JPS6310146B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing urethane compounds. More specifically, the present invention relates to a method for producing a urethane compound by reacting a urea compound with carbon monoxide and an organic hydroxyl compound in the presence of an oxidizing agent to oxidatively carbonylate it. Urethane compounds 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 isocyanates without using phosgene. As a method for producing such urethane compounds using carbon monoxide, aromatic nitro compounds,
A method of reductively urethanizing an aromatic nitroso compound, an aromatic azo compound, an aromatic azoxy compound, etc. in the absence of an oxidizing agent, and a method of oxidatively urethanizing an aromatic amino compound are known. Furthermore, a method of oxidatively converting N・N'-diarylurea into urethane has also been proposed (Japanese Patent Application Laid-Open No. 1983-1999-
Publication No. 120552). In this method, a group noble metal or its compound is used as the main catalyst, and a metal capable of carrying out a redox reaction in the reaction system, such as copper chloride, iron chloride, iron oxychloride, vanadium chloride, vanadium oxychloride, etc., is used as a promoter. It is necessary to dissolve the chloride in the reaction system. However, these dissolved metal chlorides are highly corrosive to metal materials such as reaction vessels, piping, valves, etc., and therefore there is an equipment problem in that expensive metal materials must be used.
Furthermore, these dissolved metal chlorides are separated from high boiling point substances such as aromatic urethane products,
The drawback is that recovery requires complicated operations and a large amount of cost. In order to overcome these drawbacks, the present inventors have conducted intensive research on a method for producing urethane compounds by oxidatively urethanizing urea compounds. We have discovered a completely new catalyst system that allows the reaction to proceed catalytically without using the chloride of the element that carries out the reaction, and based on this knowledge we have completed the present invention. That is, in the present invention, in producing a urethane compound by reacting a urea compound with carbon monoxide and an organic hydroxyl compound in the presence of an oxidizing agent, (i) a compound selected from platinum group metals and compounds containing platinum group elements; and (ii) at least one selected from bromine or iodine oxoacids and salts thereof. It is something. A major feature of the present invention is that at least one selected from platinum group metals and compounds containing platinum group elements is combined with at least one selected from bromine or iodine oxoacids and salts thereof. By using this catalyst system, urethane compounds can be obtained from urea compounds with good selectivity and in high yields. These facts are truly surprising and were completely unknown until now, and could not have been expected from the prior art mentioned above (Japanese Patent Laid-Open Publication No. 120552/1983). That is, in the prior art, a catalyst system is used in which a platinum group compound is used as a main catalyst and a chloride of an element capable of carrying out a redox reaction is used as a co-catalyst. is a combination of palladium chloride and iron oxychloride. 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 trivalent iron oxychloride to divalent palladium. At the same time as it returns, trivalent iron is reduced to divalent iron, and this divalent iron is further oxidized by an oxidizing agent and returns to trivalent iron, a so-called Watzker reaction type catalytic cycle. It is thought that the urethane compound, which is the main product, is produced by As described above, it has been shown that in the prior art method, 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 the elements of groups a to a and groups b to b of the periodic table, and specifically include copper, zinc, and mercury. , thallium, tin, titanium, arsenic, antimony, bismuth, vanadium, chromium, molybdenum, tungsten, manganese, iron, cobalt, and nickel. Among them, copper, vanadium, manganese, molybdenum, tungsten, antimony, Only iron is mentioned in the examples. In contrast, the method of the present invention uses a bromine or iodine oxo acid or a salt thereof,
In this method, an anion part composed of bromine or iodine and oxygen plays an important role, and the cation part can be of any type. Therefore, the reaction of the present invention is designated as proceeding by a completely different reaction mechanism than the reactions described in the prior art. Although the detailed mechanism by which the bromine or iodine oxoacids and their salts used in the present invention act in this reaction is not clear, they do not combine with platinum group metals or compounds containing platinum group elements. It is clear that when combined, they play an important role as a catalyst component in the oxidative urethanization reaction of urea compounds. That is, when only a bromine or iodine oxoacid or its salt is used, the urethanization reaction of this reaction does not substantially proceed quickly, and even when only a platinum group metal or a compound containing a platinum group element is used, Under the conditions of this reaction, the urethanization reaction hardly progresses, or even if it does progress, only a small amount of urethane compound is produced. Especially when only platinum group elements in the metallic state are used, almost no urethane compound is obtained. do not have. For example, palladium is one of the effective catalytic components for this reaction, but the reaction hardly progresses if only palladium black, which is zero-valent metal palladium, is used alone. However, if bromine or iodine oxoacid or its salt, such as potassium periodate, is added to this, urethane can be obtained in high yield and high selectivity. In this way, 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, which means that the expensive platinum group compound can be separated from the reaction system by a simple method such as filtration. , it has been shown that it can be recovered, which is industrially advantageous. Furthermore, the bromine or iodine oxoacids and their salts used in the present invention are easy to separate and recover, unlike the chlorides of heavy metals used in the prior art, and are free from contamination in the product. One of the major features of the present invention is that it does not mix as a substance.
It is one. The platinum group metals and platinum element-containing compounds used in the method of the present invention may contain at least one platinum metal element such as palladium, rhodium, platinum, ruthenium, iridium, or osmium as a component. There are no particular limitations on these elements, and these elements may be in a metallic state or may be components forming a compound. In addition, these catalyst components include activated carbon, graphite,
Silica, alumina, silica - alumina, silica -
It may be supported on a carrier such as titania, titania, zirconia, barium sulfate, calcium carbonate, asbestos, bentonite, diatomaceous earth, polymer, ion exchange resin, zeolite, molecular sieve, magnesium silicate, magnesia, etc. . Examples of platinum group elements in the metallic state include metals such as palladium, rhodium, platinum, ruthenium, iridium, and osmium, these metal blacks, and catalyst components containing these metal ions on the above-mentioned carrier, and then hydrogen and Those reduced with formaldehyde, alloys or intermetallic compounds containing these metals, etc. are used. In addition, the alloy or intermetallic compound may be made of these white metals, or may be made of other elements such as selenium, tellurium, sulfur, antimony, bismuth,
Copper, silver, gold, zinc, tin, vanadium, iron, cobalt, nickel, mercury, lead, thallium, chromium,
It may also contain molybdenum, tungsten, or 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- _Al2O3 , Pd- _SiO2 , _Pd - _TiO2 , 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,
Alloys or intermetallic compounds such as Pd-Rh; and these alloys or intermetallic compounds supported on the above-mentioned 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. ); palladium ammine complexes such as [Pd(NH ₃ ) ₄ ]X ₂ , [Pd(en) ₂ ]X ₂ (X has the same meaning as above, and en represents ethylenediamine);
PdCl ₂ (PhCN) ₂ , PdCl ₂ (PR ₃ ) ₂ , Pd(CO)
(PR ₃ ) ₃ , Pd (PPh ₃ ) 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
Complex compounds coordinated with chelate ligands such as (acac) ₂ ; Rh black; supported rhodium catalysts similar to Pd;
Ph alloys or intermetallic compounds similar to Pd and those supported on carriers; RhCl ₃ and hydrates,
RhBr ₃ and hydrates, RhI ₃ and hydrates, Ph ₂ (SO ₄ ) ₃
and inorganic salts such as hydrates; Rh ₂ (OCOCH ₃ ) ₄ ;
Rh ₂ O ₃ , PhO ₂ ; M ₃ [RhX ₆ ] and hydrate (M,
has the same meaning as above); [Rh(NH ₃ ) ₅ ]X ₃ ,
Ammine complexes of rhodium such as [Rh(en) ₃ ]X ₃ ; Rhodium carbonyl clusters such _as Rh ₄ (CO _{) 12} and Rh ₆ (CO) ₁₆ ;
(PR ₃ ) ₃ , RhCl(PPh ₃ ) ₃ , RhX(CO)L ₂ (R and X have the same meanings as above, and L is a ligand consisting of an organic phosphorus compound and an organic arsenic compound), RhH
Examples include complex compounds such as (CO)(PPh ₃ ) ₃ and organometallic compounds. In the present invention, only one type of these platinum group metals or compounds containing platinum group elements may be used, or two or more types may be used as a mixture, and there is no particular restriction on the amount used. Normally, components containing platinum group elements are 0.0001 to 50% relative to urea compounds.
A range of mole % is desirable. The bromine or iodine oxo acids and their salts used in the method of the present invention have an oxidation number of positive 1,
Oxygen acids and salts of 3, 5, and 7 bromine or iodine, specifically hypobromous acid, bromic acid, perbromate acid, hypoiodic acid, iodic acid, iodic acid, orthoperfusate. Refers to iodic acid, metaperiodic acid, and salts of these acids. Examples of such salts include hypobromites such as sodium hypobromite and potassium hypobromite; bromites such as sodium bromite; lithium bromate, sodium bromate, potassium bromine, and bromine. Rubidium bromate, cesium bromate, magnesium bromate, calcium bromate, strontium bromate, barium bromate, silver bromate, cadmium bromate, aluminum bromate, yttrium bromate, lanthanum bromate, cerium bromate, praseodymium bromate , bromates such as neodymium bromate, samarium bromate, gadolinium bromate, dysprosium bromate, holmium bromate, thulium bromate, lead bromate, ammonium bromate; perbromates such as potassium perbromate; Hypoiodates such as sodium iodate, potassium hypoiodite, rubidium hypoiodite, cesium hypoiodite, calcium hypoiodite, barium hypoiodite; lithium iodate, sodium iodate, Potassium iodate, potassium hydrogen iodate, rubidium iodate, cesium iodate, magnesium iodate, calcium iodate, strontium iodate, barium iodate, silver iodate, gold iodate, cadmium iodate, aluminum iodate, iodine Iodates such as indium iodate, lanthanum iodate, cerium iodate, proseodymium iodate, neodymium iodate, gadolinium iodate, lead iodate, ammonium iodate;
Lithium periodate, sodium metaperiodate, trisodium dihydrogen orthoperiodate, disodium trihydrogen orthoperiodate, potassium metaperiodate, dipotassium trihydrogen orthoperiodate, dihydrogen mesoperiodate tripotassium, rubidium periodate, cesium periodate, barium periodate, silver metaperiodate, silver mesoperiodate, silver orthoperiodate, silver trihydrogen orthoperiodate, cadmium periodate, Periodates such as lead iodate and ammonium periodate are used. In the method of the present invention, these bromine or iodine oxoacids and their salts may be added to the reaction system as they are, or they may be added to the reaction system in a way that produces these compounds. Among such bromine or iodine oxoacids and their salts, particularly preferred are iodine oxoacids and salts thereof. The amount of the bromine or iodine oxoacid and its salts used in the present invention is not particularly limited, but is usually 0.001 to 10,000 times the amount of the metal element in the platinum group element-containing component used. Preferably, it is used in a molar range. The urea compound used as a raw material in the present invention has the formula It refers to a compound containing at least one urea bond in one molecule as shown in the following. Here, the two lines connected to N represent bonds between the nitrogen atom and other atoms or groups. Such atoms or groups include hydrogen, halogen, alkali metal atoms, hydroxyl groups, amino groups, aliphatic groups, alicyclic groups, araliphatic groups, heterocyclic groups, and aromatic groups. Further, these nitrogens themselves may be elements constituting the ring, or the urea bond itself may be a part constituting the ring. Such urea compounds may be unsubstituted urea, monosubstituted urea, disubstituted urea, trisubstituted urea, tetrasubstituted urea, or the like. Examples of monosubstituted ureas include aliphatic monosubstituted ureas such as methylurea, ethylurea, propylurea, butylurea, and hexylurea; alicyclic monosubstituted ureas such as cyclopropylurea, cyclobutylurea, and cyclohexylurea; benzyl; Aroaliphatic monosubstituted ureas such as urea and β-phenethylurea; heterocyclic monosubstituted ureas such as furanylurea and thiophenyl urea; aromatic monosubstituted ureas such as phenyl urea, tolylurea and naphthylurea, etc. are used. It will be done. Examples of the disubstituted urea include N,N-dimethylurea, N,N-diethylurea, N,N-dipropylurea, N,N-dibutylurea, N,N-dihexylurea, and N-ethyl-N-methylurea. , N-
Aliphatic N,N-disubstituted ureas such as ethyl-N-butylurea; N,N-dicyclopropylurea, N,
Alicyclic N,N-disubstituted ureas such as N-dicyclobutylurea, N,N-dicyclohexylurea, N-cyclopropyl-N-methylurea, N-cyclohexyl-N-ethylurea; N,N-dibenzylurea , N-benzyl-N-methylurea and other aromatic aliphatic N,N-disubstituted ureas; N,N-difuranylurea, N,N-dithiophenylurea, N-furanyl-N-methylurea and other heterocyclic ureas N,N-disubstituted ureas; N,N-diphenylurea, N,N-ditolylurea, N,N-dinaphthylurea, N-phenyl-N-methylurea, N-phenyl-N-tolylurea, N- Aromatic N such as naphthyl-N-benzylurea, N-phenyl-N-cyclohexylurea,
N-disubstituted ureas; N,N'-dimethylurea, N,
N'-diethylurea, N,N'-dipropylurea,
Aliphatic N such as N,N'-dibutylurea, N,N'-dihexylurea, N-ethyl-N'-methylurea, N-ethyl-N'-butylurea, N-hexyl-N'-methylurea , N'-disubstituted ureas; N,
N'-dicyclopropylurea, N,N'-dicyclobutylurea, N,N'-dicyclohexylurea,
Alicyclic N such as N-cyclopropyl-N'-methylurea, N-cyclohexyl-N'-ethylurea,
N'-disubstituted ureas; N,N'-dibenzylurea,
Aroaliphatic N,N'-disubstituted ureas such as N-benzyl-N'-methylurea; heterocyclic N,N'-disubstituted ureas such as N,N'-difuranylurea and N,N'-dithiophenyl urea; Substituted ureas; N,N'-diphenylurea, N,N'-ditolyl urea, N,N'-dinaphthylurea, N-phenyl-N'-tolylurea, N-
Phenyl-N'-naphthylurea, N-phenyl-
Aromatic N,N'-disubstituted ureas such as N'-ethyl urea, N-naphthyl-N'-benzylurea, N-phenyl-N'-cyclohexyl urea, and cyclic nitrogen compounds such as piperidyl urea and pyrrolidinyl urea. Urea etc. are used. Examples of trisubstituted ureas include trimethylurea, triethylurea, tripropylurea, tributylurea, trihexylurea, N,N-dimethyl-N'-ethylurea, N,
N-diethyl-N'-butylurea, N-methyl-
Aliphatic trisubstituted ureas such as N-ethyl-N'-butylurea; tricyclopropylurea, tricyclohexylurea, N,N'-dicyclohexyl-
N'-methylurea, N-cyclohexyl-N-ethyl-N'-butylurea, N,N-diethyl-
Alicyclic trisubstituted ureas such as N'-cyclobutyl urea; trifuranylurea, trithiophenyl urea,
Heterocyclic trisubstituted ureas such as N,N'-difuranyl-N-methylurea; triphenylurea, tritolylurea, trinaphthylurea, N,N-diphenyl-N'-methylurea, N,N'-diphenyl-N
-cyclohexylurea, N,N-dimethyl-
Aromatic trisubstituted ureas such as N'-phenyl urea and N-phenyl-N-ethyl-N'-benzylurea; N-substituted cyclic nitrogen compounds such as N-ethylpiperidylurea and N-methylpyrrolidinyl urea Ureas and the like are used. Examples of tetra-substituted ureas include aliphatic tetra-substituted ureas such as tetramethylurea, tetraethylurea, tetrapropylurea, tetrahexylurea, diethyldimethylurea, and ethyltrimethylurea;
Aliphatic tetra-substituted ureas such as tetracyclopropyl urea, tetracyclohexyl urea, dicyclohexyl diethyl urea, cyclobutyl trimethyl urea; aromatic aliphatic tetra-substituted ureas such as tetrabenzyl urea, tribenzyl methyl urea, dibenzyl diethyl urea, benzyl trimethyl urea, etc. Ureas: Heterocyclic tetra-substituted ureas such as tetrafuranylurea, tetrathiophenylurea, furanyltrimethylurea; tetraphenylurea, tetratolylurea, tetranaphthylurea, methyltriphenylurea, diethyldiphenylurea, dicyclohexyldiphenylurea , aromatic tetra-substituted ureas such as naphthyltriethylurea, etc. are used. Examples of cyclic urea compounds having a urea bond as a ring component include 2-imidazolone, 2-imidazolidone,
Biotin, bitantoin, N,N'-hexamethylene urea, parabanic acid, benzimidazolidone, etc. are used. Furthermore, compounds having two or more urea bonds in the molecule, such as polyureas of polyamines such as N,N'-dimethylcarbamoylhexamethylenediamine and N,N'-diphenylcarbamoylphenylenediamine, or compounds represented by the following formula: Polymeric ureas having a structural unit such as that described above can also be used. In addition, in these substituted ureas, one of the substituents
or more hydrogen may be substituted with other substituents, such as lower aliphatic groups, amino groups, carboxyl groups, ester groups, alkoxy groups, cyano groups, halogens, nitro groups, urethane groups, sulfoxide groups, sulfone groups, carbonyl groups, and amide groups. , an aromatic group, an araliphatic group, or the like. In order to obtain a urethane compound as a raw material for producing isocyanates, N,N'-disubstituted ureas are preferable, and aromatic urethane compounds are particularly suitable for N,N'-disubstituted ureas.
It is easily produced using N'-diarylureas. One or more of these urea compounds may be used. 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, and 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), tetradecyl alcohol (each isomer), and aliphatic alcohols such as pentadecyl alcohol (each isomer) Cycloalkanols such as cyclohexanol and cycloheptanol; ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, propylene glycol monomethyl Alkylene glycol monoethers such as ether and propylene glycol monoethyl ether; polyhydric alcohols such as ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, glycerin, hexanetriol, and trimethylolpropane; aralkyl alcohols such as benzyl alcohol, etc. is used. Examples of phenols that can be used include phenol, various alkylphenols, various alkoxyphenols, various halogenated phenols, dihydroxybenzene, 4,4'-dihydroxy-diphenylmethane, bisphenol-A, and hydroxynaphthalene. The oxidizing agent used in the present invention may be any conventional oxidizing agent, but preferred are molecular oxygen, organic nitro compounds, or mixtures thereof. Particularly preferred is molecular oxygen. This molecular oxygen is pure oxygen or a substance containing oxygen, which may be air, or other gases that do not inhibit the reaction of air or pure oxygen, such as nitrogen,
It may be diluted by adding an inert gas such as argon, helium, or carbon gas. In some cases, it may also contain gases such as hydrogen, carbon monoxide, hydrocarbons, and halogenated hydrocarbons. Further, 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), bis-(nitrocyclohexyl)-methane, and 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 Aromatic nitro compounds include, for example, nitrobenzene, dinitrobenzene (isomers), nitrotoluene (isomers), phenylnitromethane, bis-(nitromethyl)-cyclohexane, bis-(nitromethyl)-benzene, etc. , dinitrotoluene (each isomer), nitropyridine (each isomer), dinitropyridine (each isomer), nitronaphthalene (each isomer), dinitronaphthalene (each isomer), and the like. 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. In the present invention, when the oxidizing agent is molecular oxygen,
The reaction proceeds according to the following general reaction formula. (Here, R ¹ , R ² , R ³ , and R ⁴ are hydrogen, alkali metal atoms, hydroxyl groups, amino groups, aliphatic groups, alicyclic groups, araliphatic groups, heterocyclic groups, and aromatic groups. (R represents an organic group.) Molecular oxygen may be present in less or more than equivalent amounts, 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 of the organic group is different from the substituent of the urea compound, the urethane compound depending on the structure It goes without saying that the same urethane compound can be obtained if both structures are the same. In this case, the urethanization reaction proceeds, for example, according to the following reaction formula. (Here, R ¹ , R ² , R ³ , R ⁴ and R have the same meanings as above, and R ⁵ represents an organic residue of an organic nitro compound.) When only an organic nitro compound is used as an oxidizing agent, urea The quantitative ratio of the compound to the organic nitro compound is preferably 1 mole of nitro group per 2 moles of urea group, but of course it may be carried out at a value deviating from this stoichiometric ratio. Generally, the equivalent ratio of urea groups to nitro groups is carried out from 1.1:1 to 4:1, preferably from 1.5:1 to 2.5:1. Of course, if molecular oxygen or other oxidizing agents are used at the same time, the amount of organic nitro compound may be less than the stoichiometric amount. 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 aliphatic hydrocarbons such as chromohexane, chlorocyclohexane, trichlorotrifluoroethane, methylene chloride, carbon tetrachloride; Nitriles such as acetonitrile and benzonitrile, sulfolane, methyl Sulfones such as sulfolane 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. In the method of the present invention, other additives may be added to the reaction system as necessary in order to carry out the reaction more efficiently. Examples of such additives include zeolites, salts of nitrogen-containing compounds and hydrogen halides, onium halides, tertiary amines, hydrohalic acids, boric acids, aluminic acids, carbonic acids, silicic acids, organic Alkali metal salts and alkaline earth metal salts of acids such as acids 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 1 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 A stirred autoclave with an internal volume of 140 ml was charged with N,
N′-diphenyl urea 20 mmol, ethanol 40 ml,
After adding 0.5 mg of palladium black and 1 mmol of potassium metaperiodate and replacing the inside of the system with carbon monoxide, the amount of carbon monoxide was 80 Kg/cm ² , and then the oxygen was 6 Kg/cm ²
It was press-fitted to a total pressure of 86Kg/cm ² . while stirring
After reacting at 160°C for 1 hour, the reaction mixture was filtered and the filtrate was analyzed. As a result, the reaction rate of N,N'-diphenylurea was 96%, and the yield of ethyl N-phenylcarbamate was 94%. The selectivity rate was 98%. Examples 2-9 Completely the same as Example 1 except that various bromine or iodine oxoacids or salts thereof (1 mmol) were used in place of potassium metaperiodate in Example 1.
A similar reaction was carried out. The results are shown in Table 1. In Examples 8 and 9, the reaction time was 2 hours.

【table】

[Table] Comparative Example 1 As a result of carrying out the same reaction as in Example 1 using only palladium black without using potassium metaperiodate, the reaction rate of N,N'-diphenylurea was 10
%, ethyl N-phenylcarbamate was produced in a yield of only 3%. Example 10 The same reaction as in Example 1 was carried out using 20 mmol of N,N'-dicyclohexyl urea, 50 ml of methanol, 0.5 mg of palladium black, and 1 mmol of potassium metaperiodate. As a result, the reaction of N, N'-dicyclohexyl urea was carried out. The yield was 94%, the yield of methyl N-cyclohexylcarbamate was 89%, and the selectivity was 95%. Example 11 20 mmol of N,N'-dibenzylurea, ethanol
The same reaction as in Example 1 was carried out using 40 ml of palladium black, 1 mg of palladium black, and 1 mmol of potassium metaperiodate. As a result, the reaction rate of N,N'-benzylurea was 95%, and the yield of ethyl N-benzylcarbamate was 95%. The rate was 90% and the selection rate was 95%. Example 12 30 mmol of tetramethylurea, 50 ml of methanol,
As a result of carrying out the same reaction as in Example 1 using 0.5 mg of palladium black and 1 mmol of potassium metaperiodate, the reaction rate of tetramethylurea was 76%, and N,
The yield of methyl N-dimethylcarbamate was 68% and the selectivity was 90%. Example 13 20 mmol of urea, 40 ml of ethanol, palladium black
The same reaction as in Example 1 was carried out using 0.5 mgatom and 1 mmol of potassium metaperiodate. As a result, the reaction rate of urea was 90% and the yield of ethyl carbamate was 83%.
The selection rate was 92%. Examples 14-21 The same reactions as in Example 1 were carried out, except that various platinum group metals or compounds containing platinum group elements were used in place of palladium black in Example 1. The results are shown in Table 2.

【table】

[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 a product in which palladium chloride and tellurium dioxide are co-supported on activated carbon at a molar ratio of 10:3, and then subjected to hydrogen ring reduction at 350°C. Example 22 N, N'- in a stirring autoclave with an internal volume of 200 ml.
Diphenylurea 30mmol, nitrobenzene 15m
mol, methanol 50ml, palladium chloride 0.5m
mol, add 5 mmol of potassium metaperiodate,
After replacing the system with carbon monoxide, remove the carbon monoxide.
120Kg/ ^cm2 was press-fitted. The reaction was carried out at 180° C. for 5 hours while stirring. As a result of analyzing the reaction solution, N,N'-
The reaction rates of diphenyl urea and nitrobenzene were 24% and 33%, respectively, and 13 mmol of methyl N-phenylcarbamate was produced.

Claims (1)

[Scope of Claims] 1. In producing a urethane compound by reacting a urea compound with carbon monoxide and an organic hydroxyl compound in the presence of an oxidizing agent, (i) among platinum group metals and compounds containing platinum group elements; and (ii) at least one selected from bromine or iodine oxoacids and their salts. . 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. Claim 1, wherein the platinum group metal and the compound containing the platinum group element are palladium, rhodium, a palladium compound, and a rhodium compound.
2. The method according to any one of paragraphs 2 and 3. 5 Claim 1 using at least one selected from iodine oxo acids and salts thereof
4. The method according to any one of paragraphs 2, 3, and 4. 6. The method according to any one of claims 1, 2, 3, 4, or 5, wherein the urea compound is N,N'-diarylurea. 7. The method according to claim 6, wherein the N,N'-diarylurea is N,N'-diphenylurea.