Dyeing compositions for keratinous fibres, especially for human hair, containing oxidation dye precursors and heterocyclic couplers

The invention relates to a dyeing composition for keratinous fibres containing, in a cosmetically acceptable solvent medium, at least one para-type oxidation dye precursor in combination with at least one heterocyclic coupler of formula: ##STR1## in which R denotes a hydrogen atom, a C.sub.1 -C.sub.4 radical, a C.sub.2 -C.sub.4 hydroxyalkyl radical, a C.sub.3 to C.sub.6 polyhydroxyalkyl radical, or a C.sub.2 -C.sub.6 alkoxyalkyl radical, Z, independently of R, denotes a C.sub.1 to C.sub.4 alkyl radical, a C.sub.2 to C.sub.4 hydroxyalkyl radical, a C.sub.3 to C.sub.6 polyhydroxyalkyl radical, a C.sub.2 -C.sub.6 alkoxyalkyl radical or a trifluoroethyl radical, R.sub.1 and R.sub.2 independently of each other denote a hydrogen atom or a C.sub.1 to C.sub.4 alkyl radical, or one of the addition salts of the compound of formula (I) with an inorganic acid, a process for the oxidation dyeing of hair using this composition as well as the new couplers of formula (I) where Z is other than methyl when R.sub.1, R.sub.2 and R=H, the process for their preparation, the new intermediate compounds of formula: ##STR2## and the process for their preparation.

The present invention relates to new dyeing compositions for keratinous 
fibres and especially for human hair, containing oxidation dye precursors, 
a dyeing process employing the said compositions, new heterocyclic 
couplers and the process for their preparation, as well as the new 
intermediate compounds employed in this process and the process for their 
preparation. 
It is known that the use of dyeing compositions containing oxidation dye 
precursors and especially p-phenylenediamines and ortho- or 
para-aminophenols, which are generally referred to by the term of 
oxidation bases, is known for dyeing keratinous fibres and especially 
human hair. 
It is also known that colour modifiers or couplers, and especially aromatic 
meta-diamines, meta-aminophenols and meta-diphenols are employed in order 
to modify the shades obtained with these oxidation bases. 
The hair dye formulator requires oxidation dye precursors or couplers which 
make it possible to impart to hair, in an oxidizing alkaline medium 
employed in oxidation dyeing, colours which have satisfactory resistance 
to light, to washing, to inclement weather and to perspiration. 
However, in addition to the abovementioned essential qualitites, the 
formulator increasingly needs oxidation dye precursors and/or couplers 
which make it possible to obtain low-selectivity dyes, that is to say 
colours which are substantially identical on natural hair and on hair 
sensitized by a treatment such as bleaching or permanent waving. It has 
been found, in fact, that hair whose roots are natural and whose ends have 
already been subjected to various treatments such as bleaching or 
permanent waving varies in its degree of sensitivity to the dye, which is 
reflected in poor colour uniformity between the root and the end of the 
hair, which is particularly unattractive. 
The Applicant has found that all the above requirements could be satisfied 
by virtue of the use of a dyeing composition containing, in a cosmetically 
acceptable solvent, medium, a tinctorially effective amount of at least 
one oxidation dye precursor of the "para" type in combination with at 
least one heterocyclic coupler corresponding to the following formula (I): 
##STR3## 
in which R denotes a hydrogen atom, a C.sub.1 -C.sub.4 alkyl radical, a 
C.sub.2 -C.sub.4 hydroxyalkyl radical, a C.sub.3 to C.sub.6 
polyhydroxyalkyl radical or a C.sub.2 -C.sub.6 alkoxyalkyl radical, 
independently of R, Z denotes a C.sub.1 -C.sub.6 alkyl radical, a C.sub.2 
-C.sub.4 hydroxyalkyl radical, a C.sub.3 -C.sub.6 polyhydroxyalkyl 
radical, a trifluoroethyl radical or a C.sub.2 -C.sub.6 alkoxyalkyl 
radical, and R.sub.1 and R.sub.2, which are identical or different, denote 
a hydrogen atom or a C.sub.1 -C.sub.4 alkyl radical, or an addition salt 
thereof with an inorganic acid such as hydrochloric acid, hydrobromic acid 
or sulfphuric acid. 
According to a preferred embodiment, R and Z do not simultaneously denote a 
polyhydroxyalkyl radical. 
When applied to keratinous fibres and especially to human hair, the dyeing 
composition defined above makes it possible to obtain, under the usual 
conditions of oxidation dyeing, shades which are stable to light, to 
washing and to inclement weather, and which have low selectivity, that is 
to say which are substantially identical on natural hair and on hair 
sensitized by a treatment such as bleaching or permanent waving. 
Furthermore, the combination of a coupler of formula (I) with an oxidation 
dye precursor of the "para" type such as a p-phenylenediamine or certain 
p-aminophenols, like 3-methoxy-4-aminophenol, makes it possible to obtain 
pure green shades which are particularly sought after by the person 
skilled in the art for producing matt shades, for toning down shades which 
are too vivid or too red and for applying a correction, where appropriate, 
to the tendency to reddening with time possessed by certain dyes. 
Another subject of the present invention is a process for dyeing keratinous 
fibres and especially human hair, employing the dyeing compositions 
defined above and making use of development with an oxidizing agent. 
Another subject of the present invention is the new heterocyclic couplers 
of formula (I'): 
##STR4## 
in which R denotes a hydrogen atom, a C.sub.1 -C.sub.4 alkyl radical, a 
C.sub.2 -C.sub.4 hydroxyalkyl radical, a C.sub.3 to C.sub.6 
polyhydroxyalkyl radical or a C.sub.2 -C.sub.6 alkoxyalkyl radical, 
Z denotes a C.sub.1 -C.sub.4 alkyl radical, a C.sub.2 -C.sub.4 hydroxyalkyl 
radical, a C.sub.3 -C.sub.6 polyhydroxyalkyl radical, a trifluoroethyl 
radical or a C.sub.2 -C.sub.6 alkyoxalkyl radical, 
R.sub.1 and R.sub.2 independently of each other denote a hydrogen atom or a 
C.sub.1 -C.sub.4 alkyl radical; 
provided that when R, R.sub.1 and R.sub.2 denote a hydrogen atom, Z is 
other than a methyl radical, 
as well as the addition salts formed by these compounds with an inorganic 
acid. 
The preferred compounds (I') are those in which R and Z do not 
simultaneously denote a polyhydroxyalkyl radical. 
The present invention also relates to the process for the preparation of 
the new heterocyclic couplers of formula (I'). 
The compound of formula (I') is prepared in one or more stages from the 
compound of formula (II) according to the following reaction scheme: 
##STR5## 
R, Z, R.sub.1 and R.sub.2 having the meanings indicated earlier. 
The compound of formula (I'a) is obtained either by catalytic reduction of 
the compound of formula (II) under hydrogen pressure, in the presence of 
solvent and of a catalyst such as palladium on charcoal (a reduction 
described for the preparation of 
4-amino-5-methoxy-1,2-methylenedioxybenzene in Z. Naturforsch. 33c, 
p.459-464 (1978) and in Monatsch. Chem. 88, p.541-559 (1957)), or by 
reduction of the compound of formula (II) using iron in the presence of 
acetic acid. 
The compound of formula (I') in which R is not a hydrogen atom is obtained 
from the compounds (I'a) by conventional methods for the alkylation, 
hydroxyalkylation or alkoxyalkylation of aromatic amines. 
Among these methods, the Applicant has found that the most advantageous 
alkylation method, bearing in mind the presence of the methylenedioxy 
group in the molecule, consists, in a first step, in N-formylating the 
compound (I'a) to obtain the compound (III). In a second step the compound 
(III) is alkylated in a basic medium to give the compound (IV which, when 
subjected to the action of an inorganic acid, makes it possible to obtain 
the compound (I') in which R is an alkyl radical, in accordance with the 
following reaction scheme: 
##STR6## 
R, Z, R.sub.1 and R.sub.2 having the meanings indicated earlier, with R not 
denoting a hydrogen atom. 
Among the preferred hydroxyalkylation methods, there may be mentioned the 
action of .beta.-chloroethyl chloroformate on the compound (I'a), which, 
in a first step, makes it possible to obtain the corresponding 
.beta.-chloroethyl carbamate which, in a second step, subjected to the 
action of a strong inorganic base such as sodium hydroxide or potassium 
hydroxide, makes it possible to obtain the compound (I') in which the 
radical R is a .beta.-hydroxyethyl radical. 
Another subject of the present invention is the new intermediate compound 
of the following formula (II.beta.): 
##STR7## 
in which Z denotes a C.sub.2 -C.sub.4 alkyl radical, a C.sub.2 -C.sub.4 
hydroxyalkyl radical, a C.sub.3 -C.sub.6 polyhydroxyalkyl radical, a 
trifluoroethyl radical or a C.sub.2 -C.sub.6 alkoxyalkyl radical, and 
R.sub.1 and R.sub.2 independently of each other denote a hydrogen atom or 
a C.sub.1 -C.sub.4 alkyl radical. 
Another subject of the present invention is the process for the preparation 
of the compound of formula (II'). 
The compound of formula (II') in which the radical Z is not the 
trifluoroethyl radical may be prepared: 
a) either by the reaction of a dialkyl sulphate, or an alkyl, hydroxyalkyl, 
polyhydroxyalkyl or alkoxyalkyl halide with the compound of formula: 
##STR8## 
R.sub.1 and R.sub.2 having the meanings referred to above, in the presence 
of an alkaline agent such as a carbonate and of a solvent which may be 
benzene or dimethylformamide; the compound of formula (IV) for which 
R.sub.1 =R.sub.2 =H is described in J. Org. Chem. vol. 24, p. 327-329 
(1959) and in J.A.C.S., vol. 64, p. 2983-2986 (1942); 
the compounds of formula (V) for which R.sub.1 and R.sub.2 denote an alkyl 
radical may be obtained from the 2,2-disubstituted 1,3-benzodioxole which 
is acetylated by lead tetraacetate and nitrated according to conventional 
methods using dilute nitric acid in the presence or absence of acetic acid 
and then hydrolysed according to the following reaction scheme 
##STR9## 
compounds of formula (XIII) may be obtained by the reaction of a ketone 
R.sub.1 COR.sub.2 on the pyrocatechol as indicated in AUST.J.CHEM (1980) 
Vol 33 (3) p.675-80; 
compounds of formula (XIV) may be obtained according to the method 
described in AUST.J.CHEM (1980) Vol.33 (3) p.527-43; 
b) or by nitrating using dilute nitric acid in the presence or absence of 
acetic acid, at a temperature of between 5.degree. C. and 30.degree. C., 
the compound of formula: 
##STR10## 
where Z, R.sub.1 and R.sub.2 have the meanings indicated earlier with the 
exception of trifluoroethyl in the case of Z; this route is preferably 
employed in the case of the compounds of formula (II') where Z denotes an 
alkyl or alkoxyalkyl radical. 
The compound of formula (VI) is prepared: 
a) either from the compound (VII) of formula: 
##STR11## 
where R.sub.1 and R.sub.2 have the abovementioned meanings, by the action 
of an alkyl, hydroxyalkyl, polyhydroxyalkyl or alkoxyalkyl halide or of a 
dialkyl sulphate, according to the conventional procedures for alkylation, 
hydroxyalkylation or alkoxyalkylation of phenols; 
the compounds of formula (VII) in which R.sub.1 and R.sub.2 denote an alkyl 
radical may be obtained in hydrolysing the compounds of formula (XIV). 
##STR12## 
b) or from the compound (VIII) of formula: 
##STR13## 
where Z has the meanings indicated earlier, except for trifluoroethyl, by 
the action of a dihalomethane, an aldehyde or a ketone of formula: 
##STR14## 
according to conventional procedures, especially those described in 
"Protective groups in organic synthesis", T.W. Greene, John Wiley, 
Interscience, 1981, p. 108-112. 
4-Methoxy-5-nitro-1,2-methylenedioxybenzene, a known compound of formula 
(II), is prepared either from 4-hydroxy-5-nitro-1,2,-methylenedioxybenzene 
according to Monatsch. Chem. 88, p. 541-559 (1957) by reaction with 
dimethyl sulphate in the presence of sodium carbonate and of toluene, or 
from 4-methoxy-1,2-methylenedioxybenzene according to J. Agric.Food Chem. 
vol.15, p.140 (1967) or according to Z.Naturforsch. 33c, p. 459-464 (1978) 
by nitration with nitric acid in the presence of acetic acid. 
The compound of formula (II') in which Z is the trifluoroethyl radical is 
prepared from 4,5-dinitro-1,2-methylenedioxybenzene. 
The Applicant has shown that the reaction of an alcohol Z--OH, in the 
presence of a strong base such as potassium hydroxide, with 
4,5-dinitro-1,2-methylenedioxybenzene of formula (IX), the excess alcohol 
Z--OH being used as solvent, yielded the dinitrophenol of formula (X) when 
the radical Z is an alkyl, hydroxyalkyl or polyhydroxyalkyl radical: 
##STR15## 
Under the same conditions, and in a totally surprising manner, when the 
alcohol Z--OH is trifluoroethanol, the compound of formula (II') in which 
Z denotes a trifluoroethyl radical is obtained selectively in a good 
yield, in accordance with the following reaction scheme: 
##STR16## 
As preferred radicals R which appear in the formulae (I) and (I'), there 
may be mentioned hydrogen, and methyl, ethyl, n-propyl, n-butyl, 
.beta.-hydroxyethyl, .beta.-hydroxypropyl, .gamma.-hydroxypropyl and 
.beta.,.gamma.-dihydroxypropyl radicals. 
As preferred radicals Z in the formulae (I), (I'), (I'a), (II) and (II'), 
there may be mentioned trifluoroethyl, methyl, ethyl, n-propyl, n-butyl, 
.beta.-hydroxyethyl, .beta.-hydroxypropyl, .gamma.-hydroxypropyl and 
.beta.,.gamma.-dihydroxypropyl radicals. 
Among the preferred compounds of formula (I') there may be mentioned: 
4-(.beta.-hydroxyethyl)amino-5-methoxy-1,2-methylenedioxybenzene 
4-amino-5-(2',2',2'-trifluoroethoxy)-1,2-methylenedioxybenzene 
4-methylamino-5-methoxy-1,2-methylenedioxybenzene 
4-amino-5-(.beta.-hydroxyethoxy)-1,2-methylenedioxybenzene and 
6-amino-5-methoxy-2-methyl-2-propyl-1,3-benzodioxole, 
as well as their addition salts with an inorganic acid. 
By way of compounds of formula (II') there may be mentioned 
4-nitro-5-(.beta.-hydroxyethoxy)-1,2-methylenedioxybenzene, 
4-nitro-5-(2',2',2'-trifluoroethoxy)-1,2-methylenedioxybenzene and 
5-methoxy-6-nitro-2-methyl-2-propyl-1,3-benzodioxole. 
The para-type oxidation dye precursors employed in combination with the 
heterocyclic couplers of formula (I) in the dyeing compositions for 
keratinous fibres according to the invention are chosen from 
p-phenylenediamines, p-aminophenols, and heterocyclic para precursors such 
as 2,5-diaminopyridine, 2-hydroxy-5-aminopyridine or tetraaminopyrimidine. 
By way of p-phenylenediamines there may be mentioned the compounds 
corresponding to the formula (XII) below: 
##STR17## 
in which R.sub.1, R.sub.2 and R.sub.3 are identical or different and 
denote a hydrogen or halogen atom, an alkyl radical containing 1 to 4 
carbon atoms, an alkoxy radical containing 1 to 4 carbon atoms, R.sub.4 
and R.sub.5 are identical or different and denote a hydrogen atom or an 
alkyl, hydroxyalkyl, alkoxyalkyl, carbamylkalkyl, mesylaminoalkyl, 
acetylaminoalkyl, ureidoalkyl, carbethoxyaminoalkyl, piperidinoalkyl or 
morpholinoalkyl radical, the alkyl or alkoxy groups denoted by R.sub.4 and 
R.sub.5 containing from 1 to 4 carbon atoms, or else R.sub.4 and R.sub.5, 
together with the nitrogen atom to which they are linked, can form a 
piperidino or morpholino heterocyclic ring provided that R.sub.1 or 
R.sub.3 or both R.sub.1 and R.sub.3 denote a hydrogen atom when R.sub.4 
and R.sub.5 do not denote a hydrogen atom, and the cosmetically acceptable 
salts of these compounds. 
Among the compounds of formula (XII) there may be mentioned 
p-phenylenediamine, p-tolylenediamine, methoxy-para-phenylenediamine, 
chloro-para-phenylenediamine, 2,6-dimethyl-p-phenylenediamine, 
2,5-dimethyl-para-phenylenediamine, 
2-methyl-5-methoxy-para-phenylenediamine, 
2,6-dimethyl-5-methoxy-para-phenylenediamine, 
N,N-dimethyl-para-phenylenediamine, 3-methyl-4-amino-N,N-diethylaniline, 
N,N-di(.beta.-hydroxyethyl)-para-phenylenediamine, 
3-methyl-4-amino-N,N-di(.beta.-hydroxyethyl)aniline, 
3-chloro-4-amino-N,N-di(.beta.-hydroxyethyl)aniline, 4-amino-N,N-(ethyl, 
carbamylmethyl)aniline, 3-methyl-4-amino-N,N-(ethyl, 
carbamylmethyl)-aniline, 4-amino-N,N-(ethyl, 
.beta.-piperidinoethyl)aniline, 3-methyl-4-amino-N,N-(ethyl, 
.beta.-piperidinoethyl)aniline, 4-amino-N,N-(ethyl, 
.beta.-morpholionethyl)aniline, 3-methyl-4-amino-N,N-(ethyl, 
.beta.-morpholionethyl)aniline, 4-amino-N,N-(ethyl, 
.beta.-acetylaminoethyl)aniline, 4-amino-N,.beta.-methoxyethylaniline, 
3-methyl-4-amino-N,N-(ethyl, .beta.-acetylaminoethyl)aniline, 
4-amino-N,N-(ethyl, .beta.-mesylaminoethyl)aniline, 
3-methyl-4-amino-N,N-(ethyl, .beta.-mesylaminoethyl)aniline, 
4-amino-N,N-(ethyl, .beta.-sulphoethyl)aniline, 
3-methyl-4-amino-N,N-(ethyl, .beta.-sulphoethyl)aniline, 
N-[(4'-amino)phenyl]morpholine and N-[(4'-amino)phenyl]piperidine. These 
para-type oxidation dye precursors may be added to the dyeing composition 
in the form of free base or in the form of salts, such as in the form of 
hydrochloride, hydrobromide or sulphate. 
Among the p-aminophenols there may be mentioned p-aminophenol, 
2-methyl-4-aminophenol, 4-methyl-4-aminophenol, 2-chloro-4-aminophenol, 
3-chloro-4-aminophenol, 2,6-dimethyl-4-aminophenol, 
3,5-dimethyl-4-aminophenol, 2,3-dimethyl-4-aminophenol, 
2,5-dimethyl-4-aminophenol, 2-hydroxymethyl-4-aminophenol, 
2-(.beta.-hydroxyethyl)-4-aminophenol, 2-methoxy-4-aminophenol and 
3-methoxy-4-aminophenol. 
The dyeing compositions according to the invention may also contain 
ortho-type oxidation dye precursors such as ortho-aminophenols, 
ortho-phenylenediamines, or ortho-diphenols such as 
1-amino-2-hydroxybenzene, 6-methyl-1-hydroxy-2-aminobenzene or 
4-methyl-1-amino-2-hydroxybenzene. 
The dyeing compositions according to the invention containing the 
heterocyclic coupler of formula (I) may optionally contain other couplers 
which are known as such, such as meta-diphenols, meta-aminophenols, 
meta-phenylenediamines, meta-acylaminophenols, meta-ureidophenols, 
meta-carbalkoxyaminophenols or .alpha.-naphthol, and the couplers 
containing an active methylene group such as .beta.-ketonic compounds and 
pyrazolones. 
By way of example there may be mentioned, in particular, 
2,4-dihydroxphenoxyethanol, 2,4-dihydroxyanisole, meta-aminophenol, 
resorcinol monomethyl ether, 2-methyl-5-aminophenol, 
2-methyl-N-(.beta.-hydroxyethyl)-5-aminophenol, 
2-methyl-N-(.beta.-mesylaminoethyl)-5-aminophenol, 
2,6-dimethyl-3-aminophenol, 6-hydroxybenzomorpholine, 2,4-diaminoanisole, 
2,4-diaminophenoxyethanol, 6-aminobenzomorpholine, 
[2-N-(.beta.-hydroxyethyl)amino-4-amino]phenoxyethanol, 
2-amino-4-N-(.beta.-hydroxyethyl)aminoanisole, 2,4-diaminophenyl 
.beta.,.gamma.-di-hydroxypropyl ether, 2,4-diaminophenoxyethylamine and 
their salts. 
As is well known, direct dyes such as azo or anthraquinone dyes or nitro 
derivatives of the benzene series may be added to these compositions in 
order to tinge or to enrich in highlights the colours provided by the 
oxidation dye precursors. 
The total quantity of the para-type oxidation dye precursors and of the 
couplers employed in the dyeing compositions according to the invention 
preferably represents from 0.3 to 7% by weight of the said composition. 
The concentration of compounds (I) may vary between 0.05 and 3.5% of the 
weight of the total composition. 
The cosmetically acceptable medium is generally aqueous and its pH may vary 
between 8 and 11, and it is preferably between 9 and 11. 
It is adjusted to the desired value with an alkalifying agent such as 
aqueous ammonia, alkali metal carbonates, or alkanolamines such as mono-, 
di- or triethanolamine. 
In the preferred embodiment, the dyeing compositions according to the 
invention also contain anionic, cationic, nonionic or amphoteric 
surface-active agents or mixtures thereof. Among these surface-active 
agents, there may be mentioned more particularly fatty alcohol 
alkylbenzenesulphonates, alkylnaphthalenesulphonates, sulphates, ether 
sulphates and sulphonates, quaternary ammonium salts such as 
trimethylcetylammonium bromide, cetylpyridinium bromide, optionally 
oxyethylenated fatty acid ethanolamides, polyoxyethylenated acids, 
alcohols and amines, polyglycerolated alcohols, and polyoxyethylenated or 
polyglycerolated alkylphenols, as well as polyoxyethylenated alkyl 
sulphates. The surface-active agents are present in the compositions 
according to the invention in proportions of between 0.5 and 55% by 
weight, and preferably between 2 and 50% by weight, based on the total 
weight of the composition. 
These compositions may also contain organic solvents in order to solubilize 
the compounds that might not be sufficiently soluble in water. Among these 
solvents, there may be mentioned, by way of example, lower C.sub.1 
-C.sub.4 alkanols such as ethanol and isopropanol, glycerol, glycols or 
glycol ethers such as 2-butoxyethanol, ethylene glycol, propylene glycol, 
diethylene glycol monoethyl ether and monomethyl ether, and aromatic 
alcohols such as benzyl alcohol or phenoxyethanol, similar products and 
mixtures thereof. The solvents are preferably present in a proportion of 
between 1 and 40% by weight, and in particular between 5 and 30% by weight 
based on the total weight of the composition. 
The thickening agents which may be added to the compositions according to 
the invention are taken particularly from the group consisting of sodium 
alginate, gum arabic, cellulose derivatives such as methyl cellulose, 
hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxymethyl cellulose, 
carboxymethyl cellulose, acrylic acid polymers and xanthane gum. It is 
also possible to employ inorganic thickening agents such as bentonite. 
These thickening agents are preferably present in proportions of between 
0.1 and 5% by weight, and in particular between 0.2 and 3% by weight, 
based on the total weight of the composition. 
The compositions may contain antioxidants chosen, in particular, from 
sodium sulphite, thioglycolic acid, sodium bisulphite, ascorbic acid and 
hydroquinone. These antioxidants are present in the composition in 
proportions of between 0.05 and 1.5% by weight, based on the total weight 
of the composition. 
Other adjuvants which may be employed in accordance with the invention are, 
for example, penetrating agents, sequestering agents, buffers and 
perfumes. 
The dyeing compositions according to the invention may be in various forms 
such as in the form of liquids, creams, gels or any other suitable form 
effecting the dyeing of keratinous fibres and especially human hair. They 
may also be packaged in aerosol bottles in the presence of a propellent 
agent. 
The dyeing compositions according to the invention containing an oxidation 
dye precursor and a coupler of formula (I) are employed in the methods of 
dyeing keratinous fibres and especially human hair in accordance with a 
process making use of development by means of an oxidizing agent. 
In accordance with this process, the dyeing composition described above is 
mixed with an oxidizing solution, in a sufficient quantity, at the time of 
use and the mixture obtained is then applied to the hair. 
The oxidizing solution contains oxidizing agents such as hydrogen peroxide, 
urea peroxide or persalts such as ammonium persulphate. A 20-volume 
hydrogen peroxide solution preferably employed. 
The mixture obtained is applied to the hair and left in position for 10 to 
40 minutes, preferably 15 to 30 minutes, after which the hair is rinsed, 
washed with a shampoo, rinsed again and dried. 
Another method of making use of the coupler of formula (I) according to the 
invention is to dye the hair using a method involving several steps and 
consisting, in one of the stages, in applying the para oxidation dye 
precursor by means of a composition as defined above and, in another 
stage, in applying the coupler of formula (I). The oxidizing agent is 
present in the composition which is applied in the second step or else is 
added onto the keratinous fibres themselves in a third step, the exposure 
and drying or washing conditions being identical.

The invention will be illustrated better with the aid of the following 
examples of preparation and application, which do not in any way limit the 
scope of the invention but which should be considered as being solely 
illustrative. 
PREATIVE EXAMPLE NO. 1 
Preparation of 4-amino-5-methoxy-1,2-methylenedioxybenzene hydrochloride 
##STR18## 
A suspension of 18.5 g of hydrogen-reduced iron powder in 40 ml of ethanol 
to which 3.3 ml of water and 1.7 ml of acetic acid have been added is 
heated under reflux. 0.033 mole (6.4 g) of 
4-nitro-5-methoxy-1,2-methylenedioxybenzene is added portionwise. The 
heating is continued for 30 minutes after the end of the addition. 10 ml 
of absolute ethanol are added and the boiling mixture is then filtered. 20 
ml of a 7N solution of hydrochloric acid in absolute ethanol are added to 
the filtrate. The expected product precipitates. After recrystallization 
from a water-alcohol mixture, it decomposes at 190.degree.-200.degree. C. 
Elemental analysis of the product obtained gives the following results: 
______________________________________ 
Calculated for 
Analysis C.sub.8 H.sub.10 NO.sub.3 Cl 
Found 
______________________________________ 
C % 47.19 47.14 
H % 4.95 5.00 
N % 6.88 6.83 
O % 23.57 23.65 
Cl % 17.41 17.42 
______________________________________ 
PREATIVE EXAMPLE NO. 2 
Preparation of 
4-(.beta.-hydroxyethyl)amino-5-methoxy-1,2-methylenedioxybenzene 
##STR19## 
Stage 1: Preparation of .beta.-chloroethyl 
N-[(2-methoxy-4,5-methylenedioxy)phenyl]carbamate 
0.1 mole (20.3 g) of 4-amino-5-methoxy-1,2-methylenedioxybenzene 
hydroxchloride prepared in Example 1 and 0.12 mole (12 g) of calcium 
carbonate are heated in 80 ml of dioxane on a boiling water bath. 0.11 
mole (15.7 g) of .beta.-chloroethyl chloroformate is added in small 
portions. After 30 minutes' heating, the reaction mixture is poured onto 
300 g of a mixture of ice and water. The reaction mixture is acidified and 
the expected product is separated by filtering and is reslurried in water. 
Stage 2: Preparation of 
4-(.beta.-hydroxyethyl)amino-5-methoxy-1,2-methylenedioxybenzene 
The wet .beta.-chloroethyl 
N-[(2-methoxy-4,5-methylenedioxy)phenyl]carbamate prepared in the 
preceding stage is added to 40 ml of water and 40 ml of ethanol containing 
0.33 mole of sodium hydroxide pellets. The whole is heated under reflux 
for 2 hours 30 minutes. 
After cooling, the reaction mixture is diluted with 150 ml of iced water 
and the expected product is separated by filtration; after 
recrystallization from 96.degree. ethanol it melts at 119.degree. C. 
Analysis of the product obtained gives the following results: 
______________________________________ 
Calculated for 
Analysis C.sub.10 H.sub.13 NO.sub.4 
Found 
______________________________________ 
C % 56.86 56.77 
H % 6.20 6.23 
N % 6.63 6.70 
O % 30.30 30.12 
______________________________________ 
PREATIVE EXAMPLE NO. 3 
Preparation of 
4-amino-5-(2',2',2'-trifluoroethyoxy)-1,2-methylenedioxybenzene 
##STR20## 
Stage 1: Preparation of 
4-nitro-5-(2',2',2'-trifluoroethoxy)-1,2-methylenedioxybenzene 
0.4 mole (26.4 g) of 85% strength potassium hydroxide pellets is heated to 
70.degree. C. in 0.5 mole (50 g) of 2,2,2-trifluoroethanol and then 10 ml 
of N-methylpyrrolidone are added. A solution of 0.2 mole (42.4 g) of 
4,5-dinitro-1,2-methylenedioxybenzene [(prepared according to Synthesis p 
924-925 (1978)] in 42 ml of N-methylpyrrolidone is added dropwise at 
60.degree.-65.degree. C. Heating is continued for 30 minutes after the end 
of the addition. After cooling, the reaction mixture is poured onto 1 
liter of iced water. The precipitate of the expected product is filtered 
off and, after being washed with water and dried under vacuum at 
50.degree. C. in the presence of phosphorus pentoxide, is recrystallized 
from benzene. It melts at 94.degree. C. 
Analysis of the product obtained gives the following results: 
______________________________________ 
Calculated for 
Analysis C.sub.9 H.sub.6 NO.sub.5 F.sub.3 
Found 
______________________________________ 
C % 40.77 40.75 
H % 2.28 2.28 
N % 5.28 5.36 
F % 21.50 21.79 
______________________________________ 
Stage 2: Preparation of 
4-amino-5-(2',2',2'-trifluoroethoxy)-1,2-methylenedioxybenzene 
A suspension of 55 g of iron powder in 120 ml of 96.degree. ethanol, to 
which 8.5 ml of water and 6 ml of acetic acid have been added, is heated 
under reflux. 0.1 mole (26.5 g) of 
4-nitro-5-(2',2',2'-trifluoroethyoxy)-1,2-methylenedioxybenzene is added 
portionwise. Heating is continued for 30 minutes after the end of the 
addition. The reaction mixture is filtered while boiling. The filtrate, to 
which 40 ml of a 7N solution of hydrochloric acid in ethanol is added, is 
evaporated to dryness. The hydrochloride of the expected product is 
isolated. After being dissolved in water and then neutralized with aqueous 
ammonia, the expected product precipitates out. After being dried hot 
under vacuum and then recrystallized from cyclohexane, it melts at 
78.degree. C. 
Analysis of the product obtained gives the following results: 
______________________________________ 
Calculated for 
Analysis C.sub.9 H.sub.8 NO.sub.3 F.sub.3 
Found 
______________________________________ 
C % 45.96 46.09 
H % 3.43 3.43 
N % 5.96 5.89 
F % 24.24 24.12 
______________________________________ 
PREATIVE EXAMPLE NO. 4 
Preparation of 4-methylamino-5-methoxy-1,2-methylenedioxybenzene 
##STR21## 
Stage 1: Preparation of 
4-N-formylamino-5-methoxy-1,2-methylenedioxybenzene 
0.05 mole (9.9 g) of 4-amino-5-methoxy-1,2-methylenedioxybenzene 
hydrochloride in 40 ml of formamide is heated on a boiling water bath for 
half an hour. The reaction mixture is cooled. The precipitate of the 
expected product is filtered off. After being reslurried in water and 
dried, it melts at 138.degree. C. 
Stage 2: Preparation of 
4-(N-formyl,N-methyl)-amino-5-methoxy-1,2-methylenedioxybenzene 
A solution of 0.033 mole (6.5 g) of 
4-N-formylamino-5-methoxy-1,2-methylenedioxybenzene in 22 ml of 
dimethylformamide is prepared. 22.5 ml of a 30% solution of sodium 
methylate in methanol and 10.5 ml of methyl sulphate are added alternately 
over 3 hours, the temperature being between 25.degree. C. and 45.degree. 
C. The reaction mixture is then poured onto 300 g of a mixture of ice and 
water. The expected product precipitates out. After recrystallization from 
96.degree. ethanol it melts at 112.degree. C. 
Analysis of the product obtained gives the following results: 
______________________________________ 
Calculated for 
Analysis C.sub.10 H.sub.11 NO.sub.4 
Found 
______________________________________ 
C % 57.41 57.34 
H % 5.30 5.28 
N % 6.70 6.65 
O % 30.59 30.83 
______________________________________ 
Stage 3: Preparation of 4-methylamino-5-methoxy-1,2-methylenedioxybenzene 
0.029 mole (6 g) of the compound prepared during stage 2 is heated for 1 
hour under reflux in 50 ml of a 7N alcoholic solution of hydrochloric 
acid. The reaction mixture is cooled. The hydrochloride of the expected 
product is filtered off. 
After the hydrochloride has been dissolved in the minimum quantity of water 
and neutralized with aqueous ammonia, the expected product cyrstallizes 
out. After filtration and drying it melts at 66.degree. C. 
Analysis of the product obtained gives the following results: 
______________________________________ 
Calculated for 
Analysis C.sub.9 H.sub.11 NO.sub.3 
Found 
______________________________________ 
C % 59.66 59.52 
H % 6.12 6.17 
N % 7.73 7.64 
O % 26.49 26.54 
______________________________________ 
PREATIVE EXAMPLE NO. 5 
Preparation of 4-amino-5-(.beta.-hydroxyethoxy)-1,2-methylenedioxybenzene 
hydrochloride 
##STR22## 
Stage 1: Preparation of 
4-nitro-5-(.beta.-hydroxyethyoxy)-1,2-methylenedioxybenzene 
0.1 mole (18.3 g) of 4-hydroxy-5-nitro-1,2-methylenedioxybenzene in 60 ml 
of dimethylformamide, to which 21.3 g of glycol bromohydrin and 22.1 g of 
potassium carbonate have been added, is heated on a boiling water bath. 
After 7 hours' heating, the reaction mixture is cooled. The expected 
product precipitates out. After being recrystallized from 96.degree. 
ethanol and then from benzene it melts at 122.degree. C. 
Analysis of the product obtained gives the following results: 
______________________________________ 
Calculated for 
Analysis C.sub.9 H.sub.9 NO.sub.6 
Found 
______________________________________ 
C % 47.58 47.70 
H % 3.99 4.09 
N % 6.17 6.30 
O % 42.26 42.35 
______________________________________ 
Stage 2: Preparation of 
4-amino-5-(.beta.-hydroxyethoxy)-1,2-methylenedioxybenzene hydrochloride 
A suspension of 23 g of hydrogen-reduced iron powder in 50 ml of 96.degree. 
ethanol, to which 3.5 ml of water and 2.5 ml of acetic acid have been 
added, is heated under reflux. 0.042 mole (9.5 g) of 
4-nitro-5-(.beta.-hydroxyethoxy)-1,2-methylenedioxybenzene is added 
portionwise. Heating is continued for 30 minutes after the end of the 
addition. 
After the addition of 40 ml of absolute ethanol, the reaction mixture is 
filtered while boiling. 17 ml of a 7N solution of hydrochloric acid in 
ethanol are added to the filtrate to precipitate the hydrochloride of the 
expected product. The hydrochloride is dissolved in 100 ml of water. After 
filtration to remove an insoluble brown material and neutralization with 
aqueous ammonia, 
4-amino-5-(.beta.-hydroxyethoxy)-1,2-methylenedioxybenzene precipitates 
out. After recrystallization from benzene it melts at 102.degree. C. 
Elemental analysis of the hydrochloride obtained after purification gives 
the following results: 
______________________________________ 
Calculated for 
Analysis C.sub.9 H.sub.12 NO.sub.4 Cl 
Found 
______________________________________ 
C % 46.26 46.26 
H % 5.18 5.26 
N % 6.00 5.90 
O % 27.39 27.52 
Cl % 15.17 14.94 
______________________________________ 
PREATIVE EXAMPLE NO. 6 
Preparation of 6-amino-5-methoxy-2-methyl-2-propyl-1,3-benzodioxole 
hydrochloride 
##STR23## 
Stage 1: 
Preparation of 5-methoxy-2-methyl-2-propyl-1,3-benzodioxole 
0.35 mole (48.5 g) of 1,2-dihydroxy-4-methoxybenzene, 0.38 mole (32.7 g) of 
2-pentanone and 1 g of p-toluenesulphonic acid are added to 350 ml of 
benzene. The mixture is heated under benzene reflux in order to remove the 
water formed. After 50 hours' heating, the reaction mixture is cooled and 
is then filtered through paper. After evaporation under reduced pressure, 
a brown oil is obtained and is dissolved in 500 ml of ethyl ether. After 
extraction with a solution of sodium carbonate in water in order to remove 
the unreacted 1,2-dihydroxy-4-methoxybenzene, the ethereal phase is dried 
with sodium sulphate. After evaporation of the ethyl ether under reduced 
pressure, the expected product is obtained and is employed as such in the 
following stage. 
Stage 2: Preparation of 
5-methoxy-6-nitro-2-methyl-2-propyl-1,3-benzodioxole 
0.19 mole (40 g) of 5-methoxy-2-methyl-2-propyl-1,3-benzodioxole prepared 
in the preceding stage is dissolved in 100 ml of acetic acid. After the 
solution prepared in this manner has been cooled to 15.degree. C., a 
solution consisting of 14.7 ml of nitric acid (d=1.40) and 15 ml of acetic 
acid is added dropwise over a quarter of an hour. Cooling is applied to 
keep the temperature between 20.degree. C. and 24.degree. C. Stirring is 
continued for 15 minutes after the end of the addition. 
The reaction mixture is poured onto 350 g of iced water. The expected 
product precipitates out. The precipitate is filtered off and is washed 
with water and with isopropanol. After drying, it is recrystallized from 
50 ml of 96.degree. ethyl alcohol. It melts at 67.degree. C. 
Analysis of the product obtained gives the following results: 
______________________________________ 
Calculated for 
Analysis C.sub.12 H.sub.15 NO.sub.5 
Found 
______________________________________ 
C % 56.91 56.74 
H % 5.97 6.00 
N % 5.53 5.62 
O % 31.59 31.85 
______________________________________ 
Stage 3: 
Reduction of 5-methoxy-6-nitro-2-methyl-2-propyl-1,3-benzodioxole 
A suspension of 50 g of hydrogen-reduced iron powder in 150 ml of ethanol, 
to which 7 ml of water and 5 ml of acetic acid have been added, is heated 
under reflux. 0.08 mole (20.3 g) of 
5-methoxy-6-nitro-2-methyl-2-propyl-1,3-benzodioxole is added portionwise. 
Heating is continued for 30 minutes after the end of the addition. The 
reaction mixture is filtered while boiling. 25 ml of a 7N solution of 
hydrochloric acid is added to the filtrate. 
After evaporation, a dry extract of the expected product is obtained. The 
dry extract is washed with absolute ethanol. 
After drying, analysis of the product obtained gives the following results: 
______________________________________ 
Calculated for 
Analysis C.sub.12 H.sub.17 NO.sub.3 Cl 
Found 
C % 55.49 55.61 
H % 6.99 7.00 
N % 5.39 5.37 
O % 18.48 18.55 
Cl % 13.65 13.60 
______________________________________ 
APPLICATION EXAMPLE NO. 1 
The following dyeing mixture is prepared: 
______________________________________ 
4-Amino-5-methoxy-1,2-methylenedioxybenzene 
hydrochloride 0.509 g 
4-Amino-N--.beta.-methoxyethylaniline 
dihydrochloride 0.597 g 
Alfol C 16/18 - Condea company (50/50 
cetylstearyl alcohol) 8.00 g 
Lanette Wax E - Henkel company 
(sodium cetylstearyl sulphate) 
0.50 g 
Cemulsol B - Rhone-Poulenc 
(ethoxylated castor oil) 1.00 g 
Oleoyl diethanolamide 1.50 g 
Masquol DTPA - Protex company 
(pentasodium salt of diethylene triamine 
pentaacetic acid) 2.50 g 
20% aqueous ammonia 11.00 g 
Water q.s. 100 g 
pH = 9.9 
______________________________________ 
100 g of 20-volume hydrogen peroxide are added at the time of use. When 
applied to 90% naturally white hair for 20 minutes at 30.degree. C., the 
mixture imparts to it, after shampooing and rinsing, a light olive-green 
colour. 
APPLICATION EXAMPLE NO. 2 
The following dyeing mixture is prepared: 
______________________________________ 
N,Ndi(.beta.-hydroxyethyl)-para-phenylenediamine 
dihydrochloride 0.67 g 
4-(.beta.-hydroxyethyl)amino-5-methoxy-1,2- 
methylenedioxybenzene 0.53 g 
Alfol C 16/18 - Condea company 
(50/50 cetylstearyl alcohol) 
19.00 g 
Eutanol G - Henkel company 
(2-octyldodecanol) 4.5 g 
Mergital C.S. - Henkel company 
(cetyl stearyl alcohol containing 15 moles of 
ethylene oxide) 2.5 g 
Ammonium lauryl sulphate 10.0 g 
Polymer B 4.0 g 
Cationic polymer consisting of the following 
repeat units: 
##STR24## 
Benzyl alcohol 2.0 g 
20% aqueous ammonia 11.0 g 
Trilon B 
(ethylenediaminetetraacetic acid) 
1.0 g 
35.degree. Be sodium bisulphite 
1.2 g 
Water q.s. 100 g 
pH = 9.7 
______________________________________ 
90 g of 20-volume hydrogen peroxide are added at the time of use. When 
applied to bleached hair for 20 minutes at 30.degree. C., the mixture 
imparts to it, after shampooing and rinsing, a medium olive-green colour. 
APPLICATION EXAMPLE NO. 3 
The following dyeing mixture is prepared: 
______________________________________ 
4-Amino-5-(.beta.-hydroxyethoxy)-1,2- 
methylenedioxybenzene hydrochloride 
0.584 g 
p-Phenylenediamine 0.27 g 
Oleyl alcohol polyglycerolated with 2 moles 
of glycerol 4.50 g 
Oleyl alcohol polyglycerolated with 4 moles 
of glycerol 4.50 g 
Ethomeen 0 12 -Armoon Hess Chemical company 
Ltd (oleylamine oxyethylenated with 12 moles 
of ethylene oxide) 4.50 g 
Comperlan KD - Henkel company 
(copra diethanolamide) 9.00 g 
Propylene glycol 4.00 g 
2-Butoxyethanol 8.00 g 
96.degree. ethanol 6.00 g 
Masquol DTPA - Protex company 
(pentasodium salt of diethylenetriamine- 
pentaacetic acid) 2.00 g 
Hydroquinone 0.15 g 
35.degree. Be sodium bisulphite solution 
1.30 g 
20% aqueous ammonia 10.00 g 
Water q.s. 100 g 
pH = 10.1 
______________________________________ 
100 g of 20-volume hydrogen peroxide are added at the time of use. When 
applied to bleached hair for 20 minutes at 30.degree. C., the mixture 
imparts to it, after shampooing and rinsing, a lime-green colour. 
APPLICATION EXAMPLE NO. 4 
The following dyeing mixture is prepared: 
______________________________________ 
4-(.beta.-hydroxyethyl)amino-5-methoxy-1,2- 
methylenedioxybenzene 0.53 g 
4-Amino-N--.beta.-methoxyethylaniline 
dihydrochloride 0.509 g 
Carbopol 934 - Goodrich Chemicals company 
3.00 g 
96.degree. alcohol 11.00 g 
2-Butoxyethanol 5.00 g 
Trimethylcetylammonium bromide 
2.00 g 
Trilon B 
(ethylenediaminetetraacetic acid) 
0.20 g 
20% aqueous ammonia 10.00 g 
35.degree. Be sodium bisulphite 
1.00 g 
Water q.s. 100 g 
pH = 9.6 
______________________________________ 
100 g of 20-volume hydrogen peroxide are added at the time of use. When 
applied to bleached hair for 20 minutes at 30.degree. C., the mixture 
imparts to it, after shampooing and rinsing, a pale olive-green colour. 
APPLICATION EXAMPLE NO. 5 
The following dyeing mixture is prepared: 
______________________________________ 
6-Amino-5-methoxy-2-methyl-2-propyl-1,3- 
benzodioxole hydrochloride 
1.30 g 
2,5-Diaminotoluene dihydrochloride 
0.97 g 
Cemulsol NP4 - Rhone-Poulenc 
(nonylphenol containing 4 moles of ethylene 
oxide) 21.00 g 
Cemulsol NP9 - Rhone-Poulenc 
(nonylphenol containing 9 moles of ethylene 
oxide) 24.00 g 
Oleic acid 4.00 g 
2-Butoxyethanol 3.00 g 
96.degree. ethanol 10.00 g 
Masquol DTPA - Protex company 
(pentasodium salt of diethylenetriamine- 
pentaacetic acid) 2.50 g 
35.degree. Be sodium bisulphite solution 
1.00 g 
20% aqueous ammonia 10.00 g 
Water q.s. 100 g 
pH = 10 
______________________________________ 
100 g of 20-volume hydrogen peroxide are added at the time of use. When 
applied to permanent-waved hair for 35 minutes at 30.degree. C., the 
mixture imparting to it, after shampooing and rinsing, a golden 
light-bronze colour. 
APPLICATION EXAMPLE NO. 6 
The following dyeing mixture is prepared: 
______________________________________ 
4-Amino-3-methoxyphenol 1.00 g 
4-Amino-5-methoxy-1,2-methylenedioxybenzene 
hydrochloride 1.30 g 
Carboxymethyl cellulose 2.00 g 
Ammonium lauryl sulphate 5.00 g 
Propylene glycol 8.00 g 
2-Butoxyethanol 8.00 g 
Masquol DTPA - Protex company 
(pentasodium salt of diethylenetriamine- 
pentaacetic acid) 2.00 g 
Ammonium acetate 1.00 g 
Thioglycolic acid 0.40 g 
20% aqueous ammonia 10.00 g 
Water q.s. 100 g 
pH = 11.5 
______________________________________ 
100 g of 20-volume hydrogen peroxide are added at the time of use. When 
applied to 90% naturally white hair for 30 minutes at 28.degree. C., the 
mixture imparts to it, after shampooing and rinsing, a green blond colour.