JPS6125703B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing aromatic urethane.
More specifically, the present invention relates to a method for producing an aromatic urethane by reacting an aromatic amino compound with carbon monoxide and an organic hydroxyl compound in the presence of an oxidizing agent to oxidatively carbonylate it. Aromatic urethanes are important compounds used in carbamate pesticides and the like, and recently there has been a demand for an inexpensive method for producing them as raw materials for producing aromatic isocyanates without using phosgene. Conventionally, two main methods have been proposed as methods for producing aromatic urethane compounds using carbon monoxide.
That is, one method is in the presence of alcohol,
This is a method of reductively converting an aromatic nitro compound into urethane. For example, in the case of nitrobenzene, it is represented by the following formula. However, in this reaction, 3 moles of carbon monoxide are required per mole of nitrobenzene, of which 2 moles of carbon monoxide become worthless carbon dioxide, so carbon monoxide is 1/3 of the amount used.
Moreover, in order to carry out this reaction continuously, carbon dioxide must be separated from the mixed gas of carbon monoxide and carbon dioxide, which also makes it difficult to carry out industrially. It is a drawback in As another method, a method has recently been proposed in which an aromatic amino compound is reacted with carbon monoxide and alcohol in the presence of an oxidizing agent such as oxygen or an organic nitro compound to oxidatively form a urethane. This method utilizes carbon monoxide more effectively than the above-mentioned method, and can be said to be a more preferable method.
As a promoter, a chloride of an element such as copper chloride, iron chloride, iron oxychloride, panadium chloride, panadium oxychloride, etc., which is a Lewis acid and can carry out a redox reaction in the reaction system, is dissolved in the reaction system. It is necessary to keep the
120551, JP-A-55-124750). However, these dissolved chlorides are highly corrosive to metal materials such as reaction vessels, piping, valves, etc., and this poses an equipment problem in that expensive metal materials must be used. Furthermore, separating and recovering these dissolved chlorides from high-boiling point products such as aromatic urethane or diarylurea, which is a reaction by-product, has the drawback of requiring complicated operations and a large amount of cost. In addition, when these cocatalysts are reduced through a redox reaction, the hydrogen chloride produced becomes hydrochloride of unreacted aniline, so even when reoxidized in the reaction system, the original chloride is However, when the cocatalyst is recovered, some of it is partially reduced, and when the reaction is repeated, these cocatalysts also have to be prepared again. In order to overcome these drawbacks, the present inventors have conducted extensive research on a method for producing aromatic urethane compounds by oxidatively urethanizing aromatic amino compounds, and as a result, we have discovered that this is the main cause of these drawbacks. The inventors discovered a completely new catalyst system that allows the reaction to proceed catalytically without using Lewis acids or chlorides of elements that perform redox reactions, and based on this knowledge, they completed the present invention. That is, the present invention provides a method for producing an aromatic urethane by reacting an aromatic amino compound with carbon monoxide and an organic hydroxyl compound in the presence of an oxidizing agent, the method comprising: at least one type selected from onium compounds whose anions are halogens (however, excluding ammonium compounds) and at least one type of compounds that can produce these in the reaction system. An object of the present invention is to provide a method for producing an aromatic urethane, which is characterized by using an aromatic urethane system. As described above, a major feature of the present invention is that at least one compound selected from platinum group metals and compounds containing platinum group elements and at least one compound selected from onium compounds whose anion is a halogen are used. By using a combination of catalyst systems, aromatic urethanes can be obtained from aromatic amino compounds with good selectivity and in high yields. These facts are truly surprising and have not been known until now, and are contrary to the prior art mentioned above (Japanese Unexamined Patent Publications No. 55-120551, JP-A No. 55-124750).
This was completely unexpected. In other words, the prior art uses a catalyst system in which a platinum group compound is the main catalyst and a chloride of an element capable of carrying out a redox reaction in the reaction system is used as a cocatalyst. is a combination of palladium chloride and ferric chloride. In such a system, divalent palladium is involved in the reaction, and as the reaction progresses, it is reduced to zero-valent palladium, which is reoxidized by ferric chloride and returned to divalent palladium. At the same time, ferric chloride is reduced to ferrous chloride,
Furthermore, it is thought that the main product, aromatic urethane, is produced through a so-called Watzker reaction type catalytic cycle in which this ferrous chloride is reoxidized by an oxidizing agent and returned to ferric chloride. As described above, it has been shown that in the prior art methods, the chloride of an element having a redox effect is essential as a reoxidizing agent for the main catalyst in the reaction system.
Elements that have such a function are those that can undergo redox reactions selected from elements in groups AA and BB to B of the periodic table, and specifically include copper, zinc, mercury, and thallium. ,
Tin, titanium, arsenic, antimony, bismuth, vanadium, chromium, molybdenum, tungsten,
Manganese, iron, cobalt, and nickel are listed, among which only copper, vanadium, manganese, and iron are described in the examples. On the other hand, the method of the present invention uses onium compounds whose anions are halogens or compounds capable of producing these in a reaction system, and these compounds either do not contain any metal components or Alternatively, the cation moiety cannot undergo a redox reaction under normal reaction conditions. Therefore, it is presumed that the reaction of the present invention proceeds by a completely different reaction mechanism from the reactions described in the prior art. It is unclear how onium compounds in which the anion is a halogen act in the reaction of the present invention, but when combined with a platinum group metal or a compound containing a platinum group element, aromatic It is clear that it plays an important role as a catalyst component in the oxidative urethanization reaction of amino compounds. In other words, the aromatic urethane formation reaction of this reaction will not proceed at all if only an onium compound whose anion is a halogen is used, and even if only a platinum group metal or a compound containing a platinum group element is used, the aromatic urethanization reaction will not proceed under the conditions of this reaction. hardly progresses, or even if it does, only a small amount of aromatic urethane is produced. In particular, when only platinum group elements in a metallic state are used, hardly any aromatic urethane can be obtained. For example, palladium is one of the effective catalyst components for this reaction, but this reaction hardly progresses only with palladium black, which is zero-valent metal palladium, but when the anion is a halogen. Addition of an onium compound, such as methyltriphenylphosphonium iodide, allows aromatic urethanes to be obtained almost quantitatively. As described above, in the method of the present invention, a solid platinum group compound in a metallic state can also be used as one of the catalyst components. This shows that expensive platinum group compounds can be separated and recovered from the reaction system by a simple method such as filtration. The platinum group metals and compounds containing platinum group elements used in the present invention include palladium, rhodium, platinum, ruthenium, iridium,
It includes at least one element selected from platinum group elements such as osmium, and these elements are in a metallic state or are components forming a compound. In addition, these catalyst components include activated carbon, graphite, silica, alumina,
Supported on carriers such as silica-alumina, silica-titania, titania, zirconia, barium sulfate, calcium carbonate, asbestos, bentonite, diatomaceous earth, polymers, ion exchange resins, zeolites, molecular sieves, magnesium silicate, and magnesia. It may be something. Platinum group elements in the metallic state, such as metals such as palladium, rhodium, platinum, ruthenium, iridium, and osmium, these metal blacks, and catalyst components containing these metal ions are supported on the above-mentioned carrier, and then hydrogen or Those reduced with formaldehyde, alloys or intermetallic compounds containing these metals, etc. are used. Also,
The alloy or intermetallic compound may be of these platinum group metals, or may contain other elements such as selenium, tellurium, sulfur, antimony, bismuth, copper, silver, gold, zinc, tin, vanadium, iron,
It may contain cobalt, nickel, mercury, lead, thallium, chromium, molybdenum, tungsten, and the like. On the other hand, compounds containing platinum group elements include, for example, inorganic salts such as halides, sulfates, nitrates, phosphates, and borates; organic acid salts such as acetates, oxalates, and formates; and cyanides. ; Hydroxides; Oxides; Sulfides; Nitro group, cyano group,
Complex compounds of metals such as metal salts containing anions such as halogens and oxalate ions, and salts or complexes containing ammonia, amines, phosphines, carbon monoxide, chelate ligands, etc.; organic ligands or organic Examples include organometallic compounds having groups. Among these catalyst components, those containing palladium or rhodium or both are particularly preferred, such as Pd black; Pd black;
-C, Pd-Al ₂ O ₃ , Pd-SiO ₂ , Pd-TiO ₂ , Pd-
Supported palladium catalysts such as ZrO ₂ , Pd-BaSO ₄ , Pd-CaCO ₃ , Pd-asbestos, Pd-zeolite, Pd-molecular sieve; Pd-Pb, Pd-
Se, Pd-Te, Pd-Hg, Pd-Tl, Pd-P, Pd-
Cu, Pd―Ag, Pd―Fe, Pd―Co, Pd―Ni, Pd―
Alloys or intermetallic compounds such as Rh; and alloys or intermetallic compounds thereof supported on the above supports; PdCl ₂ , PdBr ₂ , PdI ₂ , Pd
(NO ₃ ) ₂ , PdSO ₄ and other inorganic salts; Pd
(OCOCH ₃ ) ₂ , organic acid salts such as palladium oxalate; Pd(CN) ₂ ; PdO; PdS; M ₂ [PdX′ ₄ ], M ₂
Palladate salts represented by [PdX′ ₆ ] (M represents an alkali metal or ammonium ion,
X' represents a nitro group, a cyano group, or a halogen. ₎ ; Ammine complexes _of palladium such as [Pd(NH _{3 ) 4} ] ₂ (PhCN) ₂ , PdCl ₂ (PR ₃ ) ₂ , Pd
(CO)( _PR3 ) ₃ , Pd( _PPh3 ) ₄ , PdCl(R)
(PPh ₃ ) ₂ , Pd(C ₂ H ₄ )(PPh ₃ ) ₂ , Pd(C ₃ H ₅ ) ₂ and other complex compounds or organometallic compounds (R represents an organic group): Pd(acac) ₂ Complex compounds coordinated with chelate ligands such as Rh black; Supported rhodium catalysts similar to Pd; Rh alloys or intermetallic compounds similar to Pd, and those supported on supports; RhCl ₃
and hydrates, RhBr ₃ and hydrates, RhI ₃ and hydrates, Rh ₂ (SO ₄ ) ₃ and inorganic salts such as hydrates; Rh ₂
(OCOCH ₃ ) ₄ ; Rh ₂ O ₃ , RhO ₂ ; M ₃ [RhX' ₆ ] and hydrate (M and X' have the same meanings as above);
Rhodium ammine complexes such as [Rh(NH ₃ ) ₅ ]X′ ₃ , [Rh(en) ₃ ]X′ ₃ ; Rh ₄ (CO) ₁₂ , Rh ₆
Rhodium carbonyl clusters such as (CO) ₁₆ ; [RhCl(CO) ₂ ] ₂ , RhCl ₃ (PR ₃ ) ₃ , RhCl
(PPh ₃ ) ₃ , RhX′(CO)L ₂ (X′ has the same meaning as above, L is a ligand consisting of an organic phosphorus compound and an organic arsenic compound), RhH(CO)(PPh ₃ ) Examples include complex compounds such as ₃ and organometallic compounds. These platinum group metals or compounds containing platinum group elements can be used alone or in combination of two or more. Furthermore, the onium compounds (however, excluding ammonium compounds) whose anion is a halogen used in the present invention are compounds containing elements with lone pairs of electrons, in which protons or other cation forms are added to these lone pairs. An element having a lone pair of electrons increases its covalent bond valence by 1 to become a cation, and has a halogen anion as a counter ion. Examples of such onium compounds include phosphonium compounds ([R ¹ R ² R ³ R ^{4 P} ]X), arsonium compounds ([R ¹ R ² R ³ R ^{4 As} ] ^{R 3} R ⁴ Sb]X], oxonium compounds ⁽ [ ^{R 1 R 2 R 3 O ]} S(O)]X), selenonium compound ([R ¹ R ^{2 R 3} Se] X), telluronium compound ⁽ [R ¹ R ^{2 R 3 Te} ] X), iodonium compounds ([R ¹ R ² I] X), and the like.
Here, R ¹ , R ² , R ³ , R ⁴ are hydrogen or aliphatic groups,
Represents a group selected from an aromatic group, an alicyclic group, and an araliphatic group, each of which may be the same,
Further, in some cases, it may be a constituent element of a ring containing an element having a lone pair of electrons. Also, X is F,
Represents a halogen selected from Cl, Br, and I. Such halogenated onium compounds, which are onium compounds whose anion is a halogen, include phosphine compounds, arsine compounds, stibine compounds, oxy compounds, sulfide compounds, sulfoxide compounds, selenide compounds, which correspond to hydrogen halides or organic halides. It is easily obtained by reaction with telluride compounds etc.
These may be produced outside the reaction system, or may be produced within the reaction system. Of course, it may be produced by other methods, or may be produced within the reaction system by other methods. Preferred among these are halogenated phosphonium compounds, halogenated arsonium compounds, and halogenated sulfonium compounds, and particularly preferred are halogenated phosphonium compounds. Examples of halogenated phosphonium compounds include symmetrical tetraalkylphosphonium compounds such as tetramethylphosphonium chloride, tetramethylphosphonium bromide, tetramethylphosphonium iodide, tetraethylphosphonium chloride, tetraethylphosphonium bromide, and tetraethylphosphonium iodide; enylphosphonium,
Alkylaryl mixed phosphonium compounds such as methyltriphenylphosphonium bromide and methyltriphenylphosphonium iodide; symmetrical tetraarylphosphonium compounds such as tetraphenylphosphonium chloride, tetraphenylphosphonium bromide, and tetraphenylphosphonium iodide ; Asymmetric tetraalkylphosphonium compounds such as ethyltrimethylphosphonium chloride, ethyltrimethylphosphonium bromide, and ethyltrimethylphosphonium iodide are preferably used. Examples of halogenated arsonium compounds include symmetrical tetraalkylarsonium compounds such as tetramethylarsonium bromide, tetramethylarsonium iodide, tetraethylarsonium bromide, and tetraethylarsonium iodide; methyltriphenylarsonium bromide , alkylaryl mixed phosphonium compounds such as methyltriphenylarsonium iodide; symmetrical tetraarylarsonium compounds such as tetraphenylarsonium bromide and tetraphenylarsonium iodide;
Asymmetric tetraalkyl arsonium compounds such as methyl triethyl arsonium iodide and dimethyl diethyl arsonium iodide are preferably used. Examples of halogenated sulfonium compounds include alkylsulfonium compounds such as trimethylsulfonium chloride, trimethylsulfonium bromide, trimethylsulfonium iodide, triethylsulfonium bromide, triethylsulfonium iodide, methyldiethylsulfonium bromide, and methyldiethylsulfonium iodide; Alkylaryl mixed phosphonium compounds such as dimethylphenylsulfonium bromide and methyldiphenylsulfonium iodide; arylphosphonium compounds such as triphenylsulfonium bromide and triphenylsulfonium iodide; bicyclo-(2,2,
1) Cyclic sulfonium compounds such as -heptane-1-sulfonium and thiopyrylium iodide are preferably used. These halogenated onium compounds can be used alone or in combination of two or more. Of course, one molecule may contain two or more onium halide groups. Further, among such halogenated onium compounds, those in which the halogen species is bromine or iodine are preferably used, and those containing iodine are particularly preferred. The aromatic amino compound used as a raw material in the present invention may be any compound in which an amino group or a monosubstituted amino group is directly bonded to an aromatic ring, but aromatic primary amines are particularly preferred.
Examples of such aromatic primary amines include aniline, diaminobenzene (each isomer), triaminobenzene (each isomer), tetraaminobenzene (each isomer), aminopyridine (each isomer),
Diaminopyridine (each isomer), triaminopyridine (each isomer), aminonaphthalene (each isomer), diaminonaphthalene (each isomer), triaminonaphthalene (each isomer), tetraminonaphthalene (each isomer) and monoamines, diamines of diphenyl compounds represented by the following general formula (),
Examples include isomers of triamine and tetraamine. (In the formula, A is a simple chemical bond, or -O-, -S
―, ―SO ₂ ―, ―CO―, ―CONH―, ―COO
-, -C(R ⁵ )(R ⁶ )-, and -N(R ⁵ )-. In addition, in these aromatic primary amines, R ⁵ and R ⁶ are H, an aliphatic group, an alicyclic group,
at least one hydrogen on the aromatic ring is another substituent,
For example, it is substituted with a halogen atom, a nitro group, a cyano group, an alkyl group, an alicyclic group, an aromatic group, an aralkyl group, an alkoxy group, a sulfoxide group, a sulfone group, a carbonyl group, an ester group, an amide group, etc. Good too. Among these aromatic amino compounds, particularly preferred are aniline, 2,4- and 2,6-diaminotoluene, chloroaniline (each isomer), dichloroaniline (each isomer), 4,4'- and 2,
4'-diaminodiphenylmethane and 1,5-diaminonaphthalene. The organic hydroxyl compound used in the present invention is a monohydric or polyhydric alcohol, or a monohydric or polyhydric phenol, and examples of such alcohol include linear or branched alcohols having 1 to 20 carbon atoms. monohydric or polyhydric alkanols or alkenols in the chain,
Examples include monovalent or polyvalent cycloalkanols, cycloalkenols, and aralkyl alcohols. Furthermore, these alcohols may contain other inert substituents, such as halogen atoms, cyano groups, alkoxy groups, sulfoxide groups, sulfone groups, carbonyl groups, ester groups, and amide groups. Specific examples of such alcohols include methanol, ethanol, propanol (each isomer), butanol (each isomer), pentanol (each isomer), hexanol (each isomer), heptanol (each isomer), Octanol (each isomer), Nonyl alcohol (each isomer), Decyl alcohol (each isomer), Undecyl alcohol (each isomer), Lauryl alcohol (each isomer), Tridecyl alcohol (each isomer), Tetra Aliphatic alcohols such as decyl alcohol (each isomer) and pentadecyl alcohol (each isomer); cycloalkanols such as cyclohexanol and cycloheptanol; ethylene glycol monomethyl ether, ethylene glycol monoethyl ether,
Alkylene glycol monoethers such as diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether; ethylene glycol, propylene glycol, diethylene glycol, dipropylene Polyhydric alcohols such as glycol, glycerin, hexanetriol, and trimethylolpropane; aracyl alcohols such as benzyl alcohol are used. Examples of phenols that can be used include phenols, various alkylphenols, various alkoxyphenols, various halogenated phenols, dihydroxybenzene, 4,4'-dihydroxy-diphenylmethane, bisphenol-A, and hydroxynaphthalene. As the oxidizing agent used in the present invention, ordinary oxidizing agents can be used, but molecular oxygen, organic nitro compounds, and mixtures thereof are preferred. Particularly preferred is molecular oxygen. Molecular oxygen is pure oxygen or something containing oxygen, which may be air, or air or pure oxygen diluted with another gas that does not inhibit the reaction, such as nitrogen, argon, helium, carbon dioxide, or other inert gas. It may be something that has been done. In some cases, it may also contain gases such as hydrogen, carbon monoxide, hydrocarbons, and halogenated hydrocarbons. The organic nitro compound may be any of alicyclic, aliphatic, and aromatic nitro compounds. Examples of alicyclic nitro compounds include nitrocyclobutane, nitrocyclopentane, nitrocyclohexane, dinitrocyclohexane (each isomer), and bis-(nitrocyclohexyl)-methane; examples of aliphatic nitro compounds include nitromethane, nitroethane, Nitropropane (each isomer), Nitrobutane (each isomer), Nitropentane (each isomer), Nitrohexane (each isomer), Nitrodecane (each isomer), 1,2-dinitroethane, Dinitropropane (each isomer) dinitrobutane (each isomer), dinitropentane (each isomer), dinitrohexane (each isomer), dinitrodecane (each isomer), phenylnitromethane, bis-(nitromethyl)-cyclohexane,
There is bis-(nitromethyl)-benzene, and examples of aromatic nitro compounds include nitrobenzene, dinitrobenzene (each isomer), nitrotoluene (each isomer), dinitrotoluene (each isomer), nitropyridine (each isomer), Examples include dinitropyridine (isomers), nitronaphthalene (isomers), dinitronaphthalene (isomers), and isomers of mononitro and dinitro compounds of the diphenyl compound represented by the general formula (). In addition, in these nitro compounds, at least one hydrogen has another substituent, such as a halogen atom, an amino group, a cyano group, an alkyl group, an alicyclic group, an aromatic group, an aralkyl group, an alkoxy group, a sulfoxide group, It may be substituted with a sulfone group, carbonyl group, ester group, amide group, etc.
Among these nitro compounds, aromatic nitro compounds are preferred, and particularly preferred are nitrobenzene, nitrotoluene (each isomer), nitroaniline (each isomer), 2,4- and 2,6-dinitrotoluene, and dichloronitrobenzene. (each isomer), 4,4'- and 2,4'-dinitrodiphenylmethane, and 1,5-dinitronaphthalene. When the oxidizing agent is molecular oxygen, the reaction proceeds according to the following general reaction formula. Ar( _NH2 )y+0.5y・_O2 +y・CO+y・ROH
→Ar(NHCOOR)y+y・H ₂ O (Here, Ar is an aromatic group, R is an organic group, y
(represents the number of amino groups in one molecule of aromatic amino compound) Molecular oxidation may be less or more than the equivalent amount, but mixtures of oxygen/carbon monoxide or oxygen/organic hydroxyl compounds are outside the explosive limits. should be used in In addition, when an organic nitro compound is used as an oxidizing agent, the organic nitro compound itself also participates in the reaction and becomes urethane, so if the structure is different from the aromatic amino compound, a urethane compound corresponding to each structure can be obtained. It goes without saying that if both have the same structure, the same aromatic urethane compound can be obtained. In this case, the urethanization reaction proceeds according to the following reaction formula, for example. 2Ar(NH ₂ )y+R′(NO ₂ )y+3y・CO+
3y・ROH→2Ar(NHCOOR)y+
R'(NHCOOR)y+2y・H ₂ O (Ar, y, and R have the same meanings as above, and R' represents a residue other than the nitro group of the organic nitro compound) When using only the organic nitro compound as an oxidizing agent The quantitative ratio of the aromatic amino compound to the organic nitro compound is preferably 1 mole of nitro group per 2 moles of amino group, but of course it may be carried out at a value far from this stoichiometric ratio. . Generally, the equivalent ratio of amino group to nitro group is
1.1:1 to 4:1, preferably 1.5:1 to
Implemented at 2.5:1. Of course, less than the stoichiometric amount of the organic nitro compound may be used if molecular oxygen or other oxidizing agents are used at the same time. The most preferred organic nitro compound in the method of the present invention is an aromatic nitro compound having the same skeleton as the aromatic amino compound. In the method of the present invention, it is preferable to use an excess of the organic hydroxyl compound as the reaction solvent, but if necessary, a solvent that does not adversely affect the reaction can also be used. Examples of such solvents include aromatic hydrocarbons such as benzene, toluene, xylene, and mesitylene; halogenated aromatics such as chlorobenzene, dichlorobenzene, trichlorobenzene, fluorobenzene, chlorotoluene, chlornaphthalene, and bromnaphthalene. Hydrocarbons; halogenated aliphatic hydrocarbons or halogenated alicyclic hydrocarbons such as chlorhexane, chlorocyclohexane, trichlorotrifluoroethane, methylene chloride, and carbon tetrachloride; nitriles such as acetonitrile and benzonitrile; sulfolane, Sulfones such as methylsulfolane and dimethylsulfolane; tetrahydrofuran, 1,
Ethers such as 4-dioxane and 1,2-dimethoxyethane; Ketones such as acetone and methyl ethyl ketone; Esters such as ethyl acetate and ethyl benzoate; N,N-dimethylformamide,
Examples include amides such as N,N-dimethylacetamide, N-methylpyrrolidone, and hexamethylphosphoramide. The amount of the catalyst used in the present invention may be arbitrary, but the component containing the platinum group element is preferably in the range of 0.0001 to 50 mol % based on the aromatic amino compound. In addition, onium compounds having halogen as an anion are usually 0.001 to 0.01 to
It is preferably used in a 10,000-fold molar range. Further, it is preferable to use the oxidizing agent in an amount equal to or greater than the stoichiometric amount relative to the aromatic amino compound, but of course it may be used in a smaller amount. In the method of the present invention, other additives may be added to the reaction system as necessary to carry out the reaction more effectively. Examples of such additives include zeolites, salts of nitrogen-containing compounds and hydrogen halides, quaternary ammonium salts, tertiary amines, and hydrogen halides, boric acid, aluminic acid, carbonic acid, silicic acid, and organic acids. Alkali metal salts and alkaline earth metal salts such as are suitable. In the method of the present invention, the reaction is usually carried out at 80 to 300°C.
Preferably it is carried out at a temperature range of 120 to 220°C. The reaction pressure is 5 to 500Kg/cm ² , preferably 20 to 300Kg/cm 2 .
Kg/ ^cm2 , and the reaction time varies depending on the reaction system, catalyst system, and other reaction conditions, but is usually from several minutes to several hours. Further, the reaction of the present invention can be carried out either batchwise or continuously in which the reaction solution is continuously drawn out while continuously supplying the reaction components. Next, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to these Examples. Example 1 40 mmol of aniline, 40 ml of ethanol, and 0.5 mg of palladium black in a stirred autoclave with an internal volume of 140 ml.
atom, methyltriphenylphosphonium iodide
After introducing 5 mmol of carbon monoxide to replace the inside of the system with carbon monoxide, 80 kg/cm ² of carbon monoxide and then 6 kg/cm ² of oxygen were introduced to bring the total pressure to 86 kg/cm ² . After reacting at 160°C for 1 hour with stirring, the reaction mixture was filtered and the filtrate was analyzed. As a result, the reaction rate of aniline was 80%, N-
The yield of ethyl phenylcarbamate was 75% and the selectivity was 94%. Examples 2 to 7 Table 1 shows the results of the same reaction as in Example 1 except that 5 mmol of various onium halide compounds were used instead of methyltriphenylphosphonium iodide.

[Table] Comparative Example 1 The same reaction as in Example 1 was carried out using only palladium black without using methyltriphenylphosphonium iodide. As a result, the reaction rate of aniline was 8%.
So, ethyl N-phenylcarbamate is only slightly
It was produced with a yield of only 1.9%. Example 8 50 mmol of aniline, 50 ml of ethanol, 1 g of Rh/C with 5W% rhodium supported on activated carbon, and 6 mmol of methyltriphenylphosphonium iodide were placed in a stirred autoclave with an internal volume of 200 ml, and the system was replaced with carbon monoxide. Afterwards, carbon monoxide was injected at 80 kg/cm ² and then oxygen at 6 kg/cm ² to bring the total pressure to 86 kg/cm ² . After reacting at 160℃ for 1 hour with stirring,
As a result of filtering the reaction mixture and analyzing the filtrate, the reaction rate of aniline was 73%, the yield of ethyl N-phenylcarbamate was 59%, and the selectivity was 81%. Comparative Example 2 The same reaction as in Example 8 was carried out without using methyltriphenylphosphonium iodide, but the reaction rate of aniline was 7% and the yield of ethyl N-phenylcarbamate was less than 1%. . Examples 9 to 15 Table 2 shows the results of similar reactions in Example 1 using various platinum group metals or compounds containing platinum group elements in place of Pd black.

[Table] In these examples, 0.5 mgatom is used as the metal element for the platinum group metal or platinum group compound, and the % expression indicates the weight % of the supported catalyst component. Pd-Te/C is obtained by co-supporting palladium chloride and tellurium dioxide at a molar ratio of 10:3 on activated carbon, which is then reduced with hydrogen at 350°C. Example 16 Add 30 mmol of aniline, 15 mmol of nitrobenzene, and methanol to a stirred autoclave with an internal volume of 200 ml.
Add 50ml of palladium chloride, 0.5mmol of palladium chloride, and 5mmol of methyltriphenylphosphonium iodide, replace the system with carbon monoxide, and then reduce the amount of carbon monoxide to 120Kg/cm ²
It was press-fitted. The reaction was carried out at 180° C. for 4 hours while stirring. Analysis of the reaction solution revealed that the reaction rates of aniline and nitrobenzene were 16% and 22%, respectively.
6 mmol of methyl N-phenylcarbamate was produced. Example 17 30 mmol of 2,4-diaminotoluene, 50 ml of methanol, 1 g of Pd/C with 10 W% palladium supported on activated carbon, and 6 mmol of tetraphenylphosphonium iodide were placed in an autoclave with an internal volume of 300 ml, and the system was heated with carbon monoxide. After replacing carbon monoxide with 120
Kg/cm ² and then 8 Kg/cm ² of oxygen were injected. After reacting at 160°C for 1 hour with stirring, the reaction mixture was filtered and the filtrate was analyzed. As a result, the reaction rate of 2,4-diaminotoluene was 79%, and tolylene-2,4
-Dimethyl dicarbamate with a yield of 65% and aminomonourethane, which is a mixture of methyl-3-amino-4-methylcarbanilate and methyl-2-methyl-5-aminocarbanilate, with a yield of 8%.
It was found that it was generated by The total selectivity in urethanization was 92%.

Claims (1)

[Scope of Claims] 1. A method for producing an aromatic urethane by reacting an aromatic amino compound with carbon monoxide and an organic hydroxyl compound in the presence of an oxidizing agent, comprising: a platinum group metal and a compound containing a platinum group element; and at least one type selected from nionium compounds whose anion is a halogen (however, excluding ammonium compounds) and compounds that can generate these in the reaction system. A method for producing aromatic urethane characterized by using a catalyst system. 2. The method according to claim 1, wherein the oxidizing agent is at least one selected from molecular oxygen and organic nitro compounds. 3. The method according to claim 2, wherein the oxidizing agent is molecular oxygen. 4. The method according to any one of claims 1 to 3, wherein the platinum group metal and the compound containing the platinum group element are palladium, rhodium, a palladium compound, and a rhodium compound. 5. The method according to any one of claims 1 to 4, wherein the onium compound is a phosphonium compound, an arsonium compound, or a sulfonium compound. 6. The method according to any one of claims 1 to 5, wherein the halogen species is iodine.