JPS61191666A - Production of aromatic carbamic acid aryl ester - Google Patents

Abstract

PURPOSE:To obtain a compound useful as a raw material for agricultural chemicals, isocyanate, and polyurethane in high yield in good operation properties, by reacting an aromatic nitro compound with an aromatic hydroxy compound and carbon monoxide in the presence of a novel catalyst. CONSTITUTION:An aromatic nitro compound is reacted with an aromatic hydroxy compound and carbon monoxide in the presence of metallic palladium or a palladium compound as a main catalyst and a cocatalyst consisting of a specific compound combination of a halogenated phosphorus compound, an iron compound, a vanadium compound and a tertiary amine in a solvent such as benzene, etc. at 160-220 deg.C at reaction pressure of 100-500kg/cm<2>G as partial pressure of carbon monoxide for 10min-10hr, to give the aimed substance. EFFECT:Since a catalytic system of this invention has extremely low corrosive properties, an inexpensive material used ordinarily is usable for a reactor.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for producing an aromatic carbamic acid aryl ester useful as a raw material for agricultural chemicals, isocyanates, or polyurethanes.

More specifically, the present invention relates to a method for producing an aromatic carbamic acid aryl ester from an aromatic nitro compound, an aromatic hydroxy compound, and carbon monoxide using a novel catalyst system.

[Conventional technology]

Aromatic isocyanates are generally produced by reacting aromatic amines obtained by reducing aromatic nitro compounds with phosgene. In recent years, new methods for producing isocyanates have been developed due to the lack of raw material resources, soaring prices, and the strong toxicity of intermediate raw materials such as phosgene.

One of these methods involves reacting an organic dil-ro compound with carbon monoxide and an organic hydroxy compound to produce the corresponding carbamic acid ester, which is then decomposed into an isocyanate and an organic hydroxy compound.

In this case, when an alcohol is used as the organic hydroxy compound, an aromatic carbamic acid alkyl ester can be obtained.

Aromatic carbamic acid alkyl esters generally have a high decomposition temperature, and when attempting to obtain aromatic isocyanates by thermal decomposition, a high temperature of 250°C or higher is usually required to obtain an effective reaction rate for industrial implementation. This causes many problems such as deterioration of raw materials and products, decrease in yield, and increase in utility costs.

On the other hand, aromatic carbamic acid esters obtained using aromatic hydroxy compounds as organic hydroxy compounds can be thermally decomposed at relatively low temperatures, which alleviates the above-mentioned problems in the thermal decomposition process. This is extremely advantageous compared to using ester as a raw material.

However, the conventional method for producing aromatic carbamic acid aryl ester from an aromatic 21-ro compound, an aromatic hydroxy compound, and carbon monoxide has various problems.

For example, Japanese Patent Publication No. 56-12.632 describes a method for producing aromatic carbamic acid esters using a catalyst consisting of palladium, ruthenium, or rhodium, a Lewis acid, and a tertiary amine; however, phenol is used as the hydroxy compound. The reaction rate is lower and the yield is lower than when alcohol is used.

Moreover, the reaction liquid becomes a slurry, making separation and purification of the catalyst and reactants troublesome.

In addition, Japanese Patent Publication No. 43-23-939 describes a method for producing aromatic carbamic acid esters in the presence of a carbonyl-containing derivative of a group I metal of the periodic table such as rhodium as a catalyst and a co-catalyst such as ferric chloride. However, when phenol is used as the hydroxy compound, the yield is significantly lower than when alcohol is used.

U.S. Pat. No. 3,531.512 (1970) proposes a method using palladium and a Lewis acid as a catalyst, but this method also has a low yield when phenol is used, and it also It is extremely corrosive to diferrous iron, stainless steel, etc., making it difficult to put it into practical use.

Furthermore, as a method for producing an aromatic carbamic acid ester with an improved catalyst system, a method using a catalyst consisting of metal palladium or a palladium compound, vanadium oxytrichloride, and a tertiary amine (Japanese Patent Application Laid-Open No. 54-22-339), A method in which a platinum group metal and/or its compound is used as a main catalyst and a Lewis acid and an oxide of a group Va or VEa metal of the periodic table, such as vanadium, are used as a co-catalyst (Japanese Patent Application Laid-open No. 128-550)
, a method using a catalyst consisting of metallic palladium or a palladium compound, an iron compound, a bicyclic amidine, and a halogen compound has been reported (Japanese Patent Application Laid-Open No. 57-32,251), and phenols are used as usable hydroxy compounds. Although they are listed, specific examples are not mentioned.

The present inventors investigated the production of aromatic carbamic acid aryl esters from aromatic nitro compounds, aromatic hydroxy compounds, and carbon monoxide, and found that they applied the conventional method using alcohol in place of aromatic hydroxy compounds. So, even if a highly active catalyst is used to produce an aromatic carbamic acid alkyl ester, there may be problems such as a decrease in the reaction rate and yield of the desired product, deterioration in the operability of the catalyst-reaction liquid, and the material of the reactor. It turns out that many problems arise.

[Problem that the invention seeks to solve]

The present invention has been made from the viewpoint of ridge production, and uses a new catalyst system to produce aromatic carbamic acid monoyl ester from an aromatic nitro compound, an aromatic hydroxy compound, and carbon monoxide in a good yield. The object of the present invention is to provide a method for manufacturing at a high rate and with good operability.

[Means to solve the problem]

The present inventors have completed the present invention as a result of intensive studies to achieve the above object. That is, the present invention provides a method for producing an aromatic carbamic acid aryl ester by reacting an aromatic nitro compound, an aromatic hydroxy compound, and carbon monoxide in the presence of a catalyst. This is a method for producing an aromatic carbamic acid aryl ester, which is characterized by carrying out the reaction at high temperature and pressure using a catalyst system consisting of a phosphorus compound, an iron compound, a vanadium compound, and a tertiary amine.

According to the method of the present invention, aromatic carbamic acid aryl esters, which can be easily thermally decomposed under mild conditions to obtain the corresponding isocyanate in high yield, can be produced at a high reaction rate and high yield compared to conventional methods. It can be produced with high yield.

Furthermore, since the catalyst metal component is extremely small compared to conventional methods, the catalyst component is well dissolved, and the reaction liquid does not substantially become a slurry, making it easy to handle.

Furthermore, material corrosion is less than in conventional methods, and equipment made of normal industrial materials can be used.

The aromatic nitro compound used as the main raw material in the method of the present invention is an aromatic compound having at least one nitro group as a nuclear substituent, and the number of nitro groups may be one or two or more. . That is, it may be a mononitro compound or a polynitro compound. Further, the aromatic compound may contain a substituent other than a nitro group.

For example, these include nitrobenzenes, dinitrobenzenes, dinitrotoluenes, nitronaphthalenes, nitroanthracenes, nitrobiphenyls, bis-trophenyl) alkanes, bis-trophenyl) ethers, bis-trophenyl) ) thioethers, bistrophenyl) sulfones, nitrodiphenoxyalkanes,
Examples include nitrophenothiazines and heterocyclic compounds such as 5-nitropyrimidine. Specific compounds include nitrobenzene, o-, m- and p-nitro1
-luene, 0-nitro-p-xylene, 1-nitronaphthalene, m- and p-dinitrobenzene, 2,4- and 2,6-cinitrotoluene, dinitromesitylene, 4.
4'-dinitrobiphenyl, 214-dinitrobiphenyl, 4.4'-'; dil-lodibenzyl, bis(4-nitrophenyl)methane, bis(4-nitrophenyl)ether, bis(2,4-dinitrophenyl) ether,
Bis(4-nitrophenyl)thioether, bis(4-
nitrophenyl) sulfone, bis(4-nitrophenoxy)ethane, α, α′-dinitro p-xylene, α,
α'-dinitro m-xylene, 2.4.6-dolinitrotoluene, 0-, m- and p-chloronitrobenzene, 2,3-13, i4hi2. s-dichloronitrobenzene, 1-chloro-2,4-dinitrobenzene, 1-bromo-4-nitrobenzene, ■-fluoro-2,4-dinitrobenzene, 0-+ m- and p-nitrophenyl carbamate, o- , m- and p-nitroanisole,
2.4-dini[lophenetol, p-nitrobenzo 1methyl)Lt, m-nitrohenzenesulfonyl chloride, 3
-nitrophthalic anhydride, 3,3'-dimethyl-4,4
Examples include '-dinitrobiphenyl, 1,5-dinitronaphthalene, etc. Further, isomers or mixtures of these aromatic nitro compounds can be used, and homologs can also be used. Further, aromatic nitrone compounds, ab, and azoxy compounds can also be used in the same manner as aromatic nitro compounds.

The aromatic hydroxy compounds used in the present invention include monovalent and polyvalent monocyclic and polycyclic aromatic hydroxy compounds. Further, these aromatic hydroxy compounds may be substituted with a substituent inert to this reaction, such as a monovalent substituent such as an alkyl group, a halogen atom, or a carboxylic acid ester group, or may be substituted with an alkylene group, an oxy group, It may be crosslinked with a divalent group such as a sulfinyl group, a sulfonyl group, or a carbonyl group.

For example, phenol, chlorophenol, talesol, ethylphenol or alkylphenols such as linear or branched propylphenol, butyl and higher nonylphenols, catechol, resorcinol, pyrogallol, phloroglucinol, α-naphthol, β-
Naphthol, anthranol, phenanthrol, 4.
Examples include 4'-dihydroxydiphenylmethane and 2,2'-isopropylidenediphenol.

The amount of these aromatic hydroxy compounds used must be at least an equimolar ratio to the amount of the aromatic nitro compound. If the molar ratio is less than the equimolar ratio, the reaction becomes slow and the yield of the target aromatic carbamic acid aryl ester decreases. Furthermore, using the aromatic hydroxy compound in a large excess relative to the aromatic nitro compound is not only not economically advisable but also tends to lower the yield. Usually 1 to 10 molar ratio to the nitro group of the aromatic nitro compound,
It is preferably used in a molar ratio of 1 to 5. In addition, the amount of aromatic hydroxy compound used in the total raw material liquid is 5 to 8.
5wt%, preferably 10-75wt%.

In the method of the present invention, metal palladium or palladium compounds are used as the main catalyst, including simple metals such as palladium black, halides, cyanides, thiocyanides,
Addition compounds or complexes with isocyanides, oxides, sulfates, nitrates, organic acid salts such as acetic acid, carbonyl compounds, triethylamine, tertiary amines such as pyridine/isoquinoline, or organic phosphorus compounds such as triphenylphosphine. Examples include complexes, divalent or zero-valent palladium complexes coordinated with neutral ligands such as carbon monoxide, and the like. Reactions also occur with noble metals other than palladium, such as platinum, ruthenium, rhodium, and iridium, and aromatic carbamic acid aryl esters are produced, but in very small quantities, making industrial use difficult.

If these can be used as they are in the reaction, they can be used as carriers such as alumina, silica, silica alumina, carbon, barium sulfate, calcium carbonate, asbestos, bentonite, diatomaceous earth, Fuller's earth, organic ion exchange resin, inorganic ion exchange resin, silicic acid. It may be supported on magnesium, aluminum silicate, molecular sheep, zeolite, or the like.

Furthermore, these carriers may be charged into the reactor separately from palladium or their compounds.

The amount of palladium used for the nitro compound can vary widely depending on the type and other reaction conditions;
1 to I in weight ratio as a single metal to the nitro compound
X 10-5, preferably 5 X 10-1 to 5x1
Used in the range 0''''4.

The method of the present invention is characterized by the use of a promoter system consisting of a combination of a special compound consisting of a halogenated phosphorus compound, an iron compound, a vanadium compound, and a tertiary amine in addition to palladium or its compound as the main catalyst. shall be.

In order to carry out the method of the present invention effectively, the use of each catalyst component is essential, but the addition of halogenated phosphorus compounds is particularly effective, increasing the activity of the catalyst system and promoting the reaction. Suppresses the formation of by-products and increases the selectivity of the target product.

Examples of the halogenated phosphorus compounds used in the method of the present invention include phosphorus trifluoride, phosphorus trichloride, phosphorus tribromide, phosphorus triiodide, phosphorus pentafluoride, phosphorus pentachloride, phosphorus pentabromide, and phosphorus tetrabromide. Phosphorus halide compounds such as niline chloride and niline tetraiodide; alkyl- or aryl-substituted phosphorus halide compounds such as dimethylbromophosphine, diphenylchlorophosphine, and ethylphospora tetrachloride; phosphoryl fluoride, phosphoryl chloride, phosphoryl bromide, - Phosphorus oxyhalides such as phosphoryl difluoride chloride, phosphoryl dichloride-fluoride, pyrophosphoryl chloride, and phosphorus oxyhalide; Quaternary phosphonium halides such as tetraethylphosphonium chloride; Phosphonyl halides such as ethylphosphonate dichloride; Examples include alkyl phosphate halogenides such as methyl phosphate dichloride.

These halogenated phosphorus compounds are palladium 1
From 0.05 to 20 gram atoms, preferably from 0.1 to 10 gram atoms of phosphorus per gram atom are used. Also, for 1 mole of raw material nitro compound, 1 x 10-3
The concentration in the reaction solution is preferably I x 10-' g or more per 1 kg of the total reaction solution.

Iron compounds include iron halides such as ferrous chloride, ferric chloride, ferrous bromide, and ferric bromide, and dichloro! ·squirrel(
Iron complexes containing halogens and bases such as 2,2'-bipyridyl)iron, tetrabromo(tetraethylammonium)iron, °tetrachloro(tetraethylammonium)iron, tetrachlorobis(tetraethylammonium)iron, dichlorotetrapyridineiron, etc. Carboxylate salts of iron, ferric acetate, ferrous oxalate, oxides of ferrous oxide, ferric oxide, triiron tetroxide, iron trihydroxide, iron monoxide hydroxide,
- Hydroxides such as iron hydroxide diacetate, ferrates such as potassium iron tetroxide, iron tris(acetylacetone), ferric nitrate, iron chloride oxide, and the like.

The iron component is added to the reaction system as a metal or as at least one compound selected from oxides, hydroxides, carbonyl compounds, and organic complex compounds. Examples of iron organic complex compounds include ferrocene, iron acetylacetonate,
Examples include iron acetylide, iron porphyrin, and iron phthalocyanine.

The amount of iron component used is usually 0.1 to 100 gram atoms as metal per 1 gram atom of palladium, preferably 0.
．． 2 to 10 Durham atoms, and to the aromatic nitro compound, I X 10-3 to 1 molar ratio, preferably 2
The molar ratio is from X 10-3 to I X 10-1. If the amount of this iron component used is too small, the expected catalytic activity cannot be obtained, and if it is too large, not only will the yield of the desired product decrease, but also the treatment of the mixture after the reaction will be troublesome, which is undesirable. .

Any vanadium compound can be selected as the vanadium compound. Furthermore, in the method of the present invention, the valence of the vanadium compound changes during the reaction, and it is thought that it exists in several valence states with a certain distribution, and the valence of vanadium in the vanadium compound that can be used is not particularly limited. .

Specific examples of vanadium compounds that can be used in the method of the present invention include chlorides such as vanadium trichloride and vanadium tetrachloride, salts of chlorides such as vanadium (IV) potassium chloride, vanadium dichloride oxide, and vanadium trichloride oxide. chloride oxides such as vanadium oxide (■), vanadium oxide (■), vanadium (V) oxide, vanadic acids such as pyrovanadic acid, metavanadate, sodium orthovanadate, ammonium metavanadate, potassium metavanadate. vanadate, vanadium sulfate (
I [I] Ammonium, vanadium salts of acids such as potassium vanadium(III) oxalate, vanadium oxysulfate (■
), vanadyl salts of acids such as vanadium oxyoxalate, acetylacetone salts such as oxybis(acetylacetone)vanadium (IV), and complex compounds coordinated with neutral ligands such as hexacarbonylvanadium.

These vanadium compounds contain 0.05 to 20 gram atoms of vanadium per 1 gram atom of palladium.
Preferably 0.1 to 10 gram atoms are used. 0.
If less than 0.5 gram atoms are used, the activity is low, and if more than 20 gram atoms are used, the selectivity decreases. Also, for 1 mole of raw material nitro compound, 1 x 10-4 to I x 10
-1 mol, preferably in the range of 1 x 10-3 to 5 x 10-2 mol.

As the tertiary amine, aliphatic, aliaromatic, alicyclic, aromatic tertiary amines and nitrogen-containing heterocyclic compounds are used. If these may be in unsubstituted form, suitable substituents inert to this reaction may be used, such as halogen atoms, alkyl groups, aryl groups, alkenyl groups, cyano groups, aldehyde groups, alkoxy groups, phenoxy groups, alkylthio groups, It may have a substituent such as a phenylthio group, a carbamyl group, a carbalkoxy group, or a thiocarbamyl group.

These include, for example, aliphatic tertiary amines such as trimethylamine, triethylamine, tripropylamine, and tributylamine, N,N-dimethylaniline, N,N-
Fatty aromatic amines such as diethylaniline, N,N-diisopropylaniline, N,N-dimethylcyclohexylamine, N,N-diethylcyclohexylamine,
N,N-diisopropylcyclohexylamine, 1.4
-Alicyclic tertiary amines such as diazabicycloC2,2,2)octane, aromatic tertiary amines such as triphenylamine
These include nitrogen-containing heterocyclic compounds such as class amines, pyridine, quinoline, and isoquinoline. Among them, nitrogen-containing heterocyclic compounds are particularly effective in improving the yield of urethane and the reaction rate. Further examples of effective nitrogen-containing heterocyclic compounds other than those mentioned above include 1-methylvirol,
1-phenylpyrrole, ■-medylimitasol, 1-
Methylindole, ■-phenylindole, indolenine, 2-isobenzazole, indolizine, 1-methylcarbazole, 2-chloropyridine, 2-bromopyridine, 2-fluoropyridine, 4-phenylpyridine, 2-, 3 -, and 4-methylpyridine, 2-methyl-5-ethylpyridine, 2,6-dimethylpyridine,
2,4.6-Dolimethylpyridine, 2-vinylpyridine, 2-styrylpyridine, 3-chloropyridine, 2.6
-dichloropyridine, 2-chloro-4-methylpyridine, 4-phenylthiopyridine, 2-methoxypyridine,
4-dimethylaminopyridine, α-picolinate phenyl ester, T-picolinate methyl ester, 2,6-dicyatspyridine, α-picolinaldehyde, α-picolinamide, 5,6,7.8-tetrahydroquinoline, 2
, 2'-dipyridyl, 2-chloroquinoline, acridine, phenanthridine, benzoquinoline, benzoisoquinoline, naphthyridine, pyrazine, 4,6. Dimethylpyrazine, 2,6-dimethylpyrazine, pyridazine, pyrimidine, quinoxaline, 2,3-dimethylquinoxaline,
Examples include quinazoline, fuclazine, phenazine, cinnoline, and pteridine. They can also be used as polymers such as polyvinylpyridine. These tertiary amines may be added to the reactor separately from the raw materials and other catalyst components, or a portion of them may be treated in advance with a portion of the other components of the catalyst system to form appropriate complexes, adducts, etc. It can also be used in place of other compounds. - For example, palladium chloride, ferrous chloride, and pyridine can be added separately to a reactor and reacted, but a palladium chloride-pyridine complex is prepared in advance, and the complex is combined with other raw materials and a catalyst. It is also possible to additionally add and react the component and the tertiary amine.

The amount of tertiary amine used is at least 0.05 molar ratio, preferably at least 0.1 molar ratio, based on the nitro group of the nitro compound used as a raw material.

If the molar ratio is less than 0.05, the reaction becomes extremely slow and the selectivity decreases.

Although the process of the present invention can be carried out without the presence of a solvent, the use of a solvent is preferred in order to effectively carry out the invention.

Examples of solvents include aromatic solvents such as benzene, toluene, and xylene, nitriles such as acetonitrile and benzonitrile, sulfolane solvents such as sulfolane, 1.1.2-)lichloro-1゜2.2-trifluoro Aliphatic halogenated hydrocarbons ffi such as ethane, halogenated aromatic hydrocarbons such as monochlorobenzene, dichlorobenzene and trichlorobenzene, ketones, esters, tetrahydrofuran, 1,4-dioxane, 1,
2-dimethoxyethane or the like can be used as a solvent.

The solvent is generally used in a weight ratio of 1 or more, preferably 3 or more, relative to the aromatic nitro compound.

Even if the amount used is large, there is no problem with the reaction, and the upper limit of the amount used is determined mainly from an economic standpoint. If a solvent is not used, the reaction rate will be slow and the yield of the target product will be poor.

In carrying out the method of the present invention, there are no particular limitations on the method of charging, but it is preferable that the nitro compound and the catalyst component be added after being dissolved or partially dissolved in the aromatic hydroxy compound or a suitable solvent.

The order of addition is also not limited, but can be varied within the constraints of the equipment used. For example, a suitable pressure reactor such as an autoclave is charged with a catalyst, an aromatic dihydrogen compound, and an aromatic hydroxy compound, carbon monoxide is introduced under pressure, and the mixture is heated and stirred until the desired reaction is completed. Carbon monoxide can also be supplied intermittently or continuously by exhausting carbon dioxide gas generated as the reaction progresses. The reaction may be carried out by any punch, semi-continuous or continuous method. Excess carbon monoxide after the reaction can be recycled.

The reaction temperature is generally maintained in the range of 100 to 250°C, with a range of 140 to 240°C being particularly preferred. Although the reaction proceeds faster at higher temperatures, a temperature of 160 to 220°C is usually sufficient.

The reaction pressure is 50 to 1000 kg as the partial pressure of carbon monoxide.
/ cal G, more preferably 100-500 k
g/cni G range.

The reaction time varies depending on the nature of the nitro compound used, the reaction temperature, the reaction pressure, the type and amount of the catalyst, the reaction apparatus, etc., but is generally carried out in the range of 10 minutes to 10 hours. After the reaction is complete, the reaction mixture is cooled and evacuated, and the reaction product is processed by conventional methods including filtration, distillation, or other suitable separation methods to free the carbamide from unreacted materials, impurities, solvents, catalysts, etc. Separation of acid aryl esters is carried out.

〔Example〕

The present invention will be specifically explained using Examples or Comparative Examples.

In all of the following Examples and Comparative Examples, an electromagnetic stirring autoclave made of stainless steel (5OS-316L) was used for all reactions.

Further, the conversion rate and yield were calculated from the results of gas chromatography analysis and liquid chromatography analysis.

In addition, the corrosion rate was calculated from the surface area of the test piece of S[lS-316L and the weight loss after reaction.
Expressed in ar.

In addition, the following abbreviations of compounds were used. dinitrotoluene is abbreviated as DNT, tolylene dicarbamic acid diphenyl ester is abbreviated as TDC-P, and N-tolyl dicarbamic acid phenyl ester is abbreviated as TNC-P. When it is necessary to indicate the position of a substituent, for example, 2 , 2.4-DNT for 4-dinitrotoluene,) rylene-2,
2 for 4-dicarbamic acid diphenyl ester.
A number indicating the position was added in front, such as 4-T D C-P.

Example-1 2.4-DN in an autoclave with an internal volume of 500ml
T15g, phenol 31g, dichlorobis(pyridine)palladium 0.189g, phosphoryl chloride 0.08
7g, vanadium trichloride oxide 0.049g, dichlorobis(pyridine)iron 0.321g, quinoline 4.9g
, a solution consisting of 162 g of 0-dichlorobenzene was heated to 80°C.
I prepared it with This solution was a homogeneous solution containing no insoluble matter.

10kg/cra of carbon monoxide inside the autoclave
After being replaced twice with a pressure of 160 kg/ctA G.

The temperature was raised to 190℃ while stirring, and the same temperature and reaction pressure 2.
50-200 kg/cII! After reacting at G for 180 minutes, the reaction mixture was cooled to 70°C and the pressure was released. The reaction solution was a substantially homogeneous solution at 70°C. The reaction solution was analyzed by liquid chromatography.

From the analysis results, the reaction solution did not contain raw material DNT or intermediate mononitro compound, and contained 12.2 g of 2.4-TDC-P.
was contained. The yield based on 2.4-DNT was 85%. Corrosion of 5OS-316L is 0.02m
It was m/year.

Example-2 625 g of crude DNT obtained by nitration of toluene (2,4-DNT
480 g, 120 g of 2.6-DNT, and a small amount of nitrotoluene and 2,3-13.4- and 2.5-D N
Contains T. ), phenol 930g, dichlorobis(pyridine)palladium 7.57g, phosphoryl chloride 3
．． 46g, vanadium trichloride oxide 1.95g, dichlorobis(pyridine)iron 12.86g, quinoline 98.
After charging 2,645 g of O-dichlorobenzene and replacing the system with carbon monoxide twice at 10 kg/cntG, 18
The pressure was increased to 0 kg/cut G. (The temperature was raised to 190℃ in about 1 hour while stirring, and the reaction pressure was increased to 260℃ at the same temperature.)
The reaction was carried out at 240 kg/cnf G for 210 minutes.

After cooling to room temperature and releasing the pressure, the reaction solution was analyzed by liquid chromatography. As a result, the reaction solution did not contain DNT or the mononitro intermediate, and 792.1 g of 2.4-T D C-P was found.
and 210.6 g of 2.6-T D C-P,
The yield was 66.4% and 17.6%, respectively, of the total amount of 2.4-DNT and 2.6-DNT as raw materials, a total of 84%.
Met. The corrosion rate was 0.06 mm/year.

Example-3 and Comparative Examples 1 to 3 The reaction was carried out in the same manner as in Example-1, except that the reaction temperature was changed to 200° C. and the reaction time was changed to 120 minutes. The results are shown in Table 1 as Example-3.

In addition, in order to clearly demonstrate the effect of the co-catalyst system of the present invention, the results of the reaction with one of the co-catalyst components removed are shown in a comparative example.
They are shown in Table 1 as 1 to 3. In all comparative examples, the yield of the target product TDC-P decreased or the reaction rate decreased, and a large amount of the intermediate product TNC-P remained. That is, in Comparative Example-1 in which phosphoryl chloride (+'0C13) was not used, the intermediate TNC-P remained even though the reaction was carried out for 30 minutes longer than in Example-3.
The yield of DC-P also decreased by 14%. Furthermore, in Comparative Example 2 in which vanadium trichloride oxide (voct3) was not used, an even larger amount of TNC-P remained and the TDC-P yield decreased.Also, the iron compound dichlorobis(pyridine)
Even in Comparative Example-3 in which iron was not used, TNC-P remained and the TDc-p yield was lower than in Example-3. In addition, Example-3 and Comparative Examples-1 to 2 using iron compounds
The material corrosion of 5US-316L is 0.125+
n/year or less, indicating that it is a class A material, but Comparative Example 3, in which no iron compound was used, had extremely large corrosion and was unsuitable as an industrial material.

Comparative Example-4 195g of phenol without using 0-dichlorobenzene
The reaction was carried out in the same manner as in Example-1 except that the following components were used. Although no unreacted DNT was detected, the TDC-P yield was 15
%, the TNC-P yield was 51%, and the reaction results were significantly inferior to those in Example-1.

Examples 4 to 7 Reactions were carried out in the same manner as in Example 1 using the nitro compounds listed in Table 2 as raw materials. The results are shown in Table 2.

Examples 8 to 21 Reactions were carried out in the same manner as in Example 1, except that the compounds shown in Table 3 were used as catalysts and the reactions were carried out under the reaction conditions described. The results are shown in Table 3.

Examples 22 to 24 The reaction was carried out in the same manner as in Example 1, except that the compounds listed in Table 4 were used as the tertiary amines. The results are shown in Table 4.

Table 4 [Effects of the Invention] According to the method of the present invention, an aromatic carbamic acid aryl ester can be produced from an aromatic nitro compound, an aromatic hydroxy compound, and carbon monoxide in a good yield and with good operability. Furthermore, the catalyst system according to the method of the present invention is extremely non-corrosive, allowing the use of commonly available inexpensive materials in the reactor.

Claims (1)

[Claims] 1) In a method for producing an aromatic carbamic acid aryl ester by reacting an aromatic nitro compound, an aromatic hydroxy compound and carbon monoxide in the presence of a catalyst, metallic palladium or a palladium compound or a halogenated phosphorus compound is used. , a method for producing an aromatic carbamic acid aryl ester, which comprises reacting at high temperature and pressure using a catalyst system consisting of an iron compound, a vanadium compound, and a tertiary amine.