyrazol-l-yl]methyl}-l- methylpyridinium chloride is obtained from 2-amino-4- hydroxyethylaminoanisole sulfate (3.6g, 86% yield).

1H-NMR (DMSO-d₆): δ = 9.09 (s, IH); 9.0-8.7 (m, signal overlap, 2H); 8.41 (d, ³J = 8.0 Hz, IH); 8.3-7.9 (s, broad, 3H); 8.14 (dd, ³J = 8.0 Hz, ³J = 6.1 Hz, IH); 7.98 (s, IH); 6.44 (s, IH); 5.88 (s, IH); 5.57 (s, 2H); 5.3-4.8 (s, broad, IH); 4.37 (s, 3H); 3.92 (s, 3H); 3.60 (t, ³ J = 5.7 Hz, 2H); 3.5-3.0 ppm (m, signal overlap, 2H and water). Example 3f: 3-[(5-Amino-4-{[2-amino-5-(2-hydroxyethoxy)-4- iminocyclohexa-2,5-dien-l-ylidene] amino}-l -pyrazol-l-yl)methyl]-l- methylpyridinium chloride is obtained from 2,4-diaminophenoxyethanol 2HC1 (2.95g, 73% yield).

1H-NM (DMSO-d₆): δ = 9.16-9.11 (m, signal overlap, 2H); 9.01 (d, ³J = 6.1 Hz, 1H); 8.53 (s, broad, 2H); 8.45 (d, ³J = 8.0 Hz, 1H); 8.14 (dd, ³J = 8.0 Hz, ³J = 6.1 Hz, 1H); 8.02 (s, broad, 2H); 7.96 (s, 1H); 6.37 (s, 1H); 5.95 (s, 1H); 5.61 (s, 2H); 5.28 (t, 1H); 4.38 (s, 3H); 4.08 (t, 2H); 3.73 ppm (m, unstructured, 2H).

Example 3g: Alternative route - 3-({5-Amino-4-[(2-amino-3,5-dimethyl-

4-oxocyclohexa-2,5-dien-l-ylidene)amino]-l -pyrazol-l-yl}methyl)-l- methylpyridinium chloride

The same dye is obtained if, in an autoclave, a solution of 3-{[5-amino-4- (phenyldiazenyl)- lH-pyrazol- 1 -yljmethyl} - 1 -methylpyridinium chloride hydrochloride (example 2a, 36.53 g, 0.1 mol) in 350 ml ethanol/water 2:1 (v/v) is hydrogenated at 9 bar of hydrogen pressure for 3 hours using 3.6 g of Pd/C (10%). Then, under nitrogen atmosphere, the catalyst is filtered off. To the obtained filtrate 3-amino-2,6-dimethylphenol (13.72 g, 0.1 mol) is added. With stirring, the pH is adjusted to 9 by the addition of ammonium hydroxide 28% followed by the addition of hydrogen peroxide 9% (95g, 0.25 mol). Within a few minutes the color of the solution changes to deep red. Stirring is continued at room temperature for 16 hours. The obtained mixture is neutralized by the addition of hydrochloric acid 10%. At a rotavapor the mixture is concentrated to approximately 50% of the volume followed by cooling in an ice bath; the precipitated dye is filtered off. Washing with ethanol and drying gives 21.14 g (56.7 % of th.) dark red-brown solid.

The compound is identical with the reference (example 3 a).

Example 4

A standard oxidative hair color composition, as example shade 7/0, to which a 0.5% amount of the cationic dyes of the invention according to Table 1 was added, was mixed, at the time of use, with an equal amount of a developer composition containing hydrogen peroxide solution (6% by weight).

The obtained composition in accordance with the invention was applied at 30°C for 30 minutes to 50% human grey hair. The hair was then rinsed, washed with a standard shampoo and dried.

Composition:

Cetearyl alcohol 18.00 g

Myristyl alcohol 1.20 g

Ceteareth-50 5.00 g

Propylene glycol 5.00 g

Cocamidopropyl betaine 1.20 g

Polyquaternium-22 0.26 g

Sodium sulfite 0.40 g

Ascorbic acid 0.40 g

Ammonium hydroxide 28% 7.50 g

EDTA 0.20 g

Perfume 0.40 g

Toluene-2,5-diamine sulfate 1.20 g

Resorcinol 0.39 g

2-Methylresorcino 1 0.13 g

m-Aminophenol 0.08 g

2,4-Diaminophenoxyethanol HC1 0.01 g

Cationic dye (I), (II) according Table 1 0.50 g

Water ad 100.00 g Table 1; Composition and dye-outs of an oxidative colorant containing the cationic dyes of the invention

The hair swatches were intensely dyed with the indicated reflexes. The obtained shades were substantially resistant to washout.

Example 5;

The cosmetic compositions of Example 4, containing the inventive dyes, were stored at various conditions (4°C, 20°C, 50°C) for 4 weeks. Then dye-outs were performed as indicated. The obtained color results showed no visual differences to the dye outs performed before the storage test.

The storage test was repeated in which 0.5% of Basic Red 51 was used instead the dyes of the current invention.

After 4 weeks the dye-outs were performed as indicated in Example 4. The obtained color result was identical with the 7/0 reference shade but not with the expected intense red shade which is obtained from the freshly prepared composition.

The result demonstrates that Basic Red 51, which according to US6001 135 has been claimed for red shades, is not stable to reducing agents, which are commonly used to stabilize oxidative hair colorants and requires therefore separate formulation. Example 6:

The following composition is prepared as part of a 3 component kit. The composition containing the inventive dyes (I) or (II) is useful to provide more fashioned nuances to a conventional oxidative colorant; various glints are obtained according to the color of the cationic dye and the used amounts.

To a conventional oxidative colorant (component 1 of the kit) can be added the composition indicated in the table below (component 2 of the kit) in various amounts, for example in an amount of 10-20% w/w. To this composition an equal amount of a developer composition (component 3 of the kit) containing hydrogen peroxide is added and mixed to obtain the ready-to-use composition.

Component 2 of the kit and composition:

Cetearyl alcohol 18.00 g

Myristyl alcohol 1.20 g

Ceteareth-50 5.00 g

Propylene glycol 5.00 g

Cocamidopropyl betaine 1.20 g

Polyquaternium-22 0.26 g

Ammonium hydroxide 28% 7.50 g

Perfume 0.40 g

Cationic dye (I), (II) according Table 1 1.0 g

Water ad 100.00 g

The order of mixing the kit components is arbitrary.

The ready-to-use composition is applied to the hair in a sufficient amount and processed for 30 minutes. The hair was then rinsed, washed with a standard shampoo and dried. The hair swatches were intensely dyed with the reflexes indicated in Table 1.

Claims

Cationic dyes of general formula (I) and (II):

wherein

l is hydrogen, a straight-chain or branched (C 1 -C6)-alkyl group, a (Cl- C4)-hydroxyalkyl group, a (C 1 -C4)-aminoalkyl group, a (Cl-C8)-alkylamino group, a di(Cl-C8)-alkylamino group, a (Cl-C4)-alkylamino-(Cl-C4)-alkyl group or a di(Cl-C4)-alkylamino-(Cl-C4)-alkyl group, a benzyl group, an aryl group or a heteroaryl group;

R2 to R6, which are equal or different, are independently from each other selected from hydrogen, a straight-chain or branched (C 1 -C6)-alkyl or -alkoxy group, a (Cl-C4)-hydroxyalkyl or -hydroxyalkoxy group, a methoxymethyl group, a nitro group, a halogen atom selected from chlorine, bromine, iodine and fluorine, a trifluoromethyl group, a cyano group, an acetylamino or an amino group;

R7 is a hydrogen atom, a methyl or an ethyl group, a hydroxy group, an amino group, a hydroxy-(C2-C3)-alkylamino group, or a methoxy group;

R9 is a hydrogen atom, an amino group, a (C 1 -C6)-alkyl group, a (Cl-C6)-alkoxy group or a (C2-C3)-hydroxyalkoxy group; Y is an oxygen atom or an NR group wherein R is (C 1 -C4)-alkyl, (C2-C4)- hydroxyalkyl; or the NR group is bonded to the R9 to form a benzoxazine system;

Q⁺ is a saturated cationic group of formula (a):

R10

— N— R1 1

R12

(a)

wherein

RIO to R12 are equal or different and independently of each other selected from a straight-chain or branched (Cl-C6)-alkyl group, a (C2-C4)-hydroxyalkyl group, a (C3-C6)-dihydroxyalkyl group, a (C3-C6)-polyhydroxyalkyl group or a (Cl-C6)-alkoxy-(Cl-C4)-alkyl group; or two of the groups RIO to R12 together with the nitrogen atom to which they are linked form a five-membered or six- membered heterocyclus optionally containing one or more other heteroatoms (for example O, N, S) and other substituents [for example F, CI, Br, I, OH, NH2 or a straight- chain or branched (C 1 -C6)-alkyl group, a straight-chain or branched (Cl- C6)-alkoxy group, a (Cl-C6)-alkoxy-(Cl-C4)-alkyl group or a hydroxyethyl group];

or Q⁺ is an unsaturated or aromatic cationic group which is selected from formula (b) to (g):

(b) (c) (d) (e) (f) (g) wherein

R14 is for hydrogen, a straight-chain or branched (C 1 -C9)-alkyl group, an amino group, a mono-(Cl-C6)-alkylamino group, a di-(C 1 -C6)-alkylamino group or a pyrrolidino group;

R15 is a (C 1 -C4)-alkyl radical which may be substituted with a hydroxy radical;

X is a monovalent or polyvalent anion selected from chloride, bromide, methylsulfonate or methylsulfate, arylsulfonate, hydrogen sulfate, sulfate, phosphate, acetate or hydroxysuccinate ion.

2. Cationic dyes of general formula (I) and (II) according to claim 1, wherein:

Rl is hydrogen;

R8 is a hydrogen atom, a chloro atom or a methyl group;

R9 is a methyl group, a methoxy group or a hydroxyethoxy group;

R10 to R12 are, equal or different and independently of each other, selected from a methyl group, ethyl group or hydroxyethyl group; or two of the R10 to R12 groups together with the nitrogen atom to which they are linked form a pyrrolidino group, morpholino group or N-methylpiperazino group;

R13 is a methyl group or a hydroxyethyl group;

R14 is hydrogen, a methyl group, p-dimethylamino group or p-pyrrolidino group;

R15 is a methyl, ethyl or hydroxyethyl group;

Y is O or NH; X is a chloride, bromide or methylsulfate;

L is a (Cl-C3)-diradical;

Q⁺ is a (C3-C9)-trialkylammonium radical, a N-methylimidazolium radical or a N-methylpyridinium radical.

3. Cationic dyes of general formula (I) and (II) according to claim 1, wherein:

l is hydrogen;

R7 is a hydroxy group, an amino group or a hydroxyethylamino group;

R8 is a hydrogen atom or a methyl group;

R9 is a methyl group, a methoxy group or a hydroxyethoxy group;

RIO to R12 are, equal or different and independently of each other, selected from a methyl group, ethyl group or hydroxyethyl group; or two of the RIO to Rl 2 groups together with the nitrogen atom to which they are linked form a pyrrolidino group, a morpholino group or a N-methylpiperazino group;

R13 is a methyl group;

R15 is a methyl, ethyl or hydroxyethyl group;

Y is O or NH;

X is chloride, bromide or methylsulfate;

L is a methylene diradical;

Q⁺ is N-methylpyridinium moiety.

4. Cationic dyes of general formula (I) and (II) according to claim 1 , selected from the group consisting of:

3- { [5-Amino-4-(phenyldiazenyl)- lH-pyrazol- 1 -yljmethyl} - 1 - methylpyridinium chloride; 3-( {5-Amino-4-[(4-methylphenyl)diazenyl] - IH-pyrazol- 1 -yl} methyl)- 1 - methylpyridinium chloride;

3-( {5-Amino-4-[(4-methylphenyl)diazenyl] - IH-pyrazol- 1 -yl} methyl)- 1 - methylpyridinium bromide;

3-( {5-Amino-4-[(3-methylphenyl)diazenyl] - IH-pyrazol- 1 -yl} methyl)- 1 - methylpyridinium chloride;

3-( {5-Amino-4-[(2-methylphenyl)diazenyl] - IH-pyrazol- 1 -yl} methyl)- 1 - methylpyridinium chloride;

3-[(5-Amino-4- { [4-(hydroxymethyl)phenyl]diazenyl} - IH-pyrazol- 1 - yl)methyl]- 1 -methylpyridinium bromide;

3-[(5-Amino-4- { [3-(hydroxymethyl)phenyl]diazenyl} - IH-pyrazol- 1 - yl)methyl]- 1 -methylpyridinium bromide;

3-[(5-Amino-4- { [2-(hydroxymethyl)phenyl]diazenyl} - IH-pyrazol- 1 - yl)methyl]- 1 -methylpyridinium bromide;

3-( {5-Amino-4-[(4-nitrophenyl)diazenyl] - IH-pyrazol- 1 -yl} methyl)- 1 - methylpyridinium chloride;

3-[(5-Amino-4- { [3-(trifluoromethyl)phenyl]diazenyl} - IH-pyrazol- 1 - yl)methyl]- 1 -methylpyridinium chloride; 3-[(5-Amino-4- { [2-(trifluoromethyl)phenyl]diazenyl} - lH-pyrazol- 1 - yl)methyl]- 1 -methylpyridinium chloride;

3-( {5-Amino-4-[(4-methoxyphenyl)diazenyl]- lH-pyrazol- 1 -yl} methyl)- 1 - methylpyridinium chloride;

3-( {5-Amino-4-[(3-methoxyphenyl)diazenyl]- lH-pyrazol- 1 -yl} methyl)- 1 - methylpyridinium chloride;

3-( {5-Amino-4-[(2-methoxyphenyl)diazenyl]- lH-pyrazol- 1 -yl} methyl)- 1 - methylpyridinium chloride;

3-( {5-Amino-4-[(4-chlorophenyl)diazenyl] - lH-pyrazol- 1 -yl} methyl)- 1 - methylpyridinium chloride;

3-( {5-Amino-4-[(3-chlorophenyl)diazenyl] - lH-pyrazol- 1 -yl} methyl)- 1 - methylpyridinium chloride;

3-( {5-Amino-4-[(2-chlorophenyl)diazenyl] - lH-pyrazol- 1 -yl} methyl)- 1 - methylpyridinium chloride;

3-( {5-Amino-4-[(2-chloro-4-methylphenyl)diazenyl] - lH-pyrazol- 1 - yl} methyl)- 1 -methylpyridinium chloride;

3-( {5-Amino-4-[(5-chloro-2-methylphenyl)diazenyl] - lH-pyrazol- 1 - yl} methyl)- 1 -methylpyridinium chloride;

3-( {5-Amino-4-[(4-chloro-2-methylphenyl)diazenyl] - lH-pyrazol- 1 - yl} methyl)- 1 -methylpyridinium chloride;

3-( {5-Amino-4-[(5-chloro-2-methoxyphenyl)diazenyl] - lH-pyrazol- 1 - yl} methyl)- 1 -methylpyridinium chloride;

3-( {5-Amino-4-[(3-chloro-4-fluorophenyl)diazenyl] - lH-pyrazol- 1 - yl} methyl)- 1 -methylpyridinium chloride;

3-( {5-Amino-4-[(2-chloro-4-nitrophenyl)diazenyl] - lH-pyrazol- 1 - yl} methyl)- 1 -methylpyridinium chloride;

3-( {5-Amino-4-[(2-chloro-5-nitrophenyl)diazenyl] - lH-pyrazol- 1 - yl} methyl)- 1 -methylpyridinium chloride; 3-( {5-Amino-4-[(4-chloro-2-nitrophenyl)diazenyl] - IH-pyrazol- 1 - yl} methyl)- 1 -methylpyridinium chloride;

3-( {5-Amino-4-[(2,4-dichlorophenyl)diazenyl]- IH-pyrazol- 1 -yl} methyl)- 1■ methylpyridinium chloride;

3-( {5-Amino-4-[(2,5-dichlorophenyl)diazenyl]- IH-pyrazol- 1 -yl} methyl)- 1■ methylpyridinium chloride;

3-( {5-Amino-4-[(2,4-dimethylphenyl)diazenyl] - IH-pyrazol- 1 -yl} methyl)- 1 methylpyridinium chloride;

3-({5-Amino-4-[(2,5-dimethylphenyl)diazenyl]-lH-pyrazol-l-yl}methyl)-l methylpyridinium chloride;

4- [(5 -Amino-4- { [4-(hydroxymethyl)phenyl]diazenyl} - 1 H-pyrazol- 1 - yl)methyl]- 1 -methylpyridinium bromide; 4-[(5-Amino-4- { [3-(hydroxymethyl)phenyl]diazenyl} - IH-pyrazol- 1 - yl)methyl]- 1 -methylpyridinium bromide;

4-[(5-Amino-4- { [2-(hydroxymethyl)phenyl]diazenyl} - IH-pyrazol- 1 - yl)methyl]- 1 -methylpyridinium bromide;

4- { [5-Amino-4-[(2-methyl-4-nitrophenyl)diazenyl]- IH-pyrazol- 1 - yl} methyl)- 1 -methylpyridinium chloride;

4- { [5-Amino-4-[(4-methyl-2-nitrophenyl)diazenyl]- IH-pyrazol- 1 - yl} methyl)- 1 -methylpyridinium chloride;

4-[(5-Amino-4- { [2-(methoxymethyl)-4-nitrophenyl]diazenyl} - lH-pyrazol- l-yl)methyl]-l -methylpyridinium methyl sulfate;

4-[(5-Amino-4- { [4-(trifluoromethyl)phenyl]diazenyl} - IH-pyrazol- 1 - yl)methyl]- 1 -methylpyridinium chloride;

4- { [5-Amino-4-[(4-chlorophenyl)diazenyl]- IH-pyrazol- 1 -yl} methyl)- 1 - methylpyridinium chloride; 4- { [5-Amino-4-[(3-chlorophenyl)diazenyl]- IH-pyrazol- 1 -yl} methyl)- 1 - methylpyridinium chloride;

4- { [5-Amino-4-[(3-chloro-4-fluorophenyl)diazenyl]- IH-pyrazol- 1 - yl} methyl)- 1 -methylpyridinium chloride;

4- { [5-Amino-4-[(2-chloro-4-nitrophenyl)diazenyl]- IH-pyrazol- 1 - yl} methyl)- 1 -methylpyridinium chloride;

4- { [5-Amino-4-[(2-chloro-5-nitrophenyl)diazenyl]- IH-pyrazol- 1 - yl} methyl)- 1 -methylpyridinium chloride;

4- { [5-Amino-4-[(4-chloro-2-nitrophenyl)diazenyl]- IH-pyrazol- 1 - yl} methyl)- 1 -methylpyridinium chloride;

4- { [5-Amino-4-[(4-chloro-3-nitrophenyl)diazenyl]- IH-pyrazol- 1 - yl} methyl)- 1 -methylpyridinium chloride;

4- { [5-Amino-4-[(5-chloro-2-nitrophenyl)diazenyl]- IH-pyrazol- 1 - yl} methyl)- 1 -methylpyridinium chloride;

4- { [5-Amino-4-[(2-cyano-4-nitrophenyl)diazenyl]- IH-pyrazol- 1 - yl} methyl)- 1 -methylpyridinium chloride;

4- { [5-Amino-4-[(2,4-dichlorophenyl)diazenyl]- IH-pyrazol- 1 -yl} methyl)- 1 - methylpyridinium chloride; 4- { [5-Amino-4-[(2,5-dichlorophenyl)diazenyl]- IH-pyrazol- 1 -yl} methyl)- 1 - methylpyridimum chloride;

4- { [5-Amino-4-[(2,4-dimethylphenyl)diazenyl]- IH-pyrazol- 1 -yl} methyl)- 1 - methylpyridinium chloride;

4- { [5-Amino-4-[(2,5-dimethylphenyl)diazenyl]- IH-pyrazol- 1 -yl} methyl)- 1 - methylpyridinium chloride;

4-( {5-Amino-4-[(4-(methoxycarbonyl)phenyl)diazenyl] - 1 H-pyrazol- 1 - yl} methyl)- 1 -methylpyridinium methyl sulfate;

3 -( { 5 - Amino-4- [(2-amino-3 , 5 -dimethyl-4-oxocyclohexa-2, 5 -dien- 1 - ylidene)amino]- 1 H-pyrazol- 1 -yl} methyl)- 1 -methylpyridinium chloride;

3 - { [5 - Amino-4-( {2- [(2-hydroxyethyl)amino] - 5 -methyl-4-oxocyclohexa-2, 5 - dien- 1 -ylidene} amino)- 1 H-pyrazol- 1 -yl] methyl} - 1 -methylpyridinium chloride;

3 -( { 5 - Amino-4- [(2-amino-4-imino-5 -methylcyclohexa-2, 5 -dien- 1 - ylidene)amino]- 1 H-pyrazol- 1 -yl} methyl)- 1 -methylpyridinium chloride;

3 -( { 5 - Amino-4- [(2-amino-4-imino-5 -methoxycyclohexa-2, 5 -dien- 1 - ylidene)amino]- 1 H-pyrazol- 1 -yl} methyl)- 1 -methylpyridinium chloride;

3 - { [5 -amino-4-( {2- [(2-hydroxyethyl)amino] -4-imino- 5 -methoxycyclohexa- 2,5-dien- 1 -ylidene} amino)- 1 H-pyrazol- 1 -yl]methyl} - 1 -methylpyridinium chloride;

4- { [5 - Amino-4-( {2- [(2-hydroxyethyl)amino] - 5 -methyl-4-oxocyclohexa-2, 5 - dien- 1 -ylidene} amino)- 1 H-pyrazol- 1 -yl] methyl} - 1 -methylpyridinium chloride;

4-( { 5 - Amino-4- [(2-amino-4-imino-5 -methylcyclohexa-2, 5 -dien- 1 - ylidene)amino]- 1 H-pyrazol- 1 -yl} methyl)- 1 -methylpyridinium chloride; 4-( { 5 - Amino-4- [(2-amino-4-imino-5 -methoxycyclohexa-2, 5 -dien- 1 - ylidene)amino]- IH-pyrazol- 1 -yl} methyl)- 1 -methylpyridinium chloride;

4- { [5 -amino-4-( {2- [(2-hydroxyethyl)amino] -4-imino- 5 -methoxycyclohexa- 2,5-dien- 1 -ylidene} amino)- IH-pyrazol- 1 -yljmethyl} - 1 -methylpyridinium chloride;

4- [(5 - Amino-4- { [2-amino- 5 -(2-hydroxyethoxy)-4-iminocyclohexa-2, 5 - dien- 1 -ylidene] amino} - IH-pyrazol- 1 -yl)methyl]- 1 -methylpyridinium chloride.

5. Cationic dyes of general formula (I) and (II) according to claim 1 selected from the group consisting of:

3- { [5-Amino-4-(phenyldiazenyl)- IH-pyrazol- 1 -yljmethyl} - 1 - methylpyridinium chloride hydroc

(1-1)

3 -[(5 -Amino-4- { [2-(hydroxymethyl)phenyl]diazenyl} - IH-pyrazol- 1 - yl)methyl]-l -methylpyridinium bromide (1-2)

3-( {5-Amino-4-[(4-methylphenyl)diazenyl] - IH-pyrazol- 1 -yl} methyl)- 1 -(2- hydroxyethyl)pyridinium bromide (1-3)

(1-3) 3 - [(5 - Amino-4- { [2-(methoxymethyl)-4-nitrophenyl] diazenyl }

l-yl)methyl]-l-methylpyridinium methyl sulfate (1-4)

)

3 -( { 5 - Amino-4- [(2-amino-3 , 5 -dimethyl-4-oxocyclohexa-2, 5 -dien- 1 - ene)amino]- IH-pyrazol- 1 -yl} chloride (II-l)

3- { [5-Amino-4-( {2-[(2-hydroxyethyl)amino]-5-methyl-4-oxocyclohexa-2,5- dien- 1 -ylidene } amino)- IH-pyrazo chloride (Π-2)

3 -( { 5 - Amino-4- [(2-amino-4-imino-5 -methylcyclohexa-2, 5 -dien- 1 - ene)amino]- IH-pyrazol- 1 -yl} chloride (II-3)

3 - [(5 - Amino-4- { [2-amino- 5 -(2-hydroxyethoxy)-4-iminocyclohexa-2, 5 -dien- 1 -ylidene] amino } - 1 H-pyrazol- 1 -yl)methyl] - 1 -methylpyridinium chloride (Π-4)

(II-4).

6. A ready-to-use composition for dyeing keratin fibers comprising in a medium suitable for dyeing:

- at least one cationic dye of general formula (I) or (II) as defined in claims 1-5,

- at least one oxidation dye;

- at least one oxidizing agent.

7. A composition according to claim 6, wherein the at least one oxidation dye is a primary intermediate which is selected from a para-phenylenediamine, a para- aminophenol, an ortho-aminophenol, or a heterocyclic oxidation dye.

8. A composition according to claim 7, wherein the primary intermediate is selected from 1,4-diamino-benzene; l,4-diamino-2-methyl-benzene; 1,4-diamino- 2-(2-hydroxyethyl)-benzene; 1 ,4-diamino-2,3-dimethyl-benzene; 1 ,4-diamino-2,6- dimethyl-benzene; 1 ,4-diamino-2-methoxymethyl-benzene; 1 ,4-diamino-2-chloro- benzene; 4- [di(2 -hydro xyethyl)amino] -aniline; 2,2'-({2-[(4- aminophenyl)amino] ethyl} imino)diethanol; (4-aminophenyl)-(3-(imidazol- 1 - yl)propyl)amine; N,N'-bis( -hydroxyethyl)-N,N'-bis(4'-aminophenyl)- 1 ,3- diaminopropanol; 4-aminophenol; 4-(methylamino)phenol, 4-amino-3- methylphenol; 2-aminomethyl-4-aminophenol; bis(5-amino-2- hydroxyphenyl)me thane; 2-amino-5-ethylphenol; 2-amino-5- methoxymethylphenol; 4,5-diamino- 1 -(2-hydroxyethyl)- IH-pyrazole; 4,5- diamino-4-methylbenzyl- IH-pyrazole; 2,3-diaminodihydroxypyrazolo pyrazolone dime tho sulfonate; 2,5-diaminopyridine; 2,4,5,6-tetraaminopyrimidine; or an acid- addition salt thereof.

9. A composition according to claim 6, further comprising a coupler which is selected from a resorcinol, a meta-phenylenediamine, a meta-aminophenol, a naphthol, a pyridine, a pyrazolone, an indole.

10. A composition according to claim according to claim 9, wherein the coupler is selected from 1,3-dihydroxybenzene; 4-chloro-l,3-dihydroxybenzene; 1,3- dihydroxy-2-methylbenzene; 3-aminophenol; 5-amino-2-methylphenol; 5-amino-

4- chloro-2-methylphenol; 3-amino-2,6-dimethylphenol; 2-methyl-5- hydroxyethylaminophenol; 3-amino-2,4-dichlorophenol; 3,4-dihydro-2H- 1 ,4- benzoxazin-6-ol; hydroxyethyl-3,4-methylenedioxyaniline; 3,4-dihydro-6- hydroxy-2H- 1 ,4-benzoxazine; 6-amino-3,4-dihydro-2H- 1 ,4-benzoxazine; 2,4- diamino- 1 -(2-hydroxyethoxy)benzene; 2-amino-4-[(2-hydroxyethyl)amino]- anisole; 1 ,3-bis(2,4-diaminophenoxy)propane; 1 -methyl-2,6-bis-(2- hydroxyethylamino)-benzene; 1 -naphthol; 2-methyl-l -naphthol; 1,5- naphthalenediol; 2,7-naphthalenediol; 2,6-diaminopyridine; 2,6-dihydroxy-3,4- dimethylpyridine; 3,5-diamino-2,6-dimethoxypyridine; 2-amino-3- hydroxypyridine; 6-methoxy-2-methylamino-3-aminopyridine; 3 -methyl- 1 -phenyl-

5- pyrazolone; 6-hydroxyindole; 5,6-dihydroxyindole; wherein couplers containing an amino group may be present as acid-addition salt.

1 1. A composition according to claim 8 or 10, wherein the acid-addition salt is selected from a hydrochloride, a hydrobromide, a sulphate or a hydroxy succinate.

12. A composition according to claim 6, wherein at least one oxidizing agent is selected from hydrogen peroxide, urea peroxide, a percarbonate salt, a bromate salt, a perborate salt or a persulfate salt.

13. A composition according to claim 6, wherein said at least one cationic dye is present in a concentration ranging from 0.001 to 10% by weight relative to the total weight of said composition.

14. A composition according to claim 6, wherein the sum of oxidation dyes ranges from 0.001 to 10% by weight relative to the total weight of said composition.

15. A composition according to claims 6-14, having a pH ranging from 5 to 1 1.

16. A composition according to claim 6, wherein the medium suitable for dyeing comprises water or a mixture of water and at least one organic solvent.

17. A composition according to claims 6-16, wherein said composition is in the form of a liquid, a cream, a gel, a foam or any form appropriate for dyeing keratin fibers.

18. A process for dyeing keratin fibers comprising:

- preparing a composition comprising, in a medium suitable for dyeing, at least one cationic dye of general formula (I) or (II) as defined in claims 1-5, at least one primary intermediate and optionally at least one coupler,

- mixing both compositions to obtain the composition according to claim 6,

- applying said composition to said keratin fibers,

19. A process for dyeing keratin fibers comprising:

- preparing a composition comprising, in a medium suitable for dyeing, at least one cationic dye of general formula (I) or (II) as defined in claims 1-5,

- preparing a composition comprising at least one primary intermediate and optionally at least one coupler,

- mixing the three separately prepared compositions to obtain the composition according to claim 6,

- applying said composition to said keratin fibers,

20. A multi-compartment dyeing kit or device comprising:

- a first compartment containing a composition comprising, in a medium suitable for dyeing, at least one oxidation dye and at least one cationic dye of general formula (I) or (II) as defined in claims 1-5, and

- a second compartment containing an oxidizing composition comprising, in a medium suitable for dyeing, at least one oxidizing agent.

21. A multi-compartment dyeing kit or device comprising:

- a first compartment containing a composition comprising, in a medium suitable for dyeing, at least one oxidation dye,

- a second compartment containing a composition comprising, in a medium which is suitable for dyeing, at least one cationic dye of general formula (I) or (II) as defined in claims 1-5, and

- a third compartment containing an oxidizing composition comprising, in a medium which is suitable for dyeing, at least one oxidizing agent.