Method for the preparation of 2,5-furandicarboxaldehyde oxime by autocatalysis

Abstract

This application discloses a method for the autocatalytic preparation of 2,5-furandicarboxaldehyde oxime. The autocatalytic preparation method includes reacting 2,5-furandicarboxaldehyde with an oxime agent using an acid to produce 2,5-furandicarboxaldehyde oxime as a catalyst, and then continuing to react the remaining 2,5-furandicarboxaldehyde with the oxime agent under the influence of the catalyst to produce 2,5-furandicarboxaldehyde oxime. This application uses an acid-triggered reaction to complete the reaction process of 2,5-furandicarboxaldehyde oxime autocatalyzed, avoiding the use of excess alkaline auxiliary agents and reducing pollutant emissions. The conversion rate of 2,5-furandicarboxaldehyde reaches 100%, and the selectivity and yield of 2,5-furandicarboxaldehyde reach 99% or more. The reaction conditions are mild, the method is simple and easy to operate, and the production cost is low, making it suitable for industrial production.

Description

[Technical field]

[0001] The present application relates to a method for preparing 2,5-furandicarboxaldehyde oxime by autocatalysis, which belongs to the technical field of chemical synthesis. [Background technology]

[0002] Biomass, the only sustainable organic carbon resource, can be selectively converted into low molecular weight biomass-based compounds by biological or chemical methods, and then converted into high quality fuels and high value-added chemical products by chemical catalysis. This is an important method for biomass conversion and utilization. 5-Hydroxymethylfurfural (HMF) is a representative product of the important biomass platform, and is widely supplied as a bridge between basic biomass feedstocks and high value-added products. 5-Hydroxymethylfurfural can be converted into the important organic synthesis intermediate nitrogen-containing heterocyclic compound 2,5-furan dicarboxyaldehyde oxime (DFFD) by oxidation and nucleophilic substitution reactions. The oxime functional group can be easily converted into various functional groups, such as nitriles by dehydration, amides by acid-catalyzed Beckmann rearrangement, primary amines by hydrogenation, and nitrogen oxides by oxidation, which can be widely applied industrially in the preparation of functional polymer materials such as polyesters, polyurethanes, and polyamides. 2,5-Furandimide also has unique physiological and biochemical properties, and has excellent antibacterial, anti-inflammatory, anticancer and antiviral effects, and can be used in the synthesis of pharmaceutical intermediates. 2,5-Furandimide is an important ligand for metal complex formation.

[0003] The preparation of oximes by nucleophilic addition is a typical and mature technique, as reported in Patent Document 1, in which hydroxylamine hydrochloride is liberated from hydrochloric acid under alkaline conditions, followed by rapid nucleophilic substitution reaction between hydroxylamine and a carbonyl compound to produce the final oxime product. By using 2 equivalents of hydroxylamine hydrochloride and potassium acetate as an auxiliary and refluxing at 50°C for 1 hour, 2,5-furandicarboxaldehyde oxime can be obtained in 50% ethanol aqueous solution with 80% selectivity. Patent Document 2 also reports that 2,5-furandicarboxaldehyde oxime can be obtained in ethanol solvent at 50°C using 2 equivalents of hydroxylamine hydrochloride and potassium acetate as an auxiliary. Xu et al. (Non-Patent Document 1) prepared 2,5-furandicarboxaldehyde oxime with 95% selectivity by using 2.6 equivalents of hydroxylamine hydrochloride and sodium acetate as an auxiliary and refluxing at 110°C for 2 hours. This method has high selectivity for oximes, but requires the use of equivalent or excess chemical equivalents of hydroxylamine hydrochloride and alkaline auxiliary, and generates a large amount of inorganic salts as by-products during the reaction, which causes serious environmental pollution and increases processing costs.In addition, the reaction conditions are strict and the separation and purification processes are complicated, which greatly restricts industrial application. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2012 / 004069 [Patent Document 2] International Publication No. 2015 / 060827 [Non-patent literature]

[0005] [Non-Patent Document 1] YM Xu et al. ACS Sustainable Chem. Eng. 2018, 6, 3, 2888-2892 Summary of the Invention [Problem to be solved by the invention]

[0006] The main objective of the present application is to provide a method for the preparation of 2,5-furandicarboxaldehyde oxime by autocatalysis to overcome the shortcomings of the prior art. [Means for solving the problem]

[0007] In order to achieve the above object of the invention, the present application adopts the following technical means.

[0008] The present application provides a method for the preparation of 2,5-furandicarboxaldehyde oxime by autocatalysis, which comprises: Nji Carboxaldehyde and an oxime agent are reacted with an acid to produce 2,5-furandicarboxyaldehyde oxime as a catalyst, and the remaining 2,5-furandicarboxyaldehyde oxime is reacted with the acid to produce 2,5-furandicarboxyaldehyde oxime as a catalyst. Nji The method includes the step of continuing to react the carboxaldehyde with the oxime agent to produce 2,5-furandicarboxaldehyde oxime.

[0009] In some embodiments, the autocatalytic process for preparing 2,5-furandicarboxaldehyde oxime comprises the steps of: 2,5-Fura Nji providing a liquid phase reaction system including a carboxaldehyde and an oxime agent; Add an acid to the liquid phase reaction system to form 2,5-fura Nji Carboxaldehyde is reacted with an oxime agent to produce 2,5-furandicarboxyaldehyde oxime as a catalyst, and the remaining 2,5-furandicarboxyaldehyde oxime is reacted with an oxime agent as a catalyst. Nji and continuing to react the carboxaldehyde with the oxime agent.

[0010] Furthermore, in the method, after an acid is added to the liquid phase reaction system, the pH value of the liquid phase reaction system is 1.0 to 7.0.

[0011] In another embodiment, the autocatalytic process for preparing 2,5-furandicarboxaldehyde oxime comprises the steps of: 2,5-Fura Nji Providing a mixture comprising a carboxaldehyde and an acid; The oxime agent was added to the mixture several times, and the 2,5-furanium oxide was produced by using the acid as a trigger. Nji Carboxaldehyde is reacted with an oxime agent to produce 2,5-furandicarboxyaldehyde oxime as a catalyst, and the remaining 2,5-furandicarboxyaldehyde oxime is reacted with an oxime agent as a catalyst. Nji and continuing to react the carboxaldehyde with the oxime agent.

[0012] In some embodiments, the acid includes, but is not limited to, an inorganic acid, an organic acid, and the like. Effect of the Invention

[0013] Compared with the prior art, the present application has at least the following beneficial effects:

[0014] 1) The method for preparing 2,5-furandicarboxyaldehyde oxime by autocatalysis provided in this application uses acid as a trigger to react, and 2,5-furandicarboxyaldehyde oxime completes the reaction process by autocatalysis. This method avoids excessive alkaline auxiliary, reduces the emission of pollutants, has low production costs, and has no "wastewater, exhaust gas, or fixed waste" during the entire reaction, which is environmentally friendly, simple to operate, safe and reliable.

[0015] 2) The autocatalytic 2,5-furanium complex provided in the present application Nji The method for preparing carboxaldehyde dioxime is to obtain 2,5-furamidinoside with high selectivity and high yield under mild temperature conditions (below 90°C) in a relatively short time (60 min). Nji Carboxaldehyde dioxime is obtained, and 2,5-fura Nji The conversion rate of carboxaldehyde reaches 100%, and the selectivity and yield of 2,5-furandicarboxaldehyde oxime reach more than 99%.

[0016] 3) The autocatalytic 2,5-furanium complexes provided herein Nji In the preparation method of carboxaldehyde dioxime, 2,5-furandicarboxyaldehyde oxime is insoluble in water, so that 2,5-furandicarboxyaldehyde oxime is easy to separate from the reaction system, and the purity can reach more than 99.5%, which can improve the quality of the product.

[0017] 4) The autocatalytic 2,5-furanium complexes provided herein Nji In the preparation method of carboxaldehyde dioxime, under the premise that the selectivity of 2,5-furan dicarboxyaldehyde oxime is ensured, hydroxylamine aqueous solution is added multiple times to completely convert hydroxylamine, thereby improving the raw material utilization rate of hydroxylamine and enhancing the reaction safety.

[0018] 5) The present application does not require the addition of other catalysts and auxiliary agents, does not generate harmful waste, has mild reaction conditions, can be carried out at room temperature and atmospheric pressure, and the complete reaction takes only 1-60 minutes. The reaction product is filtered to obtain a precipitate, and the precipitate is washed and dried to obtain the target product, 2,5-furandicarboxaldehyde oxime, with high reaction efficiency, simple method and easy operation, low production cost, and suitable for industrial production. [Brief description of the drawings]

[0019] In order to more clearly describe the technical means in the embodiments of the present application or the prior art, the drawings that need to be used in the description of the embodiments or the prior art will be briefly described below. Obviously, the drawings described below are only some embodiments of the present application, and those skilled in the art can obtain other drawings based on these drawings without creative labor.

[0020] [Figure 1] 1 is a mass spectrogram of 2,5-furandicarboxaldehyde oxime prepared in Example 1 of the present application. [Diagram 2] 1 is a high performance liquid chromatogram of 2,5-furan dicarboxyaldehyde oxime prepared in Example 1 of the present application. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] The autocatalytic process is a catalytic process in which the reaction product contributes to the reaction rate, and has the advantages of automatic continuous reaction, high reaction activity, fast reaction rate, easy product treatment, etc. There have been no reports of the autocatalytic reaction of 2,5-furandicarboxaldehyde oxime using an aqueous hydroxylamine solution as an oxime agent and adjusting the reaction system to an appropriate pH value with an acid.

[0022] In view of the above-mentioned shortcomings of the prior art, the present inventor, after years of research and a great deal of practice, proposes the technical means of the present application, which provides a method for preparing 2,5-furandicarboxaldehyde oxime by autocatalysis, the method comprising: Nji Carboxaldehyde is used as raw material, hydroxylamine aqueous solution is used as oxime agent, acid is added to adjust the pH value of the reaction system to produce 2,5-furandicarboxyaldehyde oxime, and the autocatalytic reaction process is completed. This method avoids excess alkaline auxiliary, can be carried out at room temperature and atmospheric pressure, and the complete reaction takes only 1-60 minutes. The reaction product is filtered to obtain a precipitate, and the precipitate is washed and dried to obtain the target product 2,5-furandicarboxyaldehyde oxime, with a selectivity of 2,5-furandicarboxyaldehyde oxime >99% and a purity of >99.5%.

[0023] The autocatalytic reaction mechanism of the autocatalytic preparation method of 2,5-furandicarboxaldehyde oxime of the present application is as follows: Nji The unique electron-absorption conjugation effect of the carbon atom on the furan ring of carboxaldehyde allows the formation of 2,5-furan Nji Carboxaldehyde readily undergoes dehydration to give 2,5-furanium. Nji Carboxaldehyde monoxime is formed, followed by 2,5-fura Nji The oxime hydroxyl group of carboxaldehyde monoxime undergoes a proton transfer reaction, which then gives 2,5-furanium Nji Carboxaldehyde monoxime is catalyzed to continuously produce 2,5-furandicarboxyaldehyde oxime.

[0024] The technical means, its implementation process and principle etc. are further explained and interpreted as follows.

[0025] One aspect of the present application provides a method for the autocatalytic preparation of 2,5-furandicarboxyaldehyde oxime, which comprises: Nji Carboxaldehyde and an oxime agent are reacted with an acid to produce 2,5-furandicarboxyaldehyde oxime as a catalyst, and the remaining 2,5-furandicarboxyaldehyde oxime is reacted with the acid to produce 2,5-furandicarboxyaldehyde oxime as a catalyst. Nji The method includes the step of continuing to react the carboxaldehyde with the oxime agent to produce 2,5-furandicarboxaldehyde oxime.

[0026] In some embodiments, the autocatalytic process for preparing 2,5-furandicarboxaldehyde oxime comprises the steps of: 2,5-Fura Nji providing a liquid phase reaction system including a carboxaldehyde and an oxime agent; Add an acid to the liquid phase reaction system to form 2,5-fura Nji Carboxaldehyde is reacted with an oxime agent to produce 2,5-furandicarboxyaldehyde oxime as a catalyst, and the remaining 2,5-furandicarboxyaldehyde oxime is reacted with an oxime agent as a catalyst. Nji and continuing to react the carboxaldehyde with the oxime agent.

[0027] In some embodiments, the liquid phase reaction system comprises 2,5-furan Nji Contains a carboxaldehyde, an oxime agent and a polar solvent.

[0028] In some embodiments, the oxime agent and the 2,5-fura Nji The molar ratio of carboxaldehyde is 2-10:1.

[0029] The autocatalytic method for preparing 2,5-furandicarboxyaldehyde oxime provided in the present application is Nji Carboxaldehyde, a polar solvent, an acid and an oxime agent can be mixed and reacted by autocatalysis to give 2,5-furandicarboxaldehyde oxime.

[0030] Specifically, the present application realizes the autocatalytic preparation of 2,5-furan dicarboxyaldehyde oxime through the following technical means, and Nji Carboxaldehyde, an oxime agent, is added to a polar solvent, and acid is added to adjust the pH value of the solution, and the self-catalytic effect of 2,5-furandicarboxyaldehyde oxime leads to the formation of 2,5-furandicarboxyaldehyde. Nji The carboxaldehyde is catalytically dehydrated to prepare 2,5-furandicarboxyaldehyde oxime, which is then filtered, washed and dried to obtain 2,5-furandicarboxyaldehyde oxime.

[0031] Furthermore, the preparation method at least includes adding an acid to adjust the initial pH value of the solution and preparing 2,5-furanium. Nji Carboxaldehyde and oxime agent are reacted in a polar solvent to produce 2,5-furandicarboxyaldehyde oxime, and the autocatalytic reaction process is completed. After the reaction is completed, the mixture is naturally cooled to room temperature, filtered, washed and dried to obtain the desired product, 2,5-furandicarboxyaldehyde oxime.

[0032] In some embodiments, in the method for preparing 2,5-furandicarboxaldehyde oxime through autocatalysis, after adding an acid into the liquid phase reaction system, the pH value of the liquid phase reaction system is 1.0-7.0.

[0033] Furthermore, the method includes adjusting the initial pH value of the liquid phase reaction system to between 3.0 and 4.0 with an acid. In the present application, a pH value between 3.0 and 4.0 promotes the attack of the nucleophilic reagent hydroxylamine on the carbonyl group, thereby increasing the reaction rate.

[0034] In some embodiments, after adding an acid to the liquid phase reaction system, the mass % of the acid in the formed mixed reaction product is 0.01 to 2.0 wt%, preferably 0.05 to 2.0 wt%, more preferably 0.05 to 0.5 wt%, and particularly preferably 0.1 to 0.5 wt%.

[0035] In some more preferred embodiments, the autocatalytic process for preparing 2,5-furandicarboxaldehyde oxime comprises the steps of: 2,5-Fura Nji Providing a mixture comprising a carboxaldehyde and an acid; The oxime agent was added to the mixture several times, and the 2,5-furanium oxide was produced by using the acid as a trigger. Nji Carboxaldehyde is reacted with an oxime agent to produce 2,5-furandicarboxyaldehyde oxime as a catalyst, and the remaining 2,5-furandicarboxyaldehyde oxime is reacted with an oxime agent as a catalyst. Nji and continuing to react the carboxaldehyde with the oxime agent.

[0036] In some embodiments, the mixture comprises 2,5-furanium. Nji Contains a carboxaldehyde, an acid and a polar solvent.

[0037] The method further includes preparing the oxime agent as an aqueous solution of the oxime agent and adding the aqueous solution of the oxime agent to the mixture in portions.

[0038] In some embodiments, the acid includes, but is not limited to, an inorganic acid, an organic acid, and the like.

[0039] Further, the inorganic acid includes, but is not limited to, any one or a combination of two or more of hydrochloric acid, sulfuric acid, phosphoric acid, nitric acid, and sulfurous acid.

[0040] Moreover, the inorganic acid is preferably selected from hydrochloric acid, sulfuric acid, and the like, but is not limited thereto.

[0041] Further, the organic acid may include, but is not limited to, any one or a combination of two or more of formic acid, acetic acid, lactic acid, propionic acid, butyric acid, hexanoic acid, succinic acid, citric acid, benzoic acid, oxalic acid, methylsulfonic acid, and methanesulfonic acid.

[0042] Moreover, the inorganic acid is preferably selected from acetic acid, oxalic acid, and the like, but is not limited thereto.

[0043] In some embodiments, the oxime agent is a hydroxylamine and the aqueous oxime agent solution is an aqueous hydroxylamine solution.

[0044] Furthermore, the concentration of the aqueous hydroxylamine solution is 15 to 85 wt %, and preferably 50 wt %.

[0045] In some embodiments, the aqueous hydroxylamine solution and 2,5-furafuryl Nji The mass ratio of carboxaldehyde is 1-5:1.

[0046] In some embodiments, the polar solvent includes, but is not limited to, any one or combination of two or more of water, dimethylsulfoxide, ethylene glycol, dimethylformamide, acetonitrile, methanol, ethanol, isopropanol, etc., or a mixture of water and a polar organic solvent.

[0047] Furthermore, the polar solvent is water, but is not limited thereto.

[0048] In some embodiments, the polar solvent and 2,5-furan Nji The mass ratio of carboxaldehyde is 5 to 35:1.

[0049] Furthermore, the polar solvent and 2,5-fura Nji The mass ratio of carboxaldehyde is preferably 10 to 20:1.

[0050] In some embodiments, the reaction conditions for the reaction include a reaction temperature of 0° C. to 90° C., a reaction time of 1 to 60 min, and a reaction pressure of atmospheric pressure.

[0051] Specifically, it is preferred that the upper limit of the reaction temperature is selected from 50°C, 45°C, 30°C, or 25°C, and the lower limit is selected from 5°C, 10°C, 15°C, or 25°C.

[0052] Specifically, it is preferred that the upper limit of the reaction time is selected from 60 min, 50 min, 40 min, or 30 min, and the lower limit is selected from 5 min, 10 min, 15 min, or 20 min.

[0053] Furthermore, it is preferable that the reaction temperature is 15° C. to 30° C., the reaction time is 5 to 30 minutes, and the reaction pressure is atmospheric pressure.

[0054] Further, the method includes the step of: Nji Carboxaldehyde is added to water, the initial pH value of the solution is adjusted by acid, and hydroxylamine aqueous solution is added multiple times. After the reaction is completed, the target product 2,5-furandicarboxaldehyde oxime is obtained by filtering, washing and drying. In this application, since hydroxylamine is easily decomposed when heated, the concentration of hydroxylamine in the system is controlled by adding hydroxylamine aqueous solution multiple times in order to improve the stability and safety of hydroxylamine.

[0055] Further, the method includes adding the aqueous oxime agent solution (ie, the aqueous hydroxylamine solution) to the mixture at least 4 to 8 times.

[0056] Furthermore, the hydroxylamine aqueous solution and 2,5-fura Nji The mass ratio of carboxaldehyde is 0.25 to 0.5:1.

[0057] Here, as a more specific embodiment, the method for preparing 2,5-furandicarboxyaldehyde oxime by autocatalysis comprises: NjiAdd carboxaldehyde, polar solvent and hydroxylamine aqueous solution, heat to 0-90℃, add acid to adjust pH value to an appropriate range, trigger the reaction, react for 1-60min, then naturally cool to room temperature to obtain the reaction product, which is filtered, washed and dried to obtain the target product, 2,5-furandicarboxaldehyde oxime, which is a white powder solid, and the reaction formula is as follows: [ka] Here, the hydroxylamine is derived from an aqueous hydroxylamine solution.

[0058] Here, the polar solvent is water, dimethylsulfoxide, ethylene glycol, dimethylformamide, acetonitrile, methanol, ethanol, isopropanol, or the like, or a mixed solvent of water and an organic solvent.

[0059] Here, the acid is an inorganic acid or an organic acid.

[0060] Here, the mass % of the acid in the entire reaction system is 0.01 to 2.0 wt%, preferably 0.05 to 2.0 wt%, more preferably 0.05 to 0.5 wt%, and particularly preferably 0.1 to 0.5 wt%.

[0061] Here, the pH value is controlled by the acid to a range of 1.0 to 7.0, preferably 3.0 to 4.0.

[0062] As described above, the autocatalytic preparation method of 2,5-furandicarboxaldehyde oxime provided in this application uses the generated 2,5-furandicarboxaldehyde oxime as a catalyst to complete the autocatalytic reaction process under mild conditions, improves the reaction efficiency and selectivity of 2,5-furandicarboxaldehyde oxime, obtains high-purity 2,5-furandicarboxaldehyde oxime, and has no "wastewater, exhaust, or solid waste" during the entire reaction, which is environmentally friendly, simple to operate, safe and reliable. This application does not need to add other catalysts and auxiliary agents, does not generate harmful waste, has mild reaction conditions, high reaction efficiency, simple method and easy operation, low production cost, and is suitable for industrial production.

[0063] In order to clarify the purpose, technical means and advantages of the present application, the present invention will be further described below with reference to specific embodiments and drawings. Note that the specific examples described herein are used only for the purpose of interpreting the present application, and the experimental conditions and setting parameters therein are not to be understood as limitations on the basic technical means of the present application. The scope of protection of the present application is not limited to the following examples. In addition, the technical features of each embodiment of the present application described below can be combined with each other as long as they are not contradictory.

[0064] Unless otherwise stated, all materials and reagents in the examples of this application are commercially available.

[0065] The analytical methods used in the examples of this application are as follows.

[0066] The concentration of the product was analyzed by high performance liquid chromatography (HPLC), the model is Agilent1260.

[0067] The conversion rates and selectivities in the examples of this application are calculated as follows.

[0068] In the examples of the present application, 2,5-fura Nji Both the conversion of carboxaldehyde and the selectivity of 2,5-furandicarboxaldehyde oxime are calculated based on the number of moles of carbon.

[0069] 2,5-Fura Nji Carboxaldehyde conversion rate = (1 - remaining 2,5-fura Nji Carboxaldehyde moles / initial 2,5-fura Nji (moles of carboxaldehyde) x 100% 2,5-Furandimethane carboxyaldehyde oxime selectivity = (moles of 2,5-furandicarboxyaldehyde oxime produced / moles of 2,5-furandicarboxyaldehyde oxime produced) Nji (moles of carboxaldehyde converted) x 100%

[0070] Example 1 1mmol of 2,5-fura Nji Mix 2mL of water and 4.0mmol of 50wt.% hydroxylamine aqueous solution evenly, heat to 30℃, add 0.1wt.% dilute hydrochloric acid, adjust the pH of the reaction system to 3.0, keep warm and react for 5min, after the reaction is completed, naturally cool to room temperature, filter the reaction product to obtain precipitate, wash the precipitate with deionized water and dry at 100℃ to obtain the target product, 2,5-furandicarboxyaldehyde oxime, which is a white powder solid, and the test shows that the selectivity of the product is 99.6% and the purity is 99.8%.

[0071] Example 2 2mmol of 2,5-fura Nji Mix carboxaldehyde, 3mL ethanol and 6mmol of 70wt.% hydroxylamine aqueous solution uniformly, then add 0.5wt.% dilute sulfuric acid, adjust the pH of the reaction system to 4.0, react at room temperature (25℃) for 1min, after the reaction is completed, naturally cool to room temperature, filter the reaction product to obtain precipitate, wash the precipitate with deionized water and dry at 100℃ to obtain the target product, 2,5-furandicarboxyaldehyde oxime, which is a white powder solid, and the test shows that the selectivity of the product is 99.5% and the purity is 99.7%.

[0072] Example 3 4mmol of 2,5-fura NjiMix carboxaldehyde, 14mL dimethylformamide and 40mmol of 15wt.% hydroxylamine aqueous solution uniformly, heat to 90℃, then add 0.01wt.% phosphoric acid, adjust the pH of the reaction system to 5.0, keep warm and react for 30min, after the reaction is completed, naturally cool to room temperature, distill the reaction product under reduced pressure, wash the precipitate with deionized water and dry at 100℃ to obtain the target product 2,5-furandicarboxaldehyde oxime as white powder solid, test shows that the selectivity of the product is 99.2% and the purity is 99.6%.

[0073] Example 4 8mmol of 2,5-fura Nji Mix 20mL of carboxaldehyde, 18mL of mixed solvent of water and 16mmol of 85wt.% hydroxylamine aqueous solution uniformly, react in ice bath (0℃), add 0.05wt.% acetic acid, adjust pH of reaction system to 3.5, react for 60min, cool naturally to room temperature after reaction is completed, filter reaction product to obtain precipitate, wash precipitate with deionized water and dry at 100℃ to obtain target product 2,5-furandicarboxaldehyde oxime, test shows selectivity of product is 99.4% and purity is 99.8%.

[0074] Example 5 20mmol of 2,5-fura Nji Mix carboxaldehyde, 44mL dimethyl sulfoxide and 100mmol of 35wt.% hydroxylamine aqueous solution uniformly, heat to 45℃, add 1.0wt.% oxalic acid, adjust the pH of the reaction system to 6.0, react for 10min, naturally cool to room temperature after the reaction is completed, filter the reaction product to obtain precipitate, wash the precipitate with deionized water and dry at 100℃ to obtain the target product 2,5-furandicarboxyaldehyde oxime, test shows that the selectivity of the product is 99.2% and the purity is 99.5%.

[0075] Example 6 40mmol of 2,5-fura NjiMix carboxyaldehyde, 80mL isopropanol and 240mmol of 20wt.% hydroxylamine aqueous solution uniformly, heat to 60℃, add 2.0wt.% citric acid, adjust pH of reaction system to 7.0, react for 15min, cool to room temperature after reaction is completed, filter reaction product to obtain precipitate, wash precipitate with deionized water and dry at 100℃ to obtain target product 2,5-furandicarboxyaldehyde oxime, test shows selectivity of product is 99.1%, purity is 99.6%.

[0076] Example 7 80mmol of 2,5-fura Nji Mix carboxaldehyde and 80mL water evenly, heat to 30℃, then add 1.5wt.% sulfurous acid, adjust the pH of the reaction system to 1.0, add 50wt.% hydroxylamine aqueous solution 4 times, add 160mmol of 50wt.% hydroxylamine aqueous solution each time, react for 20min, naturally cool to room temperature after the reaction is completed, filter the reaction product to obtain precipitate, wash the precipitate with deionized water and dry at 100℃ to obtain the target product 2,5-furandicarboxaldehyde oxime, test shows that the selectivity of the product is 99.2% and the purity is 99.3%.

[0077] Example 8 160mmol of 2,5-fura Nji Mix carboxaldehyde and 100mL water evenly, heat to 15℃, then add 0.3wt.% propionic acid, adjust pH value of reaction system to 2.0, add 50wt.% hydroxylamine aqueous solution 8 times, add 50mmol of 50wt.% hydroxylamine aqueous solution each time, react for 40min, naturally cool to room temperature after reaction is completed, filter reaction product to obtain precipitate, wash precipitate with deionized water and dry at 100℃ to obtain target product 2,5-furandicarboxaldehyde oxime, test shows that product selectivity is 99.0% and purity is 99.2%.

[0078] The mass spectrograms of the products 2,5-furandicarboxyaldehyde oxime prepared in Examples 1 to 8 above are shown in FIG. 1, and the high performance liquid chromatograms are shown in FIG.

[0079] Comparative Example 1 1mmol of 2,5-fura Nji Mix 2mL of water and 4.0mmol of 50wt.% hydroxylamine aqueous solution evenly, heat to 30℃, adjust pH of reaction system to 8.0, keep warm and react for 5min, naturally cool to room temperature after reaction is completed, filter reaction product to obtain precipitate, wash precipitate with deionized water and dry at 100℃ to obtain white powder solid, which is the target product 2,5-furandicarboxyaldehyde oxime, test shows that the selectivity of the product is 20% and the purity is 15%.

[0080] Comparative Example 2 2mmol of 2,5-fura Nji Mix carboxaldehyde, 3mL ethanol and 6mmol hydroxylamine hydrochloride homogeneously, then add 20wt.% sodium acetate, adjust the pH of the reaction system to 4.0, react at room temperature (25℃) for 10min, naturally cool to room temperature after the reaction is completed, filter the reaction product to obtain a precipitate, wash the precipitate with deionized water and dry at 100℃ to obtain the desired product, 2,5-furandicarboxaldehyde oxime, which is a white powder solid, and the test shows that the selectivity of the product is 96% and the purity is 85%.

[0081] According to the above technical means, the present application provides an autocatalytic 2,5-fura Nji The preparation method of carboxaldehyde dioxime is a highly selective and high yield method for 2,5-furanosides under mild temperature conditions (below 90°C) in a short time (60 min). Nji Carboxaldehyde dioxime is obtained, and 2,5-fura Nji The conversion rate of carboxaldehyde reaches 100%, and the selectivity and yield of 2,5-furandicarboxaldehyde oxime reach more than 99%.

[0082] All aspects, embodiments, features, and examples of the present application are exemplary and are not intended to limit the present application, the scope of which is defined by the claims. Other embodiments, modifications, and applications will be apparent to those skilled in the art without departing from the spirit and scope of the present application.

[0083] The headings and sections of this application are not limiting of the application and each section may apply to any aspect, embodiment, or feature of the application.

[0084] Throughout this application, when a composition has / contains / includes a particular component or a process has / contains / includes a particular step, it is understood that the composition taught by this application also consists essentially of or consists of that component and that the process taught by this application also consists essentially of or consists of that step.

[0085] Unless otherwise specified, the terms "include," "includes," "including," "have," "has," or "having" are to be understood as open ended and not limiting.

[0086] It should be understood that the order of steps or order of performance of certain actions is not required so long as the teachings of the present application remain operable, and two or more steps or actions may be performed simultaneously.

[0087] In addition, the present inventors have conducted tests using other raw materials, process operations, and process conditions described in this specification with reference to the embodiments of Examples 1 to 8 above, and have similarly obtained 2,5-furandicarboxyaldehyde oxime with high selectivity.

[0088] Although the present application has been described with reference to exemplary embodiments, those skilled in the art may make various other changes, omissions and / or additions without departing from the spirit and scope of the present application, and may substitute equivalents for the devices of the embodiments. Various modifications may also be made to adapt a particular situation to the teachings of the present application without departing from the scope of the present application. Accordingly, the present application is not limited to such specific embodiments, and the present application is intended to include all embodiments within the scope of the appended claims. Furthermore, unless otherwise specified, the terms first, second, etc. do not denote any order or importance, and the terms first, second, etc. are used to distinguish one element from another.

[0089] [Note] [Appendix 1] 2,5-Fura Nji Carboxaldehyde and an oxime agent are reacted with an acid to produce 2,5-furandicarboxyaldehyde oxime as a catalyst, and the remaining 2,5-furandicarboxyaldehyde oxime is reacted with the acid to produce 2,5-furandicarboxyaldehyde oxime as a catalyst. Nji 1. A method for the autocatalytic preparation of 2,5-furandicarboxaldehyde oxime, comprising the step of continuously reacting a carboxaldehyde with an oxime agent to produce 2,5-furandicarboxaldehyde oxime.

[0090] [Appendix 2] 2,5-Fura Nji providing a liquid phase reaction system including a carboxaldehyde and an oxime agent; Add an acid to the liquid phase reaction system to form 2,5-fura Nji Carboxaldehyde is reacted with an oxime agent to produce 2,5-furandicarboxyaldehyde oxime as a catalyst, and the remaining 2,5-furandicarboxyaldehyde oxime is reacted with an oxime agent as a catalyst. Nji and continuing to react the carboxaldehyde with the oxime agent.

[0091] [Appendix 3] The liquid phase reaction system is 2,5-fura NjiThe present invention relates to a method for producing a carboxyaldehyde-based oxime-based ester, comprising the steps of: Nji The method for preparing 2,5-furandicarboxaldehyde oxime by autocatalysis according to appendix 2, characterized in that the molar ratio of carboxaldehyde is 2-10:1.

[0092] [Appendix 4] After adding an acid into the liquid phase reaction system, the pH value of the liquid phase reaction system is 1.0 to 7.0, preferably 3.0 to 4.0; And / or, the method for preparing 2,5-furandicarboxyaldehyde oxime by autocatalysis described in Appendix 2, characterized in that after adding an acid to the liquid phase reaction system, the mass percentage of the acid in the formed mixed reaction product is 0.01 to 2.0 wt%, preferably 0.05 to 2.0 wt%, more preferably 0.05 to 0.5 wt%, and particularly preferably 0.1 to 0.5 wt%.

[0093] [Appendix 5] 2,5-Fura Nji Providing a mixture comprising a carboxaldehyde and an acid; The oxime agent was added to the mixture several times, and the 2,5-furanium oxide was produced by using the acid as a trigger. Nji Carboxaldehyde is reacted with an oxime agent to produce 2,5-furandicarboxyaldehyde oxime as a catalyst, and the remaining 2,5-furandicarboxyaldehyde oxime is reacted with an oxime agent as a catalyst. Nji and continuing to react the carboxaldehyde with the oxime agent.

[0094] [Appendix 6] The mixture is 2,5-furan Nji 6. The method for preparing 2,5-furandicarboxaldehyde oxime by autocatalysis as described in claim 5, comprising a carboxaldehyde, an acid and a polar solvent, and / or the method comprises preparing an oxime agent as an aqueous oxime agent solution and adding the aqueous oxime agent solution to the mixture multiple times.

[0095] [Appendix 7] The method for preparing 2,5-furandicarboxaldehyde oxime by autocatalysis described in Appendix 1, characterized in that the acid includes an inorganic acid and / or an organic acid, preferably the inorganic acid is any one or a combination of two or more of hydrochloric acid, sulfuric acid, phosphoric acid, nitric acid, and sulfurous acid, particularly preferably hydrochloric acid and / or sulfuric acid, and preferably the organic acid is any one or a combination of two or more of formic acid, acetic acid, lactic acid, propionic acid, butyric acid, hexanoic acid, succinic acid, citric acid, benzoic acid, oxalic acid, methylsulfonic acid, and methanesulfonic acid, particularly preferably acetic acid and / or oxalic acid.

[0096] [Appendix 8] The method for preparing 2,5-furandicarboxaldehyde oxime by autocatalysis according to claim 6, characterized in that the oxime agent is hydroxylamine, the aqueous oxime agent solution is an aqueous hydroxylamine solution, and preferably, the concentration of the aqueous hydroxylamine solution is 15-85 wt%.

[0097] [Appendix 9] The polar solvent is any one or a combination of two or more of water, dimethyl sulfoxide, ethylene glycol, dimethylformamide, acetonitrile, methanol, ethanol, and isopropanol, and is preferably water, and / or a mixture of the polar solvent and 2,5-furanoic acid. Nji The method for preparing 2,5-furandicarboxaldehyde oxime by autocatalysis according to claim 3 or 6, characterized in that the mass ratio of carboxaldehyde is 5-35:1, preferably 10-20:1.

[0098] [Appendix 10] the reaction temperature is 0°C to 90°C, preferably 15°C to 30°C, the reaction time is 1 to 60 minutes, preferably 5 to 30 minutes, and the reaction pressure is atmospheric pressure; and / or the method for preparing 2,5-furandicarboxaldehyde oxime by autocatalysis as described in Appendix 6, characterized in that the method comprises adding the aqueous oxime agent solution to the mixture at least 4 to 8 times.

Claims

1. Providing a liquid phase reaction system including 2,5-furan dicarboxyaldehyde and an oxime agent; adding an acid to the liquid phase reaction system to react 2,5-furandicarboxyaldehyde with an oxime agent to generate 2,5-furandicarboxyaldehyde oxime as a catalyst; and continuing to react the remaining 2,5-furandicarboxyaldehyde with the oxime agent under the action of the catalyst to generate 2,5-furandicarboxyaldehyde oxime; The reaction temperature is 0°C to 90°C, the reaction time is 1 to 60 min, and the reaction pressure is atmospheric pressure; The acid includes an inorganic acid and / or an organic acid, the inorganic acid being any one or a combination of two or more of hydrochloric acid, sulfuric acid, phosphoric acid, nitric acid, and sulfurous acid, and the organic acid being any one or a combination of two or more of formic acid, acetic acid, lactic acid, propionic acid, butyric acid, hexanoic acid, succinic acid, citric acid, benzoic acid, oxalic acid, methylsulfonic acid, and methanesulfonic acid; the oxime agent is a hydroxylamine; the molar ratio of the oxime agent to 2,5-furandicarboxyaldehyde is 2 to 10:1; The method for preparing 2,5-furandicarboxaldehyde oxime by autocatalysis, characterized in that after adding an acid into the liquid phase reaction system, the pH value of the liquid phase reaction system is 1.0-7.

0.

2. The method for preparing 2,5-furandicarboxaldehyde oxime by autocatalysis according to claim 1, characterized in that the liquid phase reaction system comprises 2,5-furandicarboxaldehyde, an oxime agent and a polar solvent.

3. The method for preparing 2,5-furandicarboxaldehyde oxime by autocatalysis according to claim 1, characterized in that after adding acid into the liquid phase reaction system, the pH value of the liquid phase reaction system is 3.0-4.

0.

4. The method for preparing 2,5-furandicarboxaldehyde oxime by autocatalysis according to claim 1, characterized in that after adding acid into the liquid phase reaction system, the mass percentage of acid in the formed mixed reaction product is 0.01-2.0 wt%.

5. Providing a mixture comprising 2,5-furan dicarboxyaldehyde and an acid; adding an oxime agent into the mixed solution multiple times, reacting 2,5-furandicarboxyaldehyde with the oxime agent using an acid as a trigger to generate 2,5-furandicarboxyaldehyde oxime as a catalyst, and continuously reacting the remaining 2,5-furandicarboxyaldehyde with the oxime agent under the action of the catalyst; The reaction temperature is 0°C to 90°C, the reaction time is 1 to 60 min, and the reaction pressure is atmospheric pressure; The acid includes an inorganic acid and / or an organic acid, the inorganic acid being any one or a combination of two or more of hydrochloric acid, sulfuric acid, phosphoric acid, nitric acid, and sulfurous acid, and the organic acid being any one or a combination of two or more of formic acid, acetic acid, lactic acid, propionic acid, butyric acid, hexanoic acid, succinic acid, citric acid, benzoic acid, oxalic acid, methylsulfonic acid, and methanesulfonic acid; the oxime agent is a hydroxylamine; the molar ratio of the oxime agent to 2,5-furandicarboxyaldehyde is 2 to 10:1; The method for preparing 2,5-furandicarboxaldehyde oxime by autocatalysis, wherein the pH value of the mixture is 1.0 to 7.

0.

6. 6. The method for preparing 2,5-furandicarboxaldehyde oxime by autocatalysis according to claim 5, wherein the mixture comprises 2,5-furandicarboxaldehyde, an acid and a polar solvent, and / or the method comprises preparing an oxime agent as an aqueous oxime agent solution and adding the aqueous oxime agent solution to the mixture multiple times.

7. The autocatalytic process for preparing 2,5-furandicarboxaldehyde oxime according to claim 1, characterized in that the inorganic acid is hydrochloric acid and / or sulfuric acid, and the organic acid is acetic acid and / or oxalic acid.

8. The method for preparing 2,5-furandicarboxaldehyde oxime by autocatalysis according to claim 6, characterized in that the oxime agent aqueous solution is hydroxylamine aqueous solution, and the concentration of the hydroxylamine aqueous solution is 15-85 wt%.

9. The method for preparing 2,5-furandicarboxaldehyde oxime by autocatalysis according to claim 2 or 6, characterized in that the polar solvent is any one or a combination of two or more of water, dimethylsulfoxide, ethylene glycol, dimethylformamide, acetonitrile, methanol, ethanol, isopropanol, and / or the mass ratio of the polar solvent to 2,5-furandicarboxaldehyde is 5-35:

1.

10. The reaction time is 5 to 30 minutes, And / or the method for preparing 2,5-furandicarboxaldehyde oxime by autocatalysis according to claim 6, characterized in that the method comprises adding the aqueous oxime agent solution to the mixture at least 4-8 times.

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