DE2808574A1 - Process for the preparation of oxalic acid esters - Google Patents

Description

PFENNING MAAS ^? R ίϊ 8 ¹ ^ 7 A

MElNlG-LEMKE-SPOTT Z O U ö 0 / α

', OHLEiSSHEIMERSTR. 299 βΟΟΟ MUNICH 40

Pf 50-01-1511B

Atlantic Richfield Company, Los Angeles, California, V. St. A.

Process for the preparation of oxalic acid esters

It is a process for the preparation of oxalic acid esters by reacting an alcohol with a mixture of carbon monoxide and Oxygen in the presence of a catalyst mixture

(a) a palladium _s rhodium, platinum, copper or cadmium salt compound or a mixture thereof,

(b) an aliphatic, cycloaliphatic, aromatic or heterocyclic amine or ammonia,

(c) an oxidizing copper (I) -, copper (H) -, iron (II) - or Ferric salt and

(d) an ammonium or substituted ammonium salt compound or acid, where the counterion is not a halogen,

described =

Optionally, a ligand or coordination complex compound can also be used the metal salt compound use =

09846/061 1

For the production of oxalic acid esters by oxidative carbonylation of alcohols in the presence of metal salt catalysts, dehydrating agents and iron (III) and copper (II) redox compounds There are already a number of known methods in solution.

The invention is now concerned with an improved process for the preparation of oxalic acid esters in high yield and below Avoidance of the problems inherent in the known processes for the carbonylation of alcohols. She is particular on one Process for the synthesis of oxalic acid esters by reacting carbon monoxide, an alcohol and oxygen under increased conditions Temperature and elevated pressure in the presence of a catalytic mixture of the following materials:

(a) a palladium, rhodium, platinum, copper or cadmium compound or a mixture thereof,

(b) at least a catalytic amount of an amine base,

(c) a catalytic amount of an oxidizing copper (I) -, Copper (II) -, iron (II) - or iron (III) salt and

(d) a catalytic amount of an ammonium or substituted ammonium salt compound.

Optionally, a ligand or coordination complex compound can also be used the metal salt compound.

US Pat. No. 3,393,136 describes a process for the preparation of oxalic acid esters which consists in that Carbon monoxide at above atmospheric pressure with a solution of a monohydroxy alcohol made with a metal salt. the platinum group and a soluble iron (III) - or copper (II) salt (redox agent) is saturated, with simultaneous Introduction of oxygen or with the application of a direct current voltage to the reaction zone. To avoid In the event of water accumulation, the liquid phase must be treated with water-absorbing agents or with dehydrating agents Agents, such as alkyl orthoformic acid esters, add.

809846/0611

In Journal of Organic Chemistry, Volume 39, No. 5, 1974, pp 701-704, is a general mechanism for the oxidative carbonylation of alcohols to form dialkyl oxalates and use of a palladium redox system, oxygen and dehydrating agents are proposed. In the absence of the required dehydrating agent, a fair amount of carbon dioxide is produced, with no oxalic acid esters are formed. Particular attention is paid to the need for the presence of the iron or copper redox system referenced during the synthesis of the oxalic acid ester.

DT-PS 22 13 435 describes a process for the synthesis of oxalic acid and oxalic acid esters using water or alcohol emerged. The catalyst used consists of a metal salt of the platinum group, a salt of one opposite to that Platinum group metal more strongly electropositive metal, such as cupric chloride, and an alkali salt, such as lithium chloride. Oxygen is used as the oxidizing agent in stoichiometric amounts. A disadvantage of this implementation is that the reaction must be carried out using explosive mixtures of oxygen and carbon monoxide. In this In this case, alcohol conversions of less than 5% result. Under non-explosive conditions one only obtains Traces of oxalic acid esters.

From DT-PS 25 14 685 a process for the preparation of dialkyl oxalates is evident, which consists in the fact that one aliphatic alcohol with carbon monoxide and oxygen under pressure in the presence of a catalyst composed of a mixture consists of a salt of a metal from the platinum group and a copper or iron salt, and a reaction accelerator, including nitrates, sulfates, bicarbonates, carbonates, tert, amines and hydroxides, as well as carboxylates of alkali and alkaline earth metals, pyridine, quinoline, urea and thiourea belong, implements. The conversion of the alcohol used to form the dialkyl oxalates is part of this process however small and generally less than 9 mole percent.

809846 / Ö611

From the DT-OS 26 01 139 one is known from the DT-PS 25 14 685 Similar process for the preparation of oxalic acid or its alkyl esters known, according to the aliphatic alcohols or Water with oxygen and carbon monoxide in the presence of palladium salts, redox salts and an amine or ammonia as Base are implemented.

The oxalic acid esters which can be prepared according to the invention are widely used in industry, for example as solvents for cellulose ethers or esters, as well as for resins, as intermediates for the production of dyes and for Manufacture of medicines.

According to the invention there is now an improved method for created oxidative carbonylation of an alcohol to form an oxalic acid ester. The procedure yields a high conversion of the alcohol used and leads to the oxalic acid ester in an excellent yield. The formation of carbonate esters, carbon dioxide and alkyl formates as well as other by-products such as those in such Reactions occur frequently, is suppressed according to the invention by using an ammonium or as part of the catalyst substituted ammonium salt compound, namely an amine salt, in conjunction with an amine and a palladium, Rhodium, platinum, copper or cadmium metal salt compound and an oxidizing copper (I) -, copper (II) -, iron (II) - or iron (III) salt compound or optionally also a ligand or coordination complex, such as lithium iodide, is used and the reactants in an anhydrous state begins.

It was found that the addition and presence of the amine salt in the catalytic mixture according to the invention is necessary is in order to achieve the increased selectivities and yields for the oxalic acid ester that are achieved by the known processes are not achievable. The addition of the amine salt serves to maintain the proton acidity of the reaction system.

8098A6 / 0611

Compared with the known processes for the preparation of oxalic acid esters, the process according to the invention still offers the following additional advantages:

(1) There is no need to use expensive water acceptors, which have to be recovered, to prevent the occurrence of side reactions, caused by the formation of water in the reaction system, such as the formation of alkyl oxalate

2— 2—

(ROOCCOO), oxalate di (C ₃ O ₄ ) or carbonate (CO ₃ ) anions,

essentially to inhibit

(2) the reduced oxidizing salts are easily recovered, reoxidized and recycled, and the metal salt compounds can be regenerated and also recycled,

(3) large amounts of corrosive halogen ions need not be used, and in some cases it is practical no halogen ions at all can be present,

(4) the procedure is not dangerous as it is not explosive Mixtures of oxygen and carbon monoxide works,

(5) Instead of the not so cheap platinum group metals or metal salt compounds, cheaper copper or Use cadmium salt compounds,

(6) you can work with ammonia or a primary or secondary amine or a tertiary amine base =

According to the invention there is thus an improved method of production of oxalic acid esters created in high yield by catalytic oxidative carbonylation, which consists in that at least stoichiometric amounts of an alcohol with a mixture of carbon monoxide and oxygen at increased Temperature 'and elevated pressure in the presence of a catalyst

809846/061 1

which consists of a mixture of a metal salt compound, a catalytic amount of an amine base, an oxidizing metal salt compound and an acid or an ammonium or substituted ammonium salt compound. This process gives the desired oxalic acid ester in better selectivity and ^N is associated with a higher conversion to the oxalic acid esters compared to the carbonates and other by-products which are only present in trace amounts. It has also been found that, optionally, catalytic amounts of various ligand compounds which are not effective alone can also be used in conjunction with the metal salt compounds, the amines, the amine salts and the oxidizing salts.

The object of the invention is primarily to create a process for the preparation of oxalic acid esters in high yield with high reactant conversion while avoiding the problems inherent in the known processes. Furthermore, this is intended to create a new reaction system suitable for converting carbon monoxide, oxygen and alcohol into oxalic acid esters. Under use a catalytic mixture of metal salt compounds, oxidizing salts, amine salts and amines or ammonia should thereby a special catalytic oxidative carbonylation of a reaction mixture of alcohol, carbon monoxide and oxygen become possible.

The process according to the invention for the preparation of oxalic acid esters consists in that in the liquid phase, a mixture of carbon monoxide and oxygen with an alcohol, preferably an aliphatic alcohol, at elevated temperature and pressure in the presence of a catalyst system, which consists of a mixture of the following components:

(1) a palladium, rhodium, platinum, copper or cadmium salt compound or a mixture thereof with or without a ligand or coordination complex compound, such as Lithium iodide, and

809846/0811

- ¹ Y / -

(2) ammonia or a primary, secondary or tertiary amine, and further

(3) catalytic amounts of an oxidizing copper (I), copper (II), iron (II) or iron (III) salt and

(4) an ammonium salt or amine salt or an acid which is stronger than water and does not bind the metal salt compound too strongly in a complex.

As indicated above, the reaction mixture is treated with catalytic Amounts of an amine or ammonia and also with catalytic amounts of an oxidizing metal salt, one Amine salt and a metal salt compound of palladium, rhodium, platinum, copper or cadmium or mixtures thereof. The amine salt added in this way can also be formed in situ in the reaction mixture by mixing it with a for formation A sufficient amount of an acid such as sulfuric acid is added to the required amount of amine salt. So you can, for example Work with a sufficient amount of triethylamine from the beginning and then the whole thing to form triethylammonium sulfate add sulfuric acid in the desired catalytic amounts. The addition of amine and acid to form the amine salt must be controlled so precisely that there is an equilibrium between the amine base and the amine salt compound.

The conversion of alcohol, carbon monoxide and oxygen can be carried out in an autoclave or other high-pressure reactor will. The order in which the reactants and the constituents forming the catalyst mixture are added can be determined vary, but the general procedure is as follows: the reaction vessel is charged with alcohol, amine, amine salt (or the required amount of amine and acid), metal salt compound and oxidizing salt compound and optionally also a ligand or coordination complex, whereupon the

809846/0611

-jr-

corresponding amount of carbon monoxide and oxygen up to the desired Initiate reaction pressure and then the mixture to the desired temperature over a corresponding period of time heated. The reaction can be carried out batchwise or continuously, and so can the sequence in which the reactants are added can be varied so that it is adapted to the particular apparatus used. Oxygen and oxygenated Gas such as air can be pulsed or continuously added to the reaction system. The extraction and others The reaction products are treated in the customary manner, for example by distillation and / or filtration, in order to do so the desired oxalic acid ester of unreacted materials, amine, oxidizing salt, amine salt, metal salt compound and Separate by-products.

The alcohols used are in concentrations of about 50 to 99.7 percent by weight, preferably 77 to 94 percent by weight, used. The alcohols which can be used in the process according to the invention can be saturated Monohydric aliphatic, alicyclic or aralkyl alcohols act, which in addition to the hydroxyl group also may have other substituents, such as amido, alkoxy, amino, carboxy or cyano. These substituents are generally intended to do not interfere with the reaction according to the invention.

The alcohols used can be primary, secondary or tertiary alcohols, which have the general formula ROH where R is an optionally substituted aliphatic or alxcyclic radical having 1 to 20 carbon atoms with unsubstituted aliphatic alcohols having 1 to 8 carbon atoms being preferred. The substituent R can also be an unsubstituted or substituted aralkyl radical. Typical alcohols suitable according to the invention are, for example the saturated monohydroxy alcohols, such as methyl, ethyl, η, iso-, sec- and tert-butyl, amyl, hexyl, octyl,

809846/0611

Lauryl, η and iso-propyl, cetyl, benzyl, chlorobenzyl or Methoxybenzyl alcohol, as well as tolylcarbinol, cyclohexanol, Heptanol, decanol, undecanol, 2-ethylhexanol, nonanol, Myristyl alcohol, stearyl alcohol, methyl cyclohexanol, pentadecanol or oleyl and eicosyl alcohol. The preferred alcohols are the primary and secondary saturated aliphatic monohydroxy alcohols with up to 8 carbon atoms, such as methanol, Ethanol, 1- or 2-propanol or n-buty! Alcohol.

In the case of the amines that are used in the catalyst mixture according to the invention are used in at least a catalytic amount, it can be primary, secondary or tertiary amines in addition to ammonia act, and these amines can be aliphatic, cycloaliphatic, aromatic or heterocyclic amines or mixtures thereof be. The amines can be unsubstituted or other substituents contain, such as halogen, alkyl, aryl, hydroxy, amino ', alkylamino or carboxy. The amines can be used as part of the Catalyst system for the reaction in concentrations of 0.1 to 10 percent by weight, preferably 0.3 to 4 percent by weight, calculated as free amine, use.

Examples of typical amines of the type described above are mono-, di- and trimethyl-, -ethyl- and -propylamines, iso- and Diisopropylamine, allylamine, mono-, di-, tri-, iso- and Diisobutylamine, 1-methylpropylamine, 1,1-dimethylethylamine, Amylamine, cyclohexylamine, dicyclohexylamine, 1,3-dimethylbutylamine, 2-ethylhexylamine, i-cyclopentyl-2-aminopropane, 1,1,3-tetramethylbutylamine, Aniline, ethylenediamine, methylenediamine, ethanolamine, octylamine, n-decylamine, do-, tetra-, hexa-, octa-, Dido-, ditetra-, diocta-, trido- and trioctadecylamines, chloranilines, nitroanilines, toluidines, naphthylamine, N-methyl- and N-ethyl- as well as N, N-dimethyl ~ and N, N-diethylaniline, di- and triphenyl amines, Ν, Ν-diamylaniline, bericyldimethylamine, piperidine or pyrrolidine. The tertiary amines, such as triethylamine or tributylamine, are preferred.

0 S 8 4 8/0111

In the case of the metal salt compounds which can be used in the catalyst mixture in the process according to the invention, it is palladium, platinum, rhodium, copper or cadmium salts or mixtures thereof. To single connections these metal salt compounds, as such, in the form of mixtures or by formation in the reaction system can be produced directly from the metals, include the palladium, platinum and rhodium halides and sulfates, oxalates and acetates as well as the copper halides, 'where palladium (II) sulfate as well as palladium (II) and copper (I) - or - (II) halides, such as palladium (II) iodide and copper (I) iodide, to be favoured. Typical catalytic metal salt compounds are, for example, palladium (II) chloride, copper (II) chloride, Rhodium (III) chloride, copper (I) iodide, palladium (II) sulfate, Palladium (II) acetate, palladium (II) iodide, rhodium (III) bromide, Platinum (II) chloride, platinum (II) sulfate or cadmium chloride. As indicated above, the metals can be added as such to the reaction mixture as part of the catalyst mixture, wherein the salt compound is formed in situ from at least part of the metal under the reaction conditions.

The palladium, platinum, rhodium, copper or cadmium compounds used can be homogeneous under the reaction conditions be distributed in the reaction mixture. These compounds can therefore be in solution or in suspension, or they can also be on appropriate carrier materials, such as aluminum oxide, silica gel, aluminum silicates, activated carbon or zeolites. The compounds can be partially or completely soluble under the reaction conditions. The reaction is generally in the presence of a catalytic Amount of a metal salt compound carried out and runs using small amounts of those described above Metal salt compounds from. The amounts of the metal salt compounds used for the reaction generally make about 0.001 to 5 percent by weight of the alcohol used, and they are preferably about 0.01 to 2 percent by weight of the alcohol used Alcohol. By changing the pressure and temperature, larger or smaller quantities can be used.

809846/0611

- rf -

As also indicated above, in the process according to the invention one can optionally also work with a ligand or coordination complex compound of the metal salt compound in the catalytic mixture, which results in a great improvement in the selectivity for the oxalic acid ester. The ligand compounds can be, for example, alkyl or aryl phosphines, arsines or stibines, or halides, such as lithium iodide, ammonium chloride or triethylammonium iodide, etc. Complexes of the metal salt compounds which can be used in the process according to the invention include complex compounds of palladium, platinum, rhodium, cadmium and copper. The complex compounds can contain one or more atoms of these metals in the molecule, it being possible for the metals to be the same or different if more than one such atom is present. The mono- or poly-ray ligands which are present in the molecule of the complex compounds and in which at least one of the electron-donating atoms is a phosphorus, arsenic or antimony atom or is a halide ion which contains a lone pair of electrons can be, for example Act organophosphines, arsines or stibines. Suitable single beam ligands are for example alky! Phosphine such as trimethylphosphine or tributylphosphine, aryl phosphines as diethylphenylphosphine t and derived from phosphines

Radicals of the formula P (CH.,) „. Hydrocarbon oxyphosphines,

namely, phosphites such as triphenyl phosphite can also be used. On suitable multi-beam ligand compounds include tetramethyldiphosphinoethane or tetraphenyldiphosphineethane. Exactly analogous derivatives of arsenic and antimony can also be used. Because of the ease of manufacture and more favorable stability of the complexes derived therefrom are the hydrocarbon derivatives of phosphorus however preferred. The alkali iodides, such as lithium iodide or ammonium iodide, are also preferably used or substituted ammonium iodides such as triethylammonium iodide.

809846/0611

The complex compounds suitable for the process according to the invention In addition to the ligands specified above, one or more other atoms or groups can also be present in their molecule or contain molecules chemically bonded to the metal atom or atoms. Such on the metal Bonded atoms are, for example, hydrogen, nitrogen or Halogen atoms. Groups that may be bonded to the metal include, for example, hydrocarbon, Hydrocarbonoxy, carbonyl, nitrosyl, cyano

or SnCl ₃ residues. Examples of molecules linked to the

Organoisocyanides and organoisothiocyanates can be bound to metal. Individual examples of suitable complex compounds are as follows:

RhBr ₃ (PPhEt ₂ ) Rh (CO) Cl (AsEt ₃ ) ₂

RhCl (CO) PPhEt ₂ J ₂ RhCl (CO) PEt ₃ J ₂

Rh / (PhO) 3P / 3CI PdI ₂ (PPh ₃ ) ₂

Li ₃ PdI ₄ / (Sbn-Pr ₃ ) ₂ PdCl ₂ _ /

PtCl ₂ (P-ClC ₆ H ₄ PBu ₂ )

The abbreviations have the following meanings:

Et = ethyl

Ph = phenyl

Pr = propyl

Bu = butyl.

809846/0611

The complex compounds used can be introduced into the reaction system as they are, or they can also be incorporated into situ from a suitable metal or a corresponding metal compound of the type indicated above and the desired one Form ligands.

The ligand or complex compounds are used in catalytic amounts of 0 to 3 percent by weight, preferably 0.1 to 1 percent by weight, of the alcohol to be converted is used. If the pressure and reaction rate are varied, however, it is also possible work with larger or smaller quantities.

Salts to be oxidized, which are present in the catalyst mixture in an anhydrous state and in catalytic amounts of 0.1 to 10 percent by weight, preferably 2 to 6 percent by weight, in the case of the invention Methods used include the iron (II), iron (III), copper (I) as well as copper (II) salts, such as the halides, sulfates, trifluoroacetates, oxalates, naphthenates or acetates, preferably copper (II) sulfate and copper (II) trifluoroacetate, Copper (I) iodide and iron (III) sulfate. Single examples suitable oxidizing salts are copper (II) sulfate, Copper (II) trifluoroacetate, copper (II) acetate, copper (II) oxalate, Copper (II) triflate (trifluoromethanesulfonate), copper (II) fluorosulfonate, Copper (I) chloride, copper (I) sulfate, iron (III) sulfate, Iron (II) iodide, iron (II) chloride, iron (III) acetate, iron (III) oxalate, Ferric fluorosulfonate and ferric trifluoroacetate. Although halides can be used in the process according to the invention, excess halides in the form of oxidizing salts or ligand or coordination complexes disrupt the reaction system according to the invention and cause low Yields of oxalic acid esters.

The ammonium or amine salts, which are an important and indispensable Part of the catalytic mixture are in the anhydrous state and in catalytic amounts from 0.1 to 40 percent by weight, preferably 2 to 20 percent by weight,

09846/061

used in the process according to the invention, and they include, for example, the ammonium and substituted ammonium sulfates, formates, trifluoroacetates and acetates, preferably the tertiary amine sulfates, such as triethylammonium hydrogen sulfate or triethylammonium sulfate. The salts may only exist in equilibrium amounts in the reaction system. Specific examples of such salts are Diethylammoniumsulfat, Ethylammoniumsulfat, butylammonium sulfate, ammonium sulfate, Trimethylammoniumsulfat, Monomethylanunoniumsulfat _f trimethylammonium, ammonium acetate, triethylammonium formate, ammonium trifluoroacetate, methyl, ethyl or Butylammoniumtrifluoracetat.

The ammonium or amine salts can be added to the reaction mixture as such or by in situ formation in the required amount can be added by adding an acid such as sulfuric acid, benzenesulfonic acid. Phosphoric acid, orthoboric acid, p-toluenesulfonic acid, Acetic acid or trifluoroacetic acid takes place, with one lying above the required amounts of the amine base Quantities works. For salt formation, those acids are used that are compatible with the metal salt compound of the catalytic mixture or the oxidizing metal salts do not form a complex which inactivates the catalyst and the oxidizing agent. As above mentioned, the acids used for this purpose must be sufficiently strong, namely above one that is above the strength of water Have strength and at the same time be such that the anion with the metal salt used in the catalyst mixture or oxidizing salt forms practically no complex. The salts formed in situ do not necessarily have to be isolatable themselves to be and can be present in the reaction mixture under the conditions of carbonylation in equilibrium. It it does not have to be a matter of salts, which can be added as such, but can be done with salts have to do, which after adding a suitable acid to the reaction mixture, which contains excess amine, formed in situ will.

809846/061 1

- Ic * -

Solvents are not required, but it is also possible, if desired, to work with solvents which are chemically inert to the constituents of the reaction system. As such solvent, for example organic esters acetone are suitable, such as ethyl acetate _f n-propyl, isopropyl, sec- and isobutyl acetate, amyl acetate, cyclohexyl acetate, n-propyl or sulfoxides the Niederalkylphthalate, as well as the alkyl sulfones and how Propylethylsulfoxid, diisopropyl, Diisooctylsulfoxid, , Cyclohexanone or methyl formate.

The reaction can then, as stated above, best be carried out by adding oxygen and carbon monoxide at the pressure desired in each case with the mixture of alcohol and catalyst, which contains the metal salt compounds, the amine, an amine salt and an oxidizing salt and, if appropriate, also a Contains ligand or coordination complex, brings together and the whole is heated to the desired temperature. In general, a carbon monoxide partial pressure of about 35 to 350 atmospheres, preferably 63 to 155 atmospheres, is used. However, one can also work under an excess of carbon monoxide, for example in a continuous process in which one only has to work with a large excess and a large amount of carbon monoxide, in which case a corresponding return of the unreacted carbon monoxide is provided. The reaction proceeds at temperatures of from about 40 to 150 ⁰ C. In general, the process according to the invention is carried out at temperatures in the range from 60 to 100 ^° C., since sufficient reaction rates are obtained here. The reaction mixture should be appropriately heated and / or cooled from the inside and / or from the outside so that the temperature remains in the desired range.

809846/061 1

It is made with at least stoichiometric amounts of oxygen or oxygen-containing gas, such as air, worked, with any oxygen partial pressure is suitable that is outside of the explosion area. The oxygen concentration should therefore be low enough that the reaction mixture is not potentially explosive. From The Handbook od Chemistry and Physics, 48th Edition (1967) shows that the explosion limits for pure oxygen in carbon monoxide are between 6.1 and 84.5 percent by volume and 25.8 to 87.5 percent by volume for air in carbon monoxide.

The implementation time generally depends on the one to be implemented Alcohol, the reaction temperature, the reaction pressure and the amount and type of catalyst mixture to be used and the device used in each case. The implementation times vary depending on whether you have the Process carried out continuously or intermittently. The invention is further illustrated by the following examples.

Examples 1 to 12

According to Examples 1 to 12 below, one is added 300 ml large stainless steel autoclave with stirring with a solution of the respective amine, the amine salt and of the ligand complex in the alcohol. Metal salt compounds and oxidizing salt are added to the autoclave as solids added. The autoclave is with. Carbon monoxide charged up to a pressure of 127 atmospheres and then with stirring a speed of 1000 revolutions per minute heated to the reaction temperature. Then you lead in air or compressed oxygen into the autoclave in such a way that the gas mixture is not potentially explosive is, resulting in an exothermic reaction with a drop in pressure. As soon as the reaction subsides, the Autoclaves with additional air or additional oxygen. The addition of air or oxygen is repeated until

809846/061 1

Oi Q> (Π ¹ 0 'Ik Π' Ι έ. Q Ui 0 O) / Μ

until there is no further reaction. When using oxygen, one conducts after the addition of the oxygen carbon monoxide into the autoclave in order to use up the amount of oxygen after the various additions of oxygen To replace carbon monoxide.

When the reaction has ended, the reactor is cooled to ambient temperature and ventilates it to ambient pressure, after which appropriate gas samples are taken. From the liquid The reaction product is separated off solids which have precipitated out by vacuum filtration. Then the liquid is analyzed Product by gas liquid chromatography (glc) and the gaseous product by mass spectral analysis (MS).

The alcohol conversion is only calculated on the basis of the molar amounts of carbonate ester produced by the conversion and oxalic acid esters. By-products such as formate esters and the like are not reported as converted alcohol viewed.

The following Table I summarizes the catalyst mixtures, reactants and reaction conditions used in the present Examples 1 to 12, and the The results obtained are based on the subsequent Table II. Examples 8, 10 and 11 are comparative examples.

8 09846/0611

Tabel catalyst Respondents and Conditions

σ 3

• ^ 4

PdJ 0.51 g (1.41

niMol)

PdJ ₉ 0.25 g • XO, 70

mmol)

PdJ ₉ 0.26 g (0.71

mmol)

PdJ ₉ 0.26 g

(0.71 mmol)

PdJ ₉ 0.25 g (0769

mmol)

PdJ ₉ 0.25 g (0-70

mmol)

-PdJ ₉ 0.25 g (0? 70

mmol)

P 0.74 g TEA 9.4 g ^J (2.82 (92.5

mmol)

mmol)

P 0.37 g TEA 2.3 g (1.41 (23

mmol) mmol)

P 0.37 g TEA 0.6 g (1.41 (6 ₅ 0 mmol) mmol)

LiJ 0.19 g TEA 2.3 g (1.4! (23

niMol) mmol)

LiJ 0.19 g TEA 2.3 g (1.41 (23

mmol) niMol)

LiJ 0.19 g TEA 2.3 g (1.41 (23

mmol) mmol)

', 0JP 0.74 g TEA 2.5 g ^J (2.82' (25 mmol) mmol)

TEAS 13.9 g (46.3

mmol)

TEAS 3.6 g (12

mmol)

TEAS 0.9 g (3.0

mmol)

TEAS 3.5 g (11.6

mmol)

TEAS 6.9 g • (23 mmol)

TEAS 3.5 g (11.6

mmol)

N acids (7.0 g)

8th,

CuSO. 14.7 g iPrOH 54.9 g 65

(92.5 (0.914

mmol) mol)

CuSO, 3.7 g iPrOH 54.9 g 60

(23 ⁴ (0.914

mmol) mol)

CuSO, 0.96 g iPrOH 54.9 g 70

(6.0 (0.914

mmol) mol)

CuSO, 3.7 g MeOH 55.4 g

(1.73

MoI)

CuSO 3.7 g MeOH 55.4 g

(1.73
MoI)

CuSO, 3.7 g EtOH 55.2 g

/ f \ O ^ * S · Λ J ^

Cu-Nap,
(5.0 g)

(1.20

MoI)

nC ₈ H, ₇ OH 57.3 g 60
Mole)

9 132-157

134-165 164-167 148-167 147-169 144-170 162-171

10

Air 68

Air 154

Air 41

Air 118

Air 137

Air 139

air

OO O 09

cn

214 601 122 154 208 339

Tabel

I (continued)

Catalyst reaction participants and conditions

PdJ, 0.25 g (0769 mmol)

TEA 2.3 g TEAS 4.5 g chloranil 5.6 g MeOH 55.4 g

(23

mmol) '

(15

mmol)

PdJ, 0.25 g. LiJ 0.19 g TEA 2.3 g TEAS 6.9 g (0769 mmol)

(1.41

mmol)

(23

mmol)

(23

mmol)

PdJ ₀ 0.25 g LiJ 0.19 g TEA 2.3 g TEAS 6.9 g

(0769 mmol)

(1.41 mmol)

(23

mmol)

(23

mmol)

PdJ ₉ 0.25 g LiJ 0.19 g TEA 2.3 g pyridine

(0769 mmol)

CuJ 0.27g (1.41 mmol)

(1.41

mmol)

(23

mmol)

Abbreviations: TEA TEAS Cu-Nap. N, -acids iPrOH MeOH EtOH

LiJ 0.38 g TEA 2.3 g (2.82 (23 mmol) mmol)

= Triethylamine

= Triethylammonium sulfate

= Copper (II) naphthenate

= Naphthenic acids

= 2-propanol

= Methanol

= Ethanol

= Triphenylphosphine

(138 mmol)

TEAS 6.9 g (23 mmol)

(23

mmol)

CuSO. 3.7 g (23 *

mmol)

CuSO, 3.7 g (23 *

mmol)

g CuSO, 3.7 g (23
mmol)

CuSO, 3, (23
mmol)

Comparative example

^ Mixture of 0.01 g (0.092 mmol) palladium with the CuJ.

(1.73

Mole)

MeOH 55.4 g
(1.73
Mole)

H ₉ O 70.2 g
13.9
Mole)

MeOH 55.4 g
(1.73
Mole)

MeOH 55.4 g
(1.73
Mole)

8 60

60

60

125

100

9 167

116-139 105-140 119-153 172-186

10

Air 46

7703

° 2 7703

Air 489

€ 0 O OO

Meaning of the table columns

1. Example No. Catalyst (in mol)

2. Metal salt

3. Ligand or coordination complex

4. amine

5. amine salt

6. Oxidizing Salt Reactants and Conditions

7. Alcohol (moles)

8. Temperature ⁰ C

9. Total pressure atü

10. Total amount of air atü

11. Response time (minutes)

809846/0611

Table II

Example no. Alcohol conversion
(Mole percent) CO ₂ Yield (mole) Γ 15.3 0.056 Carbonate ester 2 18.4 ο, ίδΐ 0.0 3 3.1 0.0 0.0 4th 14.7 0.05 0.0 00 · 5
6th 15.7
15.2 0.085
0.15 track σ
co
OD,
-C-
CD 7th - track
0.001 O 'S ⁺ O ₅ O O ₅ O - ■ ■ ! ■
ν- 9 11.3 0 ₅ 049 0.0 1O ⁺ O ₅ O - O ₁₁ O H ⁺ 2.0 0.032 0.0 8.1 0.028 0.017 Λ · Μ · Λ * 3 · α? ^ Ϊ́ "" rant «-» 'S- ι η «TT) uOv \ Λ ^ ί-4" ν · ι «ιη im' ■ 0.01

Oxalate ester

A solid which contains copper oxalate (CuC "0, .l / 2H" 0) is filtered off from the reaction product.

Comparative examples

Examples 13 to 24

In the following Examples 13 to 24 Into a 500 ml autoclave made of stainless steel and a Plüssigkeitsabscheider is downstream provided with a condenser (about -20 C ⁰⁾ with a solution of amine, sulfuric acid and alcohol. Metal salt compound ,. Ligand complex and oxidizing salt are added to the autoclave as solids

admitted. The autoclave is charged with carbon monoxide

2
up to a pressure of 127 kg / cm and then heated it with stirring at a speed of 1500 revolutions per minute to the corresponding reaction temperature. The flow rate for the carbon monoxide is adjusted _t

that the pressure remains at 127 kg / cm, which is followed by the initiation an air stream begins. In most cases there is no exothermic reaction in between. By cooling the temperature is kept constant with tap water (- 1 ° C). Gas samples are taken periodically during the experiment the outflowing gases and analyzes them by mass spectral analysis with regard to their carbon dioxide content.

The reaction is then interrupted by alcooling to ambient temperature using tap water. the The gas supply is interrupted and the reactor is vented. During aeration, appropriate gas samples are collected and analyzed them for their carbon dioxide content.

The liquid product obtained is used to separate the precipitated solids are vacuum filtered from the liquid product and then subjected to gas-liquid chromatography.

The alcohol conversion is calculated on the basis of that amount of alcohol that is required to form oxalate esters, carbonate esters and any formate esters.

809846/06

- .23 -

The selectivities are based on the amount of consumed Calculates carbon monoxide, which is needed for the formation of carbon dioxide, oxalate, carbonate and formate, and it are the only detectable compounds that occur during the implementation through the consumption of carbon monoxide develop.

The catalyst mixtures used in the present experiments, Reactants and reaction conditions (Examples 13 to 24) are shown in Table III below, and the results obtained are summarized in Table IV below.

809846/0611

Tabel

III

catalyst Response Participants and Conditions

PdJ, 0.36 g
(170

HiMo 1)

PdJ 0.36 g
(170

mmol)

PdJ, 0.36 g
(170

H) Mo 1)

PdJ ₉ 0.36 g
(170

mmol)

PdSO. 0.24 g

(1.0

mmol)

PdJ ₀ 0.72 g
(270

mmol)

LiJ 0.27 g
(2.0

mmol)

LiJ 0.27 g
(2.0

mmol)

LiJ 0.27 g
(2.0

mmol)

LiJ 0.27 g
(2.0

mmol)

LiJ 0.53 g
(4.0
mmol)

CuSO, 5.2 g. (32? 4

mmol)

CuSO, 5.2 g (32-4 mmol)

CuSO, 5.2 g (32? 4

mmol)

CuSO 5.2 g (3274 mmol)

CuSO, 5.2 g (3274

mmol)

CuSO, 10.3 g (6478

mmol)

TEA 10 g
(100
mmol)

TEA 10 g
(100

mmol)

TEA 10 g
(100
mmol)

TEA 10 g
(100
mmol)

TEA 10 g
(100

mmol)

TEA 20 g
(200

mmol)

6 · - H ₂ SO ₄

3.42 g (33.7

mmol)

3.42 g (33.7

mmol)

3.42 g (33.7

mmol)

3.42 g (33.7

mmol)

3 _; 42 s (33.7

mmol)

6.85 g (67.4

mmol)

MeOH 158.2 g
(4.94
Mole)

MeOH 158.2 g
(4.94
Mole)

MeOH 15.8.2 g
(4.94

MeOH 153.2 g
(4.94
Mole)

MeOH 158.2 g
(4.94
Mole)

MeOH 158.2 "g
(4.94
Mole)

100

70

70

60

70

70

4.35

4.35

4.35

3.22

4.35

4.35

10

1.38

1.38

1.38

1.38

1.38

1.38

IS? OO O OO

cn

Table ', III

catalyst Respondents and Conditions

'6 -

OO
£ ■ -

Ί9

20th

21st

22nd

23

24

PdJ ₉ 0.36 (170

mmol)

PdJ ₉ 0.36

(170

mmol)

PdJ ₉ 0.36 (170

mmol)

CuJ 0.38 (2.0

mmol)

PdJ ₉ 0.36 (170 niMol)

PdJ ₉ 0.36 (170

mmol)

g LiJ 0.28 g- (2.0

Abbreviations; TEA = MeOH = EtOH =

g LiJ 0.28 g (2.0

mmol)

g LiJ 0.28 g (2.0,

mmol)

g LiJ 0.53 g (4 ₅ 0

mmol)

g LiJ 0.27 g (2.0

τηΜοΙ)

g LiJ 0.27 g (2.0

mmol)

: Triethylamine

■■ methanol ethanol

CuSO, 5.2 g (3274

mmol)

CuSO, 5.2 g (3274

mmol)

CuSO, 5.2 g (32? 4

mmol)

CuSO, 5.2 g (32? 4

mmol)

CuSO, 5.2 g (32>

mmol)

CuSO, 0.63 g (4.6

mmol)

TEA 4.2 g
(42.1

TEA 4.2 g
(42.1

TEA 2.5 g
(25

1.72 g (16.9

mmol)

1.72 g (16.9 mmol)

1.72 g (16.9

mmol)

1.72 g

(16.9 mmol)

1.72 g (16.9

mmol)

0.86 g (8.45

mmol)

MeOH 158.2 g (4.94 moles)

MeOH 158.2 g (4.94 moles)

MeOH 158.2 g (4.94 moles)

MeOH 158.2 g (4.94 moles)

EtOH 227.5 g (4.94 mol)

MeOH 158.2 g (4.94 moles)

70

70

60

100

70

70

4.35

4.35

4.35

4.35

4.35

4.35

10

1.38

1.38

1.38

1.38

1.38

1.38

OO O CO

cn

- 26 "-

Meaning of the table columns

1. Example No. Catalyst (mmol)

2. Metal salt

3. Ligand or coordination complex

4. Oxidizing salt

5. amine

6. Acid (sulfuric acid)

Respondents and Conditions

7. Alcohol (moles)

8. Temperature ⁰ C

9. CO flow (liters / min.)

10. Air flow (liters / min,)

11. Response time (minutes)

8098AR / 061

Tabel

IV

example
No. Formate
ester yield Oxalate
ester 13th - Carbonate
ester 0.055 14th 0.025 <0.01 0.304 15th 0.025 0.008 0.334 16 0.006 <0.005 0.35 co 17th
18th 0.030
0.052 0.006 0.324
0.422 97860 19th
20th 0.044
0.032 0.009
0.008 0.415
0.356 / 0611 21st 0.024 track
0.000 0.266 22nd <0.003 0.000 0.130 23 <0.001 <0.004 0.398 24 0.00 0.009 0.056 0.00

^C0 2
0.008
0.11
0.09
0.09
0.14

0.27
0.26
0.17
0.13
0.26

Alcohol conversion (mole percent)

2.7 13.1 14.2 14.5 14.1 '

38.5 17.7 15.1 11.3

5.3 16.5

2.3

Selectivities (mole percent)

Car

Formate bonate ester 0.0
3.3
3.2
0.7
3.6

3.8
3.2
3.3
0.0
0.0
0.0

^ 9.2 1.1

0.7 1.1

0.0 0.0 0.0

0.0 0.8 0.0

Oxalate it ter

84.6 81.0 84.8 87.3 78.4

6.2 14.6 11.4 11.2 16.9

72 , 6 NJ 23 O 70 , 9 OO 25th , 4 73 , 3 CD 23 , 3 66 , 7 CO 33 , 4 74 , 7 cn 24

Example 25

A solution of 197.6 mmol of triethylamine is placed in a 500 ml stainless steel autoclave with stirring. 68.0 mmoles of 96.4 percent sulfuric acid and 2.19 moles of n-butyl alcohol. 2.0 mmol palladium (II) iodide, 4.0 mmol copper (I) iodide and 8.0 mM lithium sulfate monohydrate are added to the autoclave

introduced as solids. The autoclave is then

2 with carbon monoxide to an overpressure of 74.9 kg / cm (1070

psig) and heated with stirring at a speed of 1500 rpm at 70 ⁰ C. The agitation is then stopped and air is introduced to produce a total ^{gauge pressure of 126 kg / cm 2} (1800 psig). At this pressure, an extension speed of 4.0 l / minute for carbon monoxide and 2.7 l / minute for air is maintained. Stirring is continued and the contents are allowed to react for 45 minutes while intermittent gas samples of the effluent are collected and analyzed for carbon dioxide.

The autoclave is cooled to ambient temperature with tap water, the flow of gas is interrupted and the reactor is depressurized. The exhaust gases are collected and analyzed for carbon dioxide. The liquid product is analyzed by gas-liquid chromatography analyzed after separating the precipitated solids from the liquid product by vacuum filtration. The analysis shows 0.023 mol of dibutyl carbonate and 0.267 mol of dibutyl oxalate. The gases contain 0.165 moles of carbon dioxide. Further oxalate-containing salts (0.040 mol) are determined in the liquid product.

8098 4 6/0611

Example 26

A solution of 84.2 mmol of triethylamine is placed in a 300 ml stainless steel autoclave with stirring. 33.8 mmoles of 96.4 percent sulfuric acid, 1.0 mmoles Lithium iodide and 1.71 mol of ethyl alcohol, together with 1.0 mmol of copper (I) iodide and 23.0 mmol of copper (II) sulfate as Solids. The autoclave is then filled with carbon mono-

2 oxide brought to an overpressure of 70.3 kg / cm and then heated ^{to 100 ° C. with stirring.} Then you put the

Pressure with carbon monoxide to 105 kg / cm. The autoclave is then treated with 7% oxygen and then with another 14 atmospheres of carbon monoxide. This is followed by a further 7 atmospheres of oxygen and then a further 14 atmospheres of carbon monoxide added. The total reaction pressure is between

127 and 148 kg / cm. One leaves the reaction mixture for 90 minutes at 100 ⁰ C, followed by cooling the reactor to ambient temperature and vented to ambient pressure. At one

A gas sample is taken at a pressure of 70 kg / cm. The solids are separated from the liquid by vacuum filtration. The liquid product is analyzed by gas liquid chromatography and the gas product is analyzed by mass spectral analysis to give 0.010 moles of diethyl carbonate, 0.004 moles of diethyl oxalate and 0.015 moles of carbon dioxide. The alcohol conversion is 1 _f 6 mole percent. The selectivities, expressed in mol percent, calculated on the basis of the consumption of carbon monoxide, are 30.3% diethyl carbonate, 24.2% diethyl oxalate and 45.5% carbon dioxide.

Example 27

The procedure described in Example 26 is repeated, with the exception of the catalyst system instead of copper (I) iodide, however, 1.0 mmol of cadmium iodide is used here. By analyzing the liquid

8 0 9 8 U R / 0 6 1 1

- 30 -

and even products result in O.ΟΊΟ mol of diethyl carbonate, 0.005 mol of diethyl oxalate and 0.014 mol of carbon dioxide. The alcohol conversion is 1.8 mole percent. The selectivities for diethyl carbonate are 29.4 mol percent, for diethyl oxalate 29 _f 4 mol percent and for carbon dioxide 41.2 mol percent.

B ν i?; ρ i el '? ο

A 5OO ml transmitting autoclave rontireiern steel ver with Einein cooler and a Flüssigkeitr.abscheider in the flow direction, is flat _f is charged with a solution of 1OO mflol Triothylamin. 68 mmoles of triethylammonium bisulphate and 2.19 Ilo / η-butyl alcohol. Jn (lon autoclaves are called Fostsiof fr-1 G,: ^! ItiMol J "upf er (II) -sulfate and 0.30 mmol

Pal lad i uiiiiiot,.? ] 1 on /, kti vli'ihl e given, l) eu autoclave is

"Brought>;: id in (inen Dj piece VCU 70 kg / cm and then stirring with a untrr neschwindigkejit of 1500 revolutions j.ro Iiinute to 70" with 2 Koh] rnmonf heated E5N C under a No. ^Kohl:.: Ionoxidntrömiinas ^r ' speed slides from 4.35 1 / minute

2 nute sol'jt nan daiür that as pressure at 70 kg / cm and is then begins π to introducing it to an air stream at a rate of 1, (> O l / minute. This leads to an exothermic Rr-akt.ifui. IJntoi using tap water (-1 "C) maintaining the reaction temperature at 70 ⁰ C. During the entire Vcr £ ': - hi; removes one periodically appropriate gas samples au." the exhaust gases and analyzing them on by Massensj) oktralanal yne their carbon dioxide content out.

After a conversion time of 120 minutes, the Reaction by cooling the whole using tap water at ambient temperature- The gas supply is turned off interrupted and ventilated through the reactor. During ventilation "nurse! (: rrui ont-relevant gas samples and iinalysed them

p Π υ · ■■ ',. '-

plus their carbon dioxide content. After vacuum filtration, the liquid product is used to separate the precipitated solids of this liquid product by gas liquid chromatography analyzed. This gives 0.023 mol of dibutyl carbonate, 0.171 mol of dibutyl oxalate and 0.14 mol of carbon dioxide. A calculation of the alcohol conversion gives a value of 17.7 mole percent. The selectivities are based on of carbon monoxide consumed at 4.6 mole percent dibutyl carbonate, 67.7 mole percent dibutyl oxalate and 27.7 mole percent Carbon dioxide.

Example 29

The procedure of Example 28 is repeated, but using a reaction mixture of 168.4 mmol of triethylamine, 68.0 mmol of 96 percent sulfuric acid, 2.19 mol of n-butyl alcohol, 0.30 mmol · palladium bromide and 16.2 mmol. Copper (II) sulfate is working. The implementation is at a pressure of

35 kg / cm at a temperature of 70 ⁰ C over a period of 180 minutes with a carbon monoxide flow rate of 4.35 l / min, and a Lufströmungsgeschwindigkeit of 1.60 l / min carried out. An analysis of the reaction products shows 0.051 mol of dibutyl carbonate, 0.154 mol of dibutyl oxalate and 0.11 mol of carbon dioxide. The alcohol conversion is 18.7 mole percent. The calculation of the selectivities gives 10.9 mol percent dibutyl carbonate, 65.7 mol percent dibutyl oxalate and 23.5 mol percent carbon dioxide.

Example 30 (comparison)

The method described in Examples 13 and 24 is carried out using a reaction mixture of 71 ml-Iol of triethylamine, 2.19 moles of n-butyl alcohol, 1.0 mmoles of palladium iodide, 2.0 mmol lithium iodide and 32.4 mmol · cupric sulfate repeated.

8 0 9 8 U 6/0 b 1 1

The reaction temperature is maintained at 70 ° C. over a period of 120 minutes operating with a carbon monoxide flow rate of 3.22 liters / min and an air flow rate of 1.38 liters / min. Analysis of the reaction products shows 0.001 mol of dibutyl carbonate and 0.018 mol of dibutyl oxalate. No carbon dioxide can be detected. The alcohol conversion is 1.7 mole percent. The calculation of the selectivities gives 2.7 mol percent dibutyl carbonate, 97.3 mol percent dibutyl oxalate and 0.0 mol percent carbon dioxide.

Examples 31 to 43

In the following and tabulated Examples 31 to 43, the general process conditions are followed of Examples 13 to 24 worked using "a catalytic mixture of a metal salt compound, an oxidizing salt compound, an amine and an amine salt compound or an acid with or without a ligand or coordination complex compound together with a corresponding alcohol. Gas and liquid products are analyzed by mass spectral analysis and gas-liquid chromatography. The calculation of the Alcohol conversions and the selectivities are carried out as in Examples 13 to 24.

The catalyst mixtures used in the above experiments _t reactants and process conditions (Examples 31 to 43) are shown in the following Table V and the results obtained are summarized in the subsequent Table VI.

809846/0611

T from a. 1 I e V

■ ■ 2 Catalyst (mmol) 4th 5 6th 7 (MoI) Respondents and 9 conditions Π * PtBr _n 3 CuSO,
32.4 ⁴ 207 ^ 68.0 nBuOH
2.19 8th 3.22 10 150 31 RhCl-
ι, ο CuSO.
32.4 ^ Et ₂ JIH ² 68 ⁴ Ο NBuOH
2.19 70 3.22 1.38 180 32 CuJ / CdJ-
3.0 / 1.0 ^ CuSO.
32.4 ⁴ Et ₃ N H SO. EtOH
3.43 80 3.22 1.38 180 33 PdJ ₂ LiJ
3.0 cuc _n o ₄ , k, o Et M
50 * KS ^ ¹ EtOK
4.94 320 3.22 1.05 60 34 PdJ LiJ
1.0 CuSO / Et N
50 H SO
1679 iBuOH
2.1? 70 3.22 1.38 120 ** * " PJJ LiJ
2.0 CuSO,
32, Λ ^ή Et N
50 ^y H SO
¹ 16.9 sekBuOK
2.3 8 70 3.22 1.38 120 PdJ _n
1.0 " LiJ
14.9 CuSO.
Δ
32.4 Et "Ν
207 ^J. H ₂ SO ₄ H-BuOH
■ 2.1? 70 3.22 1.38 120 J / PdJ ₉
J, ο "-
PdJ ₀
1.0 " LiJ
2.0 CuSO ^
CuO
32.4 EtN
50 H SO
49.4 EtOH
4.94
EtOH
4.94 "Ό 3.22
3.22 1.38 120
■ 20 38
39 LiJ
LiJ
2.0 70
70 1.38
OO cn

Table V (continued)

1 2 Catalyst (mmol) 4th 5 · 6th Respondents and 7 (moles) 8th 9 conditions 11 40 PdCl ₂ 3 Cu (OAc) ₉
32.4 Piperidine
5Ö CH ₃ COOH ■ MeOH
4.94 60 3.22 10 150 41
42 PdSO,
. 1.0 *
PdC O
Ι, Ο ⁴ * FeSO-
30.0
Cu (OOCH) ₉
32.4 ⁴ DMA
68.0
Cyclohexyl
arain 50 H SO
⁴ I679
HCOOH
25th n-octanol
1.27
i-PrOH
2.61 90
50 3.22
3.22 1.38 120
120 80984 43 PtCl ₉
ι, ο ifo Cu (OOCCF
32.4 h ^Et 3 ^N HOOCCF.
16.9 ^y EtOH
3.43 75 3.22 1.38
1.00 120 6/06 1.38 ^ j.

Abbreviations: 0, P »triphenylphosphine
DMA <= N, N-dimethylaniline

Meaning of the table columns T. Example no.

Catalyst (xnMol)

2. Catalyst

3. Ligand complex

4. Oxidizing salt

5. amine

6. Amine salt or acid

Reactant and Conditions Ii Alcohol (mole)

8. Temperature C

9. CO flow (l / min.)

10. Air flow (l / min.)

11. Response time (minutes)

809846/0

Table VI

Product. (Mmol)

example
Kr. OO 31 Forraiat
ester Carbonate
ester Oxalate
ester CD 32 0.021 0.181 CO
CO
CD 33 0.023 0.172 CO 34 0.120 0.075 35 0.000 0.043 36
37 0.006 0.152 38 0 _v 000
.0.016 0.165
0.200 39 0.000 0.133 40 <0.004 0.206 41 0.026 0.008 0.4 3! 42 0.001 . 0.074 43 0.016 0.156 ——. 0.043 0.163

co ₂

0.07

0.10

0.05

0.003

0.065

0.34

0.07

0.09

0.51

0.08

0.32

0.020

0.17

Alcohol conversion (mole percent)

18.4 17.8 11.4

1.7 14.8 15.2 19.7

7.4 13.0 18.3 II, S 13.2 12.0

Selectivities (mole percent)

Car

Forraiat- bonate ester

2.7

4.6
4.9
37.5
0.0
1.6
0.0
3.3
0.0

0.8

0.2

10.8

8.0

Oxalate ester

79.9 73.7 46.9 96.6 80.2 49.4 82.3 74.7 44.5 88.3 31.6 75.7 60.5

CO ₂

15.5 21.4 15.6

³ > 4 S 17.2 m 50.6 "^ 14.4 25.3 55.1

8.2 68.2 13.5 31.5

- ar -

Example 44

The procedure, charging and process conditions according to Example 25 are repeated with the exception that instead of Copper (I) iodide 4.0 mmol of iron (II) iodide is used in the autoclave and the reaction is carried out for 60 minutes.

The analysis of the liquid and gaseous products gives 0.007 mol of dibutyl carbonate, 0.082 mol of dibutyl oxalate, 0.038 mol Carbon dioxide and 0.033 moles of other oxalate-containing salts.

Examples 45-49

Examples 45 to 49, summarized in Table VII below, have the advantage of using an amine salt in the catalytic mixture according to the invention. Furthermore, Example 45 is a comparative example, according to which neither an amine salt nor an acid is used for its formation. According to Examples 46 to 49, a Amine salt (triethylammonium sulfate) used in different concentrations.

According to Examples 45 to 49, the procedure according to Example using the same reaction conditions with the exception repeats that the reaction is carried out for 60 minutes. According to each of the examples, a total of 62 mmoles Triethylamine is present as a free amine in the catalyst mixture.

The amount of catalyst used in mmol, the concentration of the amine salt in the solution in percent by weight and the Reactants and yields of dibutyl carbonate, dibutyl oxalate and carbon dioxide are summarized in Table VII ο

809846/06 1 1

Tabel

VII

example

Catalyst used (mmol)

(D

CuI Et ₃ N

H ₂ SO ₄

TEAHS

(2)

Wt%
(Et ₃ NH) ₂ SO ₄

in the Beschik- n-BuOH
solution (mole)

(3)

Products (moles)

DBC

(4)

DBO

(5)

CXJ 47

(D (2) (3) (4) (5) (6)

2.0 2.0 2.0 2.0 2.0

4.0 61.6 4.0 63.6 4.0 73.4

4.0

4.0

1.0 11.8295

150

Et ₃ N - triethylamine

TEAHS - triethylanunonium hydrogen sulfate n-BuOH - n-butyl alcohol DBC - dibutyl carbonate DBO - dibutyl oxalate (Et-NH) _? S0 ₄ - triethylairanonium sulfate

0.00 2.19 0.009 0.098 0.105 0.17 2.19 0.013 0.136 0.116 2.1 2.19 0.015 0.165 0.121 34.2 2.19 0.019 0.228 0.136 21, 0 2.19 0.041 0.291 0.197

f-Νθ OQ

Q OO

cn

Claims (34)

Claims 1. J Process for the production of oxalic acid esters, since - "u r c h marked that one is a saturated aliphatic, alicyclic or araliphatic Monohydroxy alcohol with 1 to 20 carbon atoms, which substitutes other radicals that do not interfere with the reaction can be with a mixture of carbon monoxide and oxygen at a pressure of about 35 to 350 kg / cm and a temperature in the range of about 40 to 150 ⁰ C in the presence of a v / irksamen amount of a catalyst mixture of (a) a palladium, rhodium, platinum, copper or cadmium salt compound or a mixture thereof, (b) an aliphatic, cycloaliphatic, aromatic or heterocyclic amine or ammonia, (c) an oxidizing copper (I) -, copper (II) -, iron (II) - or ferric salt compound and (D) about 0.1 to 40 percent by weight of an ammonium or substituted ammonium salt with another Counterion as a halide implements. 2. The method according to claim 1, characterized that the alcohol is a saturated aliphatic monohydroxy alcohol having 1 to 8 carbon atoms used. ORIGINAL INSPECTED 809846/0611 3. The method according to claim 2, characterized that the alcohol is methanol, ethanol ,. Propanol, a butanol or an octanol is used. 4. The method according to claim 3, characterized ge indicates that the alcohol used is methanol . 5. The method according to claim 3, characterized that the alcohol used is ethanol. 6. The method according to claim 3, characterized that the alcohol used is 2-propanol. 7. The method according to claim 3, characterized that the alcohol used is n-butyl alcohol, isobutyl alcohol or sec-butyl alcohol. 8. The method according to claim 1, characterized that the metal salt compound is a palladium, rhodium, platinum or cadmium halide, oxalate, sulfate or acetate, a copper halide or mixtures thereof are used. 9. The method according to claim 8, characterized in that there is used as the metal salt compound Palladium iodide, palladium sulfate, palladium chloride, palladium bromide, Platinum acetate, platinum chloride, platinum bromide, copper iodide, cadmium chloride, cadmium iodide and / or rhodium chloride begins. 10. The method according to claim 9, characterized in that there is used as the metal salt compound Palladium iodide is used. 11 .. The method according to claim 9, characterized that palladium sulfate is used as the metal salt compound. 12. The method according to claim 9, characterized that copper iodide is used as the metal salt compound. 13. The method according to claim 1, characterized that the amine is a primary, secondary or tertiary amine in concentrations of 0.1 up to 10 percent by weight used. 14. The method according to claim 13, characterized that the amine is used in concentrations of 0.3 to 4 percent by weight. 15. The method according to claim 13, characterized that triethylamine is used as the amine = 16. The method according to claim 1, characterized that the oxidizing salt compound copper (I) -, copper (II) -, iron (II) - or iron (III) halide, oxalate, sulfate, acetate, naphthenate or trifluoroacetate used. 8098 / f B / 0611 17. The method according to claim 16, characterized that one uses copper (I) iodide as the oxidizing salt. 18. The method according to claim 16, characterized that copper (II) sulfate is used as the oxidizing salt. 19. The method according to claim 16, characterized in that that copper oxalate is used as the oxidizing salt. 20. The method according to claim 1, characterized that the ammonium salt compound is an ammonium or substituted ammonium sulfate, trifluoroacetate and / or acetate used. 21. The method according to claim 20, characterized in that the ammonium salt compound Triethylammonium sulfate is used. 22. The method according to claim 19, characterized in that that triethylammonium hydrogen sulfate is used as the ammonium salt compound. 23. The method according to claim 1, characterized in that the ammonium salt compound used in concentrations of 2 to 20 percent by weight. Ö09846 / 061 1 24. The method according to claim 1, characterized that the ammonium or substituted ammonium salt compound in situ by adding a Acid for the reaction mixture which contains excess amine base beyond the amount required in the catalyst mixture, forms and that the acid is stronger than water and such that the anion with the metal salt or oxidizing salt there is practically no complex formation in the catalyst mixture. 25. The method according to claim 24, characterized in that the acid used is sulfuric acid used. 26. The method according to claim 1, characterized in that the reaction is carried out in the presence a catalytic amount of an organic mono- or poly-jet ligand or coordination complex from the Group alkyl, aryl or halogen substituted phosphines, arsines, stibines or halides used. 27. The method according to claim 26, characterized in that one is used as a ligand or coordination complex Tripheny! Phosphine used. 28. The method according to claim 26, characterized in that one is used as a ligand or coordination complex Lithium iodide uses. 29. The method according to claim 1, characterized in that at a pressure between 2
about 63 and 155 kg / cm and a temperature in the range from 60 to 100 ⁰ C works. 809846/061 1 30. The method according to claim 1, characterized in that the alcohol is methanol, Ethanol, 2-propanol or butanol used as the metal salt compound Palladium iodide is used, triethylamine is used as the amine, copper (II) sulfate is used as the oxidizing salt and triethylammonium sulfate is used as the ammonium salt compound . 31. The method according to claim 30, characterized that a catalytic amount of lithium iodide is added to the reaction mixture. 32. The method according to claim 1, characterized that air is used as the source of oxygen for the reaction. 33. The method according to claim 1, characterized in that one with one on a carrier located metal salt compound works. 34. The method according to claim 1, characterized that the alcohol used is n-butyl alcohol, as a metal salt compound palladium iodide, as an amine a about the amount of triethylamine that exceeds the required amount of amine base, copper (I) iodide as the oxidizing salt and the ammonium salt compound triethylammonium sulfate formed after the addition of concentrated sulfuric acid is used. 809846/0611