DE1543953C - Process for the nuclear hydroxylation of an aromatic compound - Google Patents

Description

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The invention relates to a process for core this initially in a saturated tertiary aliphahydroxylation an aromatic compound. Table alcohol dissolved and aromatic with anhydrous sodium Compounds containing one or more sulfate are treated with two layers Containing hydroxyl groups on the aromatic ring, form. The main part of the hydrogen peroxide find multiple uses in the chemical field. 5 containing alcohol layer with about 6% hydrogen-For example phenol is an important intermediate peroxide is then used as an oxidizing agent, product for the production of phenolic resins, epoxy and also for the formation of unstable per resins, Nylon, weedkillers, as well as acidic catalyst oxide also in terselective Dissolve solvents for refining tertiary butyl alcohol. These preparatory oils, Salicylic acid, picric acid and germ-io measures for the production of hydrogen peroxide Killing paints, α- and / S-naphthol are in anhydrous form and the usable katain Colorants, artificial odorous substances and pigment oxides are cumbersome and disadvantageous for ments, antioxidants for rubber, greases, an industrial process.

Oils, insecticides or in organic synthesis According to French patent 1,384,710

used by fungicides and fragrances. 15 and its additional patents 85 435 and 85 747

Even aromatics with two hydroxyl groups, such as are used for the production of phenols by oxy-

Hydroquinone, catechol and dihydroxynaph- dation of aromatic hydrocarbons organic

thalin, are versatile. For example, hydroperoxides such as benzyl hydroperoxide, cyclohexyl

Hydroquinone is an important component in photographic hydroperoxide or ethylbenzene hydroperoxide and

fish developers, in intermediate products for coloring boric anhydride or boric acid ester as a catalyst

substances, it also serves as an antioxidant. used. The organic peroxides to be used

In addition, it is an intermediate product that must first be made from hydrocarbons or

development of mono- and dibenzyl ethers of hydroalcohols and hydrogen peroxide or similar

quinone, which is obtained in fragrances and plastics. Furthermore arise with this

be turned. Catechol has numerous processes not only phenols but also alcohols

■ Possibilities of turning in photography, for dyes and aldehydes, which have to be separated, if

substances, antioxidants and stabilizers against the phenolic compounds for the aforementioned

Light. Furthermore, it is an intermediate product intended to be used.

Production of catechol dimethyl ether and the invention has therefore set itself the task of

-monomethyl ether (guaiacol). 30 the core hydroxylation of aromatic compounds

Hydroquinone is usually produced by fertilizing directly using hydrogen peroxide, that is

one aniline using manganese dioxide with elimination of intermediate stages, in counter-

oxidized to quinone and this then to hydrate an easily separable catalyst and

chinone reduced. Pyrocatechol is usually used to prevent the formation of alcohols and

by melting o-phenolsulfonic acid 35 aldehydes.

with caustic potash at a relatively high tempe- The invention relates to a method for core

temperature of about 35O ⁰ C or by heating by hydroxylation of an aromatic compound of the

Guaiacol made with hydriodic acid. That general formula

the latter procedure is quite costly and “. y

Time consuming, since guaiacol in turn by a 40 mn

cumbersome process is to be established. in Ar a mononuclear or polynuclear aromatic

Of the aromatic compounds with several hydrocarbon radicals, R primary, secondary or hydroxyl groups, pyrogallol (1,2,3-trihydroxy tertiary alkyl groups, cycloalkyl, hydroxyl, alkbenzene) is used as a protective colloid in the production of metal oxyl or hydroxyalkyl groups, X hydrogen colloidal solutions in photography, for 45 atoms, halogen atoms or nitro groups, dyes, photomechanical etchants, oxidation m and η are integers S: 1 and m + η ^ 5, preventers used in lubricating oils and the like. Phloro- by treating the aromatic compound with gucine (1,3,5-trihydroxybenzene) is used in the analy- hydrogen peroxide. The process is characterized by chemical chemistry and in dyes and art that the reaction is used in a resin. 50 Temperature in the range of about -10 to about

With regard to the importance of the mentioned +100 ⁰ C, preferably about 0 to 40 ⁰ C, in contrast

aromatic compounds containing hydroxyl groups were carried out by hydrogen fluoride,

there is quite considerable interest in core hydroxylation according to the present invention

drive to their manufacture. The invention was des- the process is partially split off ter-

half the task is based on an improved process 55 tiary alkyl groups, however, as oxidation

only phenols are formed for the production of such aromatic products containing hydroxyl groups,

to develop matic compounds that are simply As starting materials for the process of the invention

is feasible and in one stage using aromatic hydrocarbons and serve

Easily accessible starting materials runs. their derivatives, primary and secondary

U.S. Patent 2,395,638 describes a 60 alkyl aromatic, e.g. B. toluene, ο-, m-, p-xylene, ethyl process for core hydroxylation of aromatic benzene, cumene (isopropylbenzene), n-propylbenzene, Compounds by treating the aromatic cyclohexylbenzene, 1-methylnaphthalene, 1-ethylnaph compound with hydrogen peroxide in the presence of thalin, 1,2-dimethylnaphthalene, methylbiphenyl and a metal oxide that forms unstable peracids. Ethylbiphenyl; hydroxy-substituted aromatic compounds The essential condition here, however, is that 65 bonds such as phenol, hydroquinone, catechol, initially worked in a practically anhydrous environment with resorcinol, 1-hydroxynaphthalene and 1,2-dihydroxy will. Since usually of aqueous naphthalene; alkoxy-substituted aromatic compounds 30% Hydrogen peroxide is assumed, must fertilize such as anisole, phenetol, n-propoxybenzene, o-Me-

ethyl anisole, m-methyl anisole and p-methyl anisole, halogen-alkyl aromatics like ο-, m-, p-chlorotoluene, o-, m-, p-bromotoluene, o-chloroethylbenzene, o-bromoethylbenzene, 2-chloro-l-methylnaphthalene and aromatic Carbohydrate derivatives of aromatic compounds such as 1,1-diphenyl-1-deoxy-D-sorbitol and 1,1-ditolyl-1-deoxy-D-sorbitol.

Examples of tertiary alkyl substituted aromatics which can be used as starting materials in the process of the invention are mono- and polynuclear aromatic compounds having a tertiary alkyl group containing four to about twenty, for example four to about eight carbon atoms. Particular examples include tert-butylbenzene, p-tert-butyltoluene, di-tert-butyl-benzene, p-tert-amyltoluene, tert-amylbenzene, tert-hexylbenzene and higher homologues thereof, p- tert-butylphenol, p-tert-amylphenol, p-tert-hexylphenol, o-tert-butylphenol, o-tert-amylphenol, tert-butylnaphthalene, tert-amylnaphthalene and higher homologues thereof, 1-tert .-Butyl-2-naphthol, 1-tert-amyl-2-naphthol, 1-tert-hexyl-2-naphthol, tert-butylanthracene, tert-hexylanthracene, tert-heptylanthracene, tert-octylanthracene, ) 1 - tert. - butyl - 2 - anthrole, 1 - tert. - Amyl-2-anthrol, 1 - tert. - Hexyl - 2 - anthrole, tert. - Butylphenanthrene, tert. - Amylphenanthrene, tert. - Hexylphenanthrene, tert. - Heptylphenanthrene, tert. - Octylphenanthrene, 1 - tert. - butyl - 2 - phenanthrole, 1 - tert. - Amyl-2-phenanthrole and higher polycycles with tert-alkyl groups; o-tert-butylchlorobenzene, p-tert-butylchlorobenzene and higher halogenated mono- and polycycles. All aromatic starting compounds. genes can also be expressed by the general formula

reproduced, in which the symbols have the meaning given above.

It has been found that non-alkylated benzene derivatives usually less extensively than their counterparts alkylated or hydroxylated derivatives react and form a mixture that is difficult to dismantle of polyhydroxy aromatics and other derivatives thereof.

The hydrogen peroxide used can be in aqueous solution with 5 to 90 percent by weight or more Hydrogen peroxide are present. 30 to 50 or higher weight percent solutions are preferred. At lower concentrations, the aqueous portion of the solution leads to the dilution of the catalyst serving hydrogen fluoride, which is usually introduced into the reaction zone in anhydrous form. If the concentration of the hydrogen fluoride catalyst is introduced below about 60 to 70 percent by weight, the reaction proceeds slowly and finally stops. The reaction if something progresses above a concentration of 60%, it is preferable to keep it Concentration of hydrogen fluoride greater than about 80%. Applying a relative concentrated hydrogen peroxide solution is therefore appropriate. If desired, boron trifluoride can also be used or ferrofluoborate of the formula

FeF _a BF ₃

can also be used as a promoter. The catalytic activity is increased by it, and it increased yields of the desired product are obtained.

The reaction is preferably carried out at atmospheric pressure, although at a somewhat higher level Pressure can be applied. It is necessary that the essential part of the reactants and the catalyst can be kept in the liquid phase. The relative proportions of monohydroxylated resp. polyhydroxylated aromatic compound in the final product can be changed by that the ratio of the aromatic starting compound to the hydrogen peroxide used regulates. For example, if a monohydroxylated aromatic compound is desired, then the aromatic starting compound are present in excess. If, on the other hand, a multiply hydroxylated aromatic compound is the primary desired product, one becomes the relative amount of hydrogen peroxide raise. Generally speaking, the aromatic compound is said to be hydrogen peroxide in a molar ratio ranging from about 3: 1 to about 15: 1.

The process of the invention can be carried out either in a single batch or continuously. For example, if you are working in a single batch, you give the aromatic compound together with the hydrogen fluoride in a suitable device, for. B. a stirred autoclave. The hydrogen peroxide is added and the mixture is subjected to the reaction conditions given above for a predetermined residence time. The residence time can vary from about ^{1 and} ₂ hours to about 5 hours or more. After the desired residence time has elapsed, the catalyst is driven out of the reaction vessel by passing a stream of inert gas, such as nitrogen, through it. The reaction product is then obtained in the usual way. For example, the product is washed with an inert organic solvent, any hydrogen fluoride still present is neutralized, the solvent is driven off and the reagent is fractionally distilled in order to obtain the desired compounds.

The process of the invention can also be carried out continuously. In this case the aromatic compound continuously introduced into a reaction zone, which is set to the correct temperature and pressure conditions is held. Also, hydrogen peroxide is continuously added to the Reaction zone introduced. The reaction is allowed to proceed in the presence of the hydrogen fluoride catalyst, which is present in the reaction vessel or which is introduced continuously. The specified dwell time is about 0.01 to about 2 hours, after which the product is continuously withdrawn from the vessel will. Hydrogen peroxide and hydrogen fluoride can be mixed beforehand, and the resulting Solution is continuously added to the vessel. The reaction product is released from the catalyst separated and subjected to a treatment similar to that described above for the recovery of the desired aromatic hydroxyl compound has been specified.

Examples of aromatic hydroxyl compounds made by the process of the invention are phenol, o-hydroxytoluene, (o-cresol), p-hydroxytoluene, (p-cresol), 2-hydroxy-p-xylene,

4-hydroxy-o-xylene, 2-hydroxyethylbenzene (o-ethylphenol), 2,4-dihydroxyethylbenzene, 2-hydroxy-l-methylnaphthalene, 2 - hydroxy - 1 - methylanthracene, pyrocatechol, hydroquinone, hydroxyquinone, pyro-

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Gallol, guaiacol, 2-hydroxyphenetol, 2,4-dihydroxy borrowed manner as in Example 1 has been treated

anisole, 2 - hydroxy - ρ - methyl anisole, 2 - hydroxy- was. Distillation of the residues provided a

o-ch! ortoluene and l, l-di- (p-hydroxyphenyl) -l-deoxy mixture of o-ethyl-phenol, p-ethyl-phenol and

D-sorbitol. Ethyl hydroquinone.

The following examples serve to further explain 5

refinement of the method of the invention. Example 3

^e ' ^s P' ^e Into an autoclave equipped with a turbo mixer 368 g (4.0 mol) of toluene were put into an autoclave made of rust-resistant io and 500 anisole mixer equipped with a turbo stainless steel mixer cm ^{3 of} n-pentane introduced as a solvent, steel introduced. Subsequently, while the autoclave was placed in an ice bath, 218 g (10.9 mol) of hydrogen fluoride were introduced and then so that the temperature was maintained in the range from about 0 to gradually 43.7 g of 30 weight percent aqueous 5 ° C. Then 235 g of hydrogen peroxide solution were added in the course of 65 ml of anhydrous hydrogen fluoride and 32.8 g of a 30 mm groove. The molar ratio of toluene to 15 percent strength by weight aqueous hydrogen peroxide solution was 10.3: 1. The mixture according to Example 1 is added. The addition was stirred for an additional 10 minutes. While the hydrogen peroxide took place for a total of 75 minutes residence time, the temperature became about 53 minutes. After the addition had ended, the temperature was kept in the range from about 26 to 34.degree. the molar ratio of anisole to hydrogen peroxide. After the specified residence time had elapsed, the 20 was 3.4: 1. The reaction mixture was stirred for a further 7 minutes of hydrogen fluoride from the autoclave with a stick in order to flush the total residence time to 60 minutes with material flow for 2 hours before the autoclave was brought in. After this time the fluorine was opened. The reaction product was purged into a beaker of nitrogen flow for 2 hours. The reaction was transferred and the parts of the reaction vessel were then poured into a vessel and washed with benzene. The washing liquid autoclave parts were washed with benzene. After was added to the reaction product. The solution that separated the benzene from the reaction product was decanted into another beaker and a lower, aqueous, acidic layer was separated from the small amount of an acidic, aqueous layer of benzene. The latter was then neutralized, separated off, and the product, which was somewhat insoluble in benzene, contained the benzene was removed by distillation and held. The decanted benzene solution was treated to remove residual hydrogen fluoride under reduced pressure and fractionally distilled to remove the residue. An infrared analysis of the pro-suction filtered and the removal of benzene ducts showed the presence of o-methoxyphenol and unreacted toluene distilled. The benzene and p-methoxyphenol.
insoluble product that is left in the reaction vessel

remained, was with the product in the aqueous, B ice ρ ie 1 4
acidic phase combined and extracted with ether.

The extract was used to remove residual fluorine- 268 g (2.0 mol) of tert-butylbenzene were added to a Treated with hydrogen and rust-distilled from an autoclave equipped with a turbo mixer to remove ether. The residue from both product portions 40 solid steel given. Then the was combined and autoclave closed under reduced pressure and fractionated with 452 g of water fluorine distilled. 21.9 g of isomeric material were obtained. Over the course of 28 minutes were Cresols, consisting of 13.9 g of o-cresol, 7.4 g of p-Kre and 21.9 g of an aqueous 30 weight percent sol and 0.6 g m-cresol. hydrogen peroxide solution gradually into the

45 vessel given. The mixture was stirred for a further 7 minutes

Example 2 th stirred, and for the entire 35 minutes

Residence time became the temperature by immersion

The feed contained 424 grams (4.0 moles) of ethyl held in an ice bath at about 0 to 6 ° C. Subsequent

benzene. It was placed in an autoclave, which was biting from the hydrogen fluoride from the autoclave

Game 1 given type described, whereupon 215 g 50 with a nitrogen flow in the course of about

anhydrous hydrogen fluoride and 41.5 g 30 ° / ₀ ige rinsed for 2 hours before the autoclave was opened

Hydrogen peroxide solution according to the measure.

Examples of Example 1 were introduced. The reaction product was placed in a beaker Autoclave was placed in an ice bath and while transferred, the autoclave parts were rinsed with benzene of the reaction time of 60 minutes was washed to 55, the washing liquid became the reagent Temperature in the range of about 0 to 7 ° C added tion product. Then the solution was in held. After this time, the fluorine was poured into another beaker, resulting in the separation of hydrogen from the autoclave with the help of an embroidery of a small amount of an aqueous, acidic Rinsed stream of material for about 2 hours. Then layer was led with a benzene-insoluble product, the autoclave was opened and the reaction product 60. The decanted benzene solution was used for removal won. The autoclave was treated with benzene, residual hydrogen fluoride, and aqueous wash, and the washing liquid was extracted with the alkali and distilled. 42 g were obtained Reaction product combined. As the solution in a di-tert-butylbenzene. The aqueous, alkaline solution Another vessel was decanted, a layer entered was acidified with hydrochloric acid and with ether separation a. After neutralization and recovery, 65 extracted. The ether was draining from the extract of the benzene by distillation, the distilled, and a residue remained, the one Residues with those from the ether extract of the mixture of phenol, catechol, hydroquinone combined aqueous layer, which also represented ahn- and traces of tert-butylphenol. This

Composition was determined by infrared analysis. The amounts corresponded to 30, 13 and 35% of the theoretical yields based on the hydrogen peroxide.

Example 5

424 g (4.0 mol) of m-xylene was treated in a similar manner as in the above examples, that is, 222 g of anhydrous hydrogen fluoride and 43.7 g 30gewichtsprozentige hydrogen peroxide were added in the autoclave in a temperature range of about 0 to 12 ⁰ C. was held. The hydrogen peroxide was added over the course of about 30 minutes, followed by stirring for a further 30 minutes, which means a total residence time of 60 minutes. At the end of this time the hydrogen fluoride was purged with a stream of nitrogen and the reaction product was recovered and treated in a manner similar to the previous examples. The residues from the benzene layer and the aqueous layer were combined and fractionally distilled under reduced pressure. Infrared analysis of the cuts resulting from the distillation showed the presence of 2,4-xylenol (ie 2,4-dimethylphenol), 2,6-xylenol and 3,5-xylenol, with 2,4-xylenol making up the largest proportion.

Example 6

A charge of 507 g (4 moles) of o-chlorotoluene and 500 cmf of n-pentane was placed in an autoclave. Then 208 g of anhydrous hydrogen fluoride and 38.2 g of 30 weight percent hydrogen peroxide solution were added. The hydrogen peroxide was added in the course of 80 minutes, while the autoclave temperature was kept ^{in the range from about 0 to 6 ° C. by means of an ice bath.} After the addition of the hydrogen peroxide had ended, the reaction mixture was stirred for a further 10 minutes, which means a total residence time of 90 minutes. At the end of this time, the hydrogen fluoride was purged from the autoclave with a stream of nitrogen over the course of about 2 hours. The reaction product was treated in a similar manner to the previous examples. The desired hydroxylated o-chlorotoluene was obtained by pentane extraction.

For example, 7

396 g (3.7 mol) of o-cresol were treated with 44.8 g of 30 percent strength by weight hydrogen peroxide solution and 223 g of anhydrous hydrogen fluoride for a total residence time of 60 minutes in an autoclave, the temperature of which was kept ^{in the range from about 2 to 7 ° C. by an ice bath} would. At the end of the residence time, the hydrogen fluoride was purged with a stream of nitrogen and the reaction product was treated in a manner similar to the previous examples. After the solvents containing benzene and ether had been removed, the residues were fractionally distilled under reduced pressure. The below 2.4 Torr at 120 to 15O ⁰ C boiling cuts with 2,3-dihydroxytoluene were recovered. A small amount of 2,5-dihydroxytoluene was also recovered.

Example 8

A mixture of 282 grams (3.0 moles) of phenol and 220 grams of benzene was placed in a turbo-blended stainless steel autoclave. The autoclave temperature was kept in the range from about 20 to 27 ^{° C.} 423 g of hydrogen fluoride and 32.8 g of 30 weight percent hydrogen peroxide solution were introduced into the autoclave. The hydrogen peroxide was added over the course of about 44 minutes. The reaction mixture was stirred for an additional 60 minutes, which means a total residence time of 60 minutes. After this time had elapsed, the hydrogen fluoride was purged from the autoclave with a stream of nitrogen for about 2 hours before the autoclave was opened. The reaction product was transferred to a vessel while the autoclave and mixer insert were washed with benzene. The benzene wash was combined with the main product. The benzene solution was then decanted into another vessel, which resulted in the separation of the benzene solution from a lower aqueous layer which contained a small amount of the relatively benzene-insoluble product. The aqueous acidic layer was washed with benzene and. then extracted with ether. Benzene solution and ether extract were neutralized to remove any free hydrogen fluoride that might still be present. It was then filtered with suction. The solvents and unreacted phenol were distilled off by distillation under reduced pressure, and the residue was "crystallized. The infrared analysis of the residue showed that it mainly consisted of a mixture of. Catechol and hydroquinone. ·.: ■ '. ^: " . '■'. ',

Example 9

268 g (2.0 mol) of tert-butylbenzene and 234 g of benzene were introduced into an autoclave of the type described in Example 1. The autoclave was then closed and charged with 233 g of hydrogen fluoride. Thereupon 21.9 g of 30 ° / ₀ sodium hydrogen peroxide were introduced into the autoclave in the course of 45 minutes, slowly. After the addition of the peroxide had ended, the mixture was stirred for a further 10 minutes. The temperature of the autoclave was kept in the range from about 0 to 6 ^° C. during the entire contact time by means of an ice bath. After a total residence time of 45 minutes had elapsed, the hydrogen fluoride was purged with a stream of nitrogen over the course of 2 hours. Then the autoclave was opened and the reaction product was recovered. As in Example 1, the parts of the autoclave were washed with benzene and the washing liquid was combined with the reaction product. When the solution was decanted into another vessel, separation into a benzene-insoluble product and an aqueous, acidic phase occurred. The benzene solution was neutralized to remove residual hydrogen fluoride and then extracted with aqueous alkali. Distillation of the benzene solution yielded about 229 g of tert-butylbenzene and 16 g of p-di-tert-butylbenzene. The alkaline extract was acidified, the released phenolic compounds were taken up in ether, and the ether was distilled off. The composition of the residue was determined by gas-liquid chromatography and infrared spectroscopy. The result was a content of phenol, pyrocatechol, hydroquinone and p-tert-butylphenol in amounts corresponding to 40, 7, 16 and 6% of the theoretical yields.

ino 00 / ΌΟ /.

Example 10

40.5 g (0.21 mole) p-di-tert-butylbenzene and 65 g Benzene (0.83 mole) was placed in an autoclave and mixed with 433 g of hydrogen fluoride and 21.9 g Treated with 30% hydrogen peroxide. During the 55 minute hydrogen peroxide addition the autoclave was maintained at a temperature in the range of about 0 to 6 ° C. After the addition of the hydrogen peroxide, the reaction mixture was stirred for a further 10 minutes. Then the Flush hydrogen fluoride from the autoclave with a stream of nitrogen and open the autoclave. The reaction product was treated in a manner similar to that given above; H. remaining Hydrogen fluoride in the benzene layer was neutralized, extracted with an aqueous alkali and distilled to obtain mono- and di-tert-butylbenzene. The alkali soluble product showed a content of phenol in 33% yield, pyrocatechol in 21% yield, hydroquinone in 30% and tert-butylphenol in 1% yield.

Example 11

368 g (2.0 mol) of 1-tert-butylnaphthalene were with Treated hydrogen fluoride and hydrogen peroxide in a similar manner as in Example 1 under similar reaction conditions. Then the hydrogen fluoride flushed with a stream of nitrogen from the reaction vessel over the course of 2 hours and that Reaction vessel opened. The reaction products were prepared in a manner similar to the above Examples gained. Infrared and gas-liquid chromatography demonstrated the presence of hydroxynaphthalene, 1,2-dihydroxynaphthalene and di-tert-butylnaphthalene. '

Example 12

396 g (2.0 mol) of l-tert-Amylnaphthalin were as * above with hydrogen fluoride and hydrogen peroxide in a similar manner ¹ * nTderr. Examples. After ίο extraction of the product 'in üjicfli; Way, the analysis showed the presence of hyOTpxynaphthalene, dihydroxynaphthalene and di-tert-amylnaphthalene.

Claims (1)

Claim: Process for the core hydroxylation of an aromatic compound of the general formula RmArX » in which Ar is a mono- or polynuclear aromatic hydrocarbon radical, R is primary, secondary or tertiary alkyl groups, cycloalkyl, hydroxyl, alkoxyl or hydroxyalkyl groups, X is hydrogen atoms, halogen atoms or nitro groups, m and η are integers S: 1 and m + η is ^ 5, by treating the aromatic compound with hydrogen peroxide, characterized in that, preferably about 0 the reaction is performed at a temperature in the range of about -10 to about +100 ⁰ C to 40 ⁰ C, in the presence of hydrogen fluoride.