Title of Invention	"PREPARATION OF HALOGENATED 4-AMINOPHENOLS"
Abstract	The present invention relates to halogenated 4-aminophenols and to halogenated 4-(phenyl-diazenyl)phenols, to a process for their preparation and to the use of the halogenated 4-hydroxy-phenols for preparing active ingredients, especially in pharmaceuticals and agrochemicals.

Full Text

The present invention relates to halogenated 4-aminophenols and to halogenated 4-(phenyl-diazenyl)phenols, to a process for their preparation and to the use of the halogenated 4-hydroxy-phenols for preparing active ingredients, especially in pharmaceuticals and agrochemicals. Halogenated phenols, especially fluorinated phenols, are valuable starring materials for the preparation of active ingredients in pharmaceuticals and agrochemicals, since the fluorine substituents increase the lipophilicity and therefore the membrane permeability of the entire active ingredient molecule. For example, fluorinated 4-hydroxyanilines are particularly suitable as starting materials for preparing active ingredients which are used for treating chronic bronchitis (see also WO 03/08413 and PCT/03/02154). The preparation, for example, of 2,5-difluoro-4-hydroxyaniline is typically effected by nitrating 2,5-difluorophenol and subsequently reducing (see JP-A 63 310850). A disadvantage of this synthetic route is that the nitration reaction does not proceed selectively and the 4-nitrophenol desired as an intermediate is obtainable only in poor yields. There is therefore a need to provide a process which enables the preparation of halogenated 4-aminophenols in good yields and in a simple manner. A process has now been found for preparing compounds of the formula (I) (Formula Removed) in which m is 0, 1, 2 or 3 and n is 1, 2, 3 or 4, where the sum of m + n is a maximum of 4, and R is hydrogen, C1-C12-alkyl or C5-C15-arylalkyl and R2 is in each case independently C1-C12-fluoroalkyl, C1-C12-fluoroalkylthio or C1-C12- fluoroalkoxy and Hal is in each case independently bromine, chlorine or fluorine, characterized in that • in a step Al), compounds of the formula (II) (Formula Removed) in which p is 0, 1, 2 or 3 and R3 is in each case independently fluorine, chlorine, bromine, iodine, cyano, fhiocyanato, hydroxysulphonyl or alkali metal salts thereof, nitro, C1-C12-alkyl, C1-C12-fluoroalkyl, C1-C12-fluoroalkyoxy, C1-C12-fluoroalkylthio, C1-C12-alkoxy, C1-C12-alkoxycarbonyl, di(C1-C12-alkyl)amino, C4-C14-aryl or C5-C15-arylalkyl are converted to diazonium salts of the formula (HI) (Formula Removed) in which An" is the anion of an acid and • in a step A2), the diazonium salts of the formula (III) are reacted with compounds of the formula (IV) (Formula Removed) in which m, n, Hal and R2 are each as defined under the formula (I) in the presence of base to give compounds of the formula (V) (Formula Removed) and • in a step B), the compounds of the formula (V) are converted using a reducing agent to the compounds of the formula (I) in which R1 is hydrogen and • optionally, in a step C), these compounds are converted by O-alkylation to compounds of the formula (I) in which R1 is C1-C12-alkyl. This excludes the preparation of 4-amino-3,5-difiuorophenol and 4-amino-3-fluorophenol. Optionally, in a step D), • the compounds of the formula (I) can be converted by reacting with compounds of the formulae (VIIa) or (VIIb) (Formula Removed) in which R4 is 2,4-difluorophenyl, 4-fluorophenyl, 2,3-difluorophenyl or 4-fluoro-3-chloro- phenyl and R5 is optionally mono- or poly-chlorine- or -fluorine-substituted phenyl to compounds of the formula (VIII) (Formula Removed) in which R1, R2, R4, Hal, n and m are each as defined above. Step D) may be carried out in a manner known per se, for example similar to that described in US 4,851,535. Optionally, in a step E), • the compounds of the formula (VIII) can be converted by reacting with compounds of the formula (IX) (Formula Removed) in which R is C1-C12-alkyl, C5-C15-arylalkyl or C4-C14-aryl to compounds of the formula (X) (Formula Removed) in which R1, R2, R4, R6, Hal, n and m are each as defined above. The reaction of the compounds of the formula (VIII) with compounds of the formula (IX) to give compounds of the formula (X) may be effected, for example, by heating the two reactants in an organic solvent, preferably an aliphatic alcohol, for example methanol. The compounds mentioned as exceptions for steps A) to C) are excluded in the same manner for steps D) and E). In the context of the invention, all radical definitions, parameters and illustrations above and listed herein below, in general or specified within areas of preference, i.e. the particular areas and areas of preference, may be combined as desired. Alkyl and Alkoxy are in each case independently a straight-chain, cyclic, branched or unbranched alkyl and alkoxy radical respectively. The same applies to the nonaromatic moiety of an arylalkyl radical. C1-C4-Alkyl is, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl and tert-butyl, and C1-C12-alkyl is additionally, for example, n-pentyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, neopentyl, 1-ethylpropyl, cyclohexyl, cyclopentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl and n-dodecyl. Fluoroalkyl, fluoroalkoxy and fluoroalkylthio are in each case independently a straight-chain, cyclic, branched or unbranched alkyl, alkoxy and alkylthio radical respectively, each of which is singly, multiply or fully substituted by fluorine atoms. For example, C1-C12-fluoroalkyl is trifluoromethyl, 2,2,2-trifluoroethyl, pentafluoroethyl, nona-fluorobutyl, heptafluoroisopropyl, perfluorooctyl and perfluorododecyl. For example, C1-C12-fluoroalkoxy is trifiuoromethoxy, 2,2,2-trifluoroethoxy, pentafluoroethoxy, nonafluorobutoxy, heptafluoroisopropoxy, perfiuorooctoxy and perfluorododecoxy. For example, C1-C12-fluoroalkylthio is trifluoromethylthio, 2,2,2-trifluoroethylthio, pentafluoro-ethylthio, nonafluorobutylthio, heptafluoroisopropylthio, perfluorooctylthio and perfluorododecyl-thio. Aryl is in each case independently a heteroaromatic radical having 5 to 14 skeleton carbon atoms of which nil, one, two or three skeleton carbon atoms per cycle, but at least one skeleton carbon atom in the entire molecule, may be substituted by heteroatoms selected from the group of nitrogen, sulphur and oxygen, and is preferably a carbocyclic aromatic radical having 6 to 14 skeleton carbon atoms. In addition, the carbocyclic aromatic radical or heteroaromatic radical may be substituted by up to five identical or different substituents per cycle which are selected from the group of fluorine, cyano, nitro, C1-C12-alkyl, C1-C12-fluoroalkyl, C1-C12-fluoroalkoxy, C1-C12-fluoroalkylthio, C1-C12-alkoxy, di(C1-C12-alkyl)amino. Arylalkyl is in each case independently a straight-chain, cyclic, branched or unbranched alkyl radical as defined above, each of which may be singly, multiply or fully substituted by aryl radicals as defined above. The preferred substitution patterns are defined herein below: n is preferably 1 or 2, m is preferably 0 or 1, R1 is preferably hydrogen or methyl, more preferably hydrogen, R2 is preferably trifluoromethyl, trifluoromethoxy and trifluoromethylthio, Hal is preferably bromine, chlorine or fluorine, and at least one Hal radical is more preferably fluorine. In compounds of the formula (II), p is preferably 0. The process according to the invention is especially suitable for preparing 4-amino-2,3-difluorophenol, 4-amino-2,5-difiuorophenol, 4-amino-2,6-difluorophenol, 4-amino-2-fluorophenol, 4-amino-3 -chloro-5-fluorophenol, 4-amino-3 -chloro-2-fluorophenol, 4-amino-5 -chloro-2-fluoro-phenol, 4-amino-3-bromo-5-fluorophenol, 4-amino-2-(trifiuoromethoxy)phenol and 4-amino-3-(trifluoromethoxy )phenol. Many of the compounds of the formula (I) are novel and likewise encompassed by the invention, although the following are excluded: 4-amino-3,5-difluorophenol, 4-amino-2,5-difluorophenol, 4-amino-2,6-difluorophenol, 4-amino-2-chloro-6-fluorophenol, 4-amino-2-chloro-3-fluorophenol, 4-amino-2-chloro-5-fluorophenol, 4-amino-2-bromo-5-fluorophenol, 4-amino-2-fluorophenol, 4-amino-3 -fluorophenol, 4-amino-2-(trifluoromethyl)phenol, 4-amino-5 -chloro-2-(trifluoro-methyl)phenol, 4-amino-2-chloro-6-(trifluoromethyl)phenol and 4-amino-3-(trifluoromethyl)-phenol. Particularly preferred individual compounds of the formula (I) include: 4-amino-2,3-difluorophenol, 4-amino-3-chloro-5-fluorophenol, 4-amino-3-chloro-2-fluorophenol, 4-amino-5-chloro-2-fluorophenol, 4-amino-3-bromo-5-fluorophenol, 4-amino-2-(trifluoro-methoxy)phenol and 4-amino-3-(trifluoromethoxy)phenol. In step Al), the compounds of the formula (III) can be prepared from compounds of the formula (II) in a manner known per se. Advantageously, the compounds of the formula (II) are reacted with a nitrite source in the presence of water and acid. The acids used may be, for example, mineral acids such as hydrochloric acid, hydrobromic acid, sulphuric acid or tetrafluoroboric acid, or else organic sulphonic acids. The nitrite source used may be, for example, the alkali metal nitrites, especially sodium nitrite or potassium nitrite, and also organic nitrites, especially tert-butyl nitrite or methyl nitrite. Preference is given to alkali metal nitrites which are preferably used dissolved in water. The molar ratio of protons of the acid used to compounds of the formula (IT) may be, for example, 1 to 15, preferably 2 to 10 and more preferably 2.5 to 6.5. The molar ratio of compounds of the formula (IT) to the nitrite source may be, for example, 0.8 to 4, preferably 1.0 to 2.5 and more preferably 1.05 to 1.5. The reaction temperature in step Al) may be, for example, -20°C to 40°C, preferably -10°C to 20°C and more preferably -5°C to 10°C; the reaction pressure may be, for example, 0.5 to 100 bar, preferably ambient pressure; the reaction time may be 10 min to 5 hours, preferably 1 hour to 3 hours. To convert the compounds of the formula (II), the procedure is, for example, to initially charge the compounds of the formula (II) in water and acid and subsequently add an aqueous solution of the alkali metal nitrite. On completion of the reaction time, an excess of alkali metal nitrite may be destroyed by adding a primary amino compound, for example urea or amidosulphuric acid. The starting compounds of the formula (II) required for step Al) are known from the literature or can be synthesized in a similar manner to the literature. In step A2), the compounds of the formula (III) obtained in step Al) are reacted with compounds of the formula (IV) in the presence of base to give compounds of the formula (V). Suitable bases are in principle all bases which are more basic than the compounds of the formula (IV), preferably by at least 2 pK units. Preference is given to using alkali metal or alkaline earth metal hydroxides, carbonates and hydrogen carbonates, of which alkali metal hydroxides, such as sodium hydroxide in particular, are preferred. The base may either be initially charged or added in the course of the reaction in such a way that the reaction medium remains alkaline. The molar ratio of compounds of the formula (III) to compounds of the formula (IV) may be, for example, 0.3 to 5, preferably 0.5 to 2 and more preferably 0.6 to 0.9. The molar ratio of compounds of the formula (III) to base may be, for example, 1 to 15, preferably 3 to 10 and more preferably 4 to 7. The reaction temperature in step A2) may be, for example, -20°C to 50°C, preferably 0° to 40°C and more preferably 5° to 30°C, the reaction pressure, for example, 0.5 to 100 bar, preferably ambient pressure. In addition, the reaction time may be, for example, 10 min to 15 hours, preferably 3 to 5 hours. The workup of the compounds of the formula (V) may be effected in a manner known per se by extraction and subsequent distillation, or, in the case of compounds of the formula (V) which are solid at 30°C, by filtration and crystallization. The compounds of the formula (V) are likewise encompassed by the invention as important intermediates, although the following are excluded: 3,5-difluoro-4-phenylazophenol, 3-fluoro-4-phenylazophenol, 3-fluoro-4-(4'-nitrophenylazo)phenol, 3-fluoro-4-(3'-nitrophenylazo)phenol, 3-fiuoro-4-(4'-thiocyanatophenylazo)phenol, 3-fiuoro-4-(4'-sulphophenylazo)phenol, ethyl 4-(2'-fiuoro-4'-hydroxyphenylazo)benzoate, 2-fluoro-4-(4'-fluorophenylazo)phenol, 2-fluoro-4-(3'-fiuorophenylazo)phenol, 2-fluoro-4-(4'-sulphophenylazo)phenol, ethyl 4-(3'-fluoro-4'-hydroxyphenylazo)benzoate, 2,3-difluoro-4-(4'-iodophenylazo)phenol, 2,3-difluoro-4-(4'-sulphophenylazo)phenol and 2,6-difluoro-4-(2'-bromophenylazo)phenol, 3-(trifluoromethyl)-4-(phenylazo)phenol and 3 -(trifluoromethyl)-4-(4' -sodium sulphonate phenylazo)phenol. The compounds of the formula (IV) are known from the literature or can be synthesized in a similar manner to the literature. In step B), compounds of the formula (V) are converted by reduction to compounds of the formula (D- The reduction may be effected, for example, by reducing agents such as sodium bisulphite, titanium(III) chloride or tin and hydrochloric acid. More advantageously, the reduction is carried out in the presence of hydrogen and catalyst. Preferred catalysts are, for example, metals or metal compounds, especially salts or complexes of nickel, palladium, platinum, cobalt, rhodium, iridium and ruthenium, and preference is given to metals such as nickel or palladium. Metals are preferably used in finely divided form, for example as Raney metal, or applied to a support material. Particular preference is given to carrying out the reduction with hydrogen and palladium on carbon. The reduction in step B) may be carried out, for example, at a reaction temperature of 0°C to 200°C, preferably at 10°C to 80°C and more preferably at 20°C to 40°C. The partial hydrogen pressure in the reduction may be, for example, 0.1 to 180 bar, preferably 0.5 to 50 bar and more preferably 1 to 3 bar. Optionally and with preference, the reduction may be carried out in the presence of solvents, as long as they are substantially inert under the reaction conditions selected. Suitable solvents are, for example, aliphatic, alicyclic or aromatic, optionally halogenated hydrocarbons, for example benzine, benzene, toluene, xylene, chlorobenzene, dichlorobenzene, petroleum ether, hexane, cyclohexane, dichloromethane, chloroform or carbon tetrachloride; ethers such as diethyl ether, diisopropyl ether, dioxane, tetrahydrofuran or ethylene glycol dimethyl ether or ethylene glycol diethyl ether; alcohols, for example methanol, ethanol and isopropanol or mixtures of solvents. In a particularly preferred embodiment, the reduction is carried out in the presence of palladium on activated carbon and in the presence of methanol or ethanol at a partial hydrogen pressure of 1 to 3 bar. The reaction time in the reduction may be 10 min to 100 hours, preferably 2 to 20 hours. The workup of the compounds of the formula (I) in which R1 is hydrogen may be effected in a manner known per se by extraction and subsequent distillation or, in the case of compounds of the formula (I) which are solid at 30°C, by recrystallization. Optionally, step C), the O-alkylation of compounds of the formula (I) in which R1 is hydrogen, is undertaken. Preference is given in this case to carrying out the reaction in the presence of an inorganic base. Suitable inorganic bases are in principle all bases which are more basic than the compounds of the formula (I) in which R1 is hydrogen, preferably by at least 3 pK units. Preferred inorganic bases are alkali metal or alkaline earth metal carbonates, hydrogencarbonates and hydroxides, and also tetraalkylammonium hydroxides, of which preference is given to alkali metal carbonates and hydroxides. Suitable alkylating agents are in particular compounds of the formula (VI) (VI) (Formula Removed) in which R1 is C1-C12-alkyl, C5-C15-arylalkyl and Act is iodine, bromine, chlorine or a sulphonate. Suitable solvents for carrying out the alkylation are in particular ethers such as methyl tert-butyl ether, dioxane, tetrahydrofuran or ethylene glycol dimethyl ether or ethylene glycol diethyl ether; amides such as N,N-dimethylformamide, N,N-dimethylacetamide, N-methylformanilide, N-methylpyrrolidone, N-methylcaprolactam or hexamethylphosphoramide; sulphoxides such as dimethyl sulphoxide, sulphones such as tetramethylenesulphone or mixtures of such organic solvents. The molar ratio of inorganic base to compounds of the formula (I) in which R1 is hydrogen may be, for example, 0.3 to 5, preferably 0.5 to 3 and more preferably 0.9 to 1.3. The molar ratio of alkylating agents to compounds of the formula (I) in which R1 is hydrogen may be, for example, 0.3 to 5, preferably 0.5 to 3 and more preferably 0.9 to 1.8. The reaction temperature in step C) may be, for example, -70°C to 100°C, preferably -20 to 60°C and more preferably 0 to 40°C. The reaction time in step C) may be, for example, 10 min to 24 hours, preferably 1 to 8 hours. In the inventive manner, the compounds of the formula (I), (VIII) and (X) are obtained in good yields starting from readily available reactants. The compounds of the formula (I), (VIII) and (X), and also the compounds of the formula (V), are especially suitable for use in a process for preparing active ingredients in pharmaceuticals and agrochemicals, or intermediates thereof. Preferred active ingredients of pharmaceuticals are those which are used to treat chronic bronchitis, and preference is given to those which are described in WO 03/08413 and PCT 03/02154. Examples Example 1 Preparation of 3,5-difluoro-4-(phenyldiazenyl)phenol At 0°C, 108.2 g (1.16 mol) of aniline are dissolved with vigorous stirring in 500 g of 27% hydrochloric acid. Afterwards, at 5° - 0°C, 95.2 g (1.38 mol) of sodium nitrite (dissolved in 283 ml of water) are added dropwise and the solution is stirred for another 60 minutes on completion of addition. Excess sodium nitrite is destroyed with amidosulphuric acid. In a further flask, 101.2 g (0.77 mol) of 3,5-difluorophenol are dissolved in a solution of 182.8 g (4.57 mol) of sodium hydroxide in 2281 ml of water, and precooled to 5°C. The above freshly prepared diazonium salt solution is added to this solution at such a rate that the internal temperature does not rise above 5°C. During the addition, the pH is monitored regularly. On completion of addition, the mixture is allowed to warm to room temperature, and stirred for a further 60 minutes, and the suspension is then adjusted to pH 4 using 2N HC1. The product is filtered off and washed repeatedly with water. After the drying in a vacuum drying cabinet, 182 g (quantitative yield) of the desired orange-brown azo compound are obtained. EI-MS: m/z 234 [M]+ Example 2 Preparation of 4-amino-3,5-difluorophenol 20.4 g (0.09 mol) of 3,5-difluoro-4-(phenyldiazenyl)phenol from Example 1 and 0.5 g of Pd/C (10%) are initially charged in 120 ml of methanol. The solution is degassed and aerated with hydrogen. The mixture is stirred at room temperature under a 1 bar hydrogen atmosphere for 16 hours. On completion of hydrogen uptake, the catalyst is filtered off and the filtrate concentrated on a rotary evaporator. The residue is chromatographed on silica gel (n-hexane/ethyl acetate, 3:1). The resulting solid is stirred with n-hexane and dried. 7.6 g (60%) of 4-amino-3,5-difluorophenol are obtained as a yellow-brown solid. 1H NMR (400 MHz, CDC13): δ = 3.40 (s, 2 H, NH2); 4.55 (s, 1 H, OH); 6.39 (m, 2 H, Ar-H) 19F NMR (376.3 MHz, CDC13): δ = -130.5 EI-MS: m/z 145 [M]+ m.p.: 150-151°C Example 3 Preparation of 2,3-difluoro-4-(phenyldiazenyl)phenol At 0°C, 27.3 ml (0.3 mol) of aniline are added dropwise with vigorous stirring to 140 ml of HC1 (semiconc). Afterwards, at 5° - 0°C, 21.7 g (0.315 mol) of NaNO2 (dissolved in 100 ml of water) are added dropwise and, on completion of addition, the solution is stirred for another 20 minutes. In a further flask, 39 g (0.3 mol) of 2,3-difluorophenol are dissolved in 300 ml of 2N NaOH and precooled to 0°C. The above freshly prepared diazo solution is added to this solution at such a rate that the internal temperature does not rise above 5°C. During the addition, the pH is monitored regularly and, if necessary, made alkaline again by means of Na2CO3. On completion of addition, the mixture is allowed to warm to room temperature, stirred for a further 30 minutes and then the suspension is adjusted to pH 3-4 using 2N HC1. The product is filtered off and washed repeatedly with water. After the drying in the vacuum drying cabinet, 61 g (87%) of the desired bright yellow azo compound are obtained. EI-MS: m/z 234 [M]+ Example 4 Preparation of 4-amino-2,3-difluorophenol 61 g (0.26 mol) of 2,3-difluoro-4-(phenyldiazenyl)phenol from Example 3 and 1 g of Pd/C (10%) are initially charged in 800 ml of ethanol. The solution is degassed and aerated with hydrogen. The mixture is stirred at room temperature under a 1 bar hydrogen atmosphere for 18 hours. On completion of hydrogen uptake, the catalyst is filtered off and the filtrate is concentrated on a rotary evaporator, in the course of which the product already crystallizes out. The resulting solid is filtered off, washed with a little cold ethanol and dried under high vacuum for 4 hours. 28 g (74%) of the desired compound are obtained as a light brown powder. 1H NMR (400 MHz, DMSO-d6) δ = 4.72 (s, 2H, NH2), 6.39 (t, 1H, Ar-H), 6.51 (t, 1H, Ar-H), 9.13 (s, 1H, OH); EI-MS: m/z 145 [M]+ Example 5 Preparation of 2,5-difluoro-4-(phenyldiazenyl)phenol At 0°C, 17.5 ml (0.19 mol) of aniline are added dropwise with vigorous stirring to 185 ml of HC1 (semiconc). Afterwards, at 5° - 0°C, 13.9 g (0.2 mol) of NaN02 (dissolved in 50 ml of water) are added dropwise and, on completion of addition, the solution is stirred for another 20 minutes. In a further flask, 25 g (0.19 mol) of 2,5-difluorophenol are dissolved in 190 ml of 2N NaOH and precooled to 0°C. The above freshly prepared diazo solution is added to this solution at such a rate that the internal temperature does not rise above 5°C. During the addition, the pH is monitored regularly and, if necessary, made alkaline again by means of Na2CO3. On completion of addition, the mixture is allowed to warm to room temperature, stirred for a further 30 minutes, and the suspension is then adjusted to pH 3-4 using 2N HC1. The product is filtered off and washed repeatedly with water. After drying in a vacuum drying cabinet at 50°C, 42 g (93%) of the desired orange-coloured azo compound are obtained. EI-MS: m/z 234 [M]+ Example 6 Preparation of 4-amino-2,5-difluorophenol 42 g (0.18 mol) of 2,5-difluoro-4-(phenyldiazenyl)phenol from Example 5 and 1 g of Pd/C (10%) are initially charged in 650 ml of ethanol. The solution is degassed and aerated with hydrogen. The mixture is stirred at room temperature under a 1 bar hydrogen atmosphere for 18 hours. On completion of hydrogen uptake, the catalyst is filtered off and the filtrate distilled under reduced pressure, and dried under high vacuum at 70°C for 4 hours. The residue (24 g) is recrystallized from ethanol and dried. 15 g (60%) of 4-amino-2,5-difluorophenol are obtained as orange-brown powder. 1H NMR (400 MHz, DMSO-ds) δ = 4.68 (s, 2H, NH2), 6.58 (m, 2H, Ar-H), 9.05 (s, 1H, OH); EI-MS: m/z 145 [M]+ Example 7 Preparation of 2-trifluoromethoxy-4-(phenyldiazenyI)phenol At 0°C, 10.23 ml (0.11 mmol) of aniline are added dropwise with vigorous stirring to 50 ml of HC1 (semiconc). Afterwards, at 5° - 0°C, 8.1 g (0.117 mol) of NaN02 (dissolved in 30 ml of water) are added dropwise and, on completion of addition, the solution is stirred for a further 20 minutes. In a further flask, 20.0 g (0.12 mol) of 2-trifluoromethoxyphenol are dissolved in 140 ml of 2N NaOH and precooled to 0°C. The above freshly prepared diazo solution is added to this solution at such a rate that the internal temperature does not rise above 5°C. During the addition, the pH is monitored regularly and, if necessary, made alkaline again by means of Na2CO3. On completion of addition, the mixture is allowed to warm to room temperature and stirred for a further 30 minutes, and the suspension is then adjusted to pH 3-4 using 2N HC1. The product is filtered off with suction and washed repeatedly with water. After drying in a vacuum drying cabinet, 26g (81%) of the desired light brown azo compound are obtained. Example 8 Preparation of 4-amino-2-trifluoromethoxyphenol 25 g (0.09 mol) of 2-trifluoromethoxy-4-(phenyldiazenyl)phenol from Example 7 and 1 g of Pd/C (10%) are initially charged in 350 ml of ethanol. The solution is degassed and aerated with hydrogen. The mixture is stirred at room temperature under a 1 bar hydrogen atmosphere for 72 hours. On completion of hydrogen uptake, the catalyst is filtered off and the filtrate concentrated on a rotary evaporator, in the course of which the product already crystallizes out. The resulting solid is filtered off with suction, washed with a little cold ethanol and dried under high vacuum for 4 hours. 8.5 g (50%) of the desired compound are obtained as a light brown powder. 1'H NMR (400 MHz, DMSO-d6) δ = 4.72 (s, 2H, NH2), 6.42 (d, 1H, J = 8.6 Hz, Ar-H), 6.5 (s, 1H, Ar-H), 6.72 (d, 1H, J = 8.6 Hz, Ar-H), 8.9 (s, 1H, OH); EI-MS: m/z 193 [M]+ WE CLAIM: 1. Process for preparing compounds of the formula (I) (Formula Removed) in which m is 0, 1, 2 or 3 and n is 1, 2, 3 or 4, where the sum of m + n is a maximum of 4, and R1 is hydrogen, C1-C12-alkyl or C5-C15-arylalkyl and R2 is in each case independently C1-C12-fluoroalkyl, C1-C12-fluoroalkylthio or C1-C12-fluoroalkoxy and Hal is in each case independently bromine, chlorine or fluorine, characterized in that • in a step Al), compounds of the formula (II) (Formula Removed) in which p is 0, 1, 2 or 3 and R3 is in each case independently fluorine, chlorine, bromine, iodine, cyano, thiocyanato, hydroxysulphonyl or alkali metal salts thereof, nitro, C1-C12- alkyl, C1-C12-fluoroalkyl, C1-C12- fluoroalkyoxy, C1-C12- fluoroalkylthio, C1-C12-alkoxy, C1-C12-alkoxycarbonyl, di(C1-C12-alkyl)amino, C4-C14-aryl or C5-C15-arylalkyl are converted to diazonium salts of the formula (III) (Formula Removed) in which An is the anion of an acid and • in a step A2), the diazonium salts of the formula (III) are reacted with compounds of the formula (IV) (Formula Removed) in which m, n, Hal and R2 are each as defined under the formula (I) in the presence of a base to give compounds of the Formula (V) (Formula Removed) and • in a step B), the compounds of the formula (V) are converted using reducing agent to the compounds of the formula (I) in which R1 is hydrogen and • in a step C), these compounds are converted by O-alkylation to compounds of the formula (I) in which R1 is C1-C12-alkyl. and • in a step D), the compounds of the formula (I) are converted by reacting with compounds of the formulae (VIIa) or (VIIb) (Formula Removed) in which R4 is 2,4-difluorophenyl, 4-fluorophenyl, 2,3-difluorophenyl or 4-fluoro-3-chloro- phenyl and R5 is optionally mono- or poly-chlorine- or -fluorine-substituted phenyl to compounds of the formula (VIII) (Formula Removed) in which R1, R2, R4, Hal, n and m are each as defined above or in Claim 1. 2. Process as claimed in claim 1, wherein 4-amino-2,3-difluorophenol, 4-amino-2,5-difluorophenol, 4-amino-2,6-difluorophenol, 4-amino-2-fluorophenol, 4-amino-3- chloro-5-fluorophenol, 4-amino-3-chloro-2-fluorophenol, 4-amino-5-chloro-2-fluoro- phenol, 4-amino-3-bromo-5-fluorophenol, 4-amino-2-(trifluoromethoxy)phenol and 4-amino-3-(trifluoromethoxy)phenol are prepared. 3. Process as claimed in one or more of claims 1 and 2, wherein a further step E) • the compounds of the formula (VIII) are converted by reacting with compound of the formula (IX) (Formula Removed) in which R6 is C1-C12-alkyl, C5-C15-arylalkyl or C4-C14-aryl to compounds of the formula (X) (Formula Removed) in which R1, R2, R4, R6, Hal, n and m are each as defined above or in Claim 1. 4. Compounds of the formula (I), excluding: 4-amino-3,5- difluorophenol, 4-amino-2,5-difluorophenol, 4-amino-2,6-difluorophenol, 4-amino-2-chloro-6-fluorophenol, 4-amino-2-chloro-3-fluorophenol, 4- amino-2-chloro-5-fluorophenol, 4-amino-2-bromo-5-fluoro-phenol, 4- amino-2-fluorophenol, 4-amino-3-fluorophenol, 4-amino-2- (trifluoromethyl)-phenol, 4-amino-5-chloro-2-(trifluoromethyl)phenol, 4- amino-2-chloro-6-(trifluoromethyl)phenol and 4-amino-3- (trifluoromethyl) phenol. 5. Compounds of the formula (V), excluding: 3,5-difluoro-4- phenylazophenol, 3-fluoro-4- phenylazophenol, 3-fluoro-4-(4'- nitrophenylazojphenol, 3-fluoro-4-(3'-nitrophenyl-azo)phenol, 3-fluoro-4- (4'-thiocyanatophenylazo)phenol, 3-fluoro-4-(4'-sulphophenylazo)phenol, ethyl 4-(2'-fluoro-4'-hydroxyphenylazo) benzoate, 2-fluoro-4-(4'-fluoro- phenylazo)phenol, 2-fluoro-4-(3'-fluorophenylazo)phenol, 2-fluoro-4-(4'- sulpho-phenylazo)phenol, ethyl 4-(3'-fluoro-4'-hydroxyphenylazo)benzoate, 2,3-difluoro-4-(4'-iodophenylazo)phenol, 2,3-difluoro-4-(4'-sulphophenyl- azo)phenol and 2,6-difluoro-4-(2'-bromophenylazo)phenol, 3- (trifluoromethyl) -4- (phenylazo)phenol and 3- (trifluoromethyl) -4- (4'-sodium sulphonate phenylazo)phenol. 6. Process for preparing compounds of the formula I substantially as hereinbefore described with reference to the foregoing examples. 7. Compound of Formula I substantially as hereinbefore described with reference to the foregoing examples.

Documents:

1570-del-2004-abstract.pdf

1570-DEL-2004-Assignment.pdf

1570-del-2004-claims.pdf

1570-del-2004-complete specification (granted).pdf

1570-del-2004-correspondence-others.pdf

1570-del-2004-correspondence-po.pdf

1570-del-2004-description (complete).pdf

1570-del-2004-form-1.pdf

1570-del-2004-form-18.pdf

1570-del-2004-form-2.pdf

1570-del-2004-form-3.pdf

1570-del-2004-form-5.pdf

1570-del-2004-form-6.pdf

1570-del-2004-gpa.pdf

1570-del-2004-petition-138.pdf