# US 10,245,223 B2 · Use for dyeing keratin fibres of a compound of azomethine type bearing a pyrazolopyridine unit

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- Number: US 10,245,223 B2
- Document ID: US10245223B2
- Status: Granted
- Kind: B2
- Application number: 15/536,739
- Filed: 2015-12-17
- Published: 2017-12-07
- Granted: 2019-04-02
- Earliest claimed: 2014-12-19
- Assignees: L'oreal
- Applicants: L'oreal
- Inventors: Aziz Fadli
- Web page: https://patentgrep.com/patent/US10245223B2

## CPC

- A61K 8/492: {having condensed rings, e.g. indol}
- A61K 8/22: Peroxides; Oxygen; Ozone
- A61Q 5/065: {Preparations for temporary colouring the hair, e.g. direct dyes}
- C07D 471/04: Ortho-condensed systems
- A61K: PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES (devices or methods specially adapted for bringing pharmaceutical products into particular physical or administering forms A61J3/00; chemical aspects of, or use of materials for deodorisation of air, for disinfection or sterilisation, or for bandages, dressings, absorbent pads or surgical articles A61L; soap compositions C11D)
- A61Q: SPECIFIC USE OF COSMETICS OR SIMILAR TOILETRY PREPARATIONS
- C07D: HETEROCYCLIC COMPOUNDS (macromolecular compounds C08)

## Abstract

The invention relates to a compound chosen from dyes of azomethine type bearing a pyrazolopyridine unit of formula (I) and the leuco forms thereof of formula (II) below, and also the optical isomers and geometrical isomers thereof, the tautomers thereof, the addition salts thereof with an acid or a base, and the solvates thereof. The invention also relates to the use of these particular compounds for dyeing keratin fibers.

## Claims

### Claim 1

A compound chosen from dyes of azomethine type bearing a pyrazolopyridine unit of formula (I), leuco forms of formula (II) thereof, optical isomers and geometrical isomers thereof, tautomers thereof, addition salts thereof with an acid or a base, and solvates or hydrates thereof:
wherein in formulae (I) and (II), independently:
Z1 represents an oxygen atom or a group —NR6—; and when Z1 represents —NR6—, then R1 and R6 may form, together with the nitrogen atom to which they are attached, an optionally substituted, 5- to 8-membered, saturated, unsaturated or aromatic heterocycle;
R1 and R6 each independently represent:
a hydrogen atom;
a C1-C10 alkyl radical optionally interrupted with one or more non-adjacent heteroatoms, and/or optionally substituted, with one or more groups chosen from i) hydroxyl, ii) optionally substituted 5- to 8-membered, saturated, unsaturated or aromatic (hetero)cycle, iii) —N(R′)R″, iv) —N+R′R″R′″ with R′, R″ and R′″ each independently representing a C1-C6 alkyl group; or
an optionally substituted, saturated, unsaturated or aromatic 5- to 8-membered (hetero)cycle;
R2, R3, R4 and R5 each independently represent:
a hydrogen atom;
an optionally substituted C1-C4 alkyl radical; or
a group chosen from —NH2, —N(H)R10, —N(R11)—R12, —OH and —OR9, with R9 and R10 representing an optionally substituted, linear or branched C1-C6 alkyl, R11 and R12, which may be identical or different, representing an optionally substituted, linear or branched C1-C6 alkyl, it being optional for R11 and R12 to form, together with the nitrogen atom to which they are attached, a saturated, unsaturated or aromatic 5- to 8-membered heterocycle optionally containing one or more other heteroatoms or groups chosen from oxygen and nitrogen, the heterocycle being optionally substituted;
R2, R3, R4 and R5 may form, in pairs, with adjacent radicals, an optionally substituted, saturated or unsaturated or aromatic (hetero)cycle;
R′2 and R′3, which may be identical or different, represent:
a hydrogen atom;
a C1-C6 alkyl radical, optionally substituted with one or more hydroxyl radicals;
a C1-C6 alkyl carboxylate radical; or
a carboxyl radical;
R′ represents:
a hydrogen atom;
a C1-C6 alkyl radical;
R′6 represents:
a hydrogen atom;
a halogen atom;
a linear or branched C1-C10 alkyl radical, optionally interrupted with one or more non-adjacent oxygen atoms and/or one or more non-adjacent divalent groups —N(R′9)— and optionally substituted with one or more radicals, which may be identical or different, chosen from —OH and —N(R′7)R′8;
a carboxyl radical;
a C1-C10 alkyl carboxylate;
a radical CONR′7R′8;
a C1-C10 alkoxy radical or a C1-C10 (poly)hydroxyalkoxy radical;
a (poly)(C1-C10 alkoxy)-(C1-C10 alkoxy) radical; or
a radical —O-Ak-N(R′9)R′10 in which Ak is a linear C1-C8 or branched C3-C8 divalent alkylene radical, optionally interrupted with one or more oxygen atoms and/or non-adjacent divalent groups —N(R′7)—;
R′7 and R′8, which may be identical or different, represent:
a hydrogen atom; or
a C1-C8 alkyl radical optionally substituted with one or more hydroxyl radicals;
R′9 and R′10, which may be identical or different, represent i) a linear or branched C1-C6 alkyl radical, ii) a C2-C6 alkenyl radical or iii) a C2-C6 alkynyl radical;
R′9 and R′10 may form, with the nitrogen that bears them, a saturated or unsaturated 5- to 8-membered heterocycle, one of the chain members optionally being an oxygen atom or a nitrogen atom, or a divalent radical —N(R′11)— with R′11 representing a hydrogen atom or a C1-C4 alkyl group, optionally substituted with one or more radicals chosen from —OH, —N(R′7)R′8 and C1-C4 alkyl;
R″ represents:
a hydrogen atom; or
a linear or branched C1-C10 alkyl radical, optionally interrupted with an oxygen atom or a divalent group —N(R)— with R representing a hydrogen atom or a C1-C4 alkyl group;
wherein when the compound of formula (I) or (II) is positively charged, then it comprises as many anionic counterions as cationic charges to achieve the electrical neutrality of the molecule.

### Claim 2 (depends on 1)

The compound according to claim 1, wherein Z1 represents an oxygen atom or an —N(H)— radical.

### Claim 3 (depends on 1)

The compound according to claim 1, wherein R1 represents a C1-C6 alkyl radical, a C1-C6 alkyl radical substituted with a hydroxyl group, a C1-C6 alkyl radical substituted with a (di)(C1-C4 alkyl)amino, or a C1-C6 alkyl radical substituted with a nitrogenous heterocycle chosen from imidazolyl, pyrrolidinyl, piperidyl, morpholinyl and piperazinyl.

### Claim 4 (depends on 1)

The compound according to claim 1, wherein R2, R3, R4 and R5 independently represent a hydrogen atom or a C1-C4 alkyl radical.

### Claim 5 (depends on 1)

The compound according to claim 1, wherein R′2 and R′3 independently represent a hydrogen atom or a C1-C4 alkyl radical optionally substituted with one or more hydroxyl radicals.

### Claim 6 (depends on 1)

The compound according to claim 1, wherein R′ represents a hydrogen atom or a C1-C4 alkyl radical.

### Claim 7 (depends on 1)

The compound according to claim 1, wherein R′6 represents i) a hydrogen atom; ii) a linear or branched C1-C6 alkyl radical, optionally substituted with a hydroxyl radical; iii) a C1-C6 hydroxyalkoxy radical; or iv) a radical —O-Ak-NR′9R′10 in which Ak denotes a linear divalent C1-C8 alkylene radical with:
R′9 and R′10 independently denoting a saturated, linear or branched C1-C4 alkyl radical; or alternatively
R′9 and R′10 form, together with the nitrogen atom that bears them, a heterocycle chosen from pyrrolidinyl, morpholinyl, imidazolyl, piperazinyl and piperidyl, said heterocycle being optionally substituted with one or more radicals chosen from —OH and C1-C4 alkyl.

### Claim 8 (depends on 1)

The compound according to claim 1, wherein R″ represents a hydrogen atom or a linear C1-C6 alkyl radical.

### Claim 9 (depends on 1)

The compound according to claim 1, chosen from the compounds of formulae (I) and (II), and also the optical isomer, geometrical isomer and tautomer forms thereof, the addition salts thereof with an acid or a base, and the solvates or hydrates thereof:
wherein in formulae (I) and (II):
R1=—CH2CH2OH, —CH2CH2N(CH3)2, —CH2CH2CH2N(CH3)2 when Z1=O,
R1=—CH2CH2N(CH3)2, —CH2CH2CH2N(CH3)2 when Z1=—N(R6)— and R6 represents a hydrogen atom,
R′, R2, R3, R4 and R5 denote a hydrogen atom,
R′2, R′3 and R″, which may be identical or different, denote a hydrogen atom or a methyl radical, and
R′6 denotes a hydrogen atom or a methyl, ethyl, —O—(CH2)2—OH, —O—(CH2)3—OH, —O—(CH2)2-Het or —O—(CH2)3-Het radical with Het representing a pyrrolidinyl or morpholino or imidazolyl or N-methylpiperazino or piperidino group.

### Claim 10 (depends on 1)

A composition for dyeing keratin fibers comprising, in a medium that is suitable for dyeing, at least one compound as defined in claim 1.

### Claim 11 (depends on 10)

The composition according to claim 10, wherein the compound are present in an amount ranging from 0.01% to 15% by weight relative to the total weight of the composition.

### Claim 12 (depends on 10)

The composition according to claim 10, wherein it also comprises one or more oxidizing agents.

### Claim 13 (depends on 10)

A process for dyeing keratin fibers, wherein a composition according to claim 10 is applied to the keratin fibers.

### Claim 14 (depends on 1)

A process for preparing compounds of formulae (I) or (II) as defined in claim 1, according to the following scheme:
comprising:
in a first stage, in reacting a pyrazolo[1,5-a]pyridine compound A1 comprising an amino group in position 3 with an indole compound A2 which is free in position 5 and comprising in position 4 an amino group,
wherein this reaction is optionally performed i) in a polar protic solvent or a mixture of water/C1-C10 alcohol ii) and/or in the presence of one or more basifying agents, chosen from sodium hydroxide, potassium hydroxide, and/or a mineral carbonate iii) and/or in the presence of a chemical oxidizing agent iv) and/or at a temperature between room temperature, i.e. 25° C., and the reflux temperature of the solvent, and
in a second stage, in maintaining the reaction medium under stirring for a time ranging from 5 minutes and 48 hours;
wherein the reaction product (I) is then optionally purified;
and further optionally wherein when compound (I) is then purified, compound (I) once purified is reduced using a reducing agent, or using transition metals or alternatively by reduction with hydrides or borohydrides, or with thioglycolic acid derivatives, to give the leuco compound (II); optionally followed by a step of purification via a standard technique to give the leuco compound (II);
and further optionally wherein when compound (I) is not then purified, compound (I) is reduced using a reducing agent as mentioned previously to give the leuco compound (II), optionally followed by a step of purification.