阅读说明：本技术 一种铜基催化剂催化糠醛和正丁醇氧化缩合制备2-(2-呋喃亚甲基)-丁醛的方法 (Method for preparing 2- (2-furylmethylene) -butyraldehyde by catalyzing oxidative condensation of furfural and n-butanol with copper-based catalyst ) 是由 仝新利 师静 孙海静 于 2021-09-27 设计创作，主要内容包括：本发明公开了一种铜基催化剂催化糠醛和正丁醇氧化缩合制备2-(2-呋喃亚甲基)-丁醛的方法。该方法采用多元醇还原法制备的Cu-(2)O作为催化剂,以糠醛为底物,正丁醇为溶剂,氧气氛围下,于合适温度下实现糠醛与正丁醇氧化缩合制备2-(2-呋喃亚甲基)-丁醛。具体方法是：将糠醛和正丁醇进行混合,加入催化剂和碱性助剂,在温度为25-360℃、氧气压力为0.01-25.0MPa、搅拌转速100-9000r/min,反应0.5-72h制得产品。其优点是：1、该催化体系对糠醛与脂肪醇的氧化缩合反应具有较高的催化活性,对研究糠醛与长链醇的反应具有较大意义；2、采用“一锅法”反应工艺,缩短了反应历程,提高了主要产物收率；3、催化体系反应条件温和、能够高效率地催化糠醛和正丁醇进行选择性氧化缩合成2-(2-呋喃亚甲基)-丁醛；本发明可以适用于多种醛类包括芳香醛、脂肪醛等,并且都具有副产物少,产物收率高的特点,具有较高的普适性。(The invention discloses a method for preparing 2- (2-furanmethylene) -butyraldehyde by catalyzing furfural and n-butanol to be subjected to oxidative condensation by using a copper-based catalyst. The method adopts the Cu prepared by a polyol reduction method 2 And O is used as a catalyst, furfural is used as a substrate, n-butyl alcohol is used as a solvent, and the furfural and the n-butyl alcohol are subjected to oxidative condensation at a proper temperature in an oxygen atmosphere to prepare the 2- (2-furylmethylene) -butyraldehyde. The specific method comprises the following steps: mixing furfural and n-butanol, adding a catalyst and an alkaline assistant, and reacting at the temperature of 25-360 ℃, the oxygen pressure of 0.01-25.0MPa and the stirring speed of 100-9000r/min for 0.5-72h to obtain the product. The advantages are that: 1. the catalytic system has higher catalytic activity for the oxidation condensation reaction of furfural and fatty alcohol, and has great significance for researching the reaction of furfural and long-chain alcohol; 2. adopts the one-pot reaction process, shortens the reaction process and improves the main productYield; 3. the catalytic system has mild reaction conditions, and can efficiently catalyze furfural and n-butanol to carry out selective oxidation and condensation to synthesize 2- (2-furan methylene) -butyraldehyde; the method can be suitable for various aldehydes including aromatic aldehyde, aliphatic aldehyde and the like, has the characteristics of few byproducts and high product yield, and has higher universality.)

1. A method for preparing 2- (2-furylmethylene) -butyraldehyde by catalyzing furfural and n-butanol to perform oxidative condensation by using a copper-based catalyst is characterized in that furfural is used as a substrate, and Cu is used as a substrate₂O is used as a catalyst to prepare 2- (2-furylmethylene) -butyraldehyde, and the specific method comprises the following steps: mixing furfural and n-butanol, adding a metal catalyst and an alkaline assistant, and reacting at the temperature of 25-360 ℃, the oxygen pressure of 0.01-25.0MPa and the stirring speed of 100-.

2. The method for preparing 2- (2-furanmethylene) -butyraldehyde by catalyzing furfural and n-butanol to be subjected to oxidative condensation by using the copper-based catalyst according to claim 1, wherein the copper-based catalyst is characterized in that: the Cu₂The preparation method of the O catalyst comprises the following steps: dissolving Cu precursor salt and polyvinylpyrrolidone in water at room temperature, adding 0.5-2M sodium citrate solution and 0.5-2M anhydrous sodium carbonate solution, stirring for 10-30min, adding 1-2M glucose solution, placing the mixed solution in an oil bath, reacting for 1-2h at 60-100 ℃, washing the precipitate with deionized water to neutrality, and drying in an oven overnight.

3. The method for preparing 2- (2-furanmethylene) -butyraldehyde by catalyzing furfural and n-butanol to be subjected to oxidative condensation by using the copper-based catalyst according to claim 1, wherein the copper-based catalyst is characterized in that: the dosages of the furfural and the n-butanol are 0.01-9.0g and 1-700mL respectively.

4. The method for preparing 2- (2-furanmethylene) -butyraldehyde by catalyzing furfural and n-butanol to be subjected to oxidative condensation by using the copper-based catalyst according to claim 1, wherein the copper-based catalyst is characterized in that: the dosage of the copper-based catalyst is 0.01-70% of the amount of the furfural substance.

5. The method for preparing 2- (2-furanmethylene) -butyraldehyde by catalyzing furfural and n-butanol to be subjected to oxidative condensation by using the copper-based catalyst according to claim 1, wherein the copper-based catalyst is characterized in that: the furfural includes but is not limited to 5-hydroxymethylfurfural, 5-chloro-2-furfural, 5-bromo-2-furfural and 5-methylfurfural.

6. The method for preparing 2- (2-furanmethylene) -butyraldehyde by catalyzing furfural and n-butanol to be subjected to oxidative condensation by using the copper-based catalyst according to claim 1, wherein the copper-based catalyst is characterized in that: the reaction temperature in the oxidation reaction process is 25-360 ℃.

7. The method for preparing 2- (2-furanmethylene) -butyraldehyde by catalyzing furfural and n-butanol to be subjected to oxidative condensation by using the copper-based catalyst according to claim 1, wherein the copper-based catalyst is characterized in that: the pressure of the oxygen in the oxidation reaction is 0.01-25 MPa.

8. The method for preparing 2- (2-furanmethylene) -butyraldehyde by catalyzing furfural and n-butanol to be subjected to oxidative condensation by using the copper-based catalyst according to claim 1, wherein the copper-based catalyst is characterized in that: the reaction time in the oxidation reaction process is 0.5-72 h.

9. The method for preparing 2- (2-furanmethylene) -butyraldehyde by catalyzing furfural and n-butanol to be subjected to oxidative condensation by using the copper-based catalyst according to claim 1, wherein the copper-based catalyst is characterized in that: the mass of the added alkaline auxiliary agent is 0.01-50% of the mass of the added furfural.

10. The method for preparing 2- (2-furanmethylene) -butyraldehyde by catalyzing furfural and n-butanol to be subjected to oxidative condensation by using the copper-based catalyst according to claim 1, wherein the copper-based catalyst is characterized in that: the alkaline assistant is one of lithium hydroxide, potassium carbonate, sodium hydroxide, cesium hydroxide, sodium carbonate and potassium phosphate.

Technical Field

The invention relates to a method for preparing 2- (2-furylmethylene) -butyraldehyde by oxidizing and condensing furfural, in particular to a method for catalyzing oxidizing and condensing furfural and n-butanol by using a copper-based catalyst.

Background

At present, the world is faced with the exhaustion of fossil energy and the extreme difficulty of global climate, and the development of renewable energy sources to replace fossil fuels has attracted extensive attention in the chemical field. Biomass, a sustainable and readily available natural energy source, can be converted through a series of reactions to produce valuable chemicals and liquid fuels. Furan derivative furfural is considered an important biomass-based platform compound, and can be obtained from agricultural raw materials, corn, wheat bran and sawdust; the structure of the compound contains furan rings and aldehyde groups, and the groups are considered as intermediates for producing high value-added chemicals in the industry. Therefore, research on the conversion of furfural to high value-added chemicals is of great significance. Among them, furfural is capable of preparing various chemical substances through simple reaction processes such as hydrogenation, oxidation, reductive amination, nitration, decarbonylation, and condensation. Research shows that selective conversion of the biomass platform compound is not only beneficial to improving the commercial utilization value of the biomass platform compound, but also can reduce energy consumption.

The oxidation condensation reaction of furfural and straight-chain alcohol in the presence of oxygen is an important furfural reaction path, and the currently adopted catalysts are all noble metal catalysts, such as Au/Al₂O₃，Au/Fe_xO_yHAP, etc., and therefore, it is of great importance to develop a cheap metal catalyst which has high catalytic efficiency, low reaction cost and is environmentally friendly.

The invention content is as follows:

the invention aims to provide a method for preparing 2- (2-furylmethylene) -butyraldehyde by catalyzing furfural and n-butanol to be subjected to oxidative condensation by using a copper-based catalyst, aiming at the technical analysis and the existing problems.

The invention has the advantages that: 1. the catalytic system has higher catalytic activity for the oxidation condensation reaction of furfural and fatty alcohol, and has great significance for researching the reaction of furfural and long-chain alcohol; 2. the one-pot reaction process is adopted, the reaction process is shortened, and the yield of the main product is improved; 3. the catalytic system has mild reaction conditions, and can efficiently catalyze furfural and n-butanol to carry out selective oxidation and condensation to synthesize 2- (2-furan methylene) -butyraldehyde; the method can be suitable for various aldehydes including aromatic aldehyde, aliphatic aldehyde and the like, has the characteristics of few byproducts and high product yield, and has higher universality.

The technical scheme adopted by the invention is as follows:

a method for preparing 2- (2-furan methylene) -butyraldehyde by catalyzing furfural and n-butanol to be subjected to oxidative condensation by using a copper-based catalyst, takes furfural as a substrate and cuprous oxide as a catalyst to prepare 2- (2-furan methylene) -butyraldehyde, and comprises the following specific steps: mixing furfural and n-butanol, adding a metal catalyst and an alkaline assistant, and reacting at the temperature of 25-360 ℃, the oxygen pressure of 0.01-25.0MPa and the stirring speed of 100-. Furthermore, the dosages of the furfural and the n-butanol are 0.01-9.0g and 1-700mL respectively.

Further, the copper-based catalyst is preferably used in an amount of 0.01 to 70% of the amount of the substance of furfural.

Further, the furfural includes, but is not limited to, 5-hydroxymethylfurfural, 5-chloro-2-furfural, 5-bromo-2-furfural and 5-methylfurfural.

Further, the reaction temperature in the oxidation reaction process is preferably 25 to 360 ℃.

Further, the preferable reaction oxygen pressure of the oxidation reaction is 0.01 to 25.0 MPa.

Further, the alkaline assistant includes lithium hydroxide, potassium carbonate, sodium hydroxide, cesium hydroxide, sodium carbonate, potassium phosphate, and the like.

Further, the reaction time in the oxidation reaction process is preferably 0.5 to 72 hours.

Further, the preferable mass of the added alkaline assistant is 0.01-50% of the mass of the added aldehyde.

Further, the added alkaline assistant is one of lithium hydroxide, potassium carbonate, sodium hydroxide, cesium hydroxide, sodium carbonate and potassium phosphate.

Further, the Cu₂The preparation method of the O catalyst comprises the following steps: dissolving Cu precursor salt and polyvinylpyrrolidone in water at room temperature, adding 0.5-2M sodium citrate solution and 0.5-2M anhydrous sodium carbonate solution, stirring for 10-30min, adding 1-2M glucose solution, placing the mixed solution in an oil bath, reacting at 60-100 deg.C for 1-2h, washing the precipitate with deionized water, and precipitatingDry overnight in an oven.

Detailed Description

The invention is further illustrated by the following examples.

Example 1:

a method for preparing 2- (2-furylmethylene) -butyraldehyde by catalyzing furfural and n-butanol to be subjected to oxidative condensation by using a copper-based catalyst comprises the following steps:

taking furfural as a substrate and Cu₂The O is used as a catalyst to study the oxidation condensation reaction of catalytic furfural and n-butanol, and the specific method comprises the following steps: dissolving 0.1g (1.04mmol) of furfural in 10mL of n-butanol, adding catalyst Cu₂0.025g of O, 0.025g of auxiliary agent lithium hydroxide and 0.3MPa of oxygen, reacting for 4 hours at the temperature of 60 ℃ and the stirring speed of 100r/min, and selectively catalyzing and oxidizing furfural by using an alkaline auxiliary agent to obtain a target product, namely 3- (2-furyl) -2-ethyl-2-acrolein and a byproduct, namely furfuryl alcohol. The reaction results were analyzed by gas chromatography with a mass spectrometer: the conversion of furfural was 94.9%, and the selectivity of 3- (2-furyl) -2-ethyl-2-propenal was 96.3%.

Example 2:

a method for preparing 2- (2-furylmethylene) -butyraldehyde by catalyzing furfural and n-butanol to be subjected to oxidative condensation by using a copper-based catalyst comprises the following steps:

taking furfural as a substrate and Cu₂The O is used as a catalyst to study the oxidation condensation reaction of catalytic furfural and n-butanol, and the specific method comprises the following steps: dissolving 0.1g (1.04mmol) of furfural in 10mL of n-butanol, adding catalyst Cu₂0.025g of O, 0.025g of sodium hydroxide as an auxiliary agent and 0.3MPa of oxygen, reacting for 4 hours at the temperature of 60 ℃ and the stirring speed of 100r/min, and selectively catalytically oxidizing furfural by using an alkaline auxiliary agent to obtain a target product, namely 3- (2-furyl) -2-ethyl-2-acrolein and a byproduct, namely furfuryl alcohol. The reaction results were analyzed by gas chromatography with a mass spectrometer: the conversion of furfural was 60.9%, and the selectivity of 3- (2-furyl) -2-ethyl-2-propenal was 33.9%.

Example 3:

a method for preparing 2- (2-furylmethylene) -butyraldehyde by catalyzing furfural and n-butanol to be subjected to oxidative condensation by using a copper-based catalyst comprises the following steps:

taking furfural as a substrate and Cu₂The O is used as a catalyst to study the oxidation condensation reaction of catalytic furfural and n-butanol, and the specific method comprises the following steps: dissolving 0.1g (1.04mmol) of furfural in 10mL of n-butanol, adding catalyst Cu₂0.025g of O, 0.025g of auxiliary agent potassium hydroxide and 0.3MPa of oxygen, reacting for 4 hours at the temperature of 60 ℃ and the stirring speed of 100r/min, and selectively catalyzing and oxidizing furfural by using an alkaline auxiliary agent to obtain a target product, namely 3- (2-furyl) -2-ethyl-2-acrolein and a byproduct, namely furfuryl alcohol. The reaction results were analyzed by gas chromatography with a mass spectrometer: the conversion of furfural was 72.8% and the selectivity to 3- (2-furyl) -2-ethyl-2-propenal was 95.3%.

Example 4:

a method for preparing 2- (2-furylmethylene) -butyraldehyde by catalyzing furfural and n-butanol to be subjected to oxidative condensation by using a copper-based catalyst comprises the following steps:

taking furfural as a substrate and Cu₂The O is used as a catalyst to study the oxidation condensation reaction of catalytic furfural and n-butanol, and the specific method comprises the following steps: dissolving 0.1g (1.04mmol) of furfural in 10mL of n-butanol, adding catalyst Cu₂0.025g of O, 0.025g of auxiliary agent cesium hydroxide and 0.3MPa of oxygen, reacting for 4 hours at the temperature of 60 ℃ and the stirring speed of 100r/min, and selectively catalytically oxidizing furfural by using an alkaline auxiliary agent to obtain a target product 3- (2-furyl) -2-ethyl-2-acrolein and a byproduct furfuryl alcohol. The reaction results were analyzed by gas chromatography with a mass spectrometer: the conversion of furfural was 75.8%, and the selectivity of 3- (2-furyl) -2-ethyl-2-propenal was 99.5%.

Example 5:

a method for preparing 2- (2-furylmethylene) -butyraldehyde by catalyzing furfural and n-butanol to be subjected to oxidative condensation by using a copper-based catalyst comprises the following steps:

taking furfural as a substrate and Cu₂The O is used as a catalyst to study the oxidation condensation reaction of catalytic furfural and n-butanol, and the specific method comprises the following steps: dissolving 0.1g (1.04mmol) of furfural in 10mL of n-butanol, adding catalyst Cu₂0.025g of O, 0.025g of auxiliary agent lithium hydroxide and 0.3MPa of oxygen, reacting for 4 hours at the temperature of 100 ℃ and the stirring speed of 100r/min, selectively catalyzing and oxidizing furfural by using an alkaline auxiliary agent,to obtain the target product 3- (2-furyl) -2-ethyl-2-acrolein and the byproduct furfuryl alcohol. The reaction results were analyzed by gas chromatography with a mass spectrometer: the conversion rate of furfural is more than 99.9 percent, and the selectivity of 3- (2-furyl) -2-ethyl-2-acrolein is 96.2 percent.

Example 6:

a method for preparing 2- (2-furylmethylene) -butyraldehyde by catalyzing furfural and n-butanol to be subjected to oxidative condensation by using a copper-based catalyst comprises the following steps:

taking furfural as a substrate and Cu₂The O is used as a catalyst to study the oxidation condensation reaction of catalytic furfural and n-butanol, and the specific method comprises the following steps: dissolving 0.1g (1.04mmol) of furfural in 10mL of n-butanol, adding catalyst Cu₂0.025g of O, 0.025g of auxiliary agent lithium hydroxide and 0.3MPa of oxygen, reacting for 4 hours at the temperature of 80 ℃ and the stirring speed of 100r/min, and selectively catalyzing and oxidizing furfural by using an alkaline auxiliary agent to obtain a target product, namely 3- (2-furyl) -2-ethyl-2-acrolein and a byproduct, namely furfuryl alcohol. The reaction results were analyzed by gas chromatography with a mass spectrometer: the conversion rate of furfural is more than 99.9 percent, and the selectivity of 3- (2-furyl) -2-ethyl-2-acrolein is 96.8 percent.

Example 7:

a method for preparing 2- (2-furylmethylene) -butyraldehyde by catalyzing furfural and n-butanol to be subjected to oxidative condensation by using a copper-based catalyst comprises the following steps:

taking furfural as a substrate and Cu₂The O is used as a catalyst to study the oxidation condensation reaction of catalytic furfural and n-butanol, and the specific method comprises the following steps: dissolving 0.1g (1.04mmol) of furfural in 10mL of n-butanol, adding catalyst Cu₂0.025g of O, 0.025g of auxiliary agent lithium hydroxide and 0.3MPa of oxygen, reacting for 4 hours at the temperature of 40 ℃ and the stirring speed of 100r/min, and selectively catalyzing and oxidizing furfural by using an alkaline auxiliary agent to obtain a target product 3- (2-furyl) -2-ethyl-2-acrolein and a byproduct furfuryl alcohol. The reaction results were analyzed by gas chromatography with a mass spectrometer: the conversion of furfural was 30.2%, and the selectivity of 3- (2-furyl) -2-ethyl-2-propenal was 89.6%.

Example 8:

a method for preparing 2- (2-furylmethylene) -butyraldehyde by catalyzing furfural and n-butanol to be subjected to oxidative condensation by using a copper-based catalyst comprises the following steps:

taking furfural as a substrate and Cu₂The O is used as a catalyst to study the oxidation condensation reaction of catalytic furfural and n-butanol, and the specific method comprises the following steps: dissolving 0.1g (1.04mmol) of furfural in 10mL of n-butanol, adding catalyst Cu₂0.025g of O, 0.025g of auxiliary agent lithium hydroxide and 0.3MPa of oxygen, reacting for 4 hours at the temperature of 25 ℃ and at the stirring speed of 100r/min, and selectively catalytically oxidizing furfural by using an alkaline auxiliary agent to obtain a target product, namely 3- (2-furyl) -2-ethyl-2-acrolein and a byproduct, namely furfuryl alcohol. The reaction results were analyzed by gas chromatography with a mass spectrometer: the conversion of furfural was 17.1% and the selectivity to 3- (2-furyl) -2-ethyl-2-propenal was 100%.

Example 9:

a method for preparing 2- (2-furylmethylene) -butyraldehyde by catalyzing furfural and n-butanol to be subjected to oxidative condensation by using a copper-based catalyst comprises the following steps:

taking furfural as a substrate and Cu₂The O is used as a catalyst to study the oxidation condensation reaction of catalytic furfural and n-butanol, and the specific method comprises the following steps: dissolving 0.1g (1.04mmol) of furfural in 10mL of n-butanol, adding catalyst Cu₂0.025g of O, 0.025g of auxiliary agent lithium hydroxide and 0.3MPa of oxygen, reacting for 6 hours at the temperature of 80 ℃ and the stirring speed of 100r/min, and selectively catalyzing and oxidizing furfural by using an alkaline auxiliary agent to obtain a target product 3- (2-furyl) -2-ethyl-2-acrolein and a byproduct furfuryl alcohol. The reaction results were analyzed by gas chromatography with a mass spectrometer: the conversion rate of furfural is more than 99.9 percent, and the selectivity of 3- (2-furyl) -2-ethyl-2-acrolein is 96.1 percent.

Example 10:

a method for preparing 2- (2-furylmethylene) -butyraldehyde by catalyzing furfural and n-butanol to be subjected to oxidative condensation by using a copper-based catalyst comprises the following steps:

taking furfural as a substrate and Cu₂The O is used as a catalyst to study the oxidation condensation reaction of catalytic furfural and n-butanol, and the specific method comprises the following steps: dissolving 0.1g (1.04mmol) of furfural in 10mL of n-butanol, adding catalyst Cu₂0.025g of O, 0.025g of auxiliary agent lithium hydroxide and 0.3MPa of oxygen, reacting for 2 hours at the temperature of 80 ℃ and the stirring speed of 100r/min, and passing through alkaliSelectively catalyzing and oxidizing furfural by using a sexual auxiliary agent to prepare a target product 3- (2-furyl) -2-ethyl-2-acrolein and a byproduct furfuryl alcohol. The reaction results were analyzed by gas chromatography with a mass spectrometer: the conversion rate of furfural is more than 99.9 percent, and the selectivity of 3- (2-furyl) -2-ethyl-2-acrolein is 95.8 percent.

Example 11:

a method for preparing 2- (2-furylmethylene) -butyraldehyde by catalyzing furfural and n-butanol to be subjected to oxidative condensation by using a copper-based catalyst comprises the following steps:

taking furfural as a substrate and Cu₂The O is used as a catalyst to study the oxidation condensation reaction of catalytic furfural and n-butanol, and the specific method comprises the following steps: dissolving 0.1g (1.04mmol) of furfural in 10mL of n-butanol, adding catalyst Cu₂0.025g of O, 0.025g of auxiliary agent lithium hydroxide and 0.3MPa of oxygen, reacting for 1h at the temperature of 80 ℃ and the stirring speed of 100r/min, and selectively catalyzing and oxidizing furfural by using an alkaline auxiliary agent to obtain a target product, namely 3- (2-furyl) -2-ethyl-2-acrolein and a byproduct, namely furfuryl alcohol. The reaction results were analyzed by gas chromatography with a mass spectrometer: the conversion rate of furfural is more than 99.9 percent, and the selectivity of 3- (2-furyl) -2-ethyl-2-acrolein is 96.4 percent.

Example 12:

a method for preparing 2- (2-furylmethylene) -butyraldehyde by catalyzing furfural and n-butanol to be subjected to oxidative condensation by using a copper-based catalyst comprises the following steps:

taking furfural as a substrate and Cu₂The O is used as a catalyst to study the oxidation condensation reaction of catalytic furfural and n-butanol, and the specific method comprises the following steps: dissolving 0.1g (1.04mmol) of furfural in 10mL of n-butanol, adding catalyst Cu₂0.025g of O, 0.025g of auxiliary agent lithium hydroxide and 0.3MPa of oxygen, reacting for 0.5h at the temperature of 80 ℃ and the stirring speed of 100r/min, and selectively catalytically oxidizing furfural by using an alkaline auxiliary agent to obtain a target product 3- (2-furyl) -2-ethyl-2-acrolein and a byproduct furfuryl alcohol. The reaction results were analyzed by gas chromatography with a mass spectrometer: the conversion rate of furfural is more than 99.9 percent, and the selectivity of 3- (2-furyl) -2-ethyl-2-acrolein is 96.6 percent.

The above-described embodiments show: by adopting the method provided by the invention, furfural and long-chain alcohol n-butanol can be efficiently catalyzed to carry out an oxidation condensation reaction to generate 2- (2-furan methylene) -butyraldehyde; 2- (2-furan methylene) -butyraldehyde is used as a direct product formed by oxidizing and condensing furfural and long-chain alcohol, further increases a carbon chain, can be used as an important intermediate of liquid fuel, and has a wide application prospect in the field of energy; meanwhile, the catalyst is cheap and easy to obtain, the reaction condition is mild, the reaction process is simple and easy to implement, and the catalyst can meet the requirements of technical economy, and is a catalytic system with application prospect.