DYE COMPOSITION OP ACIDIC COMPRISING 2,3-DIAMINO-
S/T-DlHYDRO-lH^H-PYRAZOLOtl-aJPYWVZOL-l-ONE, A PARA-
PHENYLENEDIAMINE, A META-AMINOPHENOL AND AN OXIDIZING
AGENT
The invention relates to a composition for dyeing keratin fibres, and in particular human keratin fibres such as the hair, comprising 2,3-diamino-6, "7-dihydro-1H, 5H-pyraz.olo [ 1, 2-a ] pyrazol-1-one or an addition salt thereof as first oxidation base, at least one para-phenylenediamine as second oxidation base, at least one meta-aminophenol as coupler and at least one oxidizing agent, the pH of the composition ranging from 5.5 to 7.5.
It is known practice to dye keratin fibres, and in particular human keratin fibres such as the hair, with dye compositions comprising oxidation dye precursors, in particular ortho- or para-phenylenediamines, ortho-or para-aminophenols, and heterocyclic compounds such as diarninopyrazole derivatives, pyrazolo [1,5-a]-pyrimidine derivatives, pyrimidine derivatives, pyridine derivatives, indole derivatives and indoline derivatives, which are generally known as oxidation bases. Oxidation dye precursors, or oxidation bases, are colourless or weakly coloured compounds that, when combined with oxidizing products, can give rise to dyes or coloured compounds via a process of oxidative condensation. Permanent colorations are thus obtained.
It is also known that the shades obtained with these oxidatio.n bases may be varied by combining them with couplers or coloration modifiers, the latter being chosen especially from meta-phenylenediamines, meta-aminophenols, meta-hydroxyphenols and certain heterocyclic compounds.
The variety of molecules used as regards the oxidation bases and couplers allows a wide range of colours to be

obtained.
The use of standard oxidation bases such as para-aminophenol, ortho-aminophenol and derivatives thereof optionally combined with standard couplers at acidic pH does not make it possible to obtain shades with tints in red, coppery or mahogany tones that are sufficiently visible on natural or dyed hair and uniform from the roots to the ends.
The aim of the present invention is to provide novel compositions for dyeing keratin fibres, which make it possible to obtain at acidic pH a coloration with tints in red, coppery or mahogany tones that are particularly visible, strong, chromatic and aesthetic, sparingly selective and very resistant to the various attacking factors to which the hair may be subjected, such as shampoo, light, sweat and permanent reshaping operations.
One subject of the present invention is thus a
composition for dyeing keratin fibres, comprising, in a
suitable dyeing medium:
• at least one Cirst oxidation base chosen from 2,3-diamino-6,7-dihydro-lH,5H-pyrazolo[1,2-a]pyrazol-1-one of formula (I) below, and the addition salts thereof(Formula Removed)
• at least one second oxidation base chosen from para-
phenylenediamines; at least one coupler chosen from meta-aminophenols;
and
. at least one oxidizing agent; the pH of the composition ranging from 5.5 to 7.5.
The present invention makes it possible to obtain a coloration on keratin fibres with tints in red, coppery or mahogany tones that are sufficiently visible on natural or dyed hair and uniform from the roots to the ends.
Another subject of the invention is a process for dyeing keratin fibres, and in particular human keratin fibres such aa the hair, using the composition of the present invention, and also the use of this composition for dyeing keratin fibres.
Finally, a subject of the invention is a dyeing kit comprising, firstly, a dye composition containing 2,3-diamino-6,7-dihydro-lH,5H-pyrazolo[l,2-a]pyrazol-l-one or an addition salt thereof aa first oxidation base, a para-phenylenediaroine as second oxidation base and a meta-aminophenol as coupler and, secondly, a composition containing an oxidizing agent.
Unless otherwise indicated, the limits of the ranges of values that are given in the context, of the present invention are included in these ranges.
In the context of the invention, the term "alkyl radical" means, unless otherwise indicated, linear or branched C1-C10, preferentially C1-C6 and even more preferentially C1-C4, alkyl radicals, such as methyl, ethyl, propyl, isopropyl, isobutyl, tert-butyl, pentyl or hexyl radicals.
In the context of the present invention, the heteroatom(s) may be chosen from an oxygen atom, a nitrogen atom, a sulfur atom and a phosphorus atom.
In the context of the present invention, a halogen atom may be chosen from a chlorine atom, a bromine atom, an iodine atom and a fluorine atom.
The oxidation base(s) chosen from 2,3-dianuno-6,7-dihydro-lH,5H-pyrazolo[1,2-a]pyrazol-1-one of formula (I) and the addition salts thereof is (are) each generally present in the composition of the invention in an amount of between 0.001% and 10% and preferably between 0.005% and 6% by weight approximately relative to the total weight of the dye composition.
According to one particular embodiment of the invention, the para-phenylenediamine (s) 13 (are) chosen from the compounds of formula (II) below, and the addition salts thereof: (Formula Removed)

in which:
R1 represents a hydrogen atom, a C1-C4 alkyl radical, a
C1-C4 monohydroxyalkyl radical, a C2-C4 polyhydroxyalkyl
radical, a (C1-C4) alkoxy (C1-C4) alkyl radical or a C1-C4
alkyl radical substituted with a nitrogenous, phenyl or
4'-aminophenyl group;
R2 represents a hydrogen atom, a C1-C4 alkyl radical, a
C1-C4 monohydroxyalkyl radical or C2-C4 polyhydroxyalkyl
radical, a (C1-C4) alkoxy (C1-C4) alkyl radical or a C1-C4
alkyl radical substituted with a nitrogenous group;
R1 and R2 may also form, with the nitrogen atom to which
they are linked, a 5- or 6-membered, saturated or
unsaturated cyclic group containing one or more
hetexoatoms, optionally substituted with one or more
alkyl, hydroxyl or ureido groups;
R3 represents a hydrogen atom, a halogen atom such as a
chlorine atom, a C1-C4 alkyl radical, a sulfo radical, a
carboxy radical, a C1-C4 monohydroxyalkyl radical or C1-
C4 hydroxyalkoxy radical, an acetylamino(C1-C4)alkoxy
radical, a mesylamino (C1-C4) alkoxy radical or a
carbamoylamino(C1-C4)alkoxy radical,
R4 represents a hydrogen or halogen atom or a C1-C4
alkyl radical.
Among' the nitrogenous groups of formula (II) above, mention may be made especially of amino, mono(C1-C4) alkylamino, di (C1-C4) alkylamino, tri (C1-C4) alkylamino, monohydroxy(C1-C4)alkylamino, imidazolinium and ammonium radicals.
Among the para-phenylenediamines, a more particular mention may be made of para-phenylenediarnine, para-tolylenedianune, 2-chloro-para-phenylenedianu.ne, 2,3-dimethyl-para-phenylenediamine, 2,6-dimethyl-para-phenylenediamine, 2, 6-diethyl-para-phenylenediamine, 2, 5-dimethyl-para-phenylenediamine, N,N-dimethyl-para-phenylenediamine, N, N-diethyl-para-phenylenediamine, N,N-dipropyl-para-phenylenediamine, 4-amino-N,N-diethyl-3-methylaniline, N,N-bis(p-hydroxyethyl)-para-phenylenediamine, 4-N,N-bis(p-bydroxyethyl)amino-2-methylaniline, 4 -N, N-bis ((3-hydroxyethyl) amino-2-chloroaniline, 2-p-hydroxyethyl-para-phenylene-diamine, 2-fluoro-para-phenylenediamine, 2-isopropyl-para-phenylenediamine, N- ([3-hydroxypropyl) -para-phenyl-enediamine, 2-hydroxymethyl-para-phenylenediamine, N,N-dimethyl~3-methyl-para-phenylenediamine, N-ethyl-N-(3~ hydroxyethyl)-para-phenylenediamine, N-(p,y-dihydroxy-propyl)-para-phenylenediamine, N-(4' -aminophenyl)-para-phenylenediamine, N-phenyl-para-phenylenediamine, 2-p-hydroxyethyloxy-para-phenylenediamine, 2-p-acetyl-aminoethyloxy-para-phenylenediamine, N- (p-methoxy-ethyl)-para-phenylenediamine, 4-aminophenylpyrrolidine, 2-p-hydroxyethylamino-5-aminotoluene, 2-methyl-7-N-ft-hydroxyethyl-para-phenylenediamine and 3-hydroxy-l- ( 4'-aminophenyl)pyrrolidine, and the addition salts thereof with an acid.
Among the para-phenylenediamines of formula (II) above,
para-phenylenediamine, para-tolylenediamine, 2-
isopropyl-para-phenylenediamine, 2-(3-hydroxyethyl-para-
phenylenediaraine, 2-p-hydroxyethyloxy-para-
phenylenediamine, 2, 6-dimethyl-para-phenylenediamine, 2, 6-diethyl-para-phenylenediamine, 2, 3-dimethyl-para-phenylenediamine, N,N-tais (p-hydroxyethyl) -para-phenylenediamine, 2 -chloro-par a- phenylenediamine 2-ß}-acetylaminoethyloxy-para-phenylenediamine and 6-(4~ aminophenylamino) hexan-1-ol , and the addition salts thereof with an acid are most particularly preferred.
In the composition o£ the present invention, the oxidation base (3) chosen from para-phenylenediamines is (are) each generally present in an amount of between 0.001% and 10% and preferably between 0.005% and 6% by weight approximately relative to the total weight of the dye composition.
According to one particular embodiment of the invention, the meta-aminophenol (s) is (are) chosen from the compounds of formula (III) below, and the addition
salts thereof:

(Formula Removed)
in which:
R1 and R2, which may be identical or different,
repreaent a hydrogen atom; an alkyl radical; a
monohydroxyalkyl radical; a polyhydroxyalkyl radical; a
monoaminoalkyl radical;
R1 and R2 form, together with the nitrogen atom to which
they are attached, a saturated or unsaturated, 5- to 7-
membered cyclic group containing one or more
heteroatoms, which may be unsubstituted or substituted
with one or more radicals chosen from carboxyl,
carboxamido, hydroxyl, amino, monoalkylamino and
dialkylamino radicals, and alkyl radicals optionally
substituted with one or more hydroxyl, amino,
monoalkylamino or dialkylamino radicals;
R3 represent, independently of each othec, a halogen
atom; an alkyl radical; an alkoxy radical; a monohydtoxyalkyl radical; a polyhydroxyalkyl radical; a monohydroxyalkoxy radical; a polyhydroxyalkoxy radical; n is an integer between 0 and 3.
According to one particular embodiment of the invention, R1 and R2 represent, independently of each other, a hydrogen atom; an alkyl radical, for example a methyl or ethyl radical; a monohydroxyalkyl radical, for example a ß-hydroxyethyl or y-hydroxypropyl radical; or RI and R2 form, together with the nitrogen atom to which they are attached, a ring chosen from pyrrolidine, piperidine, homopiperidine, piperazine, homopiperazine and morpholine heterocycles ; the said rings possibly being substituted with one or more hydroxyl, amino, mono (C1-C2 ) alkylamino, di(C1-C2 ) alkylamino, carboxyl or carboxamido radicals, or C1-C4 alkyl radicals optionally substituted with one or more hydroxyl, amino, mono (C1-C2 ) alkylamino or di (C1-C2 ) alkylamino radicals, and more particul-arly chosen from pyrrolidine, 2, 5-dimethylpyrrolidine, pyrrolidine-2-carboxylic acid, 3~hydroxypyrrolidine-2-carboxylic acid, 4-hydroxypyrrolidine-2-carboxylic acid, 2/4-dicarboxy pyrrolidine, 3-hydroxy-2-hydroxymethylpyrro-lidine, 2-carboxamidopyrrolidine, 3-hydroxy-2-carbox-amidopyrrolidine, 2-hydroxyrnethylpyrrolidine, 3,4-dihydroxy-2-hydroxymethylpyrrolidine, 3-hydroxypyr-rolidine, 3, 4-dihydroxypyrrolidine, 3-aminopyrrolidine, 3-methylaminopyrtolidine, 3-dimethylaminopyrrolidine, 4-amino-3-hydroxypyrrolidine, 3-hydroxy-4- (p-hydroxy-ethy-1) aminopyrrolidine, piperidine, 2, 6-dimethyl-piperidine, 2-carboxypiperidine, 2-carboxaraidopiperi-dine, 2-hydroxymethylpiperidine, 3-hydroxy-2-hydroxy-methylpiperidine, 3-hydroxypiperidine, 4-hydroxy-piperidine, 3-hydroxymethylpiperidine, homopiperidine, 2 -carboxy homopiperidine, 2-carboxamidohomopiperidine, homopiperazine, N-methylhomopiperazine, N- (2-hydroxy-ethyl) homopiperazine, piperazine, 4-methylpiperazine, 4-ethylpiperazine, 4- (p-hydroxyethyl) piperazine and
morpholine, and they more particularly form the following group: pyrrolidin-1-yl; piperidin-1-yl; piper-azin-1-yl; 4-methylpiperazin-l-yl; 4-ethylpiperazin-l-yl; 4-(p-hydroxyethyl)piperazin-l-yl; morpholin-4-yl.
According to one particular embodiment of the invention, RS is chosen from a halogen atom, an alkyl radical, an alkoxy radical and a monohydroxyalkoxy radical. By way of example, Rj is chO3en from a chlorine atom, a methyl radical, a methoxy radical and a p-hydroxyethyloxy radical.
According to one particular embodiment of the invention, n denotes 0, 1 or 2. By way of example, n is equal to 1 or 2. When n is equal to I, R? may be in position 2 and when n is equal to 2, R3 may be in positions 2 and 4 or in positions 2 and 6.
Among the substituted meta-aminophenols of formula (III) that are useful in the context of the invention, mention may be made more particularly of 5-amino~2-methoxyphenol, 5-anuno-2-(P-hydroxyethyloxy)phenol, 5-amino-2-methylphenol, 5-N~ (p-hydroxyethyl)amino-2-methylphenol, 5-N- (P-hydroxyethyl)amino-4-methoxy-2-methylphenol, 5-anuno-4-methoxy-2-methylphenol, 5-amino-4-chloro-2-methylphenol, 6-chloro-2-methyl-5-aminophenol, 5-amino-2,4-dimethoxyphenol, 5- (y-hydroxy-propylamino)-2-methylphenol, 3-dimethylaminophenol; 2-methyl-5-dimethylaminophenol; 2-ethyl-5-dimethylarruno-phenol; 2-methoxy-5-dimethylaminophenol; 2-ethoxy-5-dimethylaminophenol; 2-(p-hydroxyethyl)-5-dimethyl-aminophenol; 3-diethylaminophenol; 2-methyl-5-diethyl-aminophenol; 2-ethyl-5-diethylaminophenol; 2-methoxy-5-diethylaminophenol; 2-ethoxy-5-diethylaminophenol; 2-(p-hydroxyethyl)-5-diethylaminophenol; 3-di (p-hydroxy~ ethyl)aminophenol; 2-methyl-5-di(p-hydroxyethyl)aminophenol; 2-ethyl-5-di(p-hydroxyethyl)aminophenol; 2-methoxy-5-di(P-hydroxyethyl)aminophenol; 2-ethoxy-5-di(P-hydroxyethyl)aminophenol; 2-(p-hydroxyethyl)-5-
di (p-hydroxyethyl) arainophenol; 3-pyrrolidin-l-ylphenol; 2-methyl-5-pyrrolidin-l-ylphenol; 2-ethyl-5-pyrrolidin-1-ylphenol; 2-methoxy-5-pyrrolidin-l-ylphenol; 2-ethoxy-5-pyrcolidin-1-ylphenol; 2-(p-hydroxyethyl)-5-pyrrolidin-1-ylphenol; 3-piperidin-1-ylphenol; 2-raethyl-5-piperidin-l-ylphenol; 2-ethyl-5-pxperidin-1-ylphenol; 2-methoxy-5-piperidin-l-ylphenol; 2-ethoxy-5~ piperidin-1-ylphenol; 2-(P-hydroxyethyl)-5-piperidin-l-ylphenol; 3-piperazin-l-ylphenol; 2-raethyl-5-piperazin-1-ylphenol; 2-ethyl-5-piperazin-l-ylphenol; 2-methoxy-5-piperazin-1-ylphenol; 2-ethoxy-5-piperazin-1-ylphenol; 2-(p-hydroxyethyl)-5-piperazin-l-ylphenol; 3-(4-methylpiperazin-l-yl)phenol; 2-methyl-5-(4-methyl-piperazin-1-yl)phenol; 2-ethyl-5-(4-methylpiperazin-l-yl)phenol; 2-methoxy-5-(4-methylpiperazin-l-yl)phenol; 2-ethoxy-5- (4-methylpiperazin-l-yl) phenol; 2- ([3-hydroxyethyl)-5-(4-methylpiperazin-l-yl)phenol; 3- (4-ethylpiperazin-1-yl)phenol; 2-methy1-5-(4-ethylpiper-azin-1-yl)phenol; 2-ethyl-5-(4-ethylpiperazin-l-yl)-phenol; 2-methoxy-5-(4-ethylpiperazin-l-yl)phenol; 2-ethoxy-5- (4-ethylpiperazin-l-yl) phenol; 2- ((i-hydroxy-ethyl)-5- (4-ethylpiperazin-l-yl) phenol; 3-(4- ((3-hydroxyethyl)piperazin-1-yl)phenol; 2-methyl-5-(4- (P-hydroxyethyl)piperazin-1-yl)phenol; 2-ethyl-5-(4-5-a]pyridine; pyrazolo-[1, 5-a)pyridine-3,7-diamine; 7-morpholin-4-ylpyrazolo-[1,5-a]pyrid-3-ylan\ine; pyrazolo[l,5-a]pyridine-3,5-diamine; 5-morpholin-4-ylpyrazolo[l,5-a]pyrid-3-yl-amine; 2-[(3-anunopyrazolo(l, 5-a)pyrid-5-yl) (2-hydroxy-

ethyl) ami no) ethanol; 2- [ (3-aminopyraz'olo [ 1, 5-a] pynd-7-yl)(2-hydroxyethyl)amino)ethanol; 3-anunopyrazolo-[l,5-a]pyrid-5-ol; 3-aminopyrazolo[ 1,5-a]pyrid-4-ol; 3-aminopyrazolo[l,5-a]pyrid-6-ol; 3-aminopyrazolo-[1,5-a]pyrid-7-ol and also the addition salts thereof.
Among the pyrimidine derivatives that may be mentioned are the compounds described, for example, in patents DE 2 359 399; JP 88-169 571; JP OS 63 124; EP 0 770 375 or patent application WO 96/15765, such as 2,4,5,6-tetraaminopyrimidine, 4-hydroxy-2,5,6-triamino-pyrimidine, 2-hydroxy-4,5,6-triaminopyrimidine, 2,4-dihydroxy-5,6-diaminopyrimidine and 2,5,6-trianuno-pyrimidine, and pyrazolopyrimidine derivatives such as those mentioned in patent application FR-A-2 750 048 and among which mention may be made of pyrazolo [ 1,5-a]-pyrimidine-3,7-diamine; 2,5-dimethylpyrazolo[ 1,5-aj-pyrimidine-3,7-diamine; pyrazolo[l,5-a]pyrimidine-3, 5-diamine; 2,7-dimethylpyraz.olo[l, 5-a) pyrimidine-3, 5-diamine; 3-aminopyrazolo(1,5-a]pyrimidin-7-ol; 3-amino-pyrazolo[l,5-a)pyrimidin-5-ol; 2-(3-aminopyrazolo[1,5-a]pyrimidin-7-ylamino)ethanol, 2-(7-aminopyrazolo[1,5-a)pyrimidin-3-ylamino)ethanol, 2-[(3-aminopyrazolo[1,5-a]pyrimidin-7-yl) (2-hydroxyethyl)amino)ethanol, 2- [ (7-aminopyrazolo[1,5-a]pyrimidin-3-yl)(2-hydroxyethyl)-amino] ethanol, 5, 6-dime thyl pyrazolo [ 1, 5-a] pyriinidine-3,7-diamine, 2, 6-dimethyIpyrazolo[1,5-a]pyrimidine-3,7-diamine, 2,5,N7, N7-tetramethylpyrazolo[1,5-a]pyrimi-dine-3,7-diamine and 3-amino-5-methyl-7-imidazolyl-propylaminopyrazolo[1,5-a]pyrimidine, and the addition salts thereof and the tautomeric forms thereof, when a tautomeric equilibrium exists.
Among the pyrazole derivatives which may be mentioned are the compounds described in patents DE 3 843 892 and DE 4 133 957 and patent applications WO 94/08969, WO 94/08970, FR-A-2 733 749 and DE 195 43 988, such as 4 , 5-diamino-l-methylpyrazole, 4, 5-diamino-l- ((3-hydroxy-ethyDpyrazole, 3, 4-diaminopyrazole, 4 , 5-diamino-l- (4'

chlorobenryl)pyrazole, . 4 , 5-diamino-l, 3-dirnethyl-pyrazole, 4,5-diamino-3-methyl-1-phenylpyrazole, 4,5-diamino-l-methyl-3-phenylpyrazole, 4-aminc-l,3-dimethyl-5-hydrazinopyrazole, l-benzyl-4,5-diamino-3-methylpyrazole, 4, 5-diamino-3-tert-butyl-l-methyl-pyrazole, 4,5-diaraino-l-tert-butyl-3-methylpyrazole, 4/5-diaraino-l-(p-hydroxyethyl)-3-methylpyrazole, 4,5-diaraino-l-ethyl-3-methylpyrazole, 1, 5-diamino-l-ethyl-3- (4' -methoxyphenyl) pyrazole, 4,5-diamino-l-ethyl-.l-hydroxymethylpyrazole, 4,5-diamino-3-hydroxymethyl-l-methylpyrazole, 4, 5-diamino-3-hydroxymethyl-l-i5opro~ pylpyrazole, 4,5-diamino-3-methyl-l-isopropylpyrazole, 4-amino-5-(2'-aminoethyl)amino-1,3-dimethylpyrazole, 3,4,5-triaminopyrazole, 1-methyl-3,4,5-triaminopyra-zole, 3,5-diamino-l-methyl-4-methylaminopyrazoIe and 3, 5-diamino-4- ((3-hydroxyethyl) amino-1-methylpyrazole, and the addition salts thereof.
When the composition of the invention comprises one or more additional oxidation bases, they are each generally present in the composition of the invention in an amount of between 0.001% and 10% and preferably between 0.005% and 6% by weight approximately relative to the total weight of the dye composition.
The composition of the present invention may comprise at least one additonal coupler chosen from meta-phenylenediamines, meta-diphenols, naphthalene-based couplers and heterocyclic couplers, and the addition salts thereof.
Examples that may be mentioned include 1,3-di-hydroxybenzene, 1,3-dihydroxy-2-methylbenzene, 4-chloro-1, 3-dihydroxybenzene, 2, 4-diamino-l- ((J-hydroxyethyloxy) -benzene, 2-amino-4-(p-hydroxyethylamino)-1-roethoxy-benzene, 1,3-diaminobenzene, 1,3-bi3(2,4-diamino-phenoxy)propane, 3-ureidoaniline, 3-ureido-l-dimethyl-aminobenzene, sesamol, l-3-hydroxyethylamino-3,4-methylenedioxybenzene, a-naphthol, 2-methyl-l-naphthol,

6-hydroxyindole, 4-hydroxyindole, 4-hydroxy-N-methyl-indole, 2-amino-3-hydroxypyridine, 6-hydroxybenzo-morpholine, 3, 5-diamino-2, 6-dlmethoxypyridine, 1-N-(|3-hydroxyethyl) arnlno-3,4-methylenediox.ybenzene and 2,6-bis ((3-hydroxyethylamino) toluene, and the addition salts thereof.
When the compoeition of the invention comprises one or more additional couplers, they are each generally present in the composition of the invention in an amount of between 0.001% and 10% and preferably between 0.005% and 6% by weight approximately relative to the total weight of the dye composition.
In general, the addition salts of the oxidation bases and of the couplers that may be used in the context of the invention are chosen especially from the addition salts with an acid, such as the hydrochlorides, hydrobromides, sulfates, citrates, succinates, tartrates, lactates, (Cj-C«)alkylsulfonates, toaylates, benzenesulfonates, phosphates and acetates, and the addition salts with a base, such as sodium hydroxide, potassium hydroxide, ammonia, amines or alkanolamines.
The 'oxidizing agent(s) may be chosen from the oxidizing agents conventionally used for the oxidation dyeing of keratin fibres, for instance hydrogen peroxide, urea peroxide, alkali metal bromatea, persalts such as perborates and persulfates, peracids and oxidase enzymes, among which mention may be made of peroxidases, 2-electron oxidoreductases such as uricases and 4-electron o.xygenases, for instance laccases, the oxidase enzymes optionally being in the presence o£ the cofactors thereof. Hydrogen peroxide is particularly preferred.
The oxidizing agent(3) is (are) generally present in an amount of between 0.01% and 30% and preferably between 0,1% and 20% by weight relative to the total weight of

the composition.
The pH of the dye composition in accordance with the invention ranges from 5.5 to 7.5 and preferably from 5.7 to 6.9. It may be adjusted to the desired value by means of acidifying or basifying agents usually used in the dyeing of keratin fibres or alternatively using standard buffer systems.
Among the acidifying agents that may be mentioned, for example, are inorganic or organic acids such as hydrochloric acid, orthophosphoric acid, sulfuric acid, carboxylic acids such as acetic acid, tartaric acid, citric acid and lactic acid, and sulfonic acids.
Among the basifying agents that may be mentioned, for example, are aqueous ammonia, alkaline carbonates, alkanolamines such as mono-, di- and triethanolamine and derivatives thereof, sodium hydroxide, potassium hydroxide and the compounds of formula (V) below:
(Formula Removed)
in which W is a propylene residue that is unsubstituted or substituted wibh 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 a C1-C4 hydroxyalkyl radical.
The medium that is suitable for dyeing, also known as the dye support, is a cosmetic medium that generally consists of water or a mixture of water and at least one organic solvent to dissolve the compounds that are not sufficiently soluble in water. As organic solvent, mention may be made, for example, o£ C1-C4 lower alkanols, such as ethanol and isopropanol; polyols and polyol ethers such as 2-butoxyethanol, propylene glycol, propylene glycol monomethyl ether, diethylene

II
->*•-
glycol monoethyl ether and monomethyl ether, as well as aromatic alcohols such as benzyl alcohol or phenoxyethanol, and mixtures thereof.
The solvents are present in proportions preferably of between 1% and 40% by weight approximately relative to the total weight of the dye composition, and even more preferentially between 5% and 30% by weight approximately.
The dye composition in accordance with the invention can also contain various adjuvants conventionally used in compositions for dyeing the hair, such as anionic, cationic, nonionic, amphoteric or zwitterionic surfactants or mixtures thereof, anionic, cationic, nonionic, arophoteric or zwitterionic polymers or mixtures thereof, mineral or organic thickeners, and in particular anionic, cationic, nonionic or amphoteric associative polymeric thickeners, antioxidants, penetrants, sequeatrants, fragrances, buffers, dispersants, conditioning agents, for instance silicones, which may be volatile or non-volatile, and modified or unmodified, film-forming agents, ceramides, preserving agents and opacifiers.
The above adjuvants are generally present in an amount for each of them of between 0.01% and 20% by weight relative to the weight of the dye composition.
Needless to say, a person skilled in the art will take care to select this or these optional additional compounds such that the advantageous properties intrinsically associated with the oxidation dye composition in accordance with the invention are not, or are not substantially, adversely affected by the addition(s) envisaged.
The dye composition according to the invention may be in various forms, such as in the form of liquids,

creams or gels, or in any other form that is suitable for dyeing keratin fibres, and especially human hair.
The process in accordance with the present invention is a process in which the composition according to the invention as defined above is appl.ied to the fibres for a time that is sufficient to develop the desired coloration, after which the fibres are rinsed, optionally washed with shampoo, rinsed again and dried.
The time required to develop the coloration on the keratin fibres is generally between 2 and 60 minutes, preferably between 3 and 40 minutes and even more preferentially between 5 and 30 minutes.
According to one particular embodiment of the invention, the process comprises a first step that consists in separately storing, on the one hand, a composition (A) comprising, in a suitable dyeing medium, at least one first oxidation base chosen from 2,3-diamino-6, 7-dihydro-lH, bH-pyrazolo [ 1, 2-a]pyrazol-l-one and addition salts thereof, at least one second oxidation base chosen from para-phenylenediamines and at least one coupler chosen from meta-aminophenols, and, on the other hand, a composition (B) containing, in a suitable dyeing medium, at least one oxidizing agent, and then in mixing them together at the time of use before applying this mixture to the keratin fibres.
Compositions (A) and (B) may also contain various adjuvants conventionally used in hair dye compositions and as defined above.
The pH of composition (A) is generally between 3 and 12 approximately and preferably between 5 and 11 approximately. It may be adjusted to the desired value by means of acidifying or basifying agents as defined above, or alternatively by using standard buffer systems .

The pH of composition (B) is such that, after mixing with composition (A) , the pH of the resulting composition applied to the keratin fibres ranges from 5.5 to 7.5 and even more preferentially from 5.6 to 6.9. It may be adjusted to the desired value by means of acidifying or basifying agents as defined above, or alternatively by using standard buffer systems,
Another subject of the invention is a multi-compartment dyeing device or "kit" or any other multi-compartment conditioning system, a first compartment of which contains composition (A) as defined above and a second compartment contains composition (B) as defined above. These devices may be equipped with a means for applying the desired mixture to the hair, such as the devices described in patent FR-2 586 913 in the name of the Applicant.
A subject of the present invention is also the use, for the oxidation dyeing of keratin fibres, and in particular of human keratin fibres such as the hair, of a composition according to the invention as defined above.
The examples that follow serve to illustrate the invention without, however, being limiting in nature.
EXAMPLE
The following composition was prepared;(Table Removed)
At the time of use, 1 part by weight of the composition described above is mixed with 1 part by weight of a 20-volumes hydrogen peroxide solution whose pH is equal to 2.3. A final pH of 6.8+0.2 is obtained.
The mixture obtained is applied to locks of natural or permanent-waved grey hair containing 90% white hairs. After a leave-on time of 20 minutes at 220C±3°C, the locks are rinsed, washed with a standard shampoo, rinsed again and then dried.
The hair coloration is evaluated visually. A shade with a strong mahogany tint is obtained.

CLAIMS
1. Composition for dyeing keratin fibres, comprising,
in a suitable dyeing medium:
• at least one first oxidation base chosen from 2,3-diamino-6,7-dihydro-lH,5H~pyrazolo[l,2-a]pyrazol-l-one of formula (I) below, and the addition salts thereof(Formula Removed)
. at least one second oxidation base chosen from para-phenylenediamines;
• at least one coupler chosen from raeta-aminophenols;
and
• at least one oxidizing agent;
the pH of the composition ranging from 5.5 to 7.5.
2. Composition according to Claim 1, in which the
oxidation base(s} chosen from 2,3-dianuno-6,7-dihydro-
1H,5H-pyrazolo(1,2-a)pyrazol-l-one of formula (I) and
the addition salts thereof is (are) each present in an
amount of between 0.001% and 10% by weight
approximately relative to the total weight of the dye
composition.
3. Composition according to Claim 1 or 2, in which
the para-phenylenediarnine (s) is (are) chosen from the
compounds of formula (II) below, and the addition salts
thereof: (Formula Removed)
in which:
R1 represents a hydrogen atom, a C1-C4 alkyl radical, a
C1-C4 monohydroxyalkyl radical C2-C4 polyhydroxyalkyl radical, a (C1,-C4) alkoxy (C1-C4) alkyl radical or a C1-C4 alkyl radical substituted with a nitrogenous, phenyl or 4'-aminophenyl group;
R2 represents a hydrogen atom, a C2-C4 alkyl radical, a C1-C4 monohydroxyalkyl radical or C2-C4 polyhydroxyalkyl radical, a (C1-C4) alkoxy (C1-C4) alkyl radical or a C1-C4 alkyl radical substituted with a nitrogenous group; R1 and Rz may also form, with the nitrogen atom that bears them, a 5- or 5-membered, saturated or unsaturated cyclic group containing one or more heteroatoms, optionally substituted with one or more alkyl, hydroxyl or ureido groups;
R3 represents a hydrogen atom, a halogen atom, a C1-C4 alkyl radical, a 3ulfo radical, a carboxy radical, a C1-C4 monohydroxyalkyl radical or C1-C4 hydroxyalkoxy radical, an acetylamino(C1-C4)alkoxy radical, a mesylamino(C1-C4) alkoxy radical or a carbamoylamino(C1-C4)alkoxy radical,
R4 represents a hydrogen or halogen atom or a C1-C4 alkyl radical.
4. Composition according to any one of the preceding
claims, in which the oxidation base(s) chosen from
para-phenylenediamines is (are) each present in an
amount of between 0.001% and 10% by weight
approximately relative to the total weight of the dye
composition.
5. Composition according to ay one of the preceding
claims, in which the meta-aminophenol(s) is (are)
chosen from the compounds of formula (II) below, and
the addition salts thereof:
(Formula Removed)
in which:
R1 and R2, which may be identical or different, represent a hydrogen atom; an alky! radical,- a monohydroxyalkyl radical; a polyhydroxyalkyl radical; a monoaminoalkyl radical;
RS and R2 form, together with the nitrogen atom to which they are attached, a saturated or unsaturated, 5- to 7-membered cyclic group containing one or more heteroatoms, which may be unsubstituted or substituted with one or more radicals chosen from • carboxyl, carboxamido, hydroxyl, amino, monoalkylamino and dialkylamino radicals, and alkyl radicals optionally substituted with one or more hydroxyl, amino, monoalkylamino or dialkylamino radicals; R3 represent, independently of each other, a halogen atom; an alkyl radical; an alkoxy radical; a monohydroxyalkyl radical; a polyhydroxyalkyl radical; a monohydroxyalkoxy radical; a polyhydroxyalkoxy radical; n is an integer between 0 and 3.
6, Composition according to Claim 5, in which RI and
Rj denote, independently of each other, a hydrogen atom
or a mono- or polyhydroxyalkyl radical.
7, Composition according to any one of the preceding
claims, in which the coupler(s) chosen from roeta-
aminophenols is (are) chosen from chlorinated meta-
aminophenols.

8. Composition according to any one of the preceding
claims, in which the coupler(a) chosen from meta-
andnophenols is (are) each present in an amount of
between 0.001% and 10% by weight approximately relative
to the total weight of the dye composition.
9. Composition according to any one of the preceding
claims, comprising at least one additional oxidation
base chosen from bis (phenyl)alkylenediamines, para-
aminophenols, bis-para-aminophenols, ortho-
aminophenols, ortho-phenylenediamines and heterocyclic
bases other than 2,3-diamino-6, "7-dihydro-lH, 5H-pyrazolo[1,2-a]pyrazol-1-one, and the addition salts thereof.
10. Composition according to any one of the preceding
claims, comprising at least one additional coupler
chosen from meta-phenylenediamines, meta-diphenols,
naphthalene-based couplers and heterocyclic couplers,
and the addition salts thereof.
11. Composition according to any one of the preceding
claims, in which the oxidizing agent (s) is (are) chosen
from hydrogen peroxide, utea peroxide, alkali metal
broraates, persalts, peracids and oxidase enzymes.
12. Composition according to any one of the preceding
claims, in which the oxidizing agent (s) is (are)
present in an amount of between 0.01% and 30% by weight
relative to the total weight of the composition.
13. Process for dyeing keratin fibres, in which the
composition as defined in any one of Claims 1 to 12 is
applied to the fibres for a time that is sufficient to
develop the desired coloration, after which the fibres
are rinsed, optionally washed with shampoo, rinsed
again and dried.
14. Process according to Claim 13, comprising a
preliminary step that consists in separately storing,
on the one hand, a composition (A) comprising, in a
suitable dyeing medium, at least one first oxidation
base chosen from 2, 3-diamino-6,7-dihydro-lH,5H-
pyrazolo[1,2-a]pyrazol-l-one and the addition salts
thereof, at least one second oxidation base chosen from
para-phenylenediamines and at least one coupler chosen
from meta-aminophenols, and, on the other hand, a
composition (B) containing, in a suitable dyeing
medium, at least one oxidizing agent, and then in
mixing them together at the time of use before applying
this mixture to the keratin fibres.
15. Multi-compartment device, in which a first
compartment contains a composition (A) as defined in
Claim 14 and a second compartment contains a
composition (B) as defined in Claim 14.
16. Use, for the oxidation dyeing of keratin fibres,
of a composition as defined in any one of Claims 1 to
12.
17. .Composition and a process for dyeing keratin fibres, multi-compartment device and use for the oxidation dyeing of keratin fibres, substantially as herein described with reference to the aforesaid Examples.