Para-phenylenediamine bases with cationic heterocycles, and the use of same for oxidation dyeing keratin fibres

A compound chosen from compounds of formula (I) below:

• addition salts thereof with organic or inorganic acids or bases, optical isomers thereof, geometric isomers thereof, tautomers thereof, mesomers thereof, or solvates thereof:
• wherein:
• ALK represents a linear or branched alkylene chain comprising from 3 to 8 carbon atoms which is optionally substituted;
• HET+ represents a saturated or unsaturated, aromatic or non-aromatic cationic heterocyclic group, which is optionally substituted, comprising from 5 to 10 ring members, and comprising one or more ammonium groups;
• and
• An−, which is present or absent, represents an inorganic or organic anionic counterion, ensuring the electrical neutrality of the molecule.

A method of oxidation dyeing of keratin fibers comprising applying to the keratin fibers a compound chosen from compounds of formula (I) below:

• addition salts thereof with organic or inorganic acids or bases, optical isomers thereof, geometric isomers thereof, tautomers thereof, mesomers thereof, or solvates thereof:
• wherein:
• ALK represents a linear or branched alkylene chain comprising from 3 to 8 carbon atoms which is optionally substituted;
• HET+ represents a saturated or unsaturated, aromatic or non-aromatic cationic heterocyclic group, which is optionally substituted, comprising from 5 to 10 ring members, and comprising one or more ammonium groups;
• and
• An−, which is present or absent, represents an inorganic or organic anionic counterion, ensuring the electrical neutrality of the molecule.

A process for the preparation of a compound of formula (I) below:

• wherein:
• ALK represents a linear or branched alkylene chain comprising from 3 to 8 carbon atoms which is optionally substituted;
• HET+ represents a saturated or unsaturated, aromatic or non-aromatic cationic heterocyclic group, which is optionally substituted, comprising from 5 to 10 ring members, and comprising one or more ammonium groups;
• and
• An−, which is present or absent, represents an inorganic or organic anionic counterion, ensuring the electrical neutrality of the molecule;
• comprising:
• wherein Nu represents a Nucleophilic group comprising the cationic group HET+ , ALK−1 represents a linear or branched alkylene chain comprising from 2 to 7 carbon atoms which is optionally substituted, LG represents a leaving group, and PG represents a protecting group resistant to the reaction conditions throughout the synthesis up to the deprotection step;
• which process consists:
• either, in a first step i), in reducing the bicyclic amido derivative (a) in order to result in the 4-nitroaniline compound substituted in the a position with respect to the amino by a hydroxypropyl group (b);
• then, in a second step ii), in transforming the hydroxyl group of the compound (b) into a leaving group LG such as halogen, triflate, tosylate, mesylate, via a (C1-C6)alkylsulfonyl halide, step ii) performed in a polar or non-polar protic solvent;
• then, in a third step iii), in substituting the leaving group LG with a cationic group HET+ ;
• then, in a fourth step iv), in reducing the nitro compound (d) by catalytic hydrogenation, in order to result in the compound of formula (I);
• or, in a second step v), in reducing the 4-nitroaniline derivative substituted in the a position with respect to the amino by a hydroxypropyl group (b), by catalytic hydrogenation, in order to result in the 1,4-phenylenediamine compound substituted in the a position with respect to the amino by a hydroxypropyl group (e), then, in a third step vi), in protecting the amino groups with a protecting group, via a reagent such as R—C(Ya)—Ya—C(Ya)—R′, with R and R′, which are identical or different, representing a (C1-C6)alkyl group and Ya, which is identical or different, representing an oxygen or sulfur atom;
• followed by steps vii) and viii) of substitutions 1 and 2 under the same conditions as during steps ii) and iii), in order to result in the compounds (c) and (d) respectively, and then the compound (h) is deprotected, in an organic solvent.