A method for producing furan-based bis-hydroxymethyl compounds from a mixture containing hydroxymethylfurfural, and the corresponding mixture for use as an intermediate.

Abstract

This specification describes a method for producing furan-based bis-hydroxymethyl compounds from hydroxymethylfurfural, particularly from a mixture containing hydroxymethylfurfural, a reaction mixture containing hydroxymethylfurfural that can be obtained by the said method, and the use of the said reaction mixture in a hydrogenation method for producing 2,5-bis(hydroxymethyl)furan and / or 2,5-bis(hydroxymethyl)tetrahydrofuran.

Description

[Technical Field]

[0001] The present invention relates to a process for producing furan-based bis-hydroxymethyl compounds from hydroxymethylfurfural, particularly from mixtures comprising hydroxymethylfurfural, to a reaction mixture comprising hydroxymethylfurfural obtainable by the process according to the invention, and to the use of said reaction mixture in a hydrogenation process for producing 2,5-bis(hydroxymethyl)furan and / or 2,5-bis(hydroxymethyl)tetrahydrofuran. [Background Art]

[0002] Aldehydes derived from renewable resources such as hydroxymethylfurfural ("HMF") or furfural are important intermediates in the synthesis of monofunctional and difunctional alcohols, carboxylic acids, amines, and other derivatives. Accordingly, easy access to such aldehydes is of particular interest to the chemical industry. Unfortunately, especially HMF and furfural are thermodynamically and chemically unstable and very delicate compounds. Due to the tendency of these compounds to form humins, their isolation is often difficult, associated with high material loss and low yields.

[0003] For example, 2,5-bis(hydroxymethyl)furan and 2,5-bis(hydroxymethyl)tetrahydrofuran are attractive starting compounds in the production of a wide range of polymers such as polyesters, polyester polyols, alcohol alkoxylates, and other valuable polymeric structures. Said polymeric structures have the advantage of being derived from renewable raw materials and are generally biodegradable, so that they are extremely valuable for sustainable future products or applications.

[0004] In the existing literature, several of the following publications deal with processes for producing furan-based bis-hydroxymethyl compounds.

[0005] The document in Chinese Patent No. 103804329A describes a method for directly synthesizing 2,5-bis(hydroxymethyl)furan or 2,5-bis(hydroxymethyl)tetrahydrofuran from hexose using a catalyst.

[0006] The literature in International Publication No. 2014 / 033289 deals with the production of hydroxymethylfurfural from fructose.

[0007] S. Fulignati et al. reported the hydrogenation of 2-hydroxymethylfurfural to francyl using Ru / C as a catalyst in Applied Catalysis A, General, 578 (2019) 122-133.

[0008] PPUpare et al. discuss an integrated process for the production of 2,5-dihydroxymethylfuran from fructose in Green Chemistry 17 / 6(2015)3310-3313.

[0009] PPUpare et al. reported in Green Chemistry 20 / 4 (2018) 879-885 an integrated process for producing 2,5-dihydroxymethylfuran and its polymers from fructose.

[0010] The document in Korean Patent Application Publication No. 2017 0031269 A describes a process for selectively hydrogenating hydroxymethylfurfural using a ruthenium nanoparticle-supported catalyst.

[0011] The document in German Patent Application Publication No. 21 32 547 A1 relates to a process for hydrogenating aromatic compounds to corresponding alicyclic compounds, involving a catalyst containing ruthenium hydroxide oxide. [Overview of the Initiative] [Problems that the invention aims to solve]

[0012] However, in light of prior art, there is still a need for a simple, robust, and efficient method for producing furan-based bis-hydroxymethyl compounds from hydroxymethylfurfural, particularly 2,5-bis(hydroxymethyl)furan and / or 2,5-bis(hydroxymethyl)tetrahydrofuran.

[0013] Accordingly, the main object of the present invention was to provide a method for producing furan-based bis-hydroxymethyl compounds, particularly 2,5-bis(hydroxymethyl)furan and / or 2,5-bis(hydroxymethyl)tetrahydrofuran, in high yield, wherein the method for producing the compounds should be particularly simple and robust.

[0014] Another object of the present invention is to provide a mixture comprising an intermediate or a starting compound that can be directly used in a hydrogenation method for producing furan-based bis-hydroxymethyl compounds, particularly 2,5-bis(hydroxymethyl)furan and / or 2,5-bis(hydroxymethyl)tetrahydrofuran, while minimizing the effort required to purify or isolate the intermediate or starting compound from the mixture. [Means for solving the problem]

[0015] Herein, the main and other objectives of the present invention are a method for producing furan-based bis-hydroxymethyl compounds from hydroxymethylfurfural, S1) The hexose sugar in the reaction mixture is reacted at a temperature in the range of 50 to 200°C, and the reaction mixture further contains acid, water and organic solvent. Remove water from the reaction mixture. This is the step in which hydroxymethylfurfural is formed, S2) Preferably, the reaction mixture from step S1) is substantially neutralized by adjusting the pH of the reaction mixture from step S1) to a value in the range of 6 to 8, or substantially neutralizes the acidic components present in the reaction mixture from step S1). A substantially neutralized reaction mixture containing hydroxymethylfurfural is obtained, step and, S3) Reaction mixture containing hydroxymethylfurfural from step S1), Or a mixture containing hydroxymethylfurfural derived from or obtained from the reaction mixture containing hydroxymethylfurfural in step S1), or If (step S2) is carried out, or if this method includes step S2), a substantially neutralized reaction mixture containing hydroxymethylfurfural from step S2) Alternatively, a mixture containing hydroxymethylfurfural derived from or obtained from the substantially neutralized reaction mixture containing hydroxymethylfurfural in step S2), In the presence of a ruthenium-containing catalyst (preferably selected from the group consisting of ruthenium-supported aluminum oxide; ruthenium-supported carbon and ruthenium hydroxide, preferably ruthenium III hydroxide as further defined below), By subjecting it to hydrogenation consisting of a temperature in the range of 50 to 150°C and a hydrogen pressure in the range of 5 to 20 MPa, Steps to form 2,5-bis(hydroxymethyl)furan and / or 2,5-bis(hydroxymethyl)tetrahydrofuran It was found that this could be achieved by a method that includes [this]. [Modes for carrying out the invention]

[0016] The present invention and its parameters, characteristics, and preferred variations and combinations of elements are defined in the appended claims. Preferred embodiments, details, modifications, and advantages of the present invention are also defined and described in the following description and the examples described below.

[0017] As outlined above, the method for producing a furan-based bis-hydroxymethyl compound from hydroxymethylfurfural according to the present invention has been found to be a simple, robust and efficient method for producing furan-based bis-hydroxymethyl compounds, particularly 2,5-bis(hydroxymethyl)furan and / or 2,5-bis(hydroxymethyl)tetrahydrofuran. Furthermore, the intermediate compound hydroxymethylfurfural and the products of the process of the present invention, in particular 2,5-bis(hydroxymethyl)furan and 2,5-bis(hydroxymethyl)tetrahydrofuran, can be obtained with high purity and high yield, and it has further been found that the yield of the desired product, 2,5-bis(hydroxymethyl)furan or 2,5-bis(hydroxymethyl)tetrahydrofuran, or the specificity of the reaction, can be controlled by the selection of the reagents used and / or the selection of the applied reaction conditions.

[0018] In the process according to the invention outlined herein, the reaction mixture comprises at least a hexose sugar and, in addition to the hexose sugar: water, an organic solvent and an acid, as described in more detail below.

[0019] In the context of the present invention, "hydroxymethylfurfural" herein refers to the compound also called 5-(hydroxymethyl)furan-2-carbaldehyde (recommended IUPAC name) having CAS RN 67-47-0 according to Formula I below.

Chemical Formula

[0020] In the context of the present invention, "2,5-bis(hydroxymethyl)furan" herein refers to the compound also called (furan-2,5-diyl)dimethanol (recommended IUPAC name) having CAS RN 1883-75-6 according to Formula II below.

Chemical Formula

[0021] In connection with the present invention, "2,5-bis(hydroxymethyl)tetrahydrofuran" means the compound also known as "tetrahydrofuran-2,5-dimethanol" in both isomers ("cis" and "trans" unless otherwise specified herein) represented by Formula III shown below. [ka]

[0022] The "cis" form of 2,5-bis(hydroxymethyl)tetrahydrofuran has CAS RN2144-40-3, and the "trans" form of 2,5-bis(hydroxymethyl)tetrahydrofuran has CAS RN104-80-3.

[0023] In this method for producing furan-based bis-hydroxymethyl compounds from hydroxymethylfurfural, for example, a ruthenium-containing catalyst has been proven to be catalytically active even under robust reaction conditions, such as in the presence of nitrogen-containing compounds (e.g., nitrogen-containing compounds usable as organic solvents in this method, such as N-methyl-2-pyrrolidone) or sulfur-containing compounds, i.e., under conditions where the catalytic activity of other noble metal catalysts used in the hydrogenation reaction is often impaired, reduced, or completely lost. Therefore, the ruthenium-containing catalyst used in step S3) has been found to be particularly suitable for use.

[0024] A method according to the present invention as defined herein (or a method according to the present invention as described above or below as a preferred method), in step S1), - Hexose sugars are selected from the group consisting of D-glucose, D-fructose, D-saccharose, and mixtures thereof. Preferably, the hexose sugar contains or is D-fructose; and / or - The organic solvent is selected from the group consisting of N-alkyl-2-pyrrolidones, preferably from the group consisting of N-methyl-2-pyrrolidone and N-ethyl-2-pyrrolidone; 2-pyrrolidone; N-methylsuccinimide; 1,3-dimethyl-2-imidazolidinone; dimethylformamide; dimethyl sulfoxide; N,N-dimethyllactamide; dimethylpropylene urea and mixtures thereof. Preferably, the organic solvent is selected from the group consisting of N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N-methylsuccinimide, and mixtures thereof. More preferably, the organic solvent contains or is N-methyl-2-pyrrolidone; and / or - The acid is selected from the group consisting of sulfuric acid, hydrochloric acid, hydrobromic acid, methanesulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid, naphthalenesulfonic acid, camphorsulfonic acid, and mixtures thereof. Preferably, the acid is sulfuric acid or sulfuric acid.

[0025] In a more specific variant of the method for producing furan-based bis-hydroxymethyl compounds from hydroxymethylfurfural according to the present invention as defined herein (or each of the methods according to the present invention as described above or below as preferred methods), S1) The hexose sugar in the reaction mixture is reacted at a temperature in the range of 50-200°C, and the reaction mixture is further... - An acid selected from the group consisting of sulfuric acid, hydrochloric acid, hydrobromic acid, methanesulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid, naphthalenesulfonic acid, camphorsulfonic acid and mixtures thereof, Preferably, the acid contains or is sulfuric acid, - Water and, - An organic solvent selected from the group consisting of N-alkyl-2-pyrrolidone, preferably N-methyl-2-pyrrolidone and N-ethyl-2-pyrrolidone; 2-pyrrolidone; N-methylsuccinimide, 1,3-dimethyl-2-imidazolidinone; dimethylformamide; dimethyl sulfoxide; N,N-dimethyllactamide; dimethylpropylene urea and mixtures thereof, Preferably, the organic solvent is selected from the group consisting of N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N-methylsuccinimide, and mixtures thereof. More preferably, the organic solvent is an organic solvent containing or being N-methyl-2-pyrrolidone. Includes, Remove water from the reaction mixture. This is the step in which hydroxymethylfurfural is formed, S2) By adjusting the pH of the reaction mixture in step S1) to a value in the range of 6 to 8, the reaction reaction in step S1) is substantially neutralized, or the acidic components present in the reaction mixture in step S1) are substantially neutralized. A substantially neutralized reaction mixture containing hydroxymethylfurfural is obtained, step and, S3) Step S1) Reaction mixture containing hydroxymethylfurfural, Or a mixture containing hydroxymethylfurfural derived from or obtained from the reaction mixture containing hydroxymethylfurfural in step S1), or Step S2) A substantially neutralized reaction mixture containing hydroxymethylfurfural, Alternatively, a mixture containing hydroxymethylfurfural derived from or obtained from the substantially neutralized reaction mixture containing hydroxymethylfurfural in step S2), By subjecting the hydrogenation process to a temperature range of 50-150°C and a hydrogen pressure range of 5-20 MPa in the presence of a ruthenium-containing catalyst, Steps to form 2,5-bis(hydroxymethyl)furan and / or 2,5-bis(hydroxymethyl)tetrahydrofuran A method including this is preferred.

[0026] In step S1) of the method according to the present invention described above, the hexose sugar is preferably D-fructose or contains D-fructose. A D-fructose-containing hexose sugar particularly suitable for use in step S1) of the method according to the present invention is a mixture containing D-glucose and D-fructose, preferably a mixture containing D-glucose and D-fructose known as “high-fructose corn syrup” (“HFCS”). High-fructose corn syrup is an industrial product (usually an aqueous syrup, i.e., a syrup containing water) and is commercially available with different D-fructose content, such as 42% by weight, 55% by weight, or 90% by weight relative to the total dry weight of the HFCS. All of the HFCS types are suitable for use as hexose in step S1) of the method according to the present invention described above and below, and HFCS types with a high D-fructose content are preferred. High-purity D-fructose is preferred as the hexose sugar used in step S1) over hexose sugars containing D-fructose in varying amounts, for example, as part of a mixture with other substances, such as other hexose sugars. In step S1), the hexose sugar is preferably used in the form of an aqueous solution, preferably having a hexose sugar concentration of 25-85% (w / v), more preferably 35-75% (w / v).

[0027] In our own experiments, we have found that a bipolar, such as a bipolar aprotic solvent, is preferred for the organic solvent used in step S1) of the method according to the present invention. Particularly preferred as the organic solvent in step S1) is N-methyl-2-pyrrolidone ("NMP"). Although we do not wish to be bound by theory, it is assumed that the dipole moment of NMP has a beneficial effect on the reaction that occurs in step S1).

[0028] Furthermore, our own experiments have shown that strong acids, such as those specified above, are preferable for use in step S1) of the method according to the present invention, and have a beneficial effect on the conversion rate, the desired selectivity of the reaction, and the yield. In this regard, sulfuric acid is most preferable. When sulfuric acid is used as the acid in step S1) of the method according to the present invention, it is preferable to use concentrated sulfuric acid in a total amount in the range of 1:50 to 1:150 molar equivalents, preferably 1:75 to 1:125 molar equivalents (i.e., 1 molar equivalent of sulfuric acid : 50 molar equivalents of hexose sugar, etc.) relative to the molar amount of hexose sugar used in step S1).

[0029] Preferably, the total amount of water present at the start of step S1) of the method according to the present invention is in the range of 8 to 30% by mass, preferably 10 to 25% by mass, and more preferably 12 to 20% by mass, relative to the total mass of the organic solvent present at the start of step S1), preferably the total mass of N-methyl-2-pyrrolidone.

[0030] In the method according to the present invention as described herein, the hydroxymethylfurfural-containing mixture derived from or obtained from the reaction mixture containing hydroxymethylfurfural in step S1) or from the substantially neutralized reaction mixture containing hydroxymethylfurfural in step S2) is preferably, (i) a portion of the reaction mixture containing hydroxymethylfurfural from step S1), or a substantially neutralized portion of the reaction mixture containing hydroxymethylfurfural from step S2); or (ii) A reaction mixture containing hydroxymethylfurfural from step S1) whose volume has been reduced (preferably by removing or evaporating at least a portion of the previously present solvent), or a substantially neutralized reaction mixture containing hydroxymethylfurfural from step S2) whose volume has been reduced (preferably by removing or evaporating at least a portion of the previously present solvent); or (iii) A reaction mixture containing hydroxymethylfurfural from step S1) whose volume has been increased (preferably by adding a solvent), or a substantially neutralized reaction mixture containing hydroxymethylfurfural from step S2) whose volume has been increased (preferably by adding a solvent). It is either or includes either of them.

[0031] usually, - The reaction mixture containing hydroxymethylfurfural from step S1), or a mixture containing hydroxymethylfurfural derived from or obtained from the reaction mixture containing hydroxymethylfurfural from step S1), And / or - A substantially neutralized reaction mixture containing hydroxymethylfurfural from step S2), or a mixture containing hydroxymethylfurfural derived from or obtained from a substantially neutralized reaction mixture containing hydroxymethylfurfural from step S2). This includes typical by-products of the method for producing furan-based bis-hydroxymethyl compounds from hydroxymethylfurfural as described herein, particularly by-products selected from the group consisting of unreacted starting compounds, acetic acid, formic acid, levulinic acid, acetoxymethylfurfural, methoxymethylfurfural, and humins (including dimers of hydroxymethylfurfural, which are generally known to be humin precursors in the initial stages of humin formation).

[0032] This method for producing furan-based bis-hydroxymethyl compounds from hydroxymethylfurfural is - The reaction mixture containing hydroxymethylfurfural from step S1), or a mixture containing hydroxymethylfurfural derived from or obtained from the reaction mixture containing hydroxymethylfurfural from step S1), And / or - A substantially neutralized reaction mixture containing hydroxymethylfurfural from step S2), or a mixture containing hydroxymethylfurfural derived from or obtained from a substantially neutralized reaction mixture containing hydroxymethylfurfural from step S2). However, it can be used in the hydrogenation method of step S3) without requiring further purification or post-treatment, and nevertheless, our own experiments have shown that it is particularly simple and robust in that it can obtain one or more desired products in good yield and purity.

[0033] A method according to the present invention as defined herein (or a method according to the present invention as described above or below as a preferred method), in step S1), - Removal of water from the reaction mixture includes distilling off the water from the reaction mixture (preferably by continuously distilling off the water from the reaction mixture); and / or - The reaction is carried out for a period of 3 to 8 hours, preferably 4 to 7 hours; and / or - It is also preferable that the temperature is within the range of 60 to 190°C, preferably 80 to 180°C, more preferably 120 to 180°C, and even more preferably 140 to 180°C, for at least a portion of the total time the reaction in step S1 takes place, preferably for the entire time the reaction in step S1 takes place.

[0034] Preferably, the time indicated above for the “reaction” in step S1) includes (i) the time required to measure (add) the hexose sugar (preferably aqueous hexose sugar syrup) to the resulting mixture containing the organic solvent and the acid, and (i) the time allowed for the reaction between the reactants once the addition of the hexose sugar is complete.

[0035] Furthermore, in the method according to the present invention, it is preferable to bring the mixture obtained after step S1) to a temperature in the range of 15 to 60°C, preferably 15 to 35°C, before starting step S2) of the method.

[0036] Next, a method according to the present invention as defined herein (or a method according to the present invention as described above or below as a preferred method), the method comprising step S2), preferably in step S2), - By adding 0.8 to 1.2 molar equivalents of base relative to the molar amount of acid (as defined above) present in the reaction mixture at the start of step S1), the reaction reaction in step S1) is substantially neutralized, or the acid component present in the reaction mixture in step S1) is substantially neutralized. Preferably, the base is selected from the group consisting of alkali metal hydroxides, preferably aqueous alkali metal hydroxide solutions; alkaline earth metal hydroxides, preferably aqueous alkaline earth metal hydroxide solutions; and mixtures thereof. More preferably, the base is selected from the group consisting of sodium hydroxide, preferably an aqueous solution of sodium hydroxide; potassium hydroxide, preferably an aqueous solution of potassium hydroxide; and mixtures thereof; and / or - The reaction reaction in step S1) is substantially neutralized by adjusting the pH of the reaction mixture in step S1) to a value in the range of 6 to 8, preferably 6.5 to 7.5, and preferably by adding a base to the reaction mixture in step S1). Preferably, the base includes or is selected from the group consisting of alkali metal hydroxides, preferably aqueous alkali metal hydroxide solutions; alkaline earth metal hydroxides, preferably aqueous alkaline earth metal hydroxide solutions; and mixtures thereof. More preferably, the base is selected from the group consisting of sodium hydroxide, preferably an aqueous solution of sodium hydroxide; potassium hydroxide, preferably an aqueous solution of potassium hydroxide; and mixtures thereof.

[0037] In the method according to the present invention as defined herein (or in the preferred method according to the present invention as described above or below), in step S2), the reaction reaction in step S1) is substantially neutralized, or the acid component present in the reaction mixture in step S1) is substantially neutralized, by adding 0.8 to 1.2 molar equivalents of base relative to the molar amount of acid present in the reaction mixture at the start of step S1), preferably the molar amount of acid present in the reaction mixture at the start of step S1) is equivalent to, or such molar amount, the amount of acid added when the reaction mixture used in step S1) is prepared (or has been prepared).

[0038] In our own experiments, the method according to the present invention as defined herein, including step S2), has been found to be particularly advantageous: hydroxymethylfurfural has been found to be more stable for a longer period in the substantially neutralized reaction mixture containing hydroxymethylfurfural obtained from step S2) than in the reaction mixture containing hydroxymethylfurfural obtained from, for example, step S1), and does not decompose or undergo undesirable further reactions. Therefore, the method according to the present invention as defined herein, including step S2), yields a substantially neutralized reaction mixture containing hydroxymethylfurfural, which can be stored for a long period because it is particularly stable. Generally, the method according to the present invention as defined herein, including step S2), also contributes to an improved overall yield of furan-based bis-hydroxymethyl compounds from hydroxymethylfurfural compared to the method according to the present invention as defined herein, without step S2). While we do not wish to be bound by theory, it is assumed that the substantially neutralized reaction mixture in step S1) contributes to the stabilization of the hydroxymethylfurfural formed in step S1), thereby reducing, suppressing, or avoiding its decomposition, or reducing, suppressing, or avoiding the undesirable side reaction of humic formation of hydroxymethylfurfural.

[0039] In step S2), if the reaction mixture from step S1) is substantially neutralized by adjusting the pH of the reaction mixture from step S1) to a value in the range of 6 to 8, preferably 6.5 to 7.5, it is preferable that the pH be determined by measurement using a glass electrode.

[0040] Furthermore, a method according to the present invention as defined herein (or a preferred method according to the present invention as described above or below) is preferred, wherein in step S3), the temperature includes (or is within) the range of 60 to 150°C, preferably 60 to 140°C, and more preferably 70 to 130°C.

[0041] A particular advantage of the method according to the present invention is that, as further described below, the yield of the desired product, 2,5-bis(hydroxymethyl)furan or 2,5-bis(hydroxymethyl)tetrahydrofuran, or the specificity of the reaction, can be controlled by selecting the reagents used and / or the reaction conditions applied.

[0042] In a first variant of the method according to the present invention, the method according to the present invention as defined herein (or the method according to the present invention as described above or below as a preferred method) is preferred, and in step S3), the catalyst containing ruthenium contains or is ruthenium-supported carbon (also known as "ruthenium-supported carbon black, "Ru / C"). As used herein, "ruthenium-supported carbon" contains ruthenium-supported carbon containing a binder (preferably containing ruthenium-supported carbon "Ru / C-PTFE" containing polytetrafluoroethylene, and preferably the catalyst containing ruthenium-supported carbon containing polytetrafluoroethylene is a catalyst prepared by the method disclosed in the document International Publication No. 2020 / 069972 A1), and preferably contains a total amount of ruthenium in the range of 2 to 10% by weight, more preferably 3 to 8% by weight, based on the total weight of the "ruthenium-supported carbon" catalyst.

[0043] In particular, when it is desirable to mainly produce 2,5-bis(hydroxymethyl)tetrahydrofuran and / or to increase the yield of 2,5-bis(hydroxymethyl)tetrahydrofuran by the method according to the present invention as described herein, our own experiments have shown that it is preferable to use carbon-supported ruthenium (preferably containing ruthenium-supported carbon containing a binder, see above) as the ruthenium-containing catalyst in step S3).

[0044] Furthermore, in the method according to the present invention as defined herein (or the method according to the present invention as described above or below as a preferred method, in particular the first variant of the present invention as defined above), in S3), - Hydrogenation is carried out for a period of 5 to 30 hours, preferably 5 to 28 hours, more preferably 5 to 26 hours; and / or - The hydrogen pressure includes, or is within, a pressure in the range of 6 to 18 MPa, preferably 6 to 16 MPa, more preferably 6 to 10 MPa, for at least a portion of the entire period during which hydrogenation is carried out in step S3; and / or - The concentration of hydroxymethylfurfural in the reaction mixture containing hydroxymethylfurfural in step S1) is 5% by weight or more, preferably 10% by weight or more, relative to the total weight of the reaction mixture containing hydroxymethylfurfural in step S1). Alternatively, the concentration of hydroxymethylfurfural in the substantially neutralized reaction mixture containing hydroxymethylfurfural in step S2) is 5% by weight or more, preferably 10% by weight or more, relative to the total weight of the substantially neutralized reaction mixture containing hydroxymethylfurfural in step S2); and / or - The concentration of hydroxymethylfurfural in the reaction mixture containing hydroxymethylfurfural in step S1) is in the range of 5% by weight or more and 25% by weight or less, more preferably 5% by weight or more and 20% by weight or less, and even more preferably 10% by weight or more and 20% by weight or less, based on the total weight of the reaction mixture containing hydroxymethylfurfural in step S1); Alternatively, the concentration of hydroxymethylfurfural in the substantially neutralized reaction mixture containing hydroxymethylfurfural in step S2) is in the range of 5% by weight or more and 25% by weight or less, more preferably 5% by weight or more and 20% by weight or less, and even more preferably 10% by weight or more and 20% by weight or less, based on the total weight of the substantially neutralized reaction mixture containing hydroxymethylfurfural in step S2); and / or - The temperature is preferably within the range of 60 to 140°C, preferably 70 to 130°C, and more preferably 70 to 90°C, for at least a portion of the total period during which hydrogenation in step S3 is carried out (preferably for the entire period during step S3).

[0045] The reaction conditions defined above for temperature, hydrogen pressure, and hydrogenation time are applicable to all variations of the method according to the present invention, but when applied to the first variation of the method (i.e., when the ruthenium-containing catalyst contains ruthenium-supported carbon or ruthenium-supported carbon), each of the above-defined reaction conditions for temperature, hydrogen pressure, and hydrogenation time individually promotes the preferential formation of 2,5-bis(hydroxymethyl)tetrahydrofuran or an increase in the yield of 2,5-bis(hydroxymethyl)tetrahydrofuran relative to the yield of 2,5-bis(hydroxymethyl)furan. When two or all of the above-defined reaction conditions for temperature, hydrogen pressure, and hydrogenation time are combined in the first variation of the method according to the present invention, the effect of preferential formation of 2,5-bis(hydroxymethyl)tetrahydrofuran is even more pronounced.

[0046] In a second variation of the method according to the present invention, the method according to the present invention as defined herein (or the method according to the present invention as described above or below as a preferred method) is preferred, and in step S3), the catalyst containing ruthenium contains ruthenium hydroxide or ruthenium hydroxide, preferably containing ruthenium III hydroxide or ruthenium III hydroxide. Preferably, in this second variation of the method according to the present invention, a ruthenium oxide hydroxide catalyst synthesized according to the preparation instructions of Example 1 ("Beispiel 1") of German Patent Application Publication No. 21 32 547 (i.e., "DE-OS 21 32 547") is used.

[0047] In the method according to the present invention as described herein, when it is desired to mainly produce 2,5-bis(hydroxymethyl)furan and / or to improve the yield of 2,5-bis(hydroxymethyl)furan, our own experiments have shown that it is preferable to use the ruthenium hydroxide (preferably ruthenium III hydroxide) as the ruthenium-containing catalyst in step S3).

[0048] A method for producing a furan-based bis-hydroxymethyl compound from hydroxymethylfurfural according to a second modification of the present method (or each of the methods described above or below as preferred methods according to the present invention), S1) The hexose sugar in the reaction mixture is reacted at a temperature in the range of 50 to 200°C, and the reaction mixture further contains acid, water and organic solvent. Remove water from the reaction mixture. This is the step in which hydroxymethylfurfural is formed, S2) By adjusting the pH of the reaction mixture in step S1) to a value in the range of 6 to 8, the reaction reaction in step S1) is substantially neutralized, or the acidic components present in the reaction mixture in step S1) are substantially neutralized. A substantially neutralized reaction mixture containing hydroxymethylfurfural is obtained, and S3) Step S1) Reaction mixture containing hydroxymethylfurfural, Or a mixture containing hydroxymethylfurfural derived from or obtained from the reaction mixture containing hydroxymethylfurfural in step S1), or Step S2) A substantially neutralized reaction mixture containing hydroxymethylfurfural, Alternatively, a mixture containing hydroxymethylfurfural derived from or obtained from the substantially neutralized reaction mixture containing hydroxymethylfurfural in step S2), In the presence of a ruthenium-containing catalyst (the ruthenium-containing catalyst is either ruthenium hydroxide oxide or ruthenium hydroxide oxide, preferably ruthenium III hydroxide oxide or ruthenium III hydroxide oxide), By subjecting it to hydrogenation consisting of a temperature in the range of 50 to 150°C and a hydrogen pressure in the range of 5 to 20 MPa, Steps to form 2,5-bis(hydroxymethyl)furan and / or 2,5-bis(hydroxymethyl)tetrahydrofuran A method including this is particularly preferred.

[0049] Furthermore, a method according to the present invention as defined herein (or a preferred method according to the present invention as described above or below, in particular a second variant of the present invention as defined above), in step S3), - Hydrogenation is carried out for a period of 8 to 24 hours, preferably 8 to 18 hours, more preferably 10 to 14 hours; and / or - The hydrogen pressure includes, or is within, a pressure in the range of 8 to 18 MPa, preferably 10 to 18 MPa, more preferably 12 to 16 MPa, for at least a portion of the entire period during which hydrogenation is carried out in step S3; and / or - The temperature is preferably within the range of 70 to 140°C, preferably 80 to 120°C, and more preferably 90 to 110°C, for at least a portion of the total period during which hydrogenation in step S3 is carried out (preferably for the entire period during step S3).

[0050] The reaction conditions defined above for temperature, hydrogen pressure, and hydrogenation time are applicable to all variations of the method according to the present invention, but when applied to a second variation of the method (i.e., when the ruthenium-containing catalyst contains or is ruthenium hydroxide oxide as defined above), each of the above-defined reaction conditions for temperature, hydrogen pressure, and hydrogenation time individually promotes the preferential production of 2,5-bis(hydroxymethyl)furan or an increase in the yield of 2,5-bis(hydroxymethyl)furan relative to the yield of 2,5-bis(hydroxymethyl)tetrahydrofuran. The effect of preferential production of 2,5-bis(hydroxymethyl)furan is even more pronounced when two or all of the above-defined reaction conditions for temperature, hydrogen pressure, and hydrogenation time are combined in a second variation of the method according to the present invention.

[0051] In step S3) of the second variant of the method according to the present invention, when ruthenium hydroxide oxide (synthesized by the method described in Example 1 of DE-OS 21 32 547, see above) was used as a ruthenium-containing catalyst, the inventors made the following unexpected discovery: As could have been predicted considering the findings published in DE-OS 21 32 547, the core of the starting compound (here: hydroxymethylfurfural) was not hydrogenated, but rather, particularly when N-methyl-2-pyrrolidone was used as the organic solvent in step S1) of the method according to the present invention, the side chain of hydroxymethylfurfural was hydrogenated with high selectivity.

[0052] Next, the method according to the present invention as defined herein (or the method according to the present invention as described above or below as a preferred method), the method is: S4) A method is also preferable that includes a further step of isolating 2,5-bis(hydroxymethyl)furan and / or 2,5-bis(hydroxymethyl)tetrahydrofuran from the reaction mixture obtained after step S3).

[0053] A further advantage of the method according to the present invention as described herein is that the furan-based bis-hydroxymethyl compound produced in step S3) of the method can be isolated and purified relatively easily, and the conditions applicable thereto are relatively mild, resulting in a high yield of the desirable furan-based bis-hydroxymethyl compound, which can be obtained in high purity.

[0054] Therefore, the methods according to the present invention as defined herein (or the methods according to the present invention as described above or below as preferred methods), in particular such methods including a further step S4) (as defined above), The isolation of 2,5-bis(hydroxymethyl)furan and / or 2,5-bis(hydroxymethyl)tetrahydrofuran includes isolation by distillation or evaporation. Preferably, the process includes a step of fractional distillation or fractional evaporation. Preferably, isolation by evaporation or isolation by fractional evaporation is a method that includes thin-film evaporation.

[0055] If the isolation of 2,5-bis(hydroxymethyl)furan and / or 2,5-bis(hydroxymethyl)tetrahydrofuran involves thin-film evaporation (a step), such thin-film evaporation is preferably carried out in two or more steps ("runs"), for example, two, three, or four steps, preferably in the first step (e.g., the first, second, and / or third steps) where organic solvents, particularly N-methyl-2-pyrrolidone, water, and other lightly volatile substances are separated or partially separated as "overhead," and in the final step (e.g., the second, third, or fourth steps) where 2,5-bis(hydroxymethyl)furan or 2,5-bis(hydroxymethyl)tetrahydrofuran are isolated, respectively. By carrying out thin-film evaporation in two or more steps ("runs"), for example, two, three, or four steps, it is possible to further improve the purity of the desired product, for example, 2,5-bis(hydroxymethyl)furan or 2,5-bis(hydroxymethyl)tetrahydrofuran.

[0056] Therefore, a further advantage of the method of the present invention described herein, in particular the advantage related to step S4) of the method, is that the organic solvent used in the method can be isolated and reused (at least partially, ideally to a very high degree), which further contributes to the sustainability of the method.

[0057] According to a first variant of the method according to the present invention, there is a preferred method according to the present invention as defined herein (or a preferred method according to the present invention as described above or below), which comprises a further step S4), wherein the catalyst used in step S3) comprises or is a ruthenium-supported carbon, and in step S4), 2,5-bis(hydroxymethyl)tetrahydrofuran is isolated or preferentially isolated.

[0058] According to a second variation of the method according to the present invention, there is a preferred method according to the present invention as defined herein (or a preferred method according to the present invention as described above or below), which comprises a further step S4), wherein the catalyst used in step S3) comprises or is a ruthenium hydroxide, preferably a ruthenium III hydroxide, and in steps S3) and S4), 2,5-bis(hydroxymethyl)furan is isolated.

[0059] The present invention also relates to a substantially neutralized reaction mixture containing hydroxymethylfurfural, which can be obtained, or may be obtained, by a method for producing furan-based bis-hydroxymethyl compounds from hydroxymethylfurfural according to the present invention as defined herein, preferably obtained in step S1) of the method according to the present invention as defined herein, or which may be obtained by or after step S1).

[0060] In general, all aspects of the present invention discussed herein in connection with a method for producing furan-based bis-hydroxymethyl compounds from hydroxymethylfurfural according to the present invention as defined herein are applied, with modifications where appropriate, to an essentially neutralized reaction mixture containing hydroxymethylfurfural obtained or obtainable by the method according to the present invention as defined herein, and vice versa.

[0061] Therefore, preferably, the essentially neutralized reaction mixture containing hydroxymethylfurfural obtained or obtainable by the method according to the present invention as defined herein has a pH in the range of 6 to 8, more preferably 6.5 to 7.5.

[0062] A substantially neutralized reaction mixture containing hydroxymethylfurfural according to the present invention as described herein (or preferably a substantially neutralized reaction mixture containing hydroxymethylfurfural according to the present invention as described herein), wherein the reaction mixture in step S1) of the method for producing a furan-based bis-hydroxymethyl compound from hydroxymethylfurfural according to the present invention as described herein (or each of the methods according to the present invention as preferred) further comprises, as an organic solvent, an organic solvent selected from the group consisting of N-alkyl-2-pyrrolidone, preferably N-methyl-2-pyrrolidone and N-ethyl-2-pyrrolidone; 2-pyrrolidone; N-methylsuccinimide, 1,3-dimethyl-2-imidazolidinone; dimethylformamide; N,N-dimethyllactamide; dimethylpropylene urea; and mixtures thereof. More preferably, the organic solvent is selected from the group consisting of N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N-methylsuccinimide, and mixtures thereof. More preferably, the organic solvent is a substantially neutralized reaction mixture containing hydroxymethylfurfural, which is N-methyl-2-pyrrolidone or N-methyl-2-pyrrolidone.

[0063] Preferably, the substantially neutralized reaction mixture containing hydroxymethylfurfural obtained or obtainable by the method according to the present invention as defined herein is typically characterized by containing, as a byproduct, one or more members of the group consisting of furfural, formic acid, acetic acid, levulinic acid, acetoxymethylfurfural, methoxymethylfurfural, and humins (including dimers of hydroxymethylfurfural, which are generally known to be humin precursors in the early stages of humin formation), the humins are not further specified.

[0064] Humins are typically produced as byproducts in the method for producing furan-based bis-hydroxymethyl compounds from hydroxymethylfurfural according to the present invention, but are also known to occur during the conversion of lignocellulosic biomass to smaller, more valuable organic compounds such as hydroxymethylfurfural (spontaneously or industrially). These humins can be in the form of either a viscous liquid or a solid, depending on the process conditions involved. The formation and chemical properties of humins are usually influenced by environmental or process conditions, so the structure of humins and the mechanisms by which they are synthesized are not currently well understood. A typical intermediate that may occur as a byproduct in the process of the method according to the present invention in the early stages of humin formation is the hydroxymethylfurfural dimer. Generally, humins have a polymeric furan-type structure with hydroxyl, aldehyde, and ketone functional groups. However, their structure depends on the type or concentration of the feedstock (e.g., fructose, xylose, or glucose), reaction time, temperature, catalyst, and many other parameters involved in the process.

[0065] Next, the present invention, as defined above in this specification, Or the substantially neutralized reaction mixture containing hydroxymethylfurfural obtained in or achievable by the method according to the present invention as defined herein, preferably obtained in step S1) of the method according to the present invention as defined herein, or obtainable by or after step S1), The present invention relates to the use of 2,5-bis(hydroxymethyl)furan and / or 2,5-bis(hydroxymethyl)tetrahydrofuran in hydrogenation methods.

[0066] In general, all aspects of the present invention discussed herein in relation to a method for producing furan-based bis-hydroxymethyl compounds from hydroxymethylfurfural according to the present invention as defined herein, and / or a substantially neutralized reaction mixture containing hydroxymethylfurfural obtained or obtainable by the method according to the present invention as defined herein, are applicable, with modifications where necessary, to the use of a substantially neutralized reaction mixture containing hydroxymethylfurfural obtained or obtainable by the method according to the present invention as defined herein, and vice versa.

[0067] Furthermore, the present invention relates to the use of ruthenium hydroxide, preferably ruthenium III hydroxide, as a hydrogenation catalyst in a method for hydrogenating hydroxymethylfurfural.

[0068] In general, all aspects of the present invention discussed herein in connection with the use of a method for producing furan-based bis-hydroxymethyl compounds from hydroxymethylfurfural according to the present invention as defined herein, and / or a substantially neutralized reaction mixture containing hydroxymethylfurfural obtained or obtainable by the method according to the present invention, and / or a substantially neutralized reaction mixture containing hydroxymethylfurfural obtained or obtainable by the method according to the present invention as defined herein, are applicable, with modifications where appropriate, to the use of ruthenium hydroxide, preferably ruthenium III hydroxide, as a hydrogenation catalyst in a method for hydrogenating hydroxymethylfurfural.

[0069] The use of ruthenium hydroxide, preferably ruthenium III hydroxide, as a hydrogenation catalyst in a method for hydrogenating hydroxymethylfurfural as defined herein, wherein the ruthenium hydroxide includes ruthenium hydroxide (catalyst) synthesized according to the preparation instructions of Example 1 of DE-OS 21 32 547, or is ruthenium hydroxide (catalyst), the use of ruthenium hydroxide, preferably ruthenium III hydroxide, is preferred. [Examples]

[0070] Examples The following embodiments are intended to further illustrate and illustrate the present invention without limiting its scope.

[0071] Unless otherwise indicated, in the following embodiments, the following terms have the meanings shown: Room temperature / RT: approx. 23℃ Standard pressure: Approximately 1013 hPa GC: Gas chromatography HPLC (High-Performance Liquid Chromatography) BHM-Furan: 2,5-Bis(hydroxymethyl)furan BHM-THF: 2,5-bis(hydroxymethyl)tetrahydrofuran

[0072] Example 1: Preparation of hydroxymethylfurfural by step S1) and optionally step S2) of the method described herein. Example 1.1: Sulfuric acid (95-98% concentration, 3.8 g) was added to N-methyl-2-pyrrolidone (2005 g) at room temperature with stirring (700 U / min) in an HWS glass container (technical glass container provided by HWS Labortechnik, Mainz, Germany), and the resulting mixture was heated to 150°C. Then, aqueous fructose syrup (1000 g; 67% w / v) was continuously weighed and added to the mixture over 135 minutes, while continuously distilling off water (a total of 446 g at the end of the reaction).

[0073] After the addition of fructose syrup was complete, the reaction mixture was stirred at a temperature of 140-150°C and standard pressure for 1 hour, and then cooled to below 60°C to obtain hydroxymethylfurfural (total 2550g, pH 3.0, yield: 79% hydroxymethylfurfural, measured by HPLC) in the resulting mixture.

[0074] Approximately 5 days after the completion of the reaction in Example 1.1, it was observed that hydroxymethylfurfural in the resulting reaction mixture gradually began to decompose and / or further reacted to form undesirable by-products.

[0075] Example 1.2: Sulfuric acid (95-98% concentration, 3.8 g) was added to N-methyl-2-pyrrolidone (2010 g) in an HWS glass container with stirring (800 U / min) at RT, and the resulting mixture was heated to 150°C. Then, aqueous fructose syrup (1000 g; 67% w / v) was continuously weighed and added to the mixture over 6 hours, while continuously removing water (a total of 474 g at the end of the reaction) by distillation.

[0076] After the addition of fructose syrup was complete, the reaction mixture was stirred at a temperature of 150-155°C and standard pressure for 1 hour, then cooled to below 60°C, and neutralized with aqueous sodium hydroxide solution (30 g, 10% w / v) (pH 7.1) to obtain hydroxymethylfurfural (total 2575 g, yield: 82% hydroxymethylfurfural, measured by HPLC) in the resulting mixture.

[0077] The hydroxymethylfurfural in the substantially neutralized reaction mixture obtained remained stable for more than 5 days after the completion of the reaction in Example 1.2, and no significant decomposition or further reactions producing undesirable by-products were observed during that period.

[0078] Example 1.3: Sulfuric acid (95-98% concentration, 0.4 g) was added to N-methyl-2-pyrrolidone (202 g) in a 500 mL round-bottom flask under RT (700 U / min) with stirring, and the resulting mixture was heated to 155°C. Then, aqueous fructose syrup (112 g; 67% w / v) was continuously weighed and added to the mixture over 90 minutes under reflux conditions (without distilling off the water), thereby lowering the temperature to 120°C.

[0079] After the addition of fructose syrup was complete, the reaction mixture was stirred at 120°C and standard pressure for 5 hours, then cooled to RT and neutralized with aqueous sodium hydroxide solution (3 g, 10% w / v) (pH 7.0) to obtain hydroxymethylfurfural (total 313 g, yield: 34% hydroxymethylfurfural, measured by HPLC) in the resulting mixture.

[0080] Example 1.4: 2,5-Franzicarboxylic acid (5.9 g) was added to N-methyl-2-pyrrolidone (2001 g) in an HWS glass container with stirring (800 U / min) at RT, and the reaction mixture was heated to 160°C. Then, aqueous fructose syrup (1001 g; 67% w / v) was continuously weighed and added to the mixture over 3.5 hours, while continuously removing water (a total of 457 g at the end of the reaction) by distillation.

[0081] After the addition of fructose syrup was complete, the reaction mixture was stirred at a temperature of 160-170°C and standard pressure for 1 hour, and then cooled to below 60°C to obtain hydroxymethylfurfural (total 2536g, pH 4.9, yield: 53% hydroxymethylfurfural, measured by HPLC) in the resulting mixture.

[0082] Example 1.5: Sodium dithionite (purity over 85%, 2.1 g) was added to N-methyl-2-pyrrolidone (2000 g) in an HWS glass container with stirring (800 U / min) under RT, and the reaction mixture was heated to 160°C. Then, aqueous fructose syrup (1000 g; 67% w / v) was continuously weighed and added to the mixture over 4 hours, while continuously removing water (totaling 453 g at the end of the reaction).

[0083] After the addition of fructose syrup was complete, the reaction mixture was stirred at a temperature of 160-170°C and standard pressure for 1 hour, and then cooled to below 60°C to obtain hydroxymethylfurfural (total 2515g, pH 7.0, yield: 9% hydroxymethylfurfural, measured by HPLC) in the resulting mixture.

[0084] Example 1.6: Sulfuric acid (95-98% concentration, 0.4 g) was added to N-methylsuccinimide (200 g) in a 500 mL round-bottom flask at 70°C with stirring (800 U / min), and the resulting mixture was heated to 160°C. Then, aqueous fructose syrup (100 g; 67% w / v) was continuously weighed and added to the mixture over 3 hours while continuously removing water (50 g) by distillation (8 mL / min).

[0085] After the addition of fructose syrup was complete, the reaction mixture was stirred at 160-170°C and standard pressure for 1 hour, then cooled to below 75°C, neutralized with aqueous sodium hydroxide solution (3 g, 10% w / v), and hydroxymethylfurfural (total 232 g, yield: 79% hydroxymethylfurfural, measured by HPLC) was obtained in the resulting mixture.

[0086] Example 1.7: Sulfuric acid (95-98% concentration, 0.4g) was added to toluene (200g) in an HWS glass container with stirring (800U / min) at RT, and the resulting mixture was heated to 100°C. Then, aqueous fructose syrup (95g; 67% w / v) was continuously weighed and added to the reaction mixture over 2 hours, while continuously removing water (a total of 474g at the end of the reaction) by distillation.

[0087] After the addition of fructose syrup was complete, the reaction mixture was stirred at 100-110°C and standard pressure for 1 hour, and then cooled to RT. The organic phase was washed once with saturated aqueous sodium bicarbonate solution to obtain hydroxymethylfurfural in the resulting mixture (total 132 g, yield: 0.1% hydroxymethylfurfural, measured by HPLC).

[0088] Examples 1.8 to 1.11 were carried out in the same manner as Example 1.2 described above, but there are differences as shown in Table 1 below.

[0089] Example 1.12 was carried out in the same manner as Example 1.6 above, but there are differences as shown in Table 1 below.

[0090] [Table 1]

[0091] From the above examples, it can be seen that removing water from the reaction mixture increases the yield of hydroxymethylfurfural (see Example 1.3 for comparison), sulfuric acid is a preferred acid to use in step S1) (see Examples 1.1-1.2, 1.6 and 1.9-1.11 for confirmation), and N-methyl-2-pyrrolidone and N-methylsuccinimide are particularly preferred organic solvents to use in step S1) (see Example 1.7 for comparison).

[0092] Furthermore, the following typical by-products were identified in the crude mixture obtained after step S2) or S3) (indicated in "weight %" of the total weight of the obtained crude mixture).

[0093] [Table 2]

[0094] Example 2: Preparation of 2,5-bis(hydroxymethyl)furan and / or 2,5-bis(hydroxymethyl)tetrahydrofuran by step S3) of the method described herein. Example 2.1: As obtained from the preparation of hydroxymethylfurfural by the method described in Example 1.2 above, ruthenium-supported carbon / PTFE (5% by weight, 1.0 g) was added to 100 g of a crude mixture containing N-methyl-2-pyrrolidone and hydroxymethylfurfural (14% by weight of hydroxymethylfurfural relative to the total mass of the crude mixture, measured by HPLC).

[0095] The resulting mixture was placed in an autoclave, purged twice with nitrogen gas (500 kPa), and then purged twice with hydrogen gas (500 kPa). The reaction mixture was stirred at an initial hydrogen gas pressure of 5 MPa (700 U / min), then heated to 120°C, the hydrogen pressure was increased to 15 MPa, and maintained at 15 MPa.

[0096] The reaction mixture was stirred under these conditions for 6 hours, then cooled to RT and purged with nitrogen gas (twice at 2 MPa). The heterogeneous ruthenium catalyst was then filtered off to obtain 2,5-bis(hydroxymethyl)tetrahydrofuran in the crude mixture (10.7% by weight per 100 g of crude mixture, yield: 73%; 2,5-bis(hydroxymethyl)tetrahydrofuran relative to the amount of hydroxymethylfurfural present in the crude starting mixture containing N-methyl-2-pyrrolidone and hydroxymethylfurfural, measured by HPLC).

[0097] Examples 2.2 to 2.3 were carried out in the same manner as Example 2.1 described above, but there are differences as shown in Table 2 below.

[0098] Example 2.4: As obtained from the preparation of hydroxymethylfurfural by the method described in Example 1.2 above, ruthenium-supported aluminum oxide (0.5% by weight, 5.0 g) was added to 100 g of a crude mixture containing N-methyl-2-pyrrolidone and hydroxymethylfurfural (14.5% by weight of hydroxymethylfurfural relative to the total mass of the crude mixture, measured by HPLC).

[0099] The resulting mixture was placed in an autoclave, purged twice with nitrogen gas (500 kPa), and then purged twice with hydrogen gas (500 kPa). The reaction mixture was stirred at an initial hydrogen gas pressure of 5 MPa (700 U / min), then heated to 100°C, the hydrogen pressure was increased to 15 MPa, and maintained at 15 MPa.

[0100] The reaction mixture was stirred under these conditions for 24 hours, then cooled to RT and purged with nitrogen gas (twice at 2 MPa). The heterogeneous ruthenium catalyst was then filtered off to obtain 2,5-bis(hydroxymethyl)furan in the crude mixture (10.0% by weight per 100 g of crude mixture, yield: 68%; 2,5-bis(hydroxymethyl)tetrahydrofuran relative to the amount of hydroxymethylfurfural present in the crude mixture containing N-methyl-2-pyrrolidone and hydroxymethylfurfural, measured by HPLC).

[0101] Example 2.5 was carried out in the same manner as Example 2.4, but there are differences as shown in Table 2 below.

[0102] [Table 3]

[0103] Example 3: Isolation of 2,5-bis(hydroxymethyl)furan and / or 2,5-bis(hydroxymethyl)tetrahydrofuran by step S4) of the method described herein. 841 g of a crude solution of 2,5-bis(hydroxymethyl)tetrahydrofuran (10.3% by weight according to GC measurement) in N-methyl-2-pyrrolidone (containing trace amounts of 2,5-bis(hydroxymethyl)furan, sodium sulfate, humic acid, and water), obtained through multiple preparations by a method corresponding to the method described in Example 2.3 above, was distilled in four separate runs using a thin-film evaporator under the following conditions.

[0104] [Table 4]

[0105] The recovered fractions were analyzed by GC and NMR to confirm their structure.

[0106] Distillation yielded a colorless sample of 2,5-bis(hydroxymethyl)tetrahydrofuran (84% by weight, 72 g, yield: 70%) containing only residual N-methyl-2-pyrrolidone (approximately 16% by weight). By-products from the previous reaction (humins, etc., derived from acidic cyclization or hydrogenation), water, and salts from neutralization were completely removed.

Claims

1. A method for producing furan-based bis-hydroxymethyl compounds from hydroxymethylfurfural, S1) The hexose sugar in the reaction mixture is reacted at a temperature in the range of 50 to 200°C, and the reaction mixture further contains an acid, water and an organic solvent. Remove water from the reaction mixture, This is the step in which hydroxymethylfurfural is formed, S2) Preferably, the reaction mixture from step S1) is substantially neutralized, or the acid component present in the reaction mixture from step S1) is substantially neutralized. A substantially neutralized reaction mixture containing hydroxymethylfurfural is obtained, step and, S3) The reaction mixture containing hydroxymethylfurfural in step S1), Or a mixture containing hydroxymethylfurfural derived from or obtained from the reaction mixture containing hydroxymethylfurfural in step S1), or Step S2) The substantially neutralized reaction mixture containing hydroxymethylfurfural, Alternatively, a mixture containing hydroxymethylfurfural derived from or obtained from the substantially neutralized reaction mixture containing hydroxymethylfurfural in step S2), By subjecting it to hydrogenation in the presence of a ruthenium-containing catalyst, at a temperature in the range of 50 to 150°C and a hydrogen pressure in the range of 5 to 20 MPa, Steps to form 2,5-bis(hydroxymethyl)furan and / or 2,5-bis(hydroxymethyl)tetrahydrofuran: Methods that include...

2. In step S1), - The hexose sugar is selected from the group consisting of D-glucose, D-fructose, D-saccharose, and mixtures thereof. Preferably, the hexose sugar contains or is D-fructose; and / or - The organic solvent is selected from the group consisting of N-alkyl-2-pyrrolidone, preferably from the group consisting of N-methyl-2-pyrrolidone and N-ethyl-2-pyrrolidone; 2-pyrrolidone; N-methylsuccinimide, 1,3-dimethyl-2-imidazolidinone; dimethylformamide; dimethyl sulfoxide; N,N-dimethyllactamide; dimethylpropylene urea and mixtures thereof. Preferably, the organic solvent is selected from the group consisting of N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N-methylsuccinimide, and mixtures thereof. More preferably, the organic solvent contains or is N-methyl-2-pyrrolidone; and / or - The acid is selected from the group consisting of sulfuric acid, hydrochloric acid, hydrobromic acid, methanesulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid, naphthalenesulfonic acid, camphorsulfonic acid, and mixtures thereof. Preferably, the acid contains or is sulfuric acid, according to claim 1.

3. S1) The hexose sugar in the reaction mixture is reacted at a temperature in the range of 50 to 200°C, and the reaction mixture is further... - An acid selected from the group consisting of sulfuric acid, hydrochloric acid, hydrobromic acid, methanesulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid, naphthalenesulfonic acid, camphorsulfonic acid, and mixtures thereof, Preferably, the acid contains or is sulfuric acid, - Water and, - An organic solvent selected from the group consisting of N-alkyl-2-pyrrolidone, preferably N-methyl-2-pyrrolidone and N-ethyl-2-pyrrolidone; 2-pyrrolidone; N-methylsuccinimide, 1,3-dimethyl-2-imidazolidinone; dimethylformamide; dimethyl sulfoxide; N,N-dimethyllactamide; dimethylpropylene urea and mixtures thereof, Preferably, the organic solvent is selected from the group consisting of N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N-methylsuccinimide, and mixtures thereof. More preferably, the organic solvent is an organic solvent containing or being N-methyl-2-pyrrolidone. Includes, Remove water from the reaction mixture, This is the step in which hydroxymethylfurfural is formed, S2) By adjusting the pH of the reaction mixture in step S1) to a value in the range of 6 to 8, the reaction reaction in step S1) is substantially neutralized, or the acidic component present in the reaction mixture in step S1) is substantially neutralized. A substantially neutralized reaction mixture containing hydroxymethylfurfural is obtained, and S3) The reaction mixture containing hydroxymethylfurfural in step S1), Or a mixture containing hydroxymethylfurfural derived from or obtained from the reaction mixture containing hydroxymethylfurfural in step S1), or Step S2) The substantially neutralized reaction mixture containing hydroxymethylfurfural, Alternatively, a mixture containing hydroxymethylfurfural derived from or obtained from the substantially neutralized reaction mixture containing hydroxymethylfurfural in step S2), By subjecting it to hydrogenation in the presence of a ruthenium-containing catalyst, at a temperature in the range of 50 to 150°C and a hydrogen pressure in the range of 5 to 20 MPa, Steps to form 2,5-bis(hydroxymethyl)furan and / or 2,5-bis(hydroxymethyl)tetrahydrofuran: The method according to claim 1 or 2, including the method described in claim 1 or 2.

4. In step S1), - Removal of water from the reaction mixture includes distilling off the water from the reaction mixture; and / or - The reaction is carried out for a period of 3 to 8 hours, preferably 4 to 7 hours; and / or - The method according to any one of claims 1 to 3, wherein the temperature includes a range of 60 to 190°C, preferably 80 to 180°C, more preferably 120 to 180°C, and even more preferably 140 to 180°C.

5. The above method includes step S2), preferably in step S2), - Step S1) By adding 0.8 to 1.2 molar equivalents of base relative to the molar amount of acid present in the reaction mixture at the start of step S1), the reaction reaction in step S1) is substantially neutralized, or the acid component present in the reaction mixture in step S1) is substantially neutralized. Preferably, the base is selected from the group consisting of alkali metal hydroxides, preferably aqueous alkali metal hydroxide solutions; alkaline earth metal hydroxides, preferably aqueous alkaline earth metal hydroxide solutions; and mixtures thereof. More preferably, the base is selected from the group consisting of sodium hydroxide, preferably an aqueous solution of sodium hydroxide; potassium hydroxide, preferably an aqueous solution of potassium hydroxide; and mixtures thereof; and / or - By adjusting the pH of the reaction mixture in step S1) to a value in the range of 6 to 8, preferably 6.5 to 7.5, and preferably by adding a base to the reaction mixture in step S1), the reaction reaction in step S1) is substantially neutralized. Preferably, the base includes or is selected from the group consisting of alkali metal hydroxides, preferably aqueous alkali metal hydroxide solutions; alkaline earth metal hydroxides, preferably aqueous alkaline earth metal hydroxide solutions; and mixtures thereof. The method according to any one of claims 1 to 4, more preferably, the base is selected from the group consisting of sodium hydroxide, preferably an aqueous solution of sodium hydroxide; potassium hydroxide, preferably an aqueous solution of potassium hydroxide; and mixtures thereof.

6. The method according to any one of claims 1 to 5, wherein in step S3), the temperature includes a temperature in the range of 60 to 150°C, preferably 60 to 140°C, and more preferably 70 to 130°C.

7. The method according to any one of claims 1 to 6, wherein in step S3), the catalyst containing ruthenium contains or is ruthenium-supported carbon.

8. In step S3), - The hydrogenation is carried out for a period of time ranging from 5 to 30 hours, preferably 5 to 28 hours, and more preferably 5 to 26 hours; and / or - The hydrogen pressure includes or is within the range of 6 to 18 MPa, preferably 6 to 16 MPa, more preferably 6 to 10 MPa; and / or - The concentration of hydroxymethylfurfural in the reaction mixture containing hydroxymethylfurfural in step S1) is 5% by weight or more, preferably 10% by weight or more, based on the total weight of the reaction mixture containing hydroxymethylfurfural in step S1), Alternatively, the concentration of hydroxymethylfurfural in the substantially neutralized reaction mixture containing hydroxymethylfurfural in step S2) is 5% by weight or more, preferably 10% by weight or more, based on the total weight of the substantially neutralized reaction mixture containing hydroxymethylfurfural in step S2); and / or - The concentration of hydroxymethylfurfural in the reaction mixture containing hydroxymethylfurfural in step S1) is in the range of 5% by weight or more and 25% by weight or less, more preferably 5% by weight or more and 20% by weight or less, and even more preferably 10% by weight or more and 20% by weight or less, based on the total weight of the reaction mixture containing hydroxymethylfurfural in step S1); Alternatively, the concentration of hydroxymethylfurfural in the substantially neutralized reaction mixture containing hydroxymethylfurfural in step S2) is in the range of 5% by weight or more and 25% by weight or less, more preferably 5% by weight or more and 20% by weight or less, and even more preferably 10% by weight or more and 20% by weight or less, based on the total weight of the substantially neutralized reaction mixture containing hydroxymethylfurfural in step S2); and / or The method according to claim 7, wherein the temperature includes a range of 60 to 140°C, preferably 70 to 130°C, and more preferably 70 to 90°C.

9. The method according to any one of claims 1 to 6, wherein in step S3), the catalyst containing ruthenium contains ruthenium hydroxide or ruthenium hydroxide, preferably ruthenium III hydroxide or ruthenium III hydroxide.

10. In step S3), - The hydrogenation is carried out for a period of time ranging from 8 to 24 hours, preferably 8 to 18 hours, and more preferably 10 to 14 hours. and / or - The hydrogen pressure includes or is within the range of 8 to 18 MPa, preferably 10 to 18 MPa, more preferably 12 to 16 MPa. and / or The method according to claim 9, wherein the temperature includes a temperature in the range of 70 to 140°C, preferably 80 to 120°C, and more preferably 90 to 110°C.

11. The aforementioned method, S4) A further step of isolating 2,5-bis(hydroxymethyl)furan and / or 2,5-bis(hydroxymethyl)tetrahydrofuran from the reaction mixture obtained after step S3) The method according to any one of claims 1 to 10, including the method described in any one of claims 1 to 10.

12. Isolating 2,5-bis(hydroxymethyl)furan and / or 2,5-bis(hydroxymethyl)tetrahydrofuran includes isolating by distillation or evaporation. Preferably, the process includes a step of fractional distillation or fractional evaporation. Preferably, the method according to claim 11, wherein isolation by evaporation or isolation by fractional evaporation includes thin-film evaporation.

13. The catalyst used in step S3) is - comprising or being ruthenium-supported carbon, step S3) is carried out as defined in claim 8, and in step S4) 2,5-bis(hydroxymethyl)tetrahydrofuran is isolated; or - The method according to claim 11 or 12, comprising or comprising ruthenium hydroxide oxide, preferably ruthenium III hydroxide oxide, wherein step S3) is carried out as defined in claim 10, and in step S4) 2,5-bis(hydroxymethyl)tetrahydrofuran is isolated.

14. A substantially neutralized reaction mixture comprising hydroxymethylfurfural obtained or obtainable in the method of any one of claims 1 to 5, preferably obtained in step S1) of the method of any one of claims 1 to 5, or obtainable by or after step S1), wherein the reaction mixture is a substantially neutralized reaction mixture having a pH in the range of 6 to 8.

15. In the method according to any one of claims 1 to 5, the reaction mixture in step S1) further comprises an organic solvent selected from the group consisting of N-alkyl-2-pyrrolidone, preferably N-methyl-2-pyrrolidone and N-ethyl-2-pyrrolidone; 2-pyrrolidone; N-methylsuccinimide, 1,3-dimethyl-2-imidazolidinone; dimethylformamide; dimethyl sulfoxide; N,N-dimethyllactamide; dimethylpropylene urea and mixtures thereof. More preferably, the organic solvent is selected from the group consisting of N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N-methylsuccinimide, and mixtures thereof. More preferably, the substantially neutralized reaction mixture according to claim 14, wherein the organic solvent contains or is N-methyl-2-pyrrolidone.

16. A substantially neutralized reaction mixture containing hydroxymethylfurfural, as described in claim 14 or 15, or by any one of claims 1 to 5, Use in a hydrogenation method for producing 2,5-bis(hydroxymethyl)furan and / or 2,5-bis(hydroxymethyl)tetrahydrofuran.

17. Use of ruthenium hydroxide, preferably ruthenium III hydroxide, as a hydrogenation catalyst in a method for hydrogenating hydroxymethylfurfural.

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