HK1081528B - Process for preparing tcd-alcohol dm - Google Patents

Description

Process for preparing TCD-alcohol DM

The invention relates to a process for preparing TCD-alcohol DM {3(4), 8(9) -dimethylol tricyclo [5.2.1.0 ] from Dicyclopentadiene (DCP)^2，6]Decane } in the synthesis of a compound represented by the formula (I).

Dicyclopentadiene (DCP), which is readily available by dimerization of cyclopentadiene and is otherwise prepared on an industrial scale, can be converted into compounds having important applications, the tricyclodecane structure imparting particular properties thereto. The compounds derived from DCP having tricyclodecane structure are often named differently in the literature. According to the nomenclature of DCP derivatives disclosed in Chemiker-Zeitung, 98, 1974, pages 70-76, the nomenclature based on the tricyclodecane structure (also known as TCD structure) is also used hereinafter.

TCD-alcohol DM {3(4), 8(9) -dimethylol tricyclo [5.2.1.0^2，6]Decane has great economic value as an important intermediate in the chemical industry. The diols have a variety of uses and are of great industrial value in different applications: acrylic or methacrylic acid esters of tricyclodecanol containing OH groupsEsters (DE 2200021) were used as a component of anaerobic curing acrylate adhesives; (meth) acrylic esters of tricyclodecanol containing ether groups (EP 23686) are used for the preparation of adhesives and sealants; esters and polyesters of the tricyclodecanes class (DE 934889), which are suitable as plasticizers and important ester lubricants, odor compositions (DE-B2307627) and polyester varnishes which are resistant to acid poisoning in the field of metal coatings (DE 3134640). TCD-alcohol DM is obtainable by hydrogenating the hydroformylation product of dicyclopentadiene, known as TCD-aldehyde.

Processes for preparing aldehydes by catalytic addition of carbon monoxide and hydrogen to olefinic double bonds are known. While the reaction has previously been carried out almost exclusively using cobalt as catalyst, modern processes employ metal rhodium or rhodium compounds as catalysts, these catalysts being used alone or together with complex-forming ligands, such as organophosphines or phosphites. It is agreed in the art that the active catalyst under the reaction conditions described may be of the formula H [ Rh (CO ]_4-xL_x]A hydrogenated carbonyl compound of rhodium represented by wherein L represents a ligand and x is 0 or an integer of 1 to 3.

A special case is the hydroformylation of dienes. Although hydroformylation of conjugated dienes under the customary conditions of oxo synthesis gives almost exclusively monoaldehydes, it is possible to obtain not only monosubstituted but also disubstituted products from Dicyclopentadiene (DCP) with isolated double bonds. The hydroformylation reaction must be carried out under special conditions due to the danger of the retro-Diels-Alder reaction which takes place at the temperatures of the oxo process and the cyclopentadiene released thereby which can form complexes with transition metals and which reduces the activity of the catalysts used. It has been found to be advantageous to replace the previously used cobalt catalysts with rhodium, which allows a high selectivity for conversion to aldehydes and allows hydroformylation under conditions of low degree of retro-Diels-Alder dissociation. A review of the hydroformylation of dicyclopentadiene and the further processing of the TCD-aldehydes can be found in Chemiker-Zeitung 98, 1974, pages 70 to 76. 8(9) -formyl tricyclo [5.2.1.0^2，6]Dec-3-ene (also known as TCD-monenal) and 3(4), 8(9) -diformyl tricyclo [5.2.1.0^2，6]Decane (also known as TCD-dialdehyde) is of particular importance. Since their thermal instability leads to losses in the distillation process, the TCD-aldehydes are usually not isolated in pure form but are worked up further as crude product of the hydroformylation reaction.

For example, GB1,170,226 discloses either hydrogenating the hydroformylation mixture of dicyclopentadiene hydroformylation obtained under rhodium catalysis in the presence of a customary hydrogenation catalyst after removal of the rhodium catalyst or converting the reaction mixture at elevated temperature in the presence of synthesis gas to TCD-alcohol DM without removal of the rhodium catalyst and without addition of further hydrogenation catalysts.

According to the process involved in the preparation of 3(4), 8(9) -bis (aminomethyl) tricyclo [5.2.1.0^2，6]EP-A2-0348832 for decane (TCD-diamine), the rhodium-containing reaction mixture of the hydroformylation of dicyclopentadiene being fed without removal of the catalyst to the subsequent reductive amination, in the course of which the rhodium used in the hydroformylation stage deposits virtually completely on the hydrogenation catalyst.

Owing to the multiplicity of possible uses, TCD-alcohol DM has a high economic value and its preparation is frequently mentioned in the patent literature.

U.S. Pat. No. 4, 4647708 describes the use of ion exchangers in toluene/THF solvent (MWA-1) hydroformylation of dicyclopentadiene using Rh as a catalyst. The reaction is carried out at a CO/H temperature of 120 ℃ and a CO/H pressure of 27.5MPa₂(ratio 1: 2) in two separate continuous autoclaves. From the published experimental results, it can be seen that the yield of TCD-alcohol DM decreased from 85% to 65% over the 30-day experimental period. Therefore, the reaction system is not suitable for industrial use.

Special for AmericaThe use of Rh/Co bimetallic clusters on resins as described in US 4262147IRA-68. The selectivity of TCD-alcohol DM obtained in this one-stage synthesis under the conditions used (110 ℃ C., 11MPa, 8 h) was 68%.

DE-C3008497 describes an improved Co process in which the conversion of dicyclopentadiene is carried out at 200 ℃ and a synthesis gas pressure of 15MPa under the catalytic action of Co/tri-n-octylphosphine. After a reaction time of 5 hours, a yield of 69% of TCD-alcohol DM was obtained. The by-products formed were 11.7% of TCD-monool and 14.6% of hydroxymethylcyclopentane. Due to the high temperatures that have to be used, there is a retro-Diels-Alder reaction of dicyclopentadiene to cyclopentadiene, which leads to the formation of large amounts of hydroxymethylcyclopentane. This variant is therefore unsuitable for industrial use.

JP 11100339 discloses the hydroformylation of DCP with rhodium dicarbonylacetylacetonate, tris (2, 4-di-tert-butylphenyl) phosphite and triethylamine in isopropanol/toluene over a period of 8 hours at 120 ℃ and 8.8MPa of synthesis gas. 93% of TCD-dialdehyde are obtained and hydrogenated in isopropanol at 110 ℃ and 0.78MPa of hydrogen for 6 hours with Raney nickel to give 91% of TCD-alcohol DM. The use of these complex phosphite ligands, which are difficult to prepare, is disadvantageous from an industrial application and economic point of view. Furthermore, the widespread use of these phosphite ligands is limited by their poor stability and their higher susceptibility to hydrolysis with traces of water and acids than the more conventional phosphine ligands, and the phosphonites formed in the continuous hydroformylation process impair the lifetime of the catalyst and have to be removed from the process in a complicated manner. Furthermore, when amines are used, the TCD-alcohol DM is always contaminated with nitrogen-containing components.

EP 1065194 describes a low-pressure process for the hydroformylation of dicyclopentadiene, in which the catalyst system used is likewise rhodium/tris (2, 4-di-tert-butylphenyl) phosphite. The hydroformylation is carried out at a pressure of from 1 to 15MPa and a temperature of from 80 to 140 ℃. The solvents used are inert hydrocarbons such as toluene, diisopropylbenzene or methylcyclohexane. The hydroformylation product is worked up by multi-stage extraction using polyols such as ethylene glycol, and the addition of tertiary amines is recommended. After extraction, the crude oxo product is present predominantly in the alcohol phase, while a small portion of the monoaldehydes and dialdehydes and the majority of the rhodium and phosphine ligands are present in the hydrocarbon phase. It is stated that the extraction must be carried out in the absolute absence of oxygen. The use of extractants with the addition of tertiary amines and the requirement of absolutely oxygen-free conditions complicate the industrial application of the process and there is a risk of contamination of the TCD-alcohol DM with traces of amines.

The known processes for preparing TCD-alcohol DM by hydroformylation and subsequent hydrogenation of dicyclopentadiene necessitate the presence of special catalyst systems which are not readily available in industry or are environmentally incompatible, or only give economically unsatisfactory selectivities and yields of TCD-alcohol DM. There is therefore a need for a very simple and inexpensive process for preparing TCD-alcohol DM.

The invention therefore consists in a process for preparing 3(4), 8(9) -dimethylol tricyclo [5.2.1.0 ] by hydrogenating the hydroformylation product of dicyclopentadiene^2，6]Decane method. Which comprises carrying out the hydrogenation in the presence of water, optionally after addition of water.

It has surprisingly been found that the presence of water in the hydrogenation stage leads to a significant increase in the yield of TCD-alcohol DM. The water may be present directly in the crude hydroformylation product of the dicyclopentadiene hydroformylation used in the hydrogenation stage, or water may be added to the crude hydroformylation product before or during the hydrogenation stage.

The hydroformylation of dicyclopentadiene is usually carried out in the presence of a rhodium catalyst which is soluble in the organic reaction mixture in a homogeneous organic phase. One way of carrying out the hydroformylation reaction is by conventional methods in the absence of water. However, it is also possible to add water to the homogeneous hydroformylation mixture. When water is added to the organic phase, the amount of water used is generally determined by the water solubility in the organic reaction mixture. However, it is not excluded that water is added to the reaction mixture in an amount exceeding and above the solubility limit.

The amount of water added is generally at least 0.1% by weight, preferably at least 0.5% by weight, based in each case on the total amount used.

When water is added to the reaction mixture in an amount above and above the solubility limit, the separated water is advantageously removed before the hydroformylation stage is carried out, preferably by phase separation.

The hydroformylation stage is usually carried out in a homogeneous reaction system. The term "homogeneous reaction system" means a homogeneous solution consisting essentially of solvent (if added), catalyst, starting materials, reaction product, and added water. In some cases, it may be found appropriate to add a solvent. The solvents used are organic compounds in which the starting materials, the reaction products and the catalyst system are soluble. Examples of such compounds are aromatic hydrocarbons such as benzene and toluene or the isomeric xylenes andother solvents which may be used are paraffin oils, cyclic, straight-chain or branched hydrocarbons, such as cyclohexane, n-hexane, n-heptane or n-octane, ethers, such as tetrahydrofuran, ketones or those from EastmanA diluent such as an aliphatic alcohol, for example, 2-ethylhexanol or isobutanol, may be further added to the solvent. The proportion of solvent in the reaction medium can vary within wide limits and is generally from 10 to 90% by weight, preferably from 20 to 50% by weight, based on the reaction mixture.

However, it is not necessarily required to add a solvent in the hydroformylation stage.

If water is added to the organic hydroformylation mixture, the amount of water is advantageously such that a homogeneous liquid organic phase is still present after the addition of water and no separate aqueous phase separates out. The limit of solubility of water in the organic reaction mixture depends on various influencing factors, for example on the polarity of the solvent used and its proportion in the reaction mixture, and can be determined by simple experiments. Addition of water in amounts of less than 0.1% by weight, based on the total amount used, no longer produces any advantageous effect and is therefore unnecessary and unnecessarily complicates the reaction.

It is likewise possible to add water in the hydroformylation stage in such an amount that a separate aqueous phase is formed. However, also in this process variant in which a heterogeneous mixture of water and organic phase is used in the hydroformylation stage, the hydroformylation catalyst remains dissolved in the organic phase.

When aliphatic or aromatic hydrocarbons, such as toluene or cyclohexane, are used as solvents, in a preferred embodiment of the process according to the invention the water content is from 0.5 to 2.5% by weight, preferably from 1.0 to 2.0% by weight, based on the total amount used.

The catalyst used in the hydroformylation stage is a rhodium compound. The rhodium compounds used are generally not modified with phosphorus ligands such as phosphines or phosphites. The literature discloses such rhodium catalysts not modified with phosphines or phosphites and their suitability as catalysts for hydroformylation, and they are referred to as unmodified rhodium catalysts. This technical document assumes the rhodium compound HRh (CO)₄Are rhodium species which are catalytically active in hydroformylation using unmodified rhodium catalysts, although this has not been clearly demonstrated due to the numerous chemical mechanisms which proceed in parallel in the hydroformylation zone. Since the use of rhodium catalysts which are not modified with phosphines generally entails a relatively low rhodium content, preference is given to operating in the hydroformylation stage with unmodified rhodium catalysts. The rhodium content is generally from 5 to 100ppm, based on the homogeneous reaction mixture.

However, it is also possible to use rhodium complexes which contain organic phosphorus (III) compounds as ligands in the hydroformylation stage. Such complexes and processes for their preparation are known (for example from US-A-3527809, US-A-4148830, US-A-4247486, US-A-4283562). They can be used in the form of individual complexes or in the form of mixtures of different complexes. The rhodium concentration in the reaction medium is in the range of about 5 to about 1000 ppm by weight, and preferably 10 to 700 ppm by weight. In particular, rhodium is used in concentrations of 20 to 500 ppm by weight, based on the homogeneous reaction mixture. The catalyst used may be a rhodium complex having a stoichiometric composition. However, it has been found to be suitable to carry out the hydroformylation in the presence of a catalyst system composed of a rhodium-phosphorus complex and free, i.e.excess, phosphorus ligands which do not enter into complexation with rhodium. The free phosphorus ligand may be the same as in the rhodium complex, but a ligand other than that in the rhodium complex may also be used. The free ligand may be a single compound or consist of a mixture of different organophosphorus compounds. Examples of rhodium-phosphorus complexes which find use as catalysts are described in US-A-3527809. Preferred ligands in the rhodium complex catalyst include, for example, triarylphosphines such as triphenylphosphine; trialkylphosphines such as tri (n-octyl) phosphine, tridodecylphosphine, tris (cyclohexyl) phosphine; alkylphenylphosphines, cycloalkylphenylphosphines and organodiphosphites. Triphenylphosphine is particularly frequently used because of its ready availability.

When operating with a modified rhodium complex catalyst system, the molar ratio of rhodium to phosphorus in the homogeneous reaction mixture is generally from 1: 5 to 1: 200, but the molar ratio of phosphorus in the form of an organophosphorus compound may also be higher. Rhodium and organically bound phosphorus are preferably used in a molar ratio of 1: 10 to 1: 100.

The hydroformylation of dicyclopentadiene with carbon monoxide and hydrogen is carried out at a temperature of 70 to 150 ℃. Preferably, the temperature is maintained at 80 to 140 ℃, particularly 100 to 140 ℃. The total pressure is in the range of 5-35 MPa, preferably 10-30 MPa, especially 20-30 MPa. The molar ratio of hydrogen to carbon monoxide generally varies from 1: 10 to 10: 1, mixtures comprising hydrogen and carbon monoxide in a molar ratio of from 3: 1 to 1: 3, in particular 1: 1, being particularly suitable.

The catalyst is generally formed from the components transition metal or transition metal compound and synthesis gas under hydroformylation reaction conditions in the reaction mixture, optionally in the presence of an organophosphorus (III) compound. However, it is also possible to initially pre-form the catalyst and subsequently feed it to the actual hydroformylation stage. The conditions of the preformation generally correspond to the hydroformylation conditions.

To prepare the hydroformylation catalysts, rhodium is used in metallic form or as a compound. In metallic form, the rhodium is used in the form of fine particles or deposited as a thin film on a support, such as activated carbon, calcium carbonate, aluminium silicate, clay. Suitable rhodium compounds are salts of aliphatic monocarboxylic and polycarboxylic acids, for example rhodium 2-ethylhexanoate, rhodium acetate, rhodium oxalate, rhodium propionate or rhodium malonate. In addition, inorganic salts of hydrogen and oxygen acids, such as nitrates or sulfates, different transition metal oxides or transition metal carbonyls, such as Rh, can be used₃(CO)₁₂、Rh₆(CO)₁₆Or transition metal complexes such as cyclopentadienyl-rhodium compounds, rhodium acetylacetonate or [ RhCl (cyclooctadiene-1, 5)]₂. The rhodium-halogen compounds are less used due to the corrosive action of the halide ions.

Rhodium oxide, rhodium acetate and rhodium 2-ethylhexanoate have been found to be particularly suitable.

The hydroformylation stage may be carried out batchwise or continuously.

The hydroformylation reaction product of the dicyclopentadiene is fed to the hydrogenation stage without further purification, without removal of the catalyst and without removal of the solvent if added. It is not necessary to remove the water present and/or added beforehand in the hydroformylation stage.

If water is added in the hydroformylation stage so that its amount exceeds its solubility in the organic phase, the separated aqueous phase can be removed by phase separation before entering the hydrogenation reactor. However, it is also possible to use a heterogeneous mixture of water and organic phase in the hydrogenation stage.

However, it is not necessarily required that water is added in the hydroformylation stage in a homogeneous phase using a rhodium catalyst which is homogeneously soluble in the organic reaction mixture. In this case, the dicyclopentadiene is initially hydroformylated by customary methods in a homogeneous reaction medium.

In the process according to the invention, the hydrogenation of the hydroformylation product of dicyclopentadiene is carried out in the presence of water, optionally after addition of water. Water may be added before or during the hydrogenation to TCD-alcohol DM.

Since the crude TCD-dialdehyde used has a higher polarity than dicyclopentadiene, the solubility limit of the water added to the reaction mixture increases and water can be added in higher amounts without separating off a separate aqueous phase. Addition of water in amounts of less than 0.1% by weight, based on the total amount used, does not lead to technical advantages. Water is preferably added to the reaction mixture to a content of 0.5 to 5.0 wt.%, in particular 1.0 to 4.0 wt.%, based on the total amount used.

However, it is likewise possible to add water to the reaction mixture from the hydroformylation stage above and above the solubility limit.

The crude TCD-dialdehyde is hydrogenated to TCD-alcohol DM in the presence of customary hydrogenation catalysts under the usual reaction conditions. Generally, the hydrogenation temperature is 70-170 ℃, and the pressure used is 1-30 MPa. Suitable hydrogenation catalysts are in particular nickel catalysts.

The catalytically active metal may be applied to the support in an amount of generally from about 5 to about 70% by weight, preferably from about 10 to about 65% by weight, in particular from about 20 to about 60% by weight, based in each case on the total weight of the catalyst. Suitable catalyst supports are all customary support materials, such as, for example, alumina hydrate in its various manifestations, silicon dioxide, polysilicas (silica gels) including kieselguhr, silica xerogels, magnesium oxide, zinc oxide, zirconium oxide and activated carbon. In addition to the main components nickel and support material, the catalyst may also contain minor amounts of additives for, for example, improving its hydrogenation activity and/or its service life and/or its selectivity. The additives are known; they include, for example, oxides of sodium, potassium, magnesium, calcium, barium, zinc, aluminum, zirconium, and chromium. They are generally added to the catalyst in a total proportion of 0.1 to 50 parts by weight, based on 100 parts by weight of nickel.

However, unsupported catalysts such as Raney nickel or Raney cobalt may also be used in the hydrogenation process.

The hydrogenation stage is carried out batchwise or continuously in the liquid phase using a suspended catalyst or in the liquid or gas phase using a fixed bed catalyst; preference is given to a continuous process.

In a batch process, from 1 to 10% by weight, preferably from 2 to 6% by weight, of nickel in the form of the above-described catalyst, based on TCD-dialdehyde, are used. In a continuous process, from about 0.05 to about 5.0kg of TCD-dialdehyde are used per liter of catalyst and per hour; preferably about 0.1 to 2.0kg of TCD-dialdehyde per liter of catalyst per hour.

The hydrogenation is preferably carried out using pure hydrogen. However, it is also possible to use mixtures comprising free hydrogen and additional components which are inert under the hydrogenation conditions. In any case, care must be taken that the hydrogenation gas does not contain harmful amounts of catalyst poisons, such as sulfur-containing compounds or carbon monoxide.

Rhodium from the unremoved hydroformylation catalyst precipitates almost completely on the hydrogenation catalyst. It can be recovered by known methods.

It is recommended to use solvents or diluents in the hydrogenation stage, which can be pure substances or substance mixtures. Examples of suitable solvents or diluents are linear or cyclic ethers, such as tetrahydrofuran or dioxane; and aliphatic alcohols such as methanol, 2-ethylhexanol or isobutanol. The amount of solvent or diluent used can be freely selected in accordance with the circumstances of the apparatus and method; in general, solutions containing 10 to 75% by weight of TCD-dialdehyde are used. It has been found to be particularly useful in the process according to the invention to use the diluent present from the hydroformylation stage as solvent or diluent. In this case, suitably 1 to 10 times, preferably 1 to 5 times, the amount of solvent and diluent is present or added, based on the weight of TCD-dialdehyde.

The pure TCD-alcohol DM is recovered by conventional distillation methods. The residual amounts of rhodium used in the hydroformylation stage are obtained as distillation residue and are recovered by known methods.

The process according to the invention is illustrated in detail below with reference to some examples, but is not limited to the described embodiments.

Comparative experiment

Dicyclopentadiene is hydroformylated by the process known from GB1,170,226 in the presence of toluene under rhodium catalysis. A65% by weight solution of dicyclopentadiene in toluene is converted in the presence of 20ppm of rhodium at a temperature of 130 ℃ and a pressure of 26 MPa.

Subsequently, the crude product was hydrogenated over a fixed bed nickel catalyst at a temperature of 120 ℃ and a pressure of 10.0MPa and subsequently distilled.

The yield of TCD-alcohol DM was 70.5%, based on the dicyclopentadiene used.

Example 1

The process is similar to example 1, the only difference being that 1.60% by weight of water, based on the mixture used, is added to the mixture used for the hydroformylation of dicyclopentadiene.

The crude product obtained after hydroformylation was hydrogenated analogously to the comparative experiment without further purification and subsequent distillation.

The yield of TCD-alcohol DM was 80.3%, based on the dicyclopentadiene used.

Surprisingly, it is possible to convert the aqueous hydroformylation product or hydroformylation mixture of dicyclopentadiene hydroformylation in excellent yields after addition of water to the TCD-alcohol DM in the subsequent hydrogenation stage.

Claims (5)

1. Preparation of 3(4), 8(9) -dimethylol tricyclo [5.2.1.0 ] by hydrogenation of the hydroformylation product of dicyclopentadiene^2，6]-a process for preparing decane comprising obtaining the hydroformylation product of dicyclopentadiene by hydroformylation in a homogeneous organic phase in the presence of a homogeneously dissolved rhodium catalyst and carrying out the hydrogenation without removing the catalyst, after adding water to the hydrogenated reaction mixture to a content of 0.5 to 5.0% by weight, based on the total amount used.

2. The process of claim 1, wherein water is added to the hydrogenated reaction mixture to a level of 1.0 to 4.0 wt.%, based on total amount used.

3. The process of claim 1, wherein the hydrogenation is carried out in the presence of an aliphatic alcohol.

4. The process of claim 1, wherein the hydrogenation is carried out in the presence of a nickel catalyst.

5. The process according to claim 1, wherein the hydrogenation is carried out at a temperature of 70 to 170 ℃ and a pressure of 1 to 30 MPa.