Bleaching and dyeing; fluid treatment and chemical modification – Dyeing involving animal-derived natural fiber material ,... – Hair dyeing
Reexamination Certificate
1998-10-22
2001-10-23
Hardee, John (Department: 1751)
Bleaching and dyeing; fluid treatment and chemical modification
Dyeing involving animal-derived natural fiber material ,...
Hair dyeing
C008S410000, C008S649000, C564S440000, C564S442000, C564S443000
Reexamination Certificate
active
06306179
ABSTRACT:
The present invention relates to a new method for the synthesis of 2-hydroxyalkyl-para-phenylenediamines which are substituted or unsubstituted at the 5-position of the benzene ring, new 2-hydroxyalkyl-para-phenylenediamines which are substituted or unsubstituted at the 5-position of the benzene ring, their use for the oxidation dyeing of keratinous fibers, the dyeing compositions containing them, as well as the methods of dyeing using them.
It is known to dye keratinous fibers, in particular human hair, with dyeing compositions containing appropriate oxidation dye precursors, in particular ortho- or para-phenylenediamines, ortho- or para-aminophenols, heterocyclic compounds such as diaminopyrazole derivatives, generally called oxidation bases. The oxidation dye precursors, or oxidation bases, are colorless or weakly colored compounds which, combined with suitable oxidizing agents, can give rise, by a process of oxidative condensation, to colored and coloring compounds.
It is also known that the shades obtained with these oxidation bases can be varied by combining them with couplers or color modifiers, the latter being chosen especially from aromatic meta-diamines, meta-aminophenols, meta-diphenols and certain heterocyclic compounds.
The variety of molecules used as regards oxidation bases and couplers allows a rich palette of colors to be obtained.
Among all the oxidation bases cited above, one family which is very widely used is that of the para-phenylenediamines. The para-phenylenediamines can be provided in the form of compounds which are variously substituted on the benzene ring, in particular in the form of 2-hydroxyalkyl-para-phenylenediamines exhibiting advantageous dyeing qualities.
The dyeing compositions containing these particular para-phenylenediamines and optionally one or more couplers indeed make it possible to obtain colors with a variety of shades, of the desired intensity, and exhibiting good behavior in relation to external agents (light, adverse weather conditions, washing, permanent waving, perspiration, rubbing).
FR-A-2,647,341 discloses 2-(2,5-diaminophenyl)ethanol and its use in oxidation coloration. DE-A-3,441,148, at page 9, discloses up to the compound produced by step 3 in the scheme below. The DE application, however, does not teach the reduction reaction shown in the scheme immediately following below.
The yields which appear in this reaction scheme relate to the compounds in which n=2.
The method of synthesis described in this prior art scheme has, however, a major disadvantage since the step (2) of nitration leads to a mixture of compounds nitrated at the 4-position and of compounds nitrated at the 5-position, and only a small portion of the starting acetylated 2-hydroxyalkylanilines is converted to compounds nitrated at the 4-position of the benzene ring (that is to say 8%, after separation of the compounds nitrated at the 5-position, for the compounds in which n=2). This low yield and the need to carry out a separation of the nitrated isomers are not acceptable at the industrial level.
Furthermore, this prior art method of synthesis does not make it possible to arrive at 2-hydroxyalkyl-para-phenylenediamines capable of having a substitution at the 5-position of the benzene ring.
It was during the search to overcome these problems that the applicant discovered the method which is the subject of the invention.
The first subject of the invention is therefore a new method for the synthesis of 2-hydroxyalkyl-para-phenylenediamines which are substituted or unsubstituted at the 5-position of the benzene ring and of their addition salts with an acid, characterized in that it comprises at least the following steps:
Step No. 1: the amine function at the 1-position of the benzene ring and the alcohol function at the 2-position of the benzene ring of a 2-hydroxyalkylaniline which is substituted at the 5-position of the benzene ring with a halogen atom or with a C
1
-C
6
alkyl radical are protected;
Step No. 2: a reaction of nitration at the 4-position of the benzene ring is carried out on the compound obtained in Step No. 1;
Step No. 3: the amine function at the 1-position of the benzene ring and the alcohol function at the 2-position of the benzene ring of the compound obtained in Step No. 2 are deprotected;
Step No. 4: a reaction of reduction of the nitro group at the 4-position is carried out on the compound obtained in Step No. 3, accompanied or otherwise by a dehalogenation in the case of a 5-halogenated compound.
During the first step, the amine and alcohol functions of the 2-hydroxyalkylaniline, at the 1- and 2-positions of the benzene ring respectively, can be protected by any radical capable of protecting an amine function or an alcohol function such as, for example, an alkylcarbonyl, alkylsulfonyl or phenylsulfonyl radical.
The method of synthesis of the invention can be summarized according to the following general synthesis scheme:
in which:
n is an integer from 1 to 4 inclusive;
Protec means a protecting group for the amine function and for the alcohol function;
R′ represents a halogen atom such as bromine, chlorine or fluorine, or a C
1
-C
6
alkyl radical;
R represents a hydrogen atom or has the same meanings as R′;
R
1
, R
2
, R
3
and R
4
, which are identical or different, designate a hydrogen atom, a radical: C
1
-C
6
alkyl, C
1
-C
6
monohydroxyalkyl, C
2
-C
6
polyhydroxyalkyl, C
1
-C
6
alkoxy-C
1
-C
6
alkyl, C
1
-C
6
aminoalkyl, mono- or dihydroxy(C
1
-C
6
alkyl)amino(C
1
-C
6
alkyl); (C
1
-C
6
mono- or dialkyl)amino(C
1
-C
6
alkyl); aminoalkyl whose amine is protected with a (C
1
-C
6
alkyl)carbonyl, carbamyl or (C
1
-C
6
alkyl)sulfonyl radical; C
1
-C
6
carboxyalkyl; C
1
-C
6
cyanoalkyl; C
1
-C
6
amidoalkyl; C
1
-C
6
trifluoroalkyl; C
1
-C
6
sulfonamidoalkyl; (C
1
-C
6
alkyl)carboxy(C
1
-C
6
alkyl); (C
1
-C
6
alkyl)sulfoxy(C
1
-C
6
alkyl); (C
1
-C
6
alkyl)sulfone(C
1
-C
6
alkyl); (C
1
-C
6
alkyl)keto(C
1
-C
6
alkyl); (C
1
-C
6
N-alkyl)amido(C
1
-C
6
alkyl) or (C
1
-C
6
N-alkyl)sulfonamido(C
1
-C
6
alkyl);
it being understood that at least one of the groups —NR
1
R
2
and —NR
3
R
4
designates an —NH
2
group.
According to the invention, the alkyl radicals may be linear or branched.
The method of synthesis in accordance with the invention is essentially distinguishable from that of the prior art by the fact that the starting compound is a 2-hydroxyalkylaniline comprising a substituent at the 5-position of the benzene ring, which has the effect of orienting the nitration reaction to the 4-position of the benzene ring and, consequently, of considerably increasing the yield of the intermediate nitration reaction (Step No. 2).
By way of comparison, the applicant, in parallel with the prior art method of synthesis described above for the compounds in which n=2, carried out the synthesis of 2-&bgr;-hydroxyethyl-para-phenylenediamine with a good overall yield from 5-chloro-2-&bgr;-hydroxyethylaniline. The yield obtained after carrying out Steps 2 and 3 as described above for the general method of synthesis in accordance with the invention was 86.4%, instead of 8% for the prior art method of synthesis.
The 2-hydroxyalkyl-para-phenylenediamines which are substituted or unsubstituted at the 5-position on the benzene ring, as well as their addition salts with an acid which can be obtained according to the method in accordance with the invention, preferably correspond to the following formula (I):
in which:
n is an integer from 1 to 4 inclusive;
R designates a hydrogen atom or a halogen atom such as bromine, chlorine or fluorine, a C
1
-C
6
alkyl radical or a group OZ or SZ in which Z designates a C
1
-C
6
alkyl, C
1
-C
6
monohydroxyalkyl or C
2
-C
6
polyhydroxyalkyl radical; R
1
, R
2
, R
3
and R
4
, which are identical or different, designate a hydrogen atom, a radical: C
1
-C
6
alkyl, C
1
-C
6
monohydroxyalkyl, C
2
-C
6
polyhydroxyalkyl, C
1
-C
6
alkoxy-C
1
-C
6
alkyl, C
1
-C
6
aminoalkyl, mono- or dihydroxy(C
1
-C
6
alkyl)amino(C
1
-C
6
alkyl); (C
1
-C
6
mono- o
Genet Alain
Lagrange Alain
Finnegan Henderson Farabow Garrett & Dunner L.L.P.
Hardee John
L'Oreal (S.A.)
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