GB2168371A - New 2-nitro-4-amino anilines useful as hair dyes - Google Patents

Abstract

2-Nitro-4-amino-6-hydroxyalkylanilines of formula (I): <IMAGE> wherein: X is an unsubstituted or a mono- or polyhydroxy substituted branched or unbranched alkylene containing 2 to 6 carbon atoms; R1 and R2 are the same or different and each is hydrogen (C1-4)-alkyl, a mono or polyhydroxy-(C1-4)-alkyl, amino-(C1-4)-alkyl or a mono- or disubstituted amino-(C1-4)-alkyl wherein each substituent is (C1-4)-alkyl, or a mono- or polyhydroxy-(C1-4)-alkyl or at least one substituent and the nitrogen atom form part of a heterocyclic system; R' is hydrogen or C1-4 alkyl; or cosmetically acceptable salts of such compounds are useful in dyeing keratinous fibres, particularly human hair.

Description

SPECIFICATION New 2-nitro-4-amino anilines The present invention relates to new 2-nitro-4-amino-6-hydroxyalkaylanilines, the process for preparation thereof and their use in dyeing keratinous fibres, and more especially human hair.

It is well known that, to perform direct dyeing on hair or endow the latter with complementary glints in the case of oxidation dyeing, nitro derivatives of the benzene series can be used. The use has already been recommended of nitro-para-phenylenediamines in which the nitrogen atoms are mono-or disubstituted, both in direct dyeing and in oxidation dyeing.

Unfortunately, it was found that, in general these nitro-para-phenylenediamines possessed insufficient stability to adverse weather conditions and to washing. The applicant hence sought new nitro dyes showing better stability to adverse weather conditions and to washing, and has consequently discovered the compounds of formula (I):

in which: X denotes a branched or unbranched alkylene radical containing 2 to 6 carbon atoms, one of these atoms optionally being able to be substituted with one or more hydroxyl radicals;R1 and R2 denote, independently of each other, a hydrogen atom, an alkyl or a mono- or polyhydroxyalkyl radical or an aminoalkyl radical in which the amine group can be mono- or disubstituted with an alkyl or a mono- or polyhydroxyalkyl radical, the nitrogen atom also being able to form part of a heterocyclic system, and the alkyl radical containing 1 to 4 carbon atoms; R' denotes a hydrogen atom or a C, to C4 alkyl radical.

The subject of the present invention is hence the new 2-nitro-4-amino-6-hydroxyalkylanilines of formula (I) given above, as well as the cosmetically acceptable salts thereof, By way of preferred radicals X, ethylene, propylene, 1,1-dimethylethylene, 1,2-dimethylethylene and 1,1,2-trimethylethylene may be mentioned.

By way of radicals R, and R2 which are more especially preferred according to the invention, hydrogen and methyl, ethyl, n-propyl, ss-hydroxyethyl, By-hydroxypropyl,ss,-dihydroxypropyl,aminoethyl and ss-di- ethylaminoethyl radicals may be mentioned.

The radicals R' which are preferred according to the invention are hydrogen and the methyl radical.

Preferred compounds of formula (I) according to the invention are the following: - 2-(2,5-diamino-3-nitrophenyl)ethanol; - 1-(2,5-diamino-3-nitrophenyl)-2-propanol; - 1 -[2-amino-5-( ss-hydroxyethyl)amino-3-nitro-phenyl]-2-propanol, as well as the salts thereof.

The subject of the present invention is also a process for preparing the compounds of formula (I).

The 2-nitro-4-amino-6-hydroxyalkylanilines of formula (I), according to the invention, are prepared according to a process which consists in reacting an aqueous ammonia solution with a heterocyclic compound of formula (IV) below, and then performing selective reduction of the 2,4-dinitro-6hydroxyalkylaniline of formula (III) obtained, to obtain a 2-nitro-4-amino-6-hydroxyalkylaniline of formula (II), which is then optionally subjected to a conventional chemical alkylation, hydroxyalkylation or aminoalkylation process to obtain the final compound of formula (I). The scheme for the process is as follows:

R' and X having the meaning given above.

This process enables excellent yields of the final compound of formula (II) or (I) to be obtained.

The reaction of ammonia with the heterocyclic compound of formula (IV) is performed at a temperature between 20 and 120"C, optionally under pressure and optionally in the presence of polar protic solvents such as water, alcohols, glycols or glycol ethers, or polar aprotic solvents such as formamide, dimethylformamide, dioxane or tetrahydrofuran.

The selective reduction of the compound of formula (III) is performed by transfer of hydrogen from cyclohexene to the compound (III), Pd/C being used as catalyst, in the presence of alcohol, water and an inorganic acid such as concentrated hydrochloric acid.

The compounds (Il) can also be obtained by selective reduction of the compounds (III) in a polar solvent such as a C1-Cs alcohol, by introduction of hydrogen in the presence of a hydrogenation catalyst such as Pd/C and an aqueous solution of an inorganic acid such as HCI, H2SO4 or HsPO4, at a temperature between 20 and 90"C. This process is described in French Patent 1,303,215.

Compounds of formula (IV) are obtained by nitration of the compounds of formula (V) below:

in which X and R' have the meanings given above.

The compounds of formula (V) are known.

The nitration is performed by adding the compound (V) to fuming nitric acid at a temperature between 30 and 35C according to G. CHATELUS, Ann. Chim. 4, 505-547 (1949), or by adding the compound (V) to a mixture of concentrated sulphuric and nitric acids at a temperature in the region of 5"C according to Charles D. HURD, Rostyslaw DOWBENKO, JACS 80, p. 4711-14 (1958). The di-nitro compound (IV) is then isolated by diluting the reaction medium with water.

The compounds of formula (IV) in which X denotes an ethylene, propylene, 1,1-dimethylene, 1,2-dimethyl-ethylene or 1,1,2-trimethylethylene radical are known.

The alkylation, hydroxyalkylation or aminoalkylation by which the desired compound of formula (I) is obtained from the compound of formula (II) may be effected according to the processes described in French Patents 2,348,911, 2,497,662, and 2,492,370 (L'OREAL) or by other well known methods.

The subject of the present invention is also a dyeing composition for keratinous fibres, and more especially for human hair, containing a 2-nitro-4-amino-6-hydroxyalkylaniline of formula (I) above, as well as a process for dyeing keratinous fibres, and more especially human hair, using the said dyeing composition.

The dyeing compositions according to the invention contain, in a solvent medium, at least one compound corresponding to the formula (I), or one of its cosmetically acceptable salts, and can be used for direct dyeing of keratinous fibres or for oxidation dyeing of these fibres, in which case the compounds of formula (I) confer glints which are complimentary to the basic coloration obtained by oxidative development of precursors of oxidation dyes.

These compositions contain the compounds according to the invention in proportions of between 0.001 and 5% by weight, and preferably between 0.05 and 2% by weight, relative to the total weight of the composition.

The solvent medium is preferably a cosmetic vehicle generally consisting of water, but organic solvents can also be added into the compositions to solubilise compounds which would not be sufficiently soluble in water. Among these solvents, there may be mentioned lower alkanols such as ethanol and isopropanol, aromatic alcohols such as benzyl alcohol, polyols such as glycerol, glycols or glycol ethers such as 2-butoxyethanol or 2-ethoxyethanol, ethylene glycol and propylene glycol, diethylene glycol monomethyl ether and monoethyl ether and also similar products and mixtures thereof. These solvents are preferably present in proportions ranging from 1 to 75% by weight, and especially from 5 to 50% by weight, relative to the total weight of the composition.

These compositions can contain anionic, cationic, nonionic or amphoteric surfactants, or mixtures thereof. These surfactants are present in the compositions of the invention in proportions of between 0.5 and 55% by weight, and preferably between 4 and 40% by weight, relative to the total weight of the composition.

The compositions can be thickened, preferably with compounds chosen from sodium alginate, gum arabic, cellulose derivatives such as methylcellulose, hydroxyethylcellulose, hydroxypropylmethylcellulose and carboxymethylcellulose and various polymers which have the function of a thickener such as, more especially, acrylic acid derivatives. it is also possible to use inorganic thickening agents such as bentonite. These thickening agents are preferably present in proportions of between 0.5 and 10% by weight, and especially between 0.5 and 2% by weight, relative to the total weight of the composition.

The compositions according to the invention can also contain various adjuvants customarily used in dyeing compositions for the hair, and especially penetrants, dispersants, sequestering agents, film-forming agents, buffers and perfumes.

These compositions can take various forms such as liquid, cream or gel form, or any other form suitable for carrying out hair dyeing. They can in addition be packaged in aerosol containers in the presence of a propellant.

The pH of these dyeing compositions can be between 3 and 11.5, and preferably between 5 and 11.5. It is adjusted to the desired value using an alkalinising agent such as ammonia solution, sodium carbonate, potassium carbonate or ammonium carbonate, sodium hydroxide or potassium hydroxide, alkanolamines such as mono-, di- or tri-ethanolamine, 2-amino-2-methyl-1-propanol, 2-amino-2-methyl-1,3-propanediol, or alkylamines such as ethylamine or tri-ethylamine, or using an acidifying agent such as phosphoric, hydrochloric, tartaric, acetic, lactic or citric acid.

When the compositions are intended for use in a process for direct dyeing of hair, they can contain, in addition to the compounds according to the invention, other direct dyes such as azo or anthraquinone dyes, for example 1,4,5,8-tetraaminoanthraquinone, indophenols, indoanilines and nitro dyes of the ben zene series other than the compounds of formula (I).

The concentrations of these direct dyes other than the dyes of formula (I) can be between 0.001 and 5% by weight relative to the total weight of the composition.

These compositions, employed in a direct dyeing process, are applied on the keratinous fibres for an exposure time which varies from 5 to 50 minutes, the fibres are then rinsed, optionally washed with shampoo, rinsed again and dried.

The compositions according to the invention can also be employed in the form of hair setting lotions intended at one and the same time to endow the hair with a light coloration or with glints, and to im prove the shape-retention of the set. In this case, they take the form of aqueous, alcoholic or hydroalco holic solutions containing at least one cosmetic resin, and they are applied on damp hair which has been washed and rinsed beforehand and which is optionally coiled and then dried.

The cosmetic resins which are used in the setting lotions can be, in particular, polyvinylpyrrolidone, crotonic acid/vinyl acetate, vinylpyrrolidone/vinyl acetate, maleic anhydride/butyl vinyl ether and maleic anhydride/methyl vinyl ether copolymers, as well as any other cationic, anionic, non ionic or amphoteric polymer customarily used in this type of composition. These cosmetic resins participate in the compositions of the invention in the proportion of 0.5 to 4% by weight, and preferably from 1 to 3% by weight, based on the total weight of the composition.

When the compositions according to the invention constitute oxidation dyes, involving development with an oxidising agent, the compounds of formula (I) according to the invention are mainly used for the purpose of contributing glints to the final dyeing.

These compositions then contain, in combination with at least one nitro dye of formula (I) and optionally other direct dyes, oxidation dye precursors.

The compositions can contain, for example, para-phenylenediamines such as: para-phenylenediamine, para-tolylenediamine, 2-chloro-para-phenylenediamine, 2,6-di-methyl-para-phenylenediamine, 2,6-di methyl-3-methoxy-para-phenylenediamine, N-(ss-methoxyethyl)-para-phenylenedia mine, N,N-bis(ss-hy- droxyethyl)-para-phenylenediamine, 4-[N-ethyl-N-(carbamylmethyl)amino]aniline and also the salts thereof.

They can also contain para-aminophenols, for example: para-aminophenol, N-methyl-para-aminophenol, 2-chloro-4-aminophenol, 3-chloro-4-aminophenol, 2-methyl-4-aminophenol and the salts thereof.

They can also contain orthoaminophenol.

They can also contain heterocyclic derivatives, for example: 2,5-diaminopyridine and 7-aminobenzomorpholine.

The compositions according to the invention can contain, in combination with the oxidation dye precursors, couplers which are well-known in the state of the art.

By way of couplers, there may be mentioned, in particular: meta-diphenols, meta-aminophenols and the salts thereof, meta-phenylenediamines and the salts thereof, meta-acylaminophenols, meta-ureidophenols and meta-carbalkoxyaminophenols.

As other couplers which can be used in the compositions according to the invention, there may finally be mentioned: a-naphthol, couplers possessing an active methylene group such as diketo compounds and pyrazolones, and heterocyclic couplers derived from pyridine and benzomorpholine.

These compositions contain, in addition to the oxidation dye precursors, reducing agents present in proportions of between 0.05 and 3% by weight relative to the total weight of the composition.

The oxidation dye precursors can be used, in the compositions of the invention, at concentrations of between 0.001 and 5% by weight, and preferably between 0.03 and 2% by weight, based on the total weight of the composition. The couplers can also be present in proportions of between 0.001 and 5% by weight, and preferably between 0.015 and 2% by weight. The pH of these oxidation dyeing compositions is preferably between 7 and 11.5, and is adjusted using alkalinising agents defined above.

The process of dyeing the keratinous fibres, especially human hair, employing development by an oxidising agent, consists in applying on the hair the dyeing composition containing both a dye according to the invention and dye precursors. The development of the coloration can then be accomplished slowly in the presence of the oxygen in the air, but a chemical development system is preferably used, this most frequently being chosen from hydrogen peroxide, urea peroxide and persalts. A solution of "20 volumes" hydrogen peroxide is used in particular.

When the composition with the oxidising agent has been applied on the keratinous fibres, it is left in place for 10 to 50 minutes, preferably 15 to 30 minutes, after which the keratinous fibres are rinsed, optionally washed with shampoo, rinsed again and dried.

The examples which follow are intended to illustrate the invention without being limitative in nature.

Example 1 Preparation of 2-(2,5-diamino-3-nitrophenyl)ethanol

1st stage Preparation of 2-(2-amino-3,5-dinitrophenyl)ethanol 0.17 Mole (35.7 g) of 2,3-dihydro-5,7-dinitrobenzofuran, prepared according to Chatelus Ann. Chim.

[12], 4,505-547 (1949) is suspended in 350 ml of 20% strength ammonia solution and 220 ml of formamide.

After 8 hours' heating at 1100C, a further 100 ml of 20% strength ammonia solution are added. Heating is maintained for 4 hours. When the reaction medium is cooled, the expected product precipitates.

After being drained, washed with ice-cold water until neutral and dried under vacuum, 0.13 mole (30.3 g) of a product melting at 1510C is obtained, and this is recrystallized from dioxane.

Analysis of the product gives the following results: Analysis Calculated for Found C8H8N305 %C 42.29 42.24 %H 3.99 3.91 %N 18.50 18.60 35.21 35.14 2nd stage Preparation of 2-(2,5-diamino-3-nitrophenyl)ethanol To a suspension of 15.7 g of Pd/C (containing 10% Pd) in 290 ml of absolute ethanol to which 35 ml of concentrated hydrochloric acid and 64 ml of cyclohexene have been added, 0.141 mole (32 g) of 2-(2amino-3,5-dinitro-phenyl)ethanol is added. After 1 h 45 min of heating under reflux, the reaction medium is filtered hot to remove the catalyst. The filtrate is evaporated to dryness under vacuum and the dry extract, after being washed with absolute ethanol, is solubilised hot in water. 15 ml of 20% strength ammonia solution are added. When the mixture is cooled a red precipitate of the expected product is obtained, and this, after being drained, is recrystallized from Methyl Cellosolve. After being dried, the product melts at 1900C.

Molecular mass calculated for CSH1,N303: 197.

Molecular mass found by potentiometric assay in acetic acid using perchloric acid: 199.5.

Analysis of the product obtained gives the following results: Analysis Calculated for Found Cslliill,Os %C 48.72 48.88 %H 5.62 5.67 21.31 21.33 24.34 24.60 Example 2 Preparation of 1-(2,5-diamino-3-nitrophenyl)-2-propanol

1st stage Preparation of 1-(2-amino-3,5-dinitrophenyl)-2-propano 0.39 Mole (88 g) of 2,3-dihydro-5,7-dinitro-2-methylbenzofuran, prepared according to J.A.C.S. 80 p.

4711-4714 (1958), is suspended in 1.1 litre of 20% strength ammonia solution and 600 ml of Methyl Cellosolve. After 18 hours' heating at 70"C, the reaction mixture is cooled. The precipitate formed is drained and, after being made into a paste in water until neutral and then dried under vacuum, is recrystallized from 170 ml of dioxane. After being dried under vacuum, 0.30 mole (72 g) of the expected product is obtained; it melts at 1770C.

Analysis gives the following results: Analysis Calculated for Found C0lliiNOo %C 44.81 44.87 4.60 4.62 %N 17.42 17.45 %O 33.17 33.08 2nd stage Preparation of 1-(2,5-diamino-3-nitrophenyl)-2-propanol To a suspension of 5.6 g of Pd/C (containing 10% Pd) in 100 ml of absolute ethanol to which 12.5 ml of concentrated hydrochloric acid and 23 ml of cyclohexene have been added, 0.05 mole (12.05 g) of 1-(2 amino-3,5-dinitrophenyl)-2-propanol is added. After 3 hours' heating under reflux, the reaction medium is filtered hot to remove the catalyst.The filtrate is evaporated to dryness, and the dry extract is made into a paste in an ethanol/ethyl ether mixture and then solubilised hot in the minimum of water. 15 ml of 20% strength ammonia solution are added in order to displace the hydrochloride. The expected product precipitates. After being drained, washed with water and recrystallized from 96" strength ethanol, it melts at 168"C.

Molecular mass calculated for C0H13N3O3: 211 Molecular mass found by potentiometric assay in acetic acid using perchloric acid: 210.

Analysis of the product obtained gives the following results: Analysis Calculated for Found CgH13N303 %C 51.17 51.31 %H 6.20 6.21 %N 19.90 20.03 22.73 22.66 Example 3 Preparation of 1-l2-amino-S-r-hydroxyethyl)amino-3-nitrophenyly-2-propanol

1st stage Preparation of t3-chloro ethyl f4-amino-5-((3-h ydroxyprop yl)-3-nitrophenyljcarbamate 0.07 Mole (14.8 g) of 1-(2,5-diamino-3-nitrophenyl)-2-propanol, obtained in Preparation Example 2, is dissolved in 59 ml of dioxane to which 22 ml of water have been added. 0.0385 Mole (5.3 g) of potassium carbonate is added. The temperature is raised to 900C, and then 0.077 mole (11 g) -chloroethyl chloroformate is then introduced in small portions with stirring.When the addition is complete, the reaction mixture is poured onto 400 g of water/ice mixture. The expected product precipitates; after being drained and dried under vacuum, 21.8 g of the expected product are obtained. It melts at 115"C.

2nd stage Preparation of N-[4-amino-5-(ss-hydroxypropyl)-3-nitrophenyl] oxazolidone 0.056 Mole (17.8 g) of ss-chloroethyl [4-amino-5-(ss-hydroxypropyl)-3-nitrophenyl]carbamate is suspended in 107 ml of 96" strength alcohol. 12 ml of a solution of sodium methylate at 30% strength in methanol are added dropwise, the temperature being maintained at 10 C. After being drained and made into a paste in water, 0.041 mole (11.6 g) of the expected product is obtained.

3rd stage Preparation of 1-/2-amino-5-(-hycroxyeth yl)-amino-3-nitropnenylj-2-propanol 0.041 Mole (11.5 g) of N-[4-amino-5-(p-hydroxy-prnpyl) -3-nitrophenyl]oxazolidone is introduced into 46 mlof 96" strength alcohol. The temperature is raised to 85"C and 8.2 ml of 10 N sodium hydroxide solution is poured in dropwise. Heating is maintained for 15 minutes after the addition is complete. After filtration, the filtrate is evaporated to dryness and the residue is then taken up with 40 ml of water. The expected product crystallizes; after recrystallization from water, it melts at 1300C.

Molecular mass calculated for C,1H,7N304: 255 Molecular mass found by potentiometric assay in acetic acid using perchloric acid: 256.

Analysis of the product obtained gives the following results: Analysis Calculated for Found C1,H,7N304 %C 51.75 51.80 %H 6.71 6.70 %N 16.46 16.62 25.07 25.18 Example 4 The following dyeing composition is prepared: 2-(2,5-Diamino-3-nitrophenyl)ethanol 0.54 g 2-Butoxyethanol 15 9 CELLOSIZE WP 03 2 g (Tallow alkyl)dimethylhydroxyethylammonium chloride 2g Monoethanolamine in 20% strength aqueous solution 1g Water q.s. 100g pH 9.8 When applied on hair for 15 minutes at 30"C, this mixture endows it, after shampooing and rinsing, with a coloration: 7.5 R 5/10 on hair which has been bleached white 7.5 R 5.5/6 on hair which is naturally 90% white, these colours being expressed according to Munsell's notation.

Example 5 The following dyeing composition is prepared: 1 (2,5-Diamino-3-nitrophenyl)-2-propanolii 0.3 g 2-Butoxyethanol 10 9 96 strength alcohol 5g CELLOSIZE WP 03 2g Ammonium lauryl sulphate 5g Water q.s. 100g pH 6.9 When applied on hair for 20 minutes at 28"C, this mixture endows it, after shampooing and rinsing, with a coloration: 8 R 5/10 on hair which has been bleached, white 7.5 R 5.5/6 on hair which is naturally 90% white, these colours being expressed according to Munsell's notation.

Example 6 The following dyeing composition is prepared: 1 -[2-Amino-5-(ss-hydroxyethyl)amino-3- nitrophenyl]-2-propanol 0.7 g 96 strength alcohol 10 g ALFOL CS!18 89 Lanette Wax E 0.5 g CEMULSOL B 1 g Oleic diethanolamide 1.5 g 5% strength ammonia solution q.s. pH9.9 Water q.s. 100 g When applied on hair for 10 minutes at 28"C, this mixture endows it, after shampooing and rinsing, with a coloration: 7.5 RP 4/9 on hair which has been bleached white 7.5 RP 5.5/4 on hair which is natrually 90% white, these colours being expressed according to Munsell's notation.

Example 7 The following dyeing composition is prepared: 1 -(2,5-Diamino-3-nitrophenyl)-2-propanol 0.16 g 2-Amino-3-nitrotoluene 0.095 g 3-Nitro-4-[(w-hydroxypropyl)amino]aniline 0.12 g 1 ,4,5,8-Tetraaminoanthraquinone 0.12 g (Cibacete microdisperse sapphire blue) LAURAMIDE 1.5 g Lauric acid 1g CELLOSIZE WP 03 59 Monoethanolamine 2g Water q.s. 100 g pH 9.5 When applied for 20 minutes at 28"C on hair which is naturally 90% white, this mixture endows it, after shampooing and rinsing, with a coppery blonde coloration.

Example 8 The following dyeing composition is prepared: 2-(2,5-Diamino-3-nitrophenyl)ethanol 0.2 g 2-Amino-3-nitrophenol 0.15 g 3-NitroA-methylamino-N-(-aminoethyl)aniline 0.08 g hydrobromide 96 strength alcohol 10 g LAURAMIDE 1.5 g Lauric acid ig CELLOSIZE WP 03 5 g Monoethanolamine 2 g Water q.s. 100g pH 9.7 When applied for 25 minutes at 28"C on hair which has been bleached white, this mixture endows it, after shampooing and rinsing, with a reddish-copper coloration.

Example 9 The following dyeing composition is prepared: 1 -[2-Am ino-5-(p-hydrnxyethyl )amino-3-nitro- phenyl]-2-propanol 0.36 g 3-Nitro-4-aminophenol 0.13 g 2-(p-Hydroxyethyl)amino-5-4-[bis({-hydroxy ethyl)amino]anilino}-1,4-benzoquinone 0.17 g 96" strength alcohol 20 g CELLOSIZE WP 03 2 g (Tallow alkyl)dimethylhydroxyethylammonium chloride 2 g Triethanolamine, 5% concentration 0.2 g Water q.s. 100g pH 7.7 When applied for 20 minutes at 280C on hair which is naturally 90% white, this mixture endows it, after shampooing and rinsing, with a coppery blonde coloration.

Example 10 1 -(2,5-Diamino-3-nitrophenyl)-2-propanol 0.7 g 1-[2-Amino-5-(-hydrnxyethyl)amino-3-nitro- phenyl]-2-propanol 0.06 g 2,5-Diaminopyridine dihydrochloride 0.05 g para-Aminophenol 0.08 g lx-Naphthol 0.035 9 7-Hydroxybenzomorpholine 0.07 g 1-(2,4-Diaminophenoxy)-2,3-propanediol di hydrochloride 0.04 g N-(p-Methoxyethyl)-para-phenylenediamine dihydrochloride 0.04 g Polyglycerolated oleic alcohol (2 moles of glycerol) 4.5 g Polyglycerolated oleic alcohol (4 moles of glycerol) 4.5 g ETHOMEEN TO 12 4.5 g COMPERLAN KD 9g Propylene glycol 4 g 2-Butoxyethanol 8g 96%o strength ethanol 6g MASQUOL DTPA 2g Hydroquinone 0.15 9 Sodium bisulphite solution, 35 B6 1.3 g Ammonia solution, 22 Bé 10 9 Water q.s. 100g pH 10.5 At the time of use, 110 g of "20 volumes" hydrogen peroxide are added.

When applied for 20 minutes at 28 C on hair which is naturally 90% white, the mixture endows it, after shampooing and rinsing, with an ash blonde coloration.

Example 11 The following dyeing mixture is prepared: 1 -[2-Amino-5-(ss-hydroxyethyl)amino-3-nitro phenyl]-2-propanol 0.1 g 2-[2-(ss-hydroxyethyl)amino-3,5-dinitrophenyl]- ethanol 0.8 g 2-Methylresorcinol 0.06 g para-Phenylenediamine 0.05 g 2,4-Diaminophenoxyethanol dihydrochloride 0.03 g CEMULSOL NP 4 21 g CEMULSOL NP 9 24 g Oleic acid 4 g 2-Butoxyethanol 3 g 96" strength ethanol 10 9 MASQUOL DTPA 2.5 g Sodium bisulphite solution, 35 B6 1 g Ammonia solution, 22 B6 10 9 Water q.s. 100g pH 10.6 At the time of use, 100 g of "20 volumes" hydrogen peroxide are added.

When applied for 30 minutes at 28 C on bleached hair, the mixture endows it, after shampooing and rinsing, with a bluish-grey coloration.

Example 12 The following dyeing mixture is prepared: 2-(2,5-Diamino-3-nitrophenyl)ethanoi 0.08 g 2-[2-( p-hydroxyethyl )ami no-3,5-dinitro phenyl]ethanol 0.07 g para-Phenylenediamine 0.06 g Resorcinol 0.035 g 5-Acetamido-2-methylphenol 0.09 g 1 -Phenyl-3-methyl-5-pyrazolone 0.065 g CARBOPOL 934 39 965 strength alcohol 11 g 2-Butoxyethanol 5g (Tallow alkyl)dimethylhydroxyethylammonium chloride 2g TRILON B 0.2 g Ammonium solution, 22 Be 10 g Sodium bisulphite, 35 Bé 1g Water q.s. 100 g pH 10.2 At the time of use, 100 g of "20 volumes" hydrogen peroxide are added, When applied for 20 minutes at 28 C on hair which is naturally 90% white, the mixture endows it, after shampooing and rinsing, with a pinkish dark blonde coloration.

Example 13 The following dyeing mixture is prepared: 1 -[2-Amino-5-(ss-hydroxyethyl )amino-3 nitrophenyl]-2-propanol 0.08 g para-Aminophenol 0.09 g 1 ,4-Diamino-2,6-dimethylbenzene dihydrochloride 0.04 g Resorcinol 0.06 g [2-Amino-4-(p-hydrnxyethyl)aminophenoxyj- ethanol dihydrochloride 0.05 g CELLOSIZE WP 03 29 Ammonium lauryl sulphate 5g 2-Butoxyethanol 15 9 96" strength alcohol 5g Ammonia solution, 22 Bb 10 g Ammonium thiolactate 0.8 g Water q.s. 100g pH 10,1 At the time of use, 120 g of "20 volumes" hydrogen peroxide are added.

When applied for 40 minutes at 30 C on hair which is naturally 90% white, the mixture endows it, after shampooing and rinsing with a pearly light grey coloration.

The various trade names used in the above examples are clarified in greater detail below: ALFOL DCl618: cetyl/stearyl alcohol sold by Condéa.

Lanette Wax E : partially sulphated cetyl/stearyl alcohol, sold by Henkel.

CEMULSOL B : ethoxylated castor oil, sold by Rhône-Poulenc.

CELLOSIZE WP 03:hydroxyethylcellulose, sold by UNION CARBIDE.

LAURAMIDE : lauric acid monoethanolamide, sold by Witco.

ETHOMEEN TO 12: oxyethylenated oleylamine (12 moles of ethylene oxide), sold by ARMAK.

COMPERLAN KD : coconut fatty acid diethanolamide, sold by HENKEL.

MASQUOL DTPA : diethylenetriaminepentaacetic acid penta-sodium salt, sold by PROTEX.

CEMULSOL NP 4 : oxyethylenated nonylphenol (4 moles of ethylene oxide), sold by Rhône-Poulenc.

CEMULSOL NP 9 : oxyethylenated nonylphenol (9 moles of ethylene oxide) sold by Rhône-Poulenc.

CARBOPOL 934: acrylic acid polymer of M.W. 2 to 3 million, sold by GOODRICH CHEMICAL COMPANY.

TRILON B : ethylenediamine tetraacetic acid.

Claims (29)

1. A 2-nitro-4-amino-6-hydroxyalkylaniline of formula (I):

wherein: X is an unsubstituted or a mono- or polyhydroxy substituted branched or unbranched alkylene containing 2 to 6 carbon atoms; R, and R2 are the same or different and each is hydrogen (C14) alkyl, a mono- or polyhydroxy (via) alkyl, amino (via) alkyl or a mono- or disubstituted amino (C14) alkyl wherein each substituent is (C,.4) alkyl, or a mono- or polyhydroxy (C,.,) alkyl or at least one substituent and the nitrogen atom form part of a heterocyclic system; R' is hydrogen or C14) alkyl; or a cosmetically acceptable salt of such a compound.

2. A compound according to claim 1, wherein X is ethylene, propylene, 1,1-dimethylethylene, 1,2-dimethyl-ethylene or 1,1,2-trimethylethylene radical, R1 and R2 are the same or different and each is hydrogen, methyl, ethyl, n-propyl, ss-hydroxyethyl, -hydroxypropyl, ss,y-dihydroxypropyl, aminoethyl or diethylaminoethyl and R' is hydrogen or methyl.

3. A compound according to claim 1 or claim 2, selected from: 2-(2,5-diamino-3-nitrophenyl)ethanol, 1 -(2,5-diamino-3-nitrophenyl)-2-propanol and 1 -[2-amino-5-(P-hydrnxyethyl)amino-3-nitrophenyl]-2-prn- panol, and the salts of these compounds.

4. A compound according to claim 1, and substantially as hereinbefore described with reference to any one of Examples 1 to 3.

5. A process for preparing a 2-nitro-4-amino-6-hydroxy-alkylaniline of formula (I) as defined in claim 1 comprising reacting an aqueous ammonia solution with a heterocyclic compound of formula (IV):

wherein R' and X are each as defined in claim 1, at a temperature between 20 and 1200C, optionally under pressure and optionally in the presence of polar protic solvents or polar aprotic solvents, to form a 2,4-dinitro-6-hydroxyalkylaniline of formula (III)::

wherein R' and X are each as defined in claim 1, and selectively reducing the compound of formula (III) using (a) cyclohexene in the presence of palladium on carbon as a catalyst and in the presence of an alcohol, water and an inorganic acid, or (b) by introducing hydrogen into a mixture of the dinitro compound of formula (III), a polar solvent, a hydrogenation catalyst and an aqueous solution of an inorganic acid at a temperature between 20"C and 90"C, to form a compound of formula (I) wherein R1 and R2 are both hydrogen::

wherein R' and X are each as defined in claim 1, and, where necessary alkylating, hydroxyalkylating or aminoalkylating the compound of formula (I) so formed to form a compound of formula (I) wherein at least one of R, and R2 is other than hydrogen.

6. A process according to claim 5 wherein the reaction of the compound of formula (IV) with ammonia is conducted under pressure.

7. A process according to claim 5 or claim 6, wherein the reaction of the compound of formula (IV) with ammonia is conducted in the presence of a polar protic solvent or a polar aprotic solvent.

8. A process according to claim 5 and substantially as hereinbefore described with reference to any one of Examples 1 to 3.

9. A composition for dyeing keratinous fibres comprising at least one compound as defined in any one of claims 1 to 4 or as produced according to any one of claims 5 to 8 in a solvent medium.

10. A composition according to claim 9 containing from 0.001 to 5% by weight at least one compound of formula (I) relative to the total weight of the composition.

11. A composition according to claim 10, containing from 0.05 to 2% by weight of at least one compound of formula (I), relative to the total weight of the composition.

12. A composition according to any one of claims 9 to 11, having a pH of from 3 to 11.5.

13. A composition according to claim 12,having a pH of from 5 to 11.5.

14. A composition according to any one of claims 9 to 13, wherein the solvent medium comprises one or more lower alkanol, aromatic alcohol, polyol, glycol or glycol ether, or water or mixture thereof.

15. A composition according to any one of claims 9 to 14, further comprising one or more cosmetic adjuvant selected from anionic, cationic, nonionic and amphoteric surfactants and mixtures thereof, thickeners, dispersants, penetrants, sequestering agents, film-forming agents, buffers, perfumes and alkalinising and acidifying agents.

16. A composition according to any one of claims 9 to 15, formulated as a direct dye for human hair, comprising at least one compound of formula (I) and at least one other direct dye selected from azo dyes, anthraquinone dyes, indophenols, indoanilines and nitro derivatives of the benzene series.

17. A composition according to any one of claims 9 to 15, formulated as a hair setting lotion and comprising an aqueous, alcoholic or hydroalcoholic solution containing at least one cosmetic resin.

18. A composition according to any one of claims 9 to 15, formulated as an oxidation dye and comprising at least one oxidation dye precursor.

19. A composition according to claim 18 having a pH of from 7 to 11.5, and further comprising a reducing agent.

20. A composition according to claim 9, and substantially as hereinbefore described with reference to any one of Examples 4 to 13.

21. A process for dyeing keratinous fibres comprising applying a composition as defined in any one of claims 9 to 16 to the fibres, leaving the composition on the fibres for 5 to 50 minutes, then rinsing and drying the fibres.

22. A process according to claim 21 wherein after rinsing, the fibres are washed with shampoo and rinsed again then dried.

23. A process for dyeing keratinous fibres comprising applying a composition as defined in claim 17 to fibres which have previously been washed and rinsed, then drying the fibres.

24. A process according to claim 23 wherein before drying the fibres are coiled.

25. A process for dyeing keratinous fibres, comprising applying a composition as defined in claim 18 or claim 19, to the fibres, leaving the composition on the fibres for 10 to 50 minutes, then rinsing and drying the fibres.

26. A process according to claim 25, wherein an oxidising agent is added to the composition applied to the fibres.

27. A process according to claim 25 or claim 26, wherein, after rinsing the fibres are washed with shampoo, rinsed again and then dried.

28. A process according to any one of claims 21 to 27, wherein the keratinous fibres are human hairs.

29. A process according to claim 21 and substantially as herein before described with reference to any one of Examples 4 to 13.