SE192265C1 - - Google Patents

Description

Inventors: EH DeButts, HL Young, HH Espy and JT Hays Priority Requested Iran March 28, 1960 (USA) The present invention relates generally to the preparation of p-nitroso-N-substituted anilines and in particular to the preparation of p-nitrosodiphenylamine (p- nitroso-N-phenylaniline), which can then be alkylated reductively to N-isopropyl-N'-phenylp-phenylenediamine, which is distinguished by a special form to protect against ozonation and oxidation, and to the preparation of p-nitroso-Nmethylaniline, which an important intermediate in the preparation of vulcanizing agents for certain types of rubber. p-Rhinoso-N-substituted anilines are particularly useful as chemical intermediates, especially in the case that the nitroso group can be reduced to form the corresponding phenylenediamine derivatives. A suitable process for the preparation of these compounds should consist of directly aminating p-nitrosophenol, so that a direct reaction series of Irk phenol could thereby be obtained as starting material. However, this method gives very small yields of 3-5%. The present invention is based on the discovery that p-nitrosophenyl ethers can be prepared by directly reacting p-nitrosophenol with an alcohol under mild conditions with a high yield of ether product. The p-nitrosophenyl ethers thus prepared can then be aminated directly to the corresponding p-nitroso-N-substituted anilines.

Not only are these etherification and amination steps of concern per se, but the ethers obtained by the etherification also represent valuable chemical intermediates for the preparation of p-nitrosophenylamines from p-nitrosophenol. The preference further enables a direct amination series from phenol, since p-nitrosophenyl can easily be obtained therefrom.

Other processes for the preparation of p-phenylenediamines were further more expensive, such as nitrosation and subsequent rearrangement to reduce the corresponding substituted aniline or coupling of a diazotized aromatic amine to an N-substituted aniline β-pair preparation with subsequent reduction.

The present invention therefore provides a process for the preparation of p-nitroso-N-substituted aniline, which is characterized in that p-nitrosophenol is reacted with a primary or secondary alcohol in the presence of an acid at 0-1 ° C. formed the p-nitrosophenyl ether with a primary aliphatic amine or phenylamine in the presence of an acid at 0-160 ° C.

Although the p-nitrosophenyl ethers are known, there has previously been no process for producing them from available raw materials by a direct reaction series. The known procedures are indirect and give added, total exchange. The commonly used method thus involved the reduction of a p-nitrophenyl ether to the corresponding hydroxylamine, which is then coded to the p-nitrosophenyl ether. The isolation of the product usually requires a reasonable distillation with water vapor under reduced pressure. This procedure is not appealing to commercial use. On the other hand, if one tries to prefer p-nitrosophenyl directly with common etherifying agents, mixtures of compounds are obtained in which the ether of the tautomeric oxime form of p-nitrosophenol is the predominant component.

According to the present invention, after the solubilization, the unreacted alcohol reagent containing both the ether product and the unreacted p-nitrosophenol reagent in solution can be replaced by a solvent exchange having a solvent which has a sufficiently low solubility capacity for the p-nitrosphenol and sufficiently dissolves. ether, so that the p-nitrosophenol precipitates and can be easily separated, while the p-nitrosophenol can be recovered to be recycled, the ether product is retained in Riming to be isolated during a subsequent step.

If the alcohol reagent is soluble in water, in the etherification mixture formed after the etherification, the acid and unreacted p-nitrosophenol can be reacted with an aqueous solution of a hash under neutralizing conditions to neutralize the acid and convert the unreacted p-nitrosophenol to the corresponding phenolate. This can then be extracted over to the aqueous phase formed, which is then acidified to convert the phenolate to p-nitrosphenol, which precipitates under these conditions so that it can be separated and recycled. The ether product is obtained as a component in an organic phase, which is also formed during the neutralization, and is further isolated or reacted as desired.

Any primary or secondary alcohol can be used as the alcohol reagent. However, the commonly used and preferred alcohols contain at most about 30 carbonates. Examples of alcohol reagents which can be used in the practice of the invention include npropanol, isobutyl alcohol, n-decyl alcohol, lauryl alcohol, tridecyl alcohol, stearyl alcohol, n-octacosanol, ceryl alcohol, cinnamon alcohol, tetrahydrofurfurylalkyl alcohol, furrafurfurylalkyl, alcohol , p-methylbenzyl alcohol, p-chlorobenzyl alcohol, propargyl alcohol, isopropylpropargyl alcohol, 2-phenylethanol, p-hexoxybenzyl alcohol, p-methoxybenzyl alcohol, p-nitrobenzyl alcohol and hexamethylene glycol. Other examples of such alcohol reagents are shown in the following table. The present preferred alcoholic agents of the invention may be represented by the structural formula R-C-OH in which each R symbol represents a radical selected from the group consisting of vale, alkyl, alkenyl, alkinyl, phenyl, alkylphenyl, phenylalkyl, alkoxyphenyl, phenylalkenyl, alkoxyalkyl, hydroalkyl, cycloaliphatic radicals, halophenyl, nitrophenyl, furan and tetrahydrofuran, the alcohol containing at most 30 carbon atoms.

Molar ratio of alcohol to p-nitrosophenol Or generally about 1: 1 to 100: 1. A preferred, non-toxic material is often 10-30 mole percent pnitrosophenol, 70-90 mole percent alcohol and 0.25-10 mole percent acid.

The reaction between the p-nitrosophenol and the alcohol is suitably carried out at a temperature of about 15-70 ° C. The reaction time is usually at least about 2 minutes and at most about 500 minutes. Under the preferred temperature conditions it is usually about 10-200 minutes and often about 15-150 minutes. Although hazardousness usually takes place under temperature and time conditions which are outside these preferred limits, the yield of product under such conditions is usually lower than is economically feasible in commercial operation, due to undesirable side reactions at higher temperatures and too low reaction rates at store temperature.

The contact time of course depends on the applied temperature. Since higher temperatures promote higher etherification rates and different alcohol reagents are used in the practice of the invention, it is important to keep the time and temperature within the above ranges to obtain optimum yield.

The pressure is of no great importance for the etherification except that it must be sufficiently high to retain the reagents in the liquid phase. Thus, a pressure is applied which is at least equal to the ang pressure of the system.

An arbitrary acid can be used as a catalyst in carrying out the reaction, although stronger acids are preferred because they give a higher reaction rate. Unless an acid catalyst is used, the joke does not react. The reaction rate depends on the amount of catalyst in the system, so that higher reaction rates are obtained when using a larger amount of catalyst. The molar ratio of the acid catalyst to p-nitrosophenol introduced into the etherification reaction is generally about 1: 1 and usually about 0.005: 1 to 0.2: 1. With a catalyst content exceeding that corresponding to the molar ratio 1: 1, intrada often joke onskvarda side reactions with consequent impaired exchange of ether product. For a given catalyst there is usually an optimal content, sox depends on the temperature and the ether formed. When using sulfuric acid as catalyst, a content of about 2 mol% shaved on the p-nitrosophenol reagent is thus suitably applied. Examples of acid catalysts which may be mentioned are sulfuric acid, chloroquatic acid, phosphoric acid, p-toluenesulphonic acid, bromobatic acid, iodovatic acid, iodic acid, perchloric acid, periodic acid, nitric acid, benzenesulphonic acid, methanesulfuric acid, orthophosphoric acid, pyrophosphoric acid, pyrophosphoric acid, , Aluminum chloride, boron trifluoride, ferric chloride, acid clays, for example silica-alumina, superfiltros and ion exchange resins in the acid form, such as sulfonated polyvinylbenzene. Solid acid catalysts are used with particular advantage in applying the invention as baths, for example columns or layers when working with solid catalyst bath.

Although any acidic catalyst can be used in the practice of the invention, the yield of ether product is often condensed with carbonic acids other than as a catalyst, since these acids have a tendency to produce uncomplicated side reactions in the ether mixture. Some high oxygen acids, such as nitric acid, perchloric acid and periodic acid, constitute less suitable inorganic acid catalysts due to the oxidative tendency of these acids in the reaction mixture with consequent narrowing of the ether product yield.

The reaction rate and equilibrium concentrations depend on the levels of product and reagents. The highest yield of ether under given conditions is thus obtained if the alcohol reagent serves as the sole solvent for the ether mixture and the p-nitrosophenol is kept in the alcohol reagent at the maturity level, as in the form of a slurry, as the p-nitrosophenol bat usually contains , 2-3.5 molars and probably 1-3 molars.

The feed itself can be suitably carried out using the alcohol as the sole solvent for the reaction mixture for the above reasons. However, any suitable solvent which is chemically inert under the etherification conditions of the invention may be used in the etherification in which alcohols which are solid under the reaction conditions are formulated and to assist in the solution of the liquid alcohol reagent.

As auxiliary solvent, an agent in which the unreacted p-nitrosophenol Or is very unresponsive or almost insoluble is suitably used, so that the separation of unreacted p-nitrosophenol for further reaction is facilitated. Carbohydrate solvents were suitably used as Adana auxiliary solvents and substituted, as desired, the alcohol reagent suitably downstream of the ether, to facilitate precipitation and separation of the p-nitrosophenol for recycling, while the ether product Mlles remained in solution.

The equilibrium of the etherification reaction can be shifted to the ether side by fractional vacuum distillation of the ether water from the reaction mixture. The alcohol reagent can also be partially evaporated in this way as an azeatropic mixture of water and alcohol.

Although a conversion of p-nitrosophenol to ether per passage of about 45-55% to about 60-65% can thereby be achieved, a further improvement of the turnover per passage up to about 95-99% can be achieved. , by bubbling dry gas or steam or driving through the etherification mixture. This improvement is due to the fact that the feed water regenerates Ores as an Aterflode during vacuum fractionation. This water may require the etherification reaction to such an extent that undesirable side reactions do not occur, so that the distillation can in practice only be carried out for such a short time that such side reactions are prevented, which in turn reduces the Wining of turnover per passage which could otherwise be achieved.

By "drying" is meant in this context, that dry ie. substantially anhydrous, gas or anga, hereinafter referred to as "drying gas", is passed through the etherification mixture for a part of or during the feeding time and that said drying gas is separated from the reaction mixture without reflux. The leaving drying gas, as an azeotrope or as a mat, enters with it the ether water which was formed during the ether. In all continuous embodiments, it is preferred to supply the drying gas continuously as a separate stream and to divert the frail reaction mixture at the same rate, as will be described in connection with the description of the drawings. If the drying gas is formed from an alcohol, the same alcohol as the etherifying reagent, it can, especially at work batchwise, be present in the other etherifying reagents and be introduced into the etherification zone together with them. In this case, the resulting ether mixture is kept under ether conditions under temperature and pressure conditions, so that the alcohol is brought to a boil, thereby forming rising alcohol vesicles, which effect drying. Other liquid desiccants can also be added together with the embryo for drying and evaporated for drying.

Any suitable desiccant can be used, if only Or in gaseous form and with the exception of the alcohol reagent Or chemically inert, as it bubbles through the ether mixture, Sadana gases such as carbon dioxide, hydrogen, nitrogen and flue gases constitute suitable desiccants. Preferably, an alcohol and preferably the same alcohol as that introduced into the feeding zone is used as the etherifying reagent, as a desiccant, since this avoids separation of the desiccant and the alcohol reagent. As desiccants, alcohol reagents containing 3-5 carbon atoms in the molecule are suitably used, i.e. n-propanol, isopropanol, n-butanol, isobutanol, n-amyl alcohol, isoamyl alcohol and the corresponding unsaturated alcohols. These alcohols agora the preferred desiccants due to their pressure ratio to the ether water in the ether mixture, so that the concentration of water in the surface of the water during the bubbling becomes higher On the concentration of the water in the liquid, so that less desiccant is required per volume of water removed. lagre On vatskans. Of these preferred alcoholic desiccants, n-butanol and Cralkoholes are preferred. Heist n-butanol is used, since in this case the water content is often Or 10 and often several times higher than the water content of the liquid, which Or is higher than the water content obtained by using other of the preferred alcohols having 3-5 carbon atoms. . Other liquid desiccants may be used singly or diluted with an inert gas, such as nitrogen or carbon dioxide, to keep the desiccant in gaseous form. Dilution of the desiccant involves the introduction of an additional component into the reaction mixture with the consequent defense of the separation, so that this solution is dispensed with when applying the invention in practice. However, this solution is advantageously applied if a high molecular weight alcohol reagent is to be used as a desiccant and a diluent necessary to keep the alcoholic desiccant in vapor form. However, the pressure and temperature conditions of the etherification usually promote evaporation of the liquid desiccant, so that dilution is not required.

As examples of desiccants which may be used in the practice of the invention, in addition to those mentioned above, there may be mentioned the carbohydrates, such as benzene, toluene, n-hexane and cyclohexane, esters, such as ethyl acetate, n-propyl acetate, n-butyl formate, n-butyl acetate, isobutyl formate and isobutyl acetate, 4- chlorinated k-olvates, such as chloroform, carbon tetrachloride and ethylene chloride, ketones, such as diethyl ketone and methyl ethyl ketone, and ethers, such as di-butyl ether, diethyl ether and di-n-propyl ether. According to the preferred method, the desiccant used is matted and has a boiling point of 1 ° H about 70 ° C at 1 mm Hg, since the higher boiling substances and some unsaturated substances, in many cases of concern, are so unstable that they can undergo flake probing. said that pollutants are introduced or undesirable side reactions occur with the following responsibilities regarding purification and neglected exchange.

The drying is carried out under arbitrary conditions concerning temperature and pressure, which are suitable for the etherification. It is carried out suitably under temperature and pressure conditions during the etherification conditions, which contribute to the reduction of undesirable side reactions during the etherification. These conditions, furthermore, when a normal liquid desiccant is used, are also suitable for keeping this agent in vapor form. In most cases, the drying is thus carried out using a normal liquid desiccant under reduced pressure. For example, if p-nitrosophenol is to be filtered with n-butanol at about 55 ° C and n-butanol is used as desiccant, the ether mixture is dried during drying at a pressure of about 35-45 mm Hg. If it is desired to use flakes of a different drying temperature, an appropriate pressure, preferably negative pressure, should have been selected in accordance with the evaporation of the n-butanol desired during drying. When using a normal liquid desiccant and depending on the feeding reagent, the drying is preferably carried out under reduced pressure, for example about 15-30 mm Hg.

If a normal liquid desiccant is continuously introduced into the feed zone, the feed rate will, of course, depend on the ether mixture in question. However, a rate of about 1-20 and up to about 3-10 moles of liquid desiccant per mole of p-nitrosophenol in the reaction mixture and hour can be used in most cases.

However, the drying time for substantially complete removal of the drinking water does not exceed the cooking time, except in such cases that the drinking equilibrium before the shift is reached for a short time, for example up to about 20 minutes. The shortest drying time Or usually about 20 minutes and this time can be as long as 500 minutes or longer, although .. you often apply a time of about 30-50 minutes. Although the longer drying time may lead to the occurrence of side reactions in the ether mixture, the required time is shorter if vacuum fractionation were to be applied.

An arbitrary, primary, aliphatic amine or phenylamine can be used as the amination agent and the choice is usually determined by the desired end product. Aniline is the presently preferred aminating agent not only because of its reactivity and stability under the amination conditions but because aniline leads to the formation of diphenylamine derivatives, which have many well-known uses. Examples of amine reagents are: ethylamine, isopropylamine, isobutylamine, allylamine, laurylamine, β-phenylethylamine, tetrahydroabietylamine, dihydroabietylamine, hexamethylenediamine, β-aminodiphenylamine and 2-amino-2-methyl-1-propanol. Examples of other suitable amine reagents are shown in the following Table I.

Among the primary amine reagents, in the practice of the present invention, those represented by the structural formula RNH, in which R Or is a radical selected from the group consisting of alkyl, alkenyl, phenyl, halophenyl, aminophenyl, phenylalkyl, abietylalkyl, cycloaliphatic radials, are preferred. hydroxyalkyl, alkylphenyl, alkoxyphenyl, aminotolylphenyl, hydroxyphenyl, aminobiphenyl and phenylaminophenyl, the amine having at most 30 carbon atoms in the molecule.

All p-nitrosophenyl ethers formed by the first etherification step can be used for the amination, although the ether suitably contains at most 36 carbon atoms. Examples of ethers which may be mentioned are p-nitroso-phenyloctacosanol ether, ethylene glycol mono-p-nitrosophenyl ether, glycerol mono-p-nitrosophenyl ether, pentaerythritol mono-p-nitrosophenyl ether, hexamethylene glycol mono-p-nitrosophenyl ether, nitrosophenyl-hexoxy-benzyl ether, p-nitrosophenyl-n-propyl ether, p-nitrosophenyl-isobutyl ether, p-nitrosophenyl-n-decyl ether, p-nitrosophenyl lauryl ether, p-nitrosophenyl stearyl ether, p-nitrosophenyl ether, p-nitrosophenyl furfuryl, p-nitrosophenyl furfuryl p-nitrosophenyl-p-octylbenzyl ether, p-nitrosophenyl-p-methylbenzyl ether, p-nitrosophenyl-p-chlorophenyl ether, p-nitrosophenylpropargyl ether, p-nitrosophenylisopropyl-propargyl ether, p-nitrosophenyl-2-phenylethylene, p-nitroethylene, p-nitrosethyl ether pnitrosophenyl benzyl ether, p-nitrosophenyl allyl ethers, pnitrosophenyl oleyl ether, p-nitrosophenyl isopropyl ether, p-nitrosophenyl isoamyl ether, p-nitrosophenyl-2-octyl ether and p-nitrosophenylcyclohexyl ether.

In the practice of the present invention, for the present ether reagents, which are urinary represented by the structural formula NO 1 -OC-HI, it is preferred which radical R radical is selected from the group consisting of Tate, alkyl, alkenyl, alkinyl, phenyl, alkylphenyl, phenylalkyl, alkoxyphenyl, phenylalkenyl, alkyldalkyl, hydroxyalkyl, cycloaliphatic radicals, halophenyl, nitrophenyl, furan and tetrahydrofuran. The group - AND - - should, however, contain at most 30 carbon atoms, so that the ether will contain at most 36 carbon atoms. The preferred temperatures for the reaction between the p-nitrosophenyl ether and the primary amine, which is also referred to as amination in this context, are usually about 15 -100 ° C and a rise of about 25-75 ° C. Temperatures slightly above 160 ° C can be used, if so. Desired, although at such a high temperature joke Undesirable side reactions occurred, which at least partially resulted in sand division of the ether reagent and the amination product or bags with subsequent accumulation of the yield. At temperatures below 0 ° C a certain amination enters. The reaction rate Or, however, usually Ohl & lag for aft can be applied in practice, ie. for economic reasons.

The reaction time applied to the amination is generally between about 1 minute and 48 hours. The reaction time varies inversely with the temperature, the ratio of amine to acid and the reagent concentration. At a concentration of amine and ether reagents of 2 moles of each and temperatures of about 35-50 ° C while applying a molar ratio of amine to acid of, for example, 10: 1 to 20: 1, Or the preferred reaction time is about 0 When using the same reagents and applying the same molar ratio of amine to acid, at a reagent concentration of 0.8 moles of each and a temperature of 25 ° C, the reaction time may be 20-21 hours or less. At a temperature of 160 ° C, on the other hand, a reaction time of about 1 minute is often applied. Even under these conditions, relatively low product yields can be obtained due to severe side reactions.

The pressure affects the joke to a greater extent on the amination reaction, but any pressure can be applied which heals the reagents in the liquid phase.

Although the amination proceeds without the addition of any acid as a catalyst, the reaction rate becomes extremely low under such conditions. It is therefore necessary to always use an acid catalyst in order to obtain a product with a reasonable yield. Any acid can be used as a catalyst in the practice of the invention. In a particular case, however, it is advantageous to choose an acid catalyst whose amine salts are at least somewhat soluble in the other components of the reaction mixture. In most systems, the choice of the preferred catalyst also depends on the ether and amine reagents used. Thus, if aniline is used as a corn aminating agent, HCl and toluenesulfonic acid are suitably used, which form soluble salts with aniline. Furthermore, when using monomethylamine corn amination reagent, sulfuric acid is a suitable catalyst. Examples of acids which can be used as catalysts in the amination include sulfuric acid, hydrochloric acid, phosphoric acid, periodic acid, perchloric acid, nitric acid, benzenesulfonic acid, methanesulfonic acid, orthophosphoric acid, pyrophosphoric acid, mono-, di- and trichloroaltichloric acid, boron trifluoride, ferric chloride, acid clays such as silica-alumina and superfiltros, and acidic ion exchange resins such as sulfonated polyvinylbenzene. Paste, acid catalysts are used with particular advantage in the application of the invention as beds, for example columns or layers, when working with solid catalyst baths. Acids with high oxygen content, such as nitric acid, perchloric acid and periodic acid, are less suitable among the inorganic acid catalysts due to the oxidative tendency which these acids exhibit during the amination, with the consequent reduction in the yield of the amination product. The inorganic halides are also traced to the less unsaturated catalysts, since in some cases they have a tendency to lead to non-unsaturated side reactions with consequent reduction in yield.

The amination is usually carried out in the presence of a solvent, although in some cases this can be ruled out, for example in the use of aniline, which can serve as both reagent and solvent. A preferred solvent is the alcohol corresponding to the ether reagent, since the corn solvent using the alcohol and the alcohol formed as a by-product in the amination are identical, so that the problem of separating the solvent from the alcohol formed as a by-product is avoided. to the system. However, if desired, any solvent can be used in addition to the preferred solvent described above. Toluene and mixtures of toluene and methanol are typically used as solvents. Ice acetic acid is another advantageous solvent, especially as in this case it is superfluous to add a separate, acid catalyst, since the acetic acid serves as both catalyst and solvent. Other weak acids can also be used. The choice of solvent depends, of course, on the solubility of the various components of the amination mixture, so that in an amination the choice of any other solvent on the preferred alcohol can be based on the reagents used. If a solvent is used, the whole reagent concentration, including product, the reaction mixture is suitably about 1-6 moles. However, any content of release medium can be used which coats the reagents in solution. Illustrative examples of other useful solvents On alcohols may be mentioned the hydrocarbons, for example toluene, benzene, xylene, n-hexane and n-heptane, chlorinated hydrocarbons, for example chloroform, carbon tetrachloride, ethylene chloride, trichlorethylene, 1,1,1-trichloroethane, chlorobenzene and 1,2,1-trichlorobenzene, ethers, for example diethyl ether and diethylene glycol dimethyl ether, and esters, for example ethyl acetate, n-butyl acetate, dimethylformamide, tributyl phosphate and ethylene glycol.

When carrying out the amination, the ether and amine can be introduced into the ... system in arbitrary, suitable proportions. Although the molar ratio of ether to aniline in the starting material is suitably Or 1: 1, it may vary to obtain more complete conversion of one or the other of these reagents. Usually, however, 0 - a molar ratio of amine to ether of 0.5: 1 to 2: 1 is applied. However, the molar ratio of amine to acid is usually higher than 1: 1 and suitably about 2: 1 to 40: 1 or higher. The molar ratio of amine to acid selected may vary with the nature of the amine reagent. Thus, in the conversion of methylamine, a suitable molar ratio of amine to acid is about 1.5: 1 to 6: 1, often about 2: 1, while the molar ratio of aniline to acid in the conversion of aniline is about 5: 1 to 20: 1, often about 10: 1.

When using an exemplary Mt molar ratio of amine to acid, for example a molar ratio of aniline to acid of 10: 1 or higher, the amination rate appears to be substantially proportional to the product of the reagent concentrations. Thus, by adding such a ratio of amine to acid and a moldy excess of amine I relative to ether reagent, the reaction rate increases with the consequent reduction of the time required for amination.

The preference of the present invention is further illustrated in the following by some non-limiting examples.

Example 1. 123 g (1 mol) of p-nitrosophenol were introduced together with 355 ml of dry methanol and 145 ml of toluene in a 2 L reaction vessel and then heated to 45 ° C under a nitrogen atmosphere. 1 ml (0.018 mol) of concentrated sulfuric acid was then added to the resulting reaction mixture of p-nitrosophenol, alcohol and toluene. The mixture of reagents and catalyst was kept under nitrogen at the above temperature for 52 minutes, after which the acid catalyst was neutralized by adding 1.5 moles of sodium hydroxide in aqueous solution and 500 ml of toluene was then added to the neutralized mixture.

The methanol and water were evaporated in vacuo in Iran to form the neutralized solution, ram as an azeotrope with toluene, the toluene-methanol azeotrope being more volatile and thus leaving by subsequent exchange of solvents, i.e. toluene against unreacted alcohol, unreacted p-nitrosophenol precipitated as a result of its. make looseness in toluene. The precipitated p-nitrosophenol was filtered off from the toluene solution to give 638 ml of filtrate. The filter cake was dissolved in 300 ml of methanol, filtered to remove catalyst salt and then returned to the reaction vessel. 55 moles of methanol, 70 g of p-nitrosophenol and 145 ml of toluene were then introduced into the reaction vessel together with 1 ml of concentrated sulfuric acid to start a second reaction. The process was repeated four times. A total of 2.7 moles of p-nitrosophenol were consumed. The fourth & again the catalyst concentration doubled.

The filtrate from each reaction, i.e. the toluene solutions of the ether product, were combined and freed of Iran toluene in vacuo, after which the resulting solution was dissolved in 2 volumes of n-pentane and cooled to -40 ° C to crystallize pnitrosophenyl methyl ether as product. 192 g dry Over 95% p-nitrosophenyl methyl ether is obtained with an average turnover each time of 55% and a yield of 88%.

Example 2. 123 g (0.9 mol) of 90% pnitrosophenol are halided in a 2 L liquefied hydrogen gas reaction vessel together with 500 ml of anhydrous ethanol and 4.75 g (0.025 mol) of p-toluenesulfonic acid hydrate in 50 ml of ethanol, after which the mixture was heated to 45 ° C and then mills for 1 hour at this temperature under nitrogen. The catalyst in the reaction mixture was neutralized with alcoholic solution of KOH, after which the volume of the resulting solution was reduced to 200 ml under vacuum. 500 ml of n-heptane were then added and the system was again freed of 300 ml by vacuum evaporation. 250 ml of n-heptane were then added and the evaporation was repeated. In this way, the ethanol was replaced with n-heptane as a solvent for the reaction mixture and pnitrosophenol, the latter precipitated, since it has a low solubility in the n-heptane solvent, so that it could be filtered off. 360 ml of n-heptane solution of p-nitrosophenylethyl ether (filtrate) were obtained and subjected to crystallization at -40 ° C to give 54 g of dry p-nitrosophenylethyl ether crystals with a purity exceeding 95%. The turnover of the process was 40%.

Example 3. The procedure of Example 2 was repeated except that the product, pnitrosophenyl alkyl ether, was isolated by haliding the balanced mixture of ethanol, catalyst, p-nitrosophenol and p-nitrosophenyl ethyl ether in 10 volumes of water containing about 0.5 moles of NaOH. This mixture was extracted twice with a volume of n-heptane. The resulting solution of p-nitrosophenylethyl ether was evaporated to 100 ml under vacuum, after which the mixture was allowed to crystallize. The crystals were separated and dissolved in 50 ml of pentane, collected, recrystallized. The twice recrystallized material was dried and subjected to analysis for carbon, hydrogen and nitrogen. The analysis results compared the calculated contents for the gross formula of the p-nitrosophenyl alkyl ether shown in the following table Formula G8H, NO2 Beranate Found CoI 63.6% 63.7% Weight 6.00 6.04 Nitrogen 9.28 9.32 Molecular weight. . 151.2 152.0 The following alcohols were reacted with p-nitrosophenol in the presence of an acid catalyst at about 25 ° C to give the corresponding p-nitrosophenyl ether, which in the order of the indicated alcohols consisted of: p-nitrosophenylmethyl ether, p-nitrosophenylethyl ether, p-nitrosophenyl-n-butyl ether, p-nitrosophenyl acetyl ether, p-nitrosophenyl benzyl ether, ethylene glycol mono-p-nitrosophenyl ether, p-nitrosophenyl allyl ether, p-nitrosophenyl oleyl ether, p-nitrosophenyl isopropyl ether, p-nitrosophenyl ether octyl ether and p-nitrosophenylcyclohexyl ether. The results are summarized in the following table - —7 Molecular Acid Catalytic Alkacator (p-to- Conversion Hol to Pluen Sulfon Calculated on Alcohol Reagent Nitrosophesic Acid) Molin nitrosophenol in the ratio nolenic acid ** to p-in mixtures. nitrosophenol Methanol 21 0.02 Ethanol 0.0 n-butanol 9 0.02 Cetyl alcohol 2 0.16 13 Benzyl alcohol 8 0.16 Xellosolve ** 9 0.16.

Allyl alcohol 13 0.16 Oleyl alcohol 3 0.16 11 Isopropyl alcohol 11 0.04 s-amyl alcohol 8 0.16 8- 2-octyl alcohol 0.16 8- Cyclohexyl alcohol 8 0.16 8- * 1-yl monoethyl ethylene glycol.

** Determination based on ultraviolet spectrum.

Example 4. 54 g of p-nitrosophenol, 300 ml of ethanol, 620 ml of toluene and 3 ml of concentrated sulfuric acid were halided in a reaction vessel at 21. The reaction mixture formed was heated to 39 ° C under an absolute pressure of 167 mm Hg for 18 minutes, after which it in the reaction mixture already present the alcohol was bubbled through the reaction mixture and drained from the reaction vessel. The bubbling on this set took 1 hour with condensation of 585 ml of liquid. The temperature rose to ° C during this period, during which the pressure was lowered to 136 mm Hg. After this period of 1 hour, the reaction mixture was neutralized with lye and analyzed by ultraviolet spectroscopy, which showed that the mixture contained 49 g of p-nitrosophenethol, which corresponds to a conversion of 74% per pass.

Example 5. 61.5 g (0.5 mol) of about 98% p-nitrosophenol halide together with 230 ml (2.5 mol) of dry n-butanol in a 1 L reaction flask. 2.2 g of p-nitrosophenol toluenesulfonic acid monohydrate was added and the resulting reaction mixture was kept at 25 ° C while the etherification was taking place to give p-nitrosophenyl-n-butyl ether. After this period, the ether equilibrium was shifted to the ether side by bubbling 500 ml of dry n-butanol vapor, which was supplied from the outside through the reaction water to remove water ring, at about 26 mm Hg and 45 ° C for 60 minutes. The resulting reaction mixture was cooled to -40 ° C, whereby the formed p-nitrosophenyl-n-butyl ether was crystallized and then filtered off. The conversion of p-nitrosophenol to p-nitrosophenyl-n-butyl ether per passage was determined by ultraviolet analysis and was 93%.

Example 6. 61.5 g of p-nitrosophenol and 230 ml of dry n-butanol are halided in a reaction vessel pa ii with the addition of 0.5 ml of concentrated sulfuric acid with stirring, after which the Mills system under an absolute pressure of 40 mm Hg for 15 minutes at about 50-55 ° C. During this time, n-butanol bubbled through the reaction mixture due to the accumulation of n-butanol already present in the mixture, forming the n-butanol bubbles and rising through the reaction mixture so that n-butanol was bubbled through the reaction mixture as has been described, and was diverted from the reactor reactor and was substantially condensed. After 115 ml of condensed distillate had been taken out, the etherification temperature was raised to about 55 ° C and dry n-butanol was added as a liquid to the mixture continuously at about 7-8 ml / min for about 25 minutes with evaporation of the reaction mixture and bubbling at the same rate continuously throughout. The total distillate collected was 315 ml and the reaction temperature never exceeded 56 ° C. The conversion of p-nitrosophenol to p-nitrosophenyl-n-butyl ether was determined by ultraviolet analysis and was 96.7%.

Example 7. 3.69 g of p-nitrosophenol were stirred together with 46 ml of n-butanol and 1 ml of 3 molar sulfuric acid in n-butanol in a 125 ml reaction vessel under nitrogen, for 3 hours at about 25 ° C. 10 ml of 2 N sodium hydroxide solution and 30 ml of water were then added to the resulting reaction mixture to form an organic layer separated from an aqueous layer, the latter containing unreacted p-nitrosophenol as sodium p-nitrosophenolate and salt of the acid, while the organic phase was formed. of n-butanol containing dissolved p-nitrosophenol-n-butyl ether. The layers were separated and analyzed by ultraviolet spectroscopy, it being found that the entire organic layer contained 2.5 g of p-nitrosophenyl butyl ether, while the aqueous layer contained p-nitrosophenolate in an amount equivalent to 1.85 g of p-nitrosophenol. The conversion of p-nitrosophenol to p-nitroso-n-butyl ether per passage was 47%.

Example 8. 3.69 g of p-nitrosophenol were stirred together with 46 ml of n-butanol and 1 ml of 3 molar H 2 SO 4 in n-butanol in a 125 ml reaction vessel for 125 hours under nitrogen at about 25 ° C. 10 ml of 2N sodium hydroxide solution and 30 ml of water were then added to the resulting reaction mixture to form an organic layer separate from an aqueous layer, the latter containing unreacted p-nitrosophenol such as p-nitrosonebutylphenolate and the acid salt, while the organic phase contained n-butanol and p-nitrosophenyl -nbutyl ether lOst. The layers were separated and analyzed by ultraviolet spectroscopy, the organic layer being found to contain 2 g of p-nitrosophenyl butyl ether, while the aqueous layer contained 011 p-nitrosophenolate in an amount equivalent to 1.85 g of p-nitrosophenol. The conversion of p-nitrosophenol to p-nitroso-n-butyl ether per passage was 47%.

The following non-limiting examples illustrate the amination step of the invention.

Example 9. 50.2 g (0.33 mol) of p-nitrosophenyl ethyl ether were dissolved in 175 ml of absolute ethanol in a reaction vessel of 11 and kept under a pile of nitrogen.

A slurry of 30.9 g (0.33 mol) of aniline and 1.51 g (0.015 mol) of concentrated sulfuric acid in 1 ml of absolute ethanol was added to the alcohol ether solution. It formed, ether and aniline containing the mixture Miles under a nitrogen atmosphere for 16.5 hours with stirring at about 25 ° C and then neutralized with 22 ml of 10% (by weight) alcohol solution of KOH. The precipitated p-nitrosodiphenylamine product was then filtered off from the reaction mixture, washed three times with 50 ml of n-pentane each time and air dried. The filtrate and washings were combined and filtered to separate 1-12SO4 and then evaporated in live water vapor. The residue was dissolved in 50 ml of methanol and crystallized at about 30 DEG C. to give crystals of p-nitrosodiphenylamine, which were then filtered.

The total crude product, 56.3 g, yield 81.5% stripped of the ether reagent, was recrystallized from methanol to give 42.0 g of purified pnitrosodiphenylamine, m.p. 144 DEG C. The infrared spectrum of the compound corresponded to the spectrum of an edge prom. p-nitrosodiphenylamine. When determining carbon, hydrogen and oxygen, the following results are obtained: Formula C1iiN20 Beralmat Punnet Carbon 72.71% 72.36 72.56 Vate 5.09 5.19 5.24 Oxygen 8.08 8, Example 10. The reaction according to Example 9 was repeated and the reaction mixture was analyzed by ultraviolet spectroscopy. A conversion to p-nitrosodiphenylamine of 93% is obtained after 20.5 hours at room temperature.

Example 11. 10 ml (0.040 mol) of 4.0 M p-nitrosophenyl methyl ether dissolved in a mixture of 40% by volume of methanol and 60% by volume of toluene were added to 10 ml of solution in absolute methanol of 4.0 M (0.040 mol) of aniline. and 0.2 M (0.002 mol) of p-toluenesulfonic acid monohydrate in a 125 ml centrifuge tube. This was sealed, purged with nitrogen and placed in a bath at 50 ° C while the reaction mixture was magnetically stirred. After 90 minutes at 50 ° G, the reaction mixture was cooled in an ice bath and centrifuged to separate crystal product. The mother liquor was decanted and the dark blue solid was washed several times with 20 ml of n-pentane each time. The washed crystals were dried for 6.5 hours at 60 ° C under reduced pressure. The conversion to 90% p-nitrosodiphenylamine was 81% (7.1 g), based on the ether reagent.

Example 12. The procedure of Example 11 was repeated on a smaller scale and the products were analyzed by ultraviolet spectroscopy, showing that the conversion to p-nitrosodiphenylamine was 95% after reaction 90 minutes at 50 ° C.

Example 13. 160 ml of reaction mixture from preparation ay p-nitrosophenylbutyl ether by reaction of ay p-nitrosophenol with n-butanol in the presence of p-toluenesulfonic acid as catalyst had the following composition determined by ultraviolet spectroscopy: 0.436 moles of p-nitrosophenylbutyl ether, p-nitrosophenylbutyl ether -nitrosophenol and the remainder n-butanol.

This reaction mixture was quenched in a water bath at about 45 ° C. 63 ml of solution of 42.6 g (0.457 mol) of aniline and 3.04 g (0.16 mol) of p-toluenesulfonic acid monohydrate in n-butanol were added. to the nitrogen-tackled reagents, after which the reaction mixture formed was stirred at said temperature for 2.5 hours. The temperature was then lowered to 20 ° C with continued stirring for 0.5 hour and the precipitated product, p-nitrosodiphenylamine, was filtered off. The product, a bluish black substance, was collected on a filter, washed with 100 ml of water three times and dried over 1320 at room temperature under reduced pressure. The crystals formed had a purity of 88% and were formed with a conversion of 90%.

Example 14. A reaction mixture of 7 ml of n-butanol, 41.1 g of p-nitrosophenylbutyl ether, 25 ml of aniline and 3.3 g of aniline hydrochloride, molar ratio of p-nitrosophenylbutyl ether aniline / HCl equal to 1/1, 30/0, 11, was stirred. 2 h at 35 ° C, after which 25 ml of n-hexane and 100 ml of water were added. The resulting slurry was cooled to 10 ° C and filtered, after which the filter cake was washed with 100 ml of nhexane. Analysis of the entire precipitated product and filtrate by ultraviolet spectroscopy showed a conversion to p-nitrosodiphenylamine 91% on the ether reagent.

Subsequent amine ether reactions were performed in the closed system to give the corresponding pnitroso-N-substituted aniline product. These reactions were carried out in either ether or methanol as a solvent at a temperature of 25-40 ° C and a molar-containing amine to acid 2: 1 to 20: 1. The ether reagent in all cases consisted of p-nitrosophenethol to form p-nitroso -n-substituted aniline. The turnover, based on the ether reagent, waxed and cooled to be as high as 92%.

Table I.

ExampleAmin methylamine 16n-butylamine 17cyclohexylamine 18benzylamine 19ethanolamine octadecylamine 21o-toluidine 22m-toluidine 23β-toluidine Catalyst H2SO, p-toluenesulfonic acid HCl HCl HCl HCl HCl HCl H1 HC1 Product p-nitroso-N-butanoyl-p-nitro N-cyclohexylaniline p-nitroso-N-benzylaniline p-nitroso-N- (f-hydroxyethyl) -aniline p-nitroso-N-octadecylaniline o-methyl-p'-nitrosodiphenylamine m-methyl-p'-nitrosodiphenylamine p-methyl- p'-nitrosodiphenylamine Example Amine - 192 Catalyst 24 p-anisidine H2SO4 p-phenetidine HCl 26 p-chloroaniline 112SO4 27 p-phenylenediamine HCl 28 p-cyanoaniline H2SO4 29 p-nitroaniline HCl p-aminobenzoic acid HCl-amine aminophenol HCl 33 p-phenylenediamine HCl 34 p, p'-diaminodiphenylmethane H2SO4 benzidine HCl 265 - Product p-methoxy-p'-nitrosodiphenylamine p-ethoxy-p'-nitrosodiphenylamine p-chloro-p'-nitrosodiphenylamine p-amino- p'-nitrosodiphenylamine p-cyano-p'-nitrosodiphenylamine p-nitro-p'-nitrosodiphenylamine p-carboxyl-p'-nitrosodiphenylamine o-amino-p'-nitroso diphenylamine m-hydroxy-p'-nitrosodiphenylamine N, W-bis (p-nitrosophenyl) -p-phenylene-diamine N, N'-bis- (p-nitrosophenyl) -p, p'-diaminodiphenylmethane N, N'-bis - (p-nitrosophenyl) -benzidine Example 36. 15.7 ml of 0.86 molar methylamine in ethanol and 6 ml of 0.5 molar 1-12SO4 in ethanol were added with 0.75 g of p-nitrosophenol, after which the mixture formed The mixture was stirred for 23 hours at 0 DEG C. A sample of the reaction mixture formed was analyzed by ultraviolet spectroscopy, whereby a conversion of the ether to p-nitrosophenyl-Nmethylaniline of 41% was observed.

The following example 3744 illustrates etherification and amination in a sequence.

Examples 37-44. A series of etherings were performed in which an alcohol was reacted with pnitrosophenol at 25 ° C in the presence of p-toluenesulfonic acid as a catalyst to give a corresponding p-nitrosophenyl ether in the manner described in the previous examples. Aniline was mixed with the resulting ether mixture in all cases and reacted with the ether product at about 25 ° C to form p-nitrosodiphenylamine, the ether mixture formed containing sufficient p-toluenesulfonic acid as catalyst to catalyze the aniline-ether reaction. The conversion to p-nitrosodiphenylamine on the ether reagent fluctuated and could be as high as more than 90%. The molar ratios of amine to ether and amine to acid were approximately the same as in Table I.

The alcohols which were separately reacted with pnitrosophenol in the presence of the acid catalyst to form the ether are shown in the following table. Aniline was then added to the resulting ether mixture to form p-nitrosophenylamine as described above. 42 allyl alcohol p-nitrosophenyl allyl ether 43 furfuryl alcohol p-nitrosophenylfurfuryl ether 44 cetyl alcohol p-nitrosophenyl acetyl ether

Claims (14)

1. Patent claim: A process for the preparation of p-nitroso-N-substituted aniline, characterized in that p-nitrosophenol is reacted with a primal or secondary alcohol in the presence of an acid and at a temperature between 0 and 150 ° C and thereby The p-nitrosophenyl ether formed is reacted with a primary aliphatic amine or phenylamine in the presence of an acid and at a temperature between 0 and 160 ° C. Process according to claim 1, characterized in that the digestion water is removed by passing a substantially anhydrous desiccant through the reaction mixture. Process according to Claim 2, characterized in that the same alcohol as the one which was reacted with the nitrosophenol, namely n-butanol, was used as desiccant. Process according to Claim 1, characterized in that the pure fractional distillation is removed from the fermentation water. 5. A process according to any one of claims 1-4, characterized in that a water-soluble alcohol is used and after completion of the etherification the acid catalyst neutralizes with an alkaline aqueous solution, i.e. an aqueous solution of an alkali metal hydroxide, separates the p-nitrosophenyl ether from the unreacted pnitrosophene replacing the alcohol serving as a reactant and solvent with a solvent which has a high capacity to release p-nitrosophenyl ether but little able to release p-nitrosophenol, and separates the pnitrosophenol and returns it to the etherification step. Process according to Claim 5, characterized in that a heat-releasing agent was added to the ether mixture, that the alcohol serving as reactant and solvent. Table Example Alcohol ether product 37 2-octyl alcohol p-nitrosophenyl octyl ether 38cyclohexylalkylethoxyethoxyethoxy-pethonyl-oxyloxy-ethyl p-nitrosophenyl oleyl ether 41 benzyl alcohol p-nitrosophenyl benzyl ethers - - after etherification, the mixture is removed from the mixture by distillation, so that unreacted p-nitrosophenol precipitates and is filtered off, and the exchange solvent in the filtrate, which contains ether and substitute solvent, solvent, thereby facilitating subsequent crystallization of the ether. 7. Process according to claim 1, characterized in that a water-insoluble alcohol is combined and the unreacted nitrosophenol is neutralized in the reaction mixture with an alkaline aqueous solution, preferably of an alkali metal hydroxide, before the amine is added, the nitrosophenolate thus formed is separated and the nitrolene is regenerated. , which is returned to the feeding step. Process according to claim 1, characterized in that the ether mixture is dried to produce a conversion of nitrosophenol per passage of at least 00%, and that the whole ether mixture is then mixed with the amine. Method according to claim 8, characterized in that the feeding is carried out in two steps with the drying during the second step. 10. A process according to any one of the preceding claims, characterized in that aniline is used as the amine, the total product being p-nitrosodiphenylamine. 11. A process according to claim 10, characterized in that the p-nitrosodiphenylamine formed which precipitates is filtered off, the filtrate in Andamal to provide an organic phase and a. aqueous phase is led to a neutralization zone containing an alkaline aqueous solution, to unreacted p-nitrosophenol present in the aqueous phase as p-nitrosophenolate, surgores and Aterfores to the digestion step, that the organic phase is led to an acidification zone containing water, in and for providing an additional organic and an aqueous phase, and that unreacted aniline, which is present in the aqueous phase as an amine salt, returns Ores to the etherification step. Method according to claim 11, characterized in that the order between the neutralization and acidification steps is reversed. 13. A process according to any one of the preceding claims, characterized in that a molar ratio of alcohol to p-nitrosophenol of 1: 1 to 200: 1, a molar ratio of p-nitrosophenol of 0.005: 1 to 0.2: 1, and that one hails one. temperature of 15-70 ° C and a reaction time of 10-200 minutes during the etherification. 14. A process according to any one of the preceding claims, characterized in that during the amination a molar ratio of amine to acid of 5: 1 to 20: 1, a molar ratio of amine to ether of 0.5: 1, a temperature of 15-100 ° is applied C and a reaction time of 1 mm to 48 hours. Request publications: