JPS642583B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing a urethane compound, and more particularly 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. It is something. Urethanes are important compounds used in carbamate pesticides and the like, and recently there has been a demand for inexpensive methods of 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 for 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 Lewis acid such as copper chloride, iron chloride, iron oxychloride, vanadium chloride, vanadium oxychloride, etc. is used as a cocatalyst, and a redox reaction is carried out in the reaction system. It is necessary to dissolve chlorides containing metals 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, in order to separate and recover these dissolved metal chlorides from high boiling point substances such as aromatic urethane products, there is a drawback that complicated operations and large costs are required. 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 various completely new catalyst systems that allow the reaction to proceed catalytically without using the chloride of the element that carries out the redox reaction, and have filed a separate application. It has become clear that halogen compounds, especially compounds containing bromine or iodine, play an important role as cocatalysts in these catalyst systems, but as a result of further investigation, we have found that this new catalyst system has a specific chelate. that the yield and selectivity of the urethane compound can be further improved by adding a reagent;
and further improved the selectivity of carbon monoxide to urethane compounds, and based on these findings, the present invention was completed. 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, (a)
at least one selected from platinum group metals and compounds containing platinum group elements, (b) at least one selected from compounds containing halogens, (c) α-dioximes, 2 , 2'-bipyridines, and 8-hydroxyquinolines. Thus, a major feature of the present invention is that at least one compound selected from platinum group metals and compounds containing platinum group elements, at least one compound selected from halogen-containing compounds, and at least one compound selected from platinum group metals and compounds containing platinum group elements; When using a catalyst system in combination with at least one type of chelating reagent selected from is obtained. This fact is based on the above-mentioned prior art (Japanese Unexamined Patent Application Publication No. 1983-1999).
120552), which could not have been predicted at all. That is, in this prior art, a catalyst system in which a platinum group compound is used as a main catalyst and a chloride of an element that can undergo a redox reaction in a reaction system is used as a co-catalyst, such as palladium chloride as a typical example, is used. A catalyst system is used in which trivalent salts such as ferric chloride or iron oxychloride are combined. In such a system, 2
Valid palladium is involved in the reaction, and as the reaction progresses, it is reduced to zero-valent palladium.
This is reoxidized by trivalent iron and returned to divalent palladium, and at the same time trivalent iron is reduced to divalent iron, and this divalent iron is further reoxidized by an oxidizing agent. It is thought that the main product, the urethane compound, is produced through a so-called Watzker reaction type catalytic cycle in which trivalent iron is returned. As described above, in the prior art methods, it has been shown that the chloride of an element having a redox effect in the reaction system is essential as a reoxidizing agent for the main catalyst. 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 and zinc. , mercury, thallium, tin, titanium, arsenic, antimony, bismuth, vanadium, chromium, molybdenum, tungsten, manganese, iron, cobalt, nickel, etc. Among them, copper, vanadium, manganese, molybdenum, tungsten, Only antimony and iron are mentioned in the examples,
Moreover, these examples are only about urethanization reactions of aromatic urea compounds, and there are no examples of reactions of aliphatic or alicyclic urea compounds. In contrast, the method of the present invention uses a halogen-containing compound and a specific chelating reagent, and does not use any of the above-mentioned metal elements having a redox effect in the reaction system.
Rather, in this reaction, the reaction can proceed more cleanly if such heavy metals are not included, and in the prior art, chlorine ions are required as an activator for metal elements with redox action, but in this reaction, Since bromine and iodine are preferable to chlorine as halogen species in , 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 not clear how the halogen-containing compound and chelating reagent used in the method of the present invention act in this reaction, but when combined with a platinum group metal or a compound containing a platinum group element, a urea compound It is clear that it plays an important role as a catalyst component in the oxidative urethanization reaction. In other words, when only a compound containing a halogen and a chelating reagent are 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, the urethanization reaction of this reaction does not proceed at all. Under the reaction conditions, the urethanization reaction hardly progresses, or even if it does proceed, only a small amount of urethane is produced, and especially when only platinum group elements in a metallic state are used, hardly any urethane compound is obtained. For example, palladium is one of the effective catalyst components for this reaction, but the reaction hardly progresses if only palladium black, which is zero-valent metal palladium, is used alone. but,
When a halogen-containing compound and a specific chelating reagent such as sodium iodide and 2,2'-bipyridine are added to this, a urethane compound can 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. More importantly, by adding a specific chelating reagent to the reaction system, the selectivity of carbon monoxide to the urethanization reaction is improved. The reason for this is not clear, but certain chelating reagents suppress the reaction in which carbon monoxide is converted to carbon dioxide gas by the by-product water in the latter stage of the reaction when most of the ureas are converted to urethane compounds. This is probably because they are doing so. Therefore, the presence of a specific chelating reagent acts particularly effectively in the latter stage of the reaction, thereby increasing the reaction rate of the urea compound and increasing the yield of the urethane compound. It has become possible to further improve the selectivity of urethane compounds based on carbon. The platinum group metal and platinum group element-containing compound used in the method of the present invention may contain at least one component selected from platinum group elements such as palladium, rhodium, platinum, ruthenium, iridium, and osmium. 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, or the like. 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 that have been reduced with formaldehyde or hydrazine, and alloys or intermetallic compounds containing these metals are used. In addition, the alloy or intermetallic compound may be one of these platinum group metals, or may contain other elements such as selenium, tellurium, sulfur, antimony, bismuth, copper, silver, gold, zinc, tin, vanadium, It may contain iron, cobalt, nickel, mercury, lead, thallium, chromium, 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-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,
Alloys or intermetallic compounds such as Pd-Rh; and those in which these alloys or intermetallic compounds are supported on a carrier as described above; PdCl ₂ , PdBr ₂ , PdI ₂ , Pd
( _NO3 ) ₂ , inorganic hydrochloric acid such as _PdSO4 ; 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, ammonium ion,
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 )
Complex compounds or organometallic compounds such as (PPh ₃ ) ₂ , Pd(C ₃ H ₅ ) ₂ (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 water Inorganic salts such as hydrates, Rh ₂ (SO ₄ ) ₃ and hydrates; Rh ₂ (OCOCH ₃ ) ₄ ; Rh ₂ O ₃ ;
RhO ₂ ; M ₃ [RhX ₆ ] and hydrates (M and X have the same meanings as above); [Rh(NH ₃ ) ₅ ]X ₃ , [Rh(en) ₃ ]
Rhodium ammine complexes such as X ₃ ; Rh ₄
Rhodium carbonyl clusters such as (CO) ₁₂ , Rh ₆ (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 ) ₃
Examples include complex compounds such as or 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. Further, the halogen-containing compound used in the present invention may be either organic or inorganic as long as it does not contain a platinum group element, such as an alkali metal halide or an alkaline earth metal halide, Compounds capable of producing onium halide compounds, halogen oxoacids or salts thereof, complex compounds containing halogens, organic halides, halogen molecules, and the like are preferably used. Examples of alkali metal and alkaline earth metal halides include sodium fluoride, cesium fluoride, barium fluoride, lithium chloride, sodium chloride, potassium chloride, rubidium chloride,
Cesium chloride, magnesium chloride, calcium chloride, strontium chloride, barium chloride, lithium bromide, sodium bromide, rubidium bromide, cesium bromide, magnesium bromide, strontium bromide, barium bromide, lithium iodide, sodium iodide Compounds of a single metal and a single halogen such as potassium iodide, rubidium iodide, cesium iodide, magnesium iodide, calcium iodide, strontium iodide, barium iodide; sodium magnesium chloride, potassium magnesium chloride, Double salts such as calcium potassium chloride and magnesium potassium bromide; potassium bromine fluoride, potassium iodine chloride, rubidium iodine chloride, cesium iodine chloride, cesium iodine chloride bromide, rubidium iodine chloride bromide, potassium iodine bromide, iodine bromide Examples include polyhalides such as cesium and rubidium iodine bromide. An onium halide compound is a compound containing an element with a lone pair of electrons, in which a proton or other cationic reagent is bonded to these lone pairs, and the element with a lone pair of electrons forms a covalent bond with a valence of 1.
increases and becomes a cation,
It has a halogen anion as a counter ion. Examples of such onium compounds include ammonium compounds ([R ¹ R ² R ³ R ^{4 N} ]X), phosphonium compounds ([R ¹ R ² R ³ R ^{4 P} ] R ^{3 R 4} As ]X) ^, oxonium compounds ⁽ [ ^{R 1 R 2 R 3 O} ] ^S (O) ^] X), selenonium compound ([ ^{R 1 R 2 R 3 Se} ] Examples include. Here, R ¹ , R ² , R ³ , and R ⁴ represent hydrogen or a group selected from an aliphatic group, an aromatic group, an alicyclic group, an araliphatic group, and a heterocyclic group, and each is the same and Alternatively, in some cases, it may be a constituent element of a ring containing an element having a lone pair of electrons.
Further, X represents a halogen selected from F, Cl, Br, and I. Of course, it may be a compound having two or more such onium groups in its molecule, or it may be a polymer containing such onium groups in its main chain or side chain. Halogenated onium compounds, which are onium compounds whose anion is a halogen, include amines or nitrogen-containing compounds, phosphine compounds, arsine compounds, oxy compounds, sulfide compounds, sulfoxide compounds, It is easily obtained by reaction with selenide compounds, telluride compounds, etc., and 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 ammonium compounds, halogenated phosphonium compounds, halogenated arsonium compounds, and halogenated sulfonium compounds, and particularly preferred are halogenated ammonium compounds and halogenated phosphonium compounds. Halogenated ammonium compounds can be easily obtained by reacting a corresponding nitrogen-containing compound with hydrogen halide, or by reacting a nitrogen-containing compound with an alkyl halide or an aryl halide. Examples include ammonia; amines such as primary amines, secondary amines, and tertiary amines; hydroxylamines; hydrazines; hydrazones; amino acids; oximes; imidoesters; amides and various nitrogen-containing There are heterocyclic compounds, etc. Preferred hydrogen halide salts of nitrogen-containing compounds include salts of ammonia such as ammonium chloride, ammonium bromide, and ammonium iodide; salts of aromatic amines such as diphenylamine and triphenylamine; methylamine, ethylamine, hexylamine, and octylamine. Salts of aliphatic amines such as amine, dimethylamine, trimethylamine, diethylamine, triethylamine, dibutylamine, tripropylamine, methylethylamine, dimethylethylamine, dibutylmethylamine, tributylamine, ethylenediamine, hexamethylenediamine; cyclopropylamine, cyclohexylamine , salts of alicyclic amines such as N-methylcyclohexylamine; salts of aromatic aliphatic amines such as benzylamine, N-methylbenzylamine, N,N-diethylbenzylamine, dibenzylamine; piperidine, perazine, morpholine,
Pyridine, quinoline, hexamethylenetetramine, oxazole, thiazole, imidazole,
Salts of nitrogen-containing heterocyclic compounds such as triazole, benzotriazole and diazabicycloundecene; salts of amides such as dimethylacetamide and N-methylpyrrolidone are used. Examples of quaternary ammonium halides include aliphatic quaternary ammonium halides such as halogenated tetramethylammonium, halogenated tetraethylammonium, halogenated tetrabutylammonium, halogenated trimethylethylammonium, and halogenated diethyldibutylammonium;
Aliphatic quaternary ammonium halides such as halogenated N,N,N-trimethylcyclohexylammonium; aromatic aliphatic quaternary ammonium halides such as halogenated tetrabenzylammonium and halogenated trimethylbenzylammonium; halogenated N,N,N - Aromatic quaternary ammonium halides such as trimethylphenylammonium and halogenated N,N,N-triethylphenylammonium; halogenated N-methylpyridinium,
Heterocyclic quaternary ammonium halides such as halogenated N-ethylquinolium, halogenated N,N-dimethylpiperidinium, and halogenated N,N'-dimethylimidazolinium are preferably used. Further, as the polymer containing a halogenated ammonium group in the main chain or side chain, for example, those having the following main structural units are preferably used.

【formula】

【formula】

【formula】

【formula】

【formula】

【formula】

【formula】

【formula】

【formula】

【formula】

【formula】

【formula】

[Formula] Here, R ¹ , R ² , R ³ , and X are as described above,
R ⁵ represents a divalent organic group. Examples of halogenated phosphonium compounds include symmetric tetraalkylphosphonium compounds such as halogenated tetramethylphosphonium, halogenated tetraethylphosphonium, and halogenated tetrabutylphosphonium; asymmetric types such as halogenated ethyltrimethylphosphonium and halogenated diethyldimethylphosphonium Tetraalkylphosphonium compounds; symmetrical tetraarylphosphonium compounds such as halogenated tetraphenylphosphonium and halogenated tetra(p-tolyl)phosphonium; asymmetrical tetraarylphosphonium compounds such as halogenated (α-naphthyl)triphenylphosphonium alkylaryl mixed phosphonium compounds such as halogenated methyltriphenylphosphonium and halogenated phenyltrimethylphosphonium; tetraaralkylphosphonium compounds such as halogenated tetrabenzylphosphonium, and the like are preferably used. Examples of halogenated arsonium compounds include symmetrical tetraalkylarsonium compounds such as tetramethylarsonium halide and tetraethylarsonium halide; asymmetrical tetraalkylarsonium compounds such as methyltriethylarsonium halide and dimethylethylarsonium halide; Alkyl arsonium compounds; symmetrical tetraaryl arsonium compounds such as halogenated tetraphenyl arsonium; alkyl halogenated methyl triphenyl arsonium, halogenated ethyl triphenyl arsonium, halogenated phenyl trimethyl arsonium, etc. Aryl mixed arsonium compounds and the like are preferably used. Examples of halogenated sulfonium compounds include symmetrical or asymmetrical alkylsulfonium compounds such as trimethylsulfonium halide, triethylsulfonium halide, and methyldiethylsulfonium halide; arylsulfonium compounds such as triphenylsulfonium halide; Preferred are alkylarylsulfonium compounds such as dimethylphenylsulfonium chloride and methyldiphenylsulfonium halide; cyclic sulfonium compounds such as halogenated bicyclo-(2,2,1)-heptane-1-sulfonium and halogenated thiopyrylium. used. Polymers containing a halogenated phosphonium group or a halogenated sulfonium group in the main chain or side chain are also preferably used, but
Examples of such polymers include those having the following main structural units.

【formula】

【formula】

[Formula] (In the formula, R ¹ , R ² , R ³ , and Acids and their salts, specifically hypochlorous acid, chlorous acid, chloric acid, perchloric acid, hypobromous acid, bromate acid, perbromate acid, hypoiodic acid, and iodic acid. , iodic acid, orthoperiodic acid, metaperiodic acid, and salts of these acids. The cations of the salts may be any ions such as ammonium ions and various metal ions, but alkali metal ions and alkaline earth metal ions are particularly preferred. Examples of such salts include hypochlorites such as sodium hypochlorite, potassium hypochlorite, calcium hypochlorite, and barium hypochlorite;
Chlorites such as sodium chlorite; lithium chlorate, sodium chlorate, potassium chlorate,
Chlorates such as rubidium chlorate, cesium chlorate, magnesium chlorate, calcium chlorate, barium chlorate; aluminum perchlorate, calcium perchlorate, barium perchlorate, cerium perchlorate, lead perchlorate, Perchlorates such as ammonium perchlorate; hypobromites such as sodium hypobromite and potassium hypobromite; bromites such as sodium bromite; lithium bromate, sodium bromate, bromine Bromate acids such as potassium bromate, rubidium bromate, cesium bromate, magnesium bromate, calcium bromate, strontium bromate, barium bromate, aluminum bromate, lanthanum bromate, samarium bromate, lead bromate, and ammonium bromate. Salts; perbromates such as potassium perbromate; sodium hypoiodite, potassium hypoiodite, rubidium hypoiodite, cesium hypoiodite, calcium hypoiodite,
Hypoiodates such as barium hypoiodate; lithium iodate, sodium iodate, potassium iodate, potassium hydrogen iodate, rubidium iodate, cesium iodate, magnesium iodate, calcium iodate, strontium iodate, barium iodate, aluminum iodate,
Iodates such as lanthanum iodate, cerium iodate, proseodymium iodate, neodymium iodate, gadolinium iodate, ammonium iodate; lithium periodate, sodium metaperiodate, trisodium dihydrogen orthoperiodate,
Disodium trihydrogen orthoperiodate, potassium metaperiodate, dipotassium trihydrogen orthoperiodate, tripotassium hydrogendimethperiodate, rubidium periodate, cesium periodate, barium periodate, periodate Periodates such as ammonium acid are used. A halogen-containing complex compound may be either a cationic or anionic compound containing a halogen, such as polyhalogenated halogenated salts such as ammonium dichlorobromate and tetramethylammonium tetrabromoiodate; hexaiodine Halogenated metal salts such as potassium tellurate and hexabromopotassium tellurate; octates (N,N-
Complexes having a ligand such as dimethylformamide) lanthanum triiodide are used. In addition, organic halogen compounds have the general formula R ⁶ (X) _n (wherein, R ⁶ is an m-valent organic group, X is a halogen,
m means an integer of 1 or more. ), and when m is 2 or more,
X may be two or more different halogen species. In addition, halogen X is a heteroatom other than carbon,
For example, it may be bonded with nitrogen, phosphorus, oxygen, sulfur, selenium, etc. Examples of such organic halides include methyl halide, ethyl halide, propyl halide (each isomer), butyl halide (each isomer), amyl halide (each isomer), hexyl halide ( (Each isomer), Octyl halide (Each isomer), Perfluorohexyl halide (Each isomer), Perfluoroheptyl halide (Each isomer), Vinyl halide, Allyl halide, Methylene halide, Haloform, Tetrahalogenmethane, alkylidene halide,
Dihalogenated ethane (each isomer), trihalogenated ethane (each isomer), tetrahalogenated ethane,
Aliphatic mono- and polyhalides such as dihalogenated butane (each isomer), dihalogenated hexane (each isomer), dihaloethylene (each isomer);
Halogenbenzene, dihalogenbenzene (each isomer), trihalogenbenzene (each isomer), tetrahalogenbenzene (each isomer), hexahalogenbenzene, halogennaphthalene, dihalogennaphthalene (each isomer), halogenpyridine (each isomer) ), halogenated toluene (each isomer), halogenated ethylbenzene (each isomer), aromatic mono- and polyhalides such as phenyl iodo dichloride, iodosobenzene, iodoxybenzene; halogenated cyclohexane, halogenated cyclobutane, etc. Alicyclic halides; Aroaliphatic halides such as halogenated benzyl and halogenated phenethyl; Heterocyclic halides such as halogenated furan, halogenated tetrahydrofuran, halogenated thiophene, halogenated imidazole, and halogenated piperidine Acid halides such as halogenated acetyl and halogenated benzoyl; N-halides such as N-halogensuccinimide, N-halogenalkylamine, N-halogenacetamide, and N-halogenbenzamide are preferably used. Furthermore, these organic groups can be substituted with various substituents, such as nitro groups, lower alkyl groups, cyano groups, alkoxy groups, aryloxy groups, aromatic groups, sulfoxide groups, sulfone groups, carbonyl groups, ester groups, amide groups, etc. or may have an unsaturated group. Further, as a compound containing a halogen, a halogen molecule itself such as bromine or iodine can also be used. Such halogen-containing compounds may be used alone or in combination of two or more. Further, when the urea compound or organic hydroxyl compound as a raw material, or the chelating reagent as another component of the catalyst, contains a halogen, it is not necessary to separately add a compound containing a halogen. Among the halogen-containing compounds used in the method of the present invention, those in which the halogen species is bromine or iodine are preferred, and those containing iodine are particularly preferred. The chelating reagent used in the present invention is selected from α-dioximes, 2,2'-dipyridines, and 8-hydroxyquinolines, and has two or more coordination groups in one ligand. At least one of the coordinating groups is an oxime group or a nitrogen-containing aromatic ring group. Such chelating reagents include α-dioximes such as dimethylglyoxime, benzyldioxime, and 1,2-cyclohexanedione dioxime; 2,2′-dioximes such as 2,2′-bipyridine and 2,2′-biquinoline; - Bipyridines; 8-hydroxyquinoline, 5,7-dichloro-8-hydroxyquinoline, 5,7-dibromo-8-hydroxyquinoline, 5,7-diiodo-8-hydroxyquinoline, 2-methyl-8-hydroxyquinoline 8-hydroxyquinolines such as these are used. These chelating reagents may be used alone or in combination of two or more. The amount of the halogen compound and chelating reagent used in the present invention is not particularly limited, but the amount of the halogen compound is usually 0.001 to 10,000 as a halogen relative to the amount of the metal element in the component containing the platinum group element used. It is preferably used in a molar range of 0.01 to 1000 times, more preferably 0.01 to 1000 molar times. In addition, the chelating reagent is preferably used in an amount of usually 0.01 to 1000 times the amount of the platinum group element, more preferably 0.1 to 50 times the amount of the platinum group element.
It is in the twice mole range. The urea compound used as a raw material of the present invention is
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, heterocyclic groups, aromatic groups, and the like. Further, these nitrogens may themselves be elements constituting a ring, or the urea bond itself may be a part constituting a 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 , Aroaliphatic N,N-disubstituted ureas such as N-benzyl-N-methylurea; Heterocycles such as N,N-difuranylurea, N,N-dithiophenylurea, N-furanyl-N-methylurea, etc. Formula N,N-disubstituted ureas; N,N-diphenylurea, N,N-ditolylurea, N,N-dinaphthylurea, N-phenyl-N-methylurea, N-phenyl-N-tolylurea, N -Naphthyl-N-benzylurea, N-
Aromatic N,N-disubstituted ureas such as phenyl-N-cyclohexylurea; N,N'-dimethylurea,
N,N'-diethyl urea, N,N'-dipropylurea, N,N'-dibutyl urea, N,N'-dihexyl urea, N-ethyl-N'-methylurea, N-ethyl-N'-butyl Aliphatic N,N'-disubstituted ureas such as urea and N-hexyl-N'-methylurea;
N,N'-dicyclopropylurea, N,N'-dicyclobutylurea, N,N'-dicyclohexylurea, N-cyclopropyl-NN'-methylurea,
Alicyclic N,N'-disubstituted ureas such as N-cyclohexyl-N'-ethylurea; Aroaliphatic N,N'- such as N,N'-dibenzylurea and N-benzyl-N'-methylurea Disubstituted ureas; Heterocyclic N,N'-disubstituted ureas such as N,N'-difuranylurea, N,N'-dithiophenylurea;N,N'-diphenylurea,N,N'-ditolyl urea , N,N'-dinaphthylurea, N-phenyl-N'-tolylurea,
Aromatic N,N'-disubstituted ureas such as N-phenyl-N'-naphthylurea, N-phenyl-N'-ethyl urea, N-naphthyl-N'-benzylurea, N-phenyl-N'-cyclohexyl, etc. and ureas of cyclic nitrogen compounds such as piperidyl urea and pyrrolidinyl urea. Examples of trisubstituted ureas include trimethylurea, triethylurea,
Tripropylurea, tributylurea, trihexylurea, N,N-dimethyl-N'-ethylurea,
Aliphatic trisubstituted ureas such as N,N-diethyl-N'-butylurea, N-methyl-N-ethyl-N'-butylurea; tricyclopropylurea, tricyclohexylurea, N,N'-dicyclohexyl- N'-methylurea, N-cyclohexyl-N'-
Methylurea, N-cyclohexyl-N-ethyl-
Alicyclic trisubstituted ureas such as N'-butyl urea, N,N-diethyl-N'-cyclobutyl urea; trifuranylurea, trithiophenyl urea, N,N'-
Heterocyclic trisubstituted ureas such as difuranyl-N-methylurea; triphenylurea, tritolylurea,
Totrinaphthylurea, N,N-diphenyl-
N'-methylurea, N,N'-diphenyl-N-cyclohexylurea, N,N-dimethyl-N'-phenylurea, N-phenyl-N-ethyl-N'-
Aromatic trisubstituted ureas such as benzyl urea; N-substituted cyclic nitrogen compound ureas such as N-ethylpiperidylurea and N-methylpyrrolidinyl urea are used. Examples of tetra-substituted ureas include aliphatic tetra-substituted ureas such as tetramethylurea, tetramethylurea, tetrapropylurea, tetrahexylurea, diethylmethylurea, and ethyltrimethylurea; tetracyclopropylurea, tetracyclohexylurea, and dicyclohexyldiethylurea. , alicyclic tetrasubstituted ureas such as cyclobutyltrimethylurea; aromatic aliphatic tetrasubstituted ureas such as tetrabenzylurea, tribenzylmethylurea, dibenzylethylurea, benzyltrimethylurea; tetrafuranylurea, tetrathiophenylurea , heterocyclic tetrasubstituted ureas such as furanyltrimethylurea;
Aromatic tetra-substituted ureas such as tetraphenyl urea, tetratolylurea, tetranaphthylurea, methyltriphenyl urea, diethyl diphenyl urea, dicyclohexyl diphenyl urea, and naphthyl triethyl urea are used. Also, as a cyclic urea compound having a urea bond as a ring component, for example,
2-imidazolone, 2-imidazolidone, piotine, hydantoin, 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, N,N'-diphenylcarbamoylphenylenediamine, or the following formula: Polymeric ureas having structural units as shown 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 by using N'-diarylureas. One or more of these urea compounds may be used. The organic hydroxyl compound used in the present invention is 1
or polyvalent or polyhydric alcohols, or monovalent or polyvalent phenols. Examples of such alcohols include linear or branched monovalent or polyhydric alkanols and alkenols having 1 to 20 carbon atoms. ,
Examples include monovalent or polyvalent cycloalkanols, cycloalkenols, and aralkyl alcohols. Furthermore, these alcohols have other substituents,
For example, halogen atoms, cyano groups, alkoxy groups,
It may contain a sulfoxide group, a sulfone group, a carbonyl group, an ester group, an amide group, etc. 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), 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 Alkylene glycol monoethers such as glycol monomethyl 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. are 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 dioxide. 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 isomer), phenylnitromethane,
Bis-(nitromethyl)-cyclohexane, bis-(nitromethyl)-benzene, etc.; examples of aromatic nitro compounds include nitrobenzene, dinitrobenzene (each isomer), nitrotoluene (each isomer), 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 , R ⁴ are hydrogen, aliphatic groups,
An atom or group selected from an alicyclic group, an araliphatic group, a heterocyclic group, an aromatic group, and R represents an organic group) Molecular oxygen may be at least or more than the equivalent amount, but oxygen /carbon monoxide or oxygen/organic hydroxyl compound mixtures should be used outside explosive limits. 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' represents an organic residue of an organic nitro compound.) When only an organic nitro compound is used as an oxidizing agent, a urea compound The quantitative ratio of the organic nitro compound and 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 far 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; nitriles such as acetonitrile and penzonitrile; sulfones such as sulfolane, methylsulfolane, and dimethylsulfolane; tetrahydrofuran, 1,4-dioxane, and the like; , ethers such as 1,2-dimethoxyethane; ketones such as acetone and methyl ethyl ketone; esters such as ethyl acetate and ethyl benzoate; N,N-dimethylformamide, N,N
- Amides such as dimethylacetamide, N-methylpyrrolidone, hexamethylphosphoramide, etc. Furthermore, chlorobenzene, dichlorobenzene, trichlorobenzene, fluorobenzene, chlorotoluene, chlornaphthalene, which is a type of organic halide used as a cocatalyst of the present invention,
Halogenated aromatic hydrocarbons such as bromnaphthalene; chlorhexane, chlorocyclohexane,
trichlorotrifluoroethane, methylene chloride,
Halogenated aliphatic hydrocarbons such as carbon tetrachloride or halogenated alicyclic hydrocarbons are also used as solvents. 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. Suitable examples of such additives include basic substances, zeolites, orthoesters, ketals, acetals, enol ethers, and trialkylorthoborates. The basic substance may be either inorganic or organic, such as alkali metals, alkaline earth metals, and oxides, hydroxides, sulfides, and salts of these metals with organic acids. , salts with weakly acidic inorganic acids, alcoholates, amides, etc.; tertiary amines, carboxylic acid amides, etc. 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 .
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 a content of 500 ml was charged with N,
N′-diphenyl urea 100 mmol, ethanol 150
ml, palladium black 1.5mgatom, sodium iodide
Add 3 mmol of 2,2′-bipyridine and 10 mmol of 2,2′-bipyridine, replace the system with carbon monoxide, and heat to 160 ml while stirring.
Heated to ~170°C. After reaching a predetermined temperature, a mixed gas consisting of 15 vol% carbon monoxide, 5 vol% oxygen, and 80 vol% nitrogen was introduced at a flow rate of 60 N/hr under a pressure of 100 Kg/cm ² and a reaction was carried out with stirring. 1.5
The reaction rate of N,N'-diphenylurea after 99 hours is
The yield of ethyl N-phenylcarbamate in % is 98
The selectivity rate was 99%. The selectivity of carbon monoxide to the urethanization reaction was 95%. When a similar reaction was carried out without using 2,2'-bipyridine, the reaction rate of N,N'-diphenylurea was 94%, the yield of ethyl N-phenylcarbamate was 89%, and the selectivity was 95%. It was %. The selectivity of carbon monoxide to the urethanization reaction was 93% when the reaction rate of N,N'-diphenylurea was 85%;
When the reaction rate of N'-diphenyl urea is 94%,
It had dropped to 85%. Note that 2,2'-bipyridine did not change at all after the reaction. Examples 2 to 10 Table 1 shows the results of reactions carried out in exactly the same manner as in Example 1, except for using the various halogen compounds and chelating reagents shown in Table 1. In these examples, 10 mmol of the chelating reagent was used. In addition, the selectivity A of ethyl N-phenylcarbamate is that based on N,N'-diphenylurea,
Selectivity B represents that on a carbon monoxide basis.

[Table] Example 11 In the same manner as in Example 1, using 100 mmol of N,N'-dicyclohexyl urea, 150 ml of methanol, 5 g of 2% Pd/SiO ₂ , 2 mmol of sodium iodide, and 5 mmol of 2,2'-bipyridine. As a result of the reaction, the reaction rate of N,N'-dicyclohexylurea was 99%, the yield of methyl N-cyclohexylcarbamate was 97%, and the selectivity was 98%. The selectivity of carbon monoxide to the urethanization reaction was 95%. Example 12 20 mmol of N,N'-di(n-butyl)urea, n-
Put 50 ml of propanol, 1 g of 5% Pd/C, 2 mmol of tetramethylammonium iodide, and 3 mmol of 2,2'-bipyridine into a 200 ml autoclave, and after replacing the system with carbon monoxide, 80 kg of carbon monoxide/
cm ² , then 6Kg/cm ² of oxygen was injected to bring the total pressure to 86Kg/cm ²
And so. As a result of reacting at 170℃ for 1 hour with stirring,
The reaction rate of N,N'-di(n-butyl)urea is 99%
The yield of propyl N-n-butylcarbamate was 96% and the selectivity was 97%. The selectivity of carbon monoxide to the urethanization reaction was 93%. Example 13 30 mmol of N,N'-diphenylurea, 15 mmol of nitrobenzene, 60 ml of ethanol, palladium chloride
3 mmol of 2,2'-bipyridine and 5 mmol of 2,2'-bipyridine were placed in a 200 ml autoclave, the atmosphere in the system was replaced with carbon monoxide, and then carbon monoxide was introduced under pressure at 120 kg/cm ² . As a result of reacting at 170°C for 5 hours with stirring, the reaction rates of N,N'-diphenylurea and nitrobenzene were 46% and 50%, respectively, and 31 mmol of ethyl N-phenylcarbamate was produced. Example 14 Constituent unit expressed by the following formula

Anion exchange resin (Amberlyst A-
26, OH type) was treated with hydroiodic acid to convert the hydroxyl group with an iodine anion,
It was then dried at 100°C under reduced pressure. 1 g of this iodine-containing anion exchange resin, 2,2'-bipyridine
Inner volume: 2 mmol, N,N'-diphenylurea 20 mmol, ethanol 40 ml, palladium black 0.5 mgatom
Place it in a 140ml stirring autoclave, replace the carbon monoxide in the system, and then remove 80kg of carbon monoxide/
cm ² , then 6Kg/cm ² of oxygen was injected to bring the total pressure to 86Kg/cm ²
And so. After reacting at 150°C for 1 hour with stirring, the reaction mixture was filtered and the filtrate was analyzed. As a result, the reaction rate of N,N'-diphenylurea was 99%.
The yield of ethyl N-phenylcarbamate was 97% and the selectivity was 98%. In addition, the selectivity of carbon monoxide to the urethanization reaction is
It was 95%. The reaction rate of N,N'-diphenylurea when 2,2'-bipyridine is not used is 94
%, and the selectivity of carbon monoxide to the urethanization reaction is
It was 83%. Using the palladium black separated by filtration and the anion exchange resin as they were, and repeating the same reaction by adding 2 mmol of 2,2'-bipyridine, the reaction rate of N,N'-diphenylurea was 99%. ,
The yield of ethyl N-phenylcarbamate was 97% and the selectivity was 98%, which were similar results. Examples 15-20 The same reactions as in Example 1 were carried out, except that various platinum group metals or compounds containing platinum group elements shown in Table 2 were used in place of palladium black in Example 1. The results are shown in Table 2. Note that selectivity A and B have the same meaning as in Table 1, the platinum group catalyst uses 1.5 mgatom as the metal element, and the percentage indicated is the weight percent of the catalyst component supported on the carrier.
shows.

【table】

Claims (1)

[Scope of Claims] 1. A method for producing urethane by reacting a urea compound with carbon monoxide and an organic hydroxyl compound in the presence of an oxidizing agent, comprising (a) a platinum group metal and a compound containing a platinum group element; (b) at least one selected from halogen-containing compounds; and (C) selected from α-dioximes, 2,2'-bipyridines, and 8-hydroxyquinolines. A method for producing a urethane compound, characterized by using a catalyst system comprising at least one type of chelating reagent. 2. The production method according to claim 1, wherein the oxidizing agent is molecular oxygen, an organic nitro compound, or both. 3. The manufacturing method according to claim 1, wherein the oxidizing agent is molecular oxygen. 4. The production 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 production method according to any one of claims 1 to 4, wherein the halogen-containing compound is an alkali metal halide or an alkaline earth metal halide. 6. The production method according to any one of claims 1 to 4, wherein the halogen-containing compound is a halogenated onium compound or a compound capable of producing these in a reaction system. 7. The production method according to any one of claims 1 to 4, wherein the halogen-containing compound is a halogen oxo acid or a salt thereof. 8. The production method according to any one of claims 1 to 4, wherein the halogen-containing compound is an organic halide. 9. Any one of claims 1 to 8, wherein the halogen-containing compound is a bromine compound.
The manufacturing method described in section. 10. The manufacturing method according to any one of claims 1 to 8, wherein the halogen-containing compound is an iodine compound. 11. The production method according to any one of claims 1 to 10, wherein the urea compound is N,N'-diarylurea. 12. The production method according to claim 11, wherein the N,N-diarylurea is N,N'-diphenylurea.