CH677663A5 - - Google Patents

Description

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CH 677 663 A5

description

The invention relates to a process for the preparation of N4-substituted 1-methoxy-2,4-diamino-benzenes according to claim 1, selected compounds thereof according to claim 2 and intermediate products according to claim 3 and aqueous colorants for keratin fibers according to claims 4 to 7.

For the coloring of hair, the so-called oxidation colors, which are created by oxidative coupling of development components (such as p-phenylenediamines, p-aminophenols, p-diaminopyridines etc.) with coupling components (such as phenols, resorcinols, m-aminophenols, m- Phenylenediamines, naphthols, pyrazolones, etc.) are of particular importance, since they are produced in intensive tones and with very good fastness properties, even under the application conditions (low dyeing temperature and short dyeing time, for example).

Oxidation colors also play an important role in fur dyeing.

Good oxidation dye precursors must first and foremost meet the following application requirements: In oxidative coupling with the respective coupling or development components, they must give the desired color, which is said to have a good ability to balance and balance on hair or fur, with sufficient intensity. The dyes formed must be generally stable and specially washable, lightfast, sweatproof and thermostable, in particular they must not tend to shift the color of the original shade under the wearing conditions.

In addition, they should be toxicologically and dermatologically harmless.

These requirements cannot always be reconciled. This becomes particularly clear in the area of the so-called blue couplers. With the 2,4-diaminoanisole, there is a state of the art compound that is almost completely satisfactory in terms of application technology, but is also controversial in toxicological terms.

The compound 2-amino-4- (β-hydroxyethylamino) anisole is mentioned several times in the prior art as a color coupling, e.g. DE-OS 3132 885, DE-OS 2 951 377, DE-OS 3 625 916 (column 1, line 55; column 4, line 10), DE-OS 3 545 371 (page 2, line 24/25; description page 5, line 32), DE-OS 3 441 148 (page 1, line 24 and example 2) and DE-OS 3 609 504 (page 5, line 20 and example 6). In very thorough literature searches, processes for the preparation of 2-amino-4- (ß-hydroxyethylamino) anisole could not be determined.

It is an object of the invention to provide a technically advanced process for the production of known and new compounds as blue couplers which a) are completely satisfactory in terms of color, b) are toxicologically unobjectionable and c) economically like the 2,4-diaminoanisole and its Derivatives can be made.

Blue couplers that meet these requirements are compounds of the general formula I and their salts with inorganic or organic acids, the economical production of which in high purity from commercially available starting products has hitherto been unknown.

The preparation of the compounds of the general formula is given in claim 1. Details of the method according to the invention are described below.

In stage a, the 4-methoxy-3-nitroacetanilide is heated according to methods known per se by heating to about 60 to 95 ° C. with a strong inorganic acid (for example hydrochloric acid, sulfuric acid or phosphoric acid) in an aqueous medium in about 3 to 8 hours deacylated (cf. Beilstein's Handbook of Organic Chemistry, Springer Verlag, Volume 13, Supplement III, page 1201). It was surprisingly found that the addition of about 10 to 15% by weight of water-dilutable, organic, inert solvents, e.g. Methanol, dimethoxyethane, ethanol, in the reaction mixture, which has previously been described in a pure aqueous medium, brings about an additional purification of the de-acylated product of the formula III without having to accept more effort or a loss in yield. The fully reacted mixture is mixed with an inorganic base, e.g. Sodium hydroxide solution, neutralized and after the mixture has cooled to about 5 to 10 ° C., the reaction product of the formula III separates and can be isolated by filtration or centrifugation. It is washed with water and dried in the customary manner.

The reaction of the compound of formula III with a chloroformic acid chloroalkyl ester of the general formula IV takes place in accordance with the known selective hydroxyalkylation of an amine with chloroformic acid chloroalkyl ester with subsequent basic treatment of the chloroalkyl carbamates, cf. Otto, J. Prakt. Chem., 2, 44. Page 15 (1890); R Adams et al. J.B. Segur J. Am. Chem. Soc, 45, p. 785 (1923); J.S. Pierce et al. R. Adams J. Am. Chem. Soc. 45, p. 790 (1923) describe in detail the reaction of the chloroalkyl chloroformate with primary aromatic amines. To form the compounds of general formula V, the compound of formula II is dissolved in an inert organic solvent, e.g. Dioxane, dimethoxyethane, Ci- to C4-alcohols, dimethylformamide, tetrahydrofuran, toluene, chlorobenzene, methyl ethyl ketone, ethylene glycol dimethyl ether or diethylene glycol dimethyl ether and heated to a temperature between room temperature and reflux temperature, preferably between 70 ° C. and reflux temperature. Ghlorameisensäu-rechloralkyiester of the general formula IV is then metered in in an equimolar amount or in a slight excess. If necessary, the solvents can be combined with water. An acid-binding agent can either be initially introduced or in parallel to the chloroformic acid

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CH677 663A5

rechloroalkyl esters are added. Suitable acid-binding agents are bases such as alkali metal hydroxides, hydrogen bicarbonates, carbonates, alkaline earth metal oxides, hydroxides, bicarbonates and carbonates as well as tertiary organic amines. The reaction takes about 4 to 12 hours.

After the reaction is complete, the carbamates are isolated by a) adding water and stirring the batch 5 cold or b) filtering off the inorganic salts and partially dissolving the solvent. or withdrawn completely, if necessary, additionally cool, e.g. by adding ice, as a result of which the carbamates of the general formula V formed are almost quantitative in solid form.

By treatment with strong bases - here alkali or alkaline earth hydroxides come into consideration, preferably 10-50% aqueous sodium or potassium hydroxide solution is used - the carbamates of general formula V are converted into the hydroxyalkyl compounds of formula VI.

Two procedures are appropriate:

a) The carbamate of formula V is in water or an organic solvent such as e.g. a (Ci-C4) -alcohol, a water-miscible ether or mixtures thereof, at room temperature

15 perature is then approximately the calculated amount of lye, that is 3 moles of lye per mole of carbamate, and the mixture is stirred until the reaction is complete, and if necessary, can be heated to reflux.

b) The alkali, which can be diluted with the solvents mentioned, is initially introduced, the carbamate is metered in with the general formula V in pure form or dissolved in one of the organic solvents mentioned.

20 medium at a temperature between room temperature and approx. 70 ° C and then stirred until the reaction is complete. In both variants, the reaction solution, which has a pH of about 12-14, can be blunted to a work-up by adding an organic or inorganic acid to a pH of about 7 to about 10. The inorganic solutions are then separated Salts, water is added if necessary and the product of the general formula VI is isolated after removal of the organic solvent.

In both of the above procedures, the reaction time is significantly shortened by adding about 25 to 30% by weight of one of the above-mentioned organic solvents to the aqueous reaction mixture, the inorganic salts still remaining dissolved in the reaction medium. 30 It takes about 4 to 12 hours to implement this.

The compounds of the general formula I can be prepared by reducing the compounds of the general formula VI with base metals or by catalytic reduction.

In the catalytic reduction, conventional catalysts such as e.g. Raney nickel, palladium on activated carbon, platinum on activated carbon are used. The reaction temperature is between room temperature 35 and 120 ° C, preferably between 40 ° and 100 ° C, the pressure is between normal pressure and 100 bar, preferably between 20 and 70 bar. Common solvents such as e.g. Water, toluene, glacial acetic acid, lower alcohols, ether compounds use. After the reduction and separation of the catalyst has taken place, the product of the general formula I can be isolated in a free form by stripping off the solvent under a protective gas, but it is preferably - also under a protective gas - converted into a salt by adding an approximately equivalent amount of an acid , which either precipitates directly or is obtained after removal of the solvent.

As inorganic acids e.g. Hydrochloric acid, sulfuric acid, phosphoric acid and as organic acids are e.g. Acetic acid, propionic acid, lactic acid or citric acid are suitable for salt formation. ^ The manufacturing process is illustrated by the following examples:

example 1

Preparation of the sulfuric acid salt of 1-methoxv-2-amino-4- (ß-hvdroxvethvlaminoVbenzol 50 A. Preparation of 1-methoxy-2-nitro-4-aminobenzene:

A mixture of 630.5 g (3 mol) of 1-methoxy-2-nitro-4-acetyiaminobenzene, 1500 ml of water and 300 ml of ethanol is heated to 80 ° C. and 1062 g of concentrated hydrochloric acid are added. The mixture is stirred at 88 ° C. for a further 3 1/2 hours, then cooled to 75 ° C. and the pH is adjusted to 7.0 with sodium hydroxide solution. 55 After the batch has cooled to about 10 ° C., the product is filtered off with suction, washed with water and dried.

Yield: 475.5 g (94% of the theoretical value)

Melting point: 54-55 ° C

60

B. Preparation of β-chloroethyl-N- (3-nitro-4-methoxyphenyl) carbamate:

420.5 g (2.5 mol) of the 1-methoxy-2-nitro-4-aminobenzene prepared above under A. are initially charged with 135 g of calcium carbonate in 1275 ml of monoethylene glycol dimethyl ether and 150 ml of water and

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heated to 78tìC. 375 g of p-chloroethyl chloroformate are added dropwise to this mixture in the course of 3 hours in such a way that the reaction mixture comes to a slight reflux with evolution of carbon dioxide. The mixture is stirred under reflux for a further 1 1/2 hours until the reaction is complete, cooled to 35 ° C. and water and ice are added. The precipitated product is filtered off, washed with water and dried.

Yield: 663 g (96.5% of the theoretical value)

Melting point: 83-84 ° C IR spectrum: see Fig. 1

1H NMR Spectrum: (CDCb) 8 = 3.6-3.8 (t, 2H, CHz-O); 5 = 3.9 (s, 3H, O-CHs); 8 • 4.3-4.5 (t, 2H, CH2-CI); 8 = 6.9-7.5 (m, 3H, Ar-H) ppm

C. Preparation of 1-methoxy-2-nitro-4- (β-hydroxyethylamino) benzene:

618 g (2.25 mol) of the β-chloroethyl-N- (3-nitro-4-methoxyphenyl) carbamate obtained above under B. are placed in 2025 ml of water and 675 ml of ethanol. The reaction mixture is heated to 60 ° C. and 766 g of 50% strength potassium hydroxide solution are added dropwise over the course of 1 1/2 hours. After stirring for 2 1/2 hours at 60 ° C., the pH of the mixture is adjusted to 8.0 with glacial acetic acid and the reaction mixture is slowly cooled. The precipitated product is filtered off, washed with water and dried at 50 ° C in a vacuum cabinet.

Yield: 439.5 g (92% of the theoretical value)

Melting point: 79 ° G IR spectrum: see Fig. 2

fH NMR Spectrum: (CDCI3) 8 = 3-3.2 (t, 2H, CH2-N); S = 3.6-3.8 (2H, CH2-O); 8 = 3.8 (s, 3H, O-CH3); 8 = 6.75-7.25 (m, 3H, Ar-H) ppm.

D. Preparation of the sulfuric acid salt of 1-methoxy-2-amino-4- (ß-hydroxyethylamino) benzene

159 g (0.75 mol) of the 1-methoxy-2-nitro-4- (ß-hydroxyethylamino) -benzene produced under C. are transferred together with 300 ml of methanol into a stainless steel autoclave, with approx. 2 g of Raney-Nicke! added and catalytically reduced within five hours at 70 ° C with a hydrogen pressure of 20 bar. After removing the catalyst, 73.5 g of sulfuric acid are added to the filtrate. After the mixture has cooled, the precipitated product is filtered off with suction, the residue is washed with a little methanol and dried at about 50 ° C. in a vacuum cabinet.

Yield; 197 g (94% of the theoretical value)

Melting point: 148-149 ° C IR spectrum: see Fig. 3

1H NMR Spectrum: (DMSO-de) 8 = 3.15-3.4 (t, 2H, CH2-N); 8 = 3.3-3.75 (2H, CH2-O; 8 "3.9 (s, 3H, O-CH3); 8 = 7.2-7.9 (m, 3H, Ar-H) ppm .

Example 2

Preparation of the sulfuric acid salt of 1-methoxv-2-amino-4-fa-hvdroxvpropvlamino1-benzene

A. Preparation of y-chloropropyl-N- (3-nitro-4-methoxyphenyl) carbamate:

168.2 g (1 mol) of 1-methoxy-2-nitro-4-aminobenzene (prepared according to Example 1A) and 54 g of calcium carbonate are dissolved in 570 ml of monoethylene glycol dimethyl ether / water mixture (9: 1) with 164 g of chloroformic acid Y-chloropropyl ester among those in Example 1B. mentioned conditions implemented and processed accordingly.

Yield; 280 g (97%) of the theoretical values)

Melting point: 74 ° C IR spectrum: see Fig. 4

IH NMR spectrum: (CDCI3) 5 = 1.9-2.15 (2H, C-CH2-C); 8 = 3.5-3.7 (t, 2H, CH2-O; 8 == 3.8 (s, 3H, O-CHs); 8 = 4.2-4.4 (t, 2H, -CH2 -CI); 8 = 6.9-7.6 (m, 3H, Ar-H) ppm.

B. Preparation of 1-methoxy-2-nitro-4- (y-hydroxypropylamino) benzene:

216 g (0.75 mol) of the chloropropyl-N- (3-nitro-4-methoxyphenyl) carbamate prepared above under A. are put under the conditions described in Example 1C. conditions mentioned with 250 g 50% potassium hydroxide solution in 675 ml water and 225 ml ethanol. After pH adjustment, the product is extracted with ethyl acetate.

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Yield: 160 g of oil (94% of the theoretical value)

IR spectrum: see Fig. 5

1H NMR Spectrum: (CDCis) 5 = 1.7-2.0 (2H, G-CH2-C); 8 = 3.1-3.3 (t, 2H, GH2-N); 8 = 3.6-3.8 (2H, CH2-O; 8 = 3.9 (s, 3H, O-CH3); 8 = 6.7-7.3 (m, 3H, Ar-H) ppm .

G. Preparation of the Sulfuric Acid Salt of 1-methoxy-2-amino-4- (yhydroxypropylamino) benzene

113 g (Q, 5 mol) of 1-methoxy-2-amino-4- (fhydroxypropylamino) benzene (prepared according to Example 2B.) Are among those in Example 1D. conditions specified hydrogenated, separated from the catalyst, treated with 49 g of sulfuric acid and the product isolated.

Yield: 140 g (95% of the theoretical value)

Melting point: 166-168 ° C (with decomposition)

IR spectrum: see Fig. 6

1H NMR Spectrum: (DMSO-de) 8 = 1.6-1.9 (2H, C-CHg-S); 5 = 3.1-3.3 (t, 2H, CHa-N); 8 = 3.4-3.6 (t, 2H, CH2-0); 8 = 3.8 (s, 3H, OCH3); 8 = 6.5-7.0 (m, 3H, Ar-H) ppm.

Example 3

Preparation of the sulfuric acid salt of 1-methoxv-2-amino-4- (B-hvdroxvproDvlaminoVbenzol

A. Preparation of 2-chloro-1-methyl) -ethyl-N- (3-nitrô-4-methoxyphenyl) carbamate:

16.8 g (0.1 mol) of 1-methoxy-2-nitro-4-aminobenzene (prepared according to Example 1A.) And 5.4 g of calcium carbamate are mixed in 55 ml of monoethylene glycol dimethyl ether / water mixture (9: 1). among those in Example 1B. specified conditions with 16.5 g of chloroformic acid (2-chloro-1-methyl) ethyl ester and worked up accordingly.

Yield: 28.5 g (99% of the theoretical value)

Melting point: 72 ° G

B. Preparation of 1-methoxy-2-nitro-4- (β-hydroxypropylamino) benzene:

27.4 g (0.095 mol) of that from Example 3A. prepared (2-chloro-1-methyl) -ethyl-N- (3-nitro-4-methoxyphenyl) carbamate in 85 ml of water and 30 ml of ethanol under the in Example 1C. conditions mentioned implemented with 32.5 g of 50% potassium hydroxide solution. After adjusting the pH, the product is extracted with ethyl acetate.

Yield: 20 g of red oil (93% of the theoretical value)

C. Preparation of the sulfuric acid salt of 1-methoxy-2-amino-4- (β-hydroxypropylamino) benzene

18.1 g (0.08 mol of the 1-methoxy-2-nitro-4- (β-hydroxypropylamino) benzene prepared above under B. are mixed with 0.3 g of Raney nickel in 180 ml of methanol under the conditions described in Example 1D hydrogenated conditions, separated from the catalyst, mixed with 7.8 g of sulfuric acid and the product isolated after concentration of the solvent.

Yield: 16 g (68% of the theoretical value).

The hair dyes according to the invention, which contain the compounds according to claim 2 and generally used for oxidation hair dyeing as coupler components, are notable for good storage stability and, when used, provide very intense shades ranging from reddish brown to blue-black with good fastness properties of the dyeings thus obtained.

When used in hair dyes, the coupler component is generally used in approximately molar amounts, based on the developer substances used. If molar use also proves to be expedient, it is not disadvantageous, however, if the coupler component is used in a certain excess or deficit.

The compounds to be used according to the invention as coupler components according to claim 2 can be used either as such or in the form of their salts with inorganic or organic acids such as e.g. can be used as chlorides, sulfates, phosphates, acetates, propionates, lactates, citrates.

In the hair colorants according to the invention, the new coupler substances according to claim 2 should be present in a concentration of about 0.001 to 5.0% by weight and in particular of 0.2 to 3.0% by weight.

Furthermore, it is not necessary that only one developer component is used; rather, a mixture of different developer compounds can also be used.

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Examples of developer components to be used are primary aromatic or heteroaromatic amines with a further functional group located in the p position, such as p-phenylenediamine, p-toluenediamine, p-aminophenol, N, N-dimethyl-p-phenylenediamine, chloro-p-phenylenediamine , Methoxy-p-phenylenediamine, 2,5-diaminopyridine and their derivatives, further compounds of the type mentioned, which additionally carry one or more functional groups, such as OH groups, NH2 groups, NHR groups or NRR groups, where R represents an optionally substituted alkyl radical having 1 to 4 carbon atoms.

It is furthermore not necessary that only the coupler components according to the invention are claimed

2 can be used; rather, other already known and used coupler components, such as e.g. a-NaphthoI, 3,4-diaminobenzoic acid, resorcinol, 4-chlororesorcinol, m-aminophenol, m-phenylenediamine, m-toluenediamine, 2,4-diaminoanisole, pyrocatechol, pyrogallol, 1,5- or 1,7-dihydroxynaphthalene, 5-amino-2-methylphenol, 6-amino-2-methylphenol or derivatives of the compounds mentioned, for example 2,4-Diaminophenyltetrahydrofurfurylether according to DE-PS

3 516 906 can be used.

In addition, the hair colorants can optionally contain customary direct-absorbing dyes, if this is necessary to achieve certain color shades. The oxidative coupling, i.e. The development of the color can basically be done with atmospheric oxygen, as with other oxidation dyes. However, chemical oxidizing agents are expediently used.

The hair colorants according to the invention are aqueous agents. This means all agents that contain water in some way, e.g. Creams, emulsions, gels or simple solutions. The composition of the hair colorants is a mixture of the dye components with the additives customary for such cosmetic preparations.

Common additives in solutions, creams, emulsions or gels are e.g. Solvents such as water, lower aliphatic alcohols, e.g. ethanol, propano! and isopropanol, or glycols such as glycerol and glycol ethers such as propylene glycol, further wetting agents or emulators from the classes of anionic, cationic, amphoteric or nonionic surface-active substances such as fatty alcohol sulfates, alkyl sulfonates, alkylbenzenesulfonates, alkyltrimethylammonium salts, alkylated alkynyls, oxyethyl alkynyls, oxyethyl alkynyls, oxethylated alkynyls, oxethylated alkynyls, oxethylated alkynyls, oxethylated alkynyls, oxethylated alkynyls, oxethylated alkynyls, oxethylated alkynyls, oxethylated alkynyls, oxethylated alkynyls, oxethylated alkynyls, oxethylated alkynyls, oxyethyl alkynyls, oxyethyl alkynyls, oxyethyl alkynyls, oxyethyl alcohols, Fatty acid alkanolamides, ethoxylated fatty acid esters, also thickeners such as higher fatty alcohols, starch, cellulose derivatives, petroleum jelly, paraffino! and fatty acids,

The components mentioned are used in the amounts customary for such purposes, for example the wetting agents and emulsifiers in concentrations of about 0.5 to 30% by weight. while the thickeners can be contained in the preparations in an amount of about 0.1 to 25% by weight.

Depending on the composition, the hair colorants according to the invention can react weakly acidic, neutral or alkaline. In particular, they have a pH in the alkaline range between 7.5 and 11.5, the setting preferably being made with ammonia. However, organic amines, e.g. Monoethanolamine and triethanolamine, or also inorganic bases such as sodium hydroxide and potassium hydroxide, are used.

In processes for oxidative dyeing of hair, the hair colorants of this invention are mixed, which contain a combination of developer substances known in hair dyeing with at least one compound according to claim 2 as a coupler substance and optionally additionally known coupler substances and direct absorbing dyes, shortly before use with an oxidizing agent and apply this mixture to the hair. Hydrogen peroxide, for example as a 6% strength aqueous solution and its addition compounds to urea, melamine or sodium borate, and mixtures of such hydrogen peroxide addition compounds with potassium peroxodisulfate, are mainly considered as oxidizing agents for developing the hair color. The application temperatures range from 15 to 40 ° C. After a development period of about 30 minutes, the hair dye is removed from the hair to be colored by rinsing. After that, the hair is washed with a mild shampoo and dried.

The following examples are intended to explain the subject of the invention in more detail:

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Example A: Hair dye in cream form

3.20 g

Sulfuric acid salt of 1-methoxy-2-amino-4- (fhydroxypropylamino) benzene

• 1.95 g of p-phenylenediamine. Hydrochloride

0.10 g m-aminophenol

2.00 g

Oleic acid

0.10 g

Polyacrylic acid

0.50 g

Sodium sulfite, anhydrous

3.50 g

Lauryl alcohol diglycol ether sulfate, sodium salt (28% aqueous solution)

15.00 g

Cetyl alcohol

73.65 g

water

100.00 g

50 g of the above-mentioned hair dye are mixed with 50 g of hydrogen peroxide solution, 6%, shortly before use. The mixture is allowed to act on light brown natural hair at 40 ° C. for 30 minutes. The dye is then rinsed out, the hair shampooed and dried. It has a rich, intense blue-black tone.

Example B: Hair dye in cream form

0.40 g

Sulfuric acid salt of 1-methoxy-2-amino-4- (ß-hydroxypropylam! No) benzene

0.05 g

1-methyl-2-hydroxy-4-amlnobenzoI

0.32 g

2-chloro-p-phenylenediamine

2.00 g

Oleic acid

0.10 g

Polyacrylic acid

0.50 g

Sodium sulfite, anhydrous

3.50 g

Lauryl alcohol diglycol ether sulfate, sodium salt (28% aqueous solution)

15.00 g

Cetyl alcohol

78.13 g

water

100.00g

50 g of the above-mentioned hair dye are mixed with 50 g of hydrogen peroxide solution, 6%, shortly before use. The mixture is allowed to act on graying natural hair at 40 ° C. for 30 minutes. The dye is then rinsed out, the hair shampooed and dried. It has a rich, intense lavender blue hue.

In the accompanying drawings with Figures 1 to 6 the infrared absorption spectra of the following compounds are given:

Fig. 1 ß-chloroethyl-N- (3-nitro-4-methoxyphenyl) carbamate;

Fig. 21-methoxy-2-nitro-4- (β-hydroxyethylamino) benzene;

3 sulfuric acid salt of 1-methoxy-2-amino-4- (β-hydroxyethylamino) benzene sulfate;

Figure 4 y-chloropropyl-N- (3-nitro-4-methoxyphenyl) carbamate;

Fig. 51-methoxy-2-nitro-4- (y-hydroxypropylamlno) benzene;

Fig. 6 sulfuric acid salt of 1-methoxy-2-amino-4- (Y-hydroxypropylamino) benzene sulfate.

Claims (1)

Claims 1. Process for the preparation of N4-substituted 1-methoxy-2,4-diaminobenzenes of the general formula I, 7 5 10th 15 20th 25th 30th 35 40 45 50 55 60 65 CH677 663 A5 OCH- NH- (I) NH-R wherein R is a radical of the general formula la -CH2-CH (A) -B (la) and when A represents a hydrogen atom therein, B is a hydroxyl group or the HO-CH2 group; when A represents a methyl group, B is a hydroxyl group; and their salts with inorganic and organic acids, characterized in that a) 4-methoxy-3-nitroacetanilide of the formula II OCH H-C-CH- Ü by treatment with a strong inorganic acid in an aqueous medium in 4-methoxy-3-nitroaniline of the formula III OCH. NH, NO, is convicted b) the compound of formula III obtained with an equimolar amount of an alkyl chloroformate of the general formula IV Cl- COO-CH (X ') - CH2-Y' (IV) wherein X 'is a hydrogen atom and Y' is a chlorine atom or a CI-CH2 group, and when X 'represents a methyl group, Y' represents a chlorine atom, and c) the resulting carbamate of the general formula V, wherein X 'and Y' have the meaning given above, 8th 5 10th 15 20th 25th 30th 35 40 45 50 55 60 65 CH 677 663 A5 OCH ■ 3 NO 2nd (V) T NH-COO-CH (X1) -CH2-Y ' under basic conditions in compounds of the general formula VI OCH3 NO 2nd (VI) nh-ch2-ch (A) -3 is transferred, where A and B have the meaning given for the formula la, and d) the compounds of the general formula VI are subjected to a reduction, and e) if appropriate, the compounds of the general formula I obtained are converted into their salts with an inorganic or organic acid . 2. Compounds of the general formula I, in which in the general formula (Ia) A denotes a methyl group and B denotes a hydrocyl group or, if A is a hydrogen atom, then B represents the HO-CH2 group. 3. Compounds of the general formula VI, as intermediates in the process according to claim 1. 4. Aqueous colorants for keratin fibers, in particular for furs and human hair, containing at least one compound as claimed in claim 2 as a coupler and at least one development component and conventional additives and auxiliaries. 5. Composition according to claim 4, containing at least one compound according to claim 2 in an amount of 0.001 to 5 percent by weight of the total composition. 6. Composition according to one of claims 4 or 5, containing directly absorbing dyes. 7. Agent according to one of claims 4 to 6, characterized in that the pH of the agent is in the range from 6.0 to 12.5 and preferably in the range from 7.5 to 11.5. 9