Method for preparing 2, 2-bis (2-tetrahydrofuryl) propane

Abstract

The invention discloses a method for preparing 2, 2-bis (2-tetrahydrofuryl) propane, and belongs to the technical field of organic synthesis. The method comprises the following steps: with furan and acetone as starting raw materials, firstly carrying out condensation reaction under the action of an organic strong acid catalyst to generate 2, 2-bis (2-furyl) propane, and then carrying out catalytic hydrogenation reduction to obtain a target product. The organic strong acid is selected from one or more of p-toluenesulfonic acid, trifluoromethanesulfonic acid, methanesulfonic acid, ethanesulfonic acid and benzenesulfonic acid. The organic strong acid is adopted to replace a traditional inorganic strong acid catalyst, the problems of equipment corrosion, post-treatment difficulty, low yield and the like are solved, the reaction condition is mild, the condensation reaction yield can reach 90% or above, the overall yield is high, the technological operation is simple, and the method is suitable for industrial production.

Description

Technical Field

[0001] This invention relates to the field of organic synthesis technology, and specifically to a method for preparing 2,2-bis(2-tetrahydrofuranyl)propane. Background Technology

[0002] 2,2-Di(2-tetrahydrofuranyl)propane (DTP) is an important chemical intermediate widely used in drug synthesis, polymer materials and fine chemical preparation.

[0003] In existing technologies, the preparation of this compound typically involves two steps: first, furan and acetone condense under an acid catalyst to form 2,2-bis(2-furanyl)propane, and then the furan ring is hydrogenated and reduced. However, the condensation reaction step often uses inorganic strong acids (such as sulfuric acid and hydrochloric acid) or Lewis acids (such as aluminum trichloride) as catalysts. These catalysts have significant drawbacks: inorganic strong acids corrode equipment, have complex post-processing, and easily generate waste pollution; Lewis acids are expensive, sensitive to moisture, and difficult to recover.

[0004] For example, patent CN108530403A discloses a method using hydrochloric acid for catalytic condensation, with a yield of only about 70%, and the post-treatment requires neutralization and washing, which is cumbersome and causes significant environmental pollution. Furthermore, existing methods have low conversion and yield rates, making them difficult to meet industrial-scale requirements.

[0005] Therefore, it is of great significance to develop an efficient, environmentally friendly, and high-yield method for preparing 2,2-bis(2-tetrahydrofuranyl)propane. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the prior art and provide a method for preparing 2,2-bis(2-tetrahydrofuranyl)propane. This method has the advantages of mild reaction conditions, simple operation, high yield, and environmental friendliness, and is suitable for industrial production.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: A method for preparing 2,2-bis(2-tetrahydrofuranyl)propane includes the following steps: Condensation reaction: In the presence of a strong organic acid catalyst, furan and acetone undergo a condensation reaction to produce 2,2-bis(2-furanyl)propane; The strong organic acid is selected from one or more of p-toluenesulfonic acid, trifluoromethanesulfonic acid, methanesulfonic acid, ethanesulfonic acid, and benzenesulfonic acid; The amount of strong organic acid used is 0.5%-10% of the molar amount of furan; The molar ratio of furan to acetone is 2:1 to 5:1; The reaction temperature is 0-100°C, and the reaction time is 1-24 hours.

[0008] Reduction reaction: The 2,2-bis(2-furanyl)propane obtained in step (1) was subjected to catalytic hydrogenation reduction to obtain 2,2-bis(2-tetrahydrofuranyl)propane; Catalytic hydrogenation reduction uses palladium on carbon or Raney nickel as catalysts; The reaction temperature is from room temperature to 100°C, the hydrogen pressure is 1-10 atm, and the reaction time is 1-12 hours.

[0009] The reaction equation for a method to prepare 2,2-bis(2-tetrahydrofuranyl)propane is as follows: .

[0010] Compared with the prior art, the present invention has the following significant advantages: High yield: The yield of the condensation reaction can reach over 90%, which is much higher than the approximately 70% of the existing technology; Easy to operate: Post-treatment only requires water washing and drying, without the need for alkali neutralization, which greatly simplifies the process. Environmentally friendly: The use of organic strong acids instead of inorganic strong acids reduces equipment corrosion and pollution from waste gas, wastewater, and solid waste. Low cost: catalysts are readily available, reaction conditions are mild, and it is suitable for large-scale production. Detailed Implementation

[0011] The present invention will be described in detail below through embodiments, but the scope of protection of the present invention is not limited thereto. The yields in the embodiments are all calculated based on furan. Example

[0012] In a 500 mL reaction flask, furan (100 mmol, 6.8 g), acetone (50 mmol, 2.9 g), and p-toluenesulfonic acid (1 mmol, 0.17 g) were added, and the mixture was stirred at room temperature for 12 hours. After the reaction was complete, the organic phase was washed with 100 mL of water, separated, dried over anhydrous magnesium sulfate, and the solvent was removed by vacuum distillation to give 2,2-bis(2-furanyl)propane in 95% yield.

[0013] The above product (10 mmol, 2.2 g) was dissolved in 50 mL of methanol, and 5% palladium on carbon (0.1 g) was added. The mixture was stirred at room temperature for 6 hours under a hydrogen atmosphere (3 atm). The catalyst was removed by filtration, and the filtrate was concentrated to give 2,2-bis(2-tetrahydrofuranyl)propane in 90% yield. Example

[0014] In a 500 ml reaction flask, furan (100 mmol, 6.8 g), acetone (50 mmol, 2.9 g), and trifluoromethanesulfonic acid (0.5 mmol, 0.075 g) were added, and the mixture was stirred at 40°C for 8 hours. The post-treatment was the same as in Example 1, yielding 2,2-bis(2-furanyl)propane in 98% yield. The reduction reaction was the same as in Example 1, yielding 2,2-bis(2-tetrahydrofuranyl)propane in 92% yield. Example

[0015] In a 500 ml reaction flask, furan (100 mmol, 6.8 g), acetone (50 mmol, 2.9 g), and methanesulfonic acid (2 mmol, 0.19 g) were added, and the mixture was stirred at 60°C for 6 hours. The post-treatment was the same as in Example 1, yielding 2,2-bis(2-furanyl)propane in 93% yield. The reduction reaction was the same as in Example 1, yielding 2,2-bis(2-tetrahydrofuranyl)propane in 88% yield.

[0016] Comparative example: In a 500 ml reaction flask, furan (100 mmol, 6.8 g), acetone (50 mmol, 2.9 g), and concentrated sulfuric acid (1 mmol, 0.098 g) were added, and the mixture was stirred at room temperature for 12 hours. Post-treatment required neutralization with alkali, washing several times with water, and drying to obtain 2,2-bis(2-furanyl)propane in 70% yield. The reduction reaction was performed as in Example 1 to give 2,2-bis(2-tetrahydrofuranyl)propane in 85% yield.

[0017] in conclusion: This invention significantly improves the conversion rate and yield of condensation reactions by using strong organic acid catalysts, avoiding equipment corrosion and environmental problems, and has high industrial application value.

Claims

1. A method for preparing 2,2-bis(2-tetrahydrofuranyl)propane, characterized in that, Includes the following steps: (1) In the presence of a strong organic acid catalyst, furan and acetone undergo a condensation reaction to produce 2,2-bis(2-furanyl)propane; (2) The 2,2-bis(2-furanyl)propane obtained in step (1) is subjected to catalytic hydrogenation reduction to obtain 2,2-bis(2-tetrahydrofuranyl)propane.

2. The method according to claim 1, characterized in that, The strong organic acid mentioned in step (1) is selected from one or more of p-toluenesulfonic acid, trifluoromethanesulfonic acid, methanesulfonic acid, ethanesulfonic acid, and benzenesulfonic acid.

3. The method according to claim 1 or 2, characterized in that, In step (1), the amount of strong organic acid used is 0.5%-10% of the molar amount of furan.

4. The method according to claim 1, characterized in that, In step (1), the molar ratio of furan to acetone is 2:1 to 5:

1.

5. The method according to claim 1, characterized in that, The reaction temperature in step (1) is 0-100°C, and the reaction time is 1-24 hours.

6. The method according to claim 1, characterized in that, In step (2), catalytic hydrogenation reduction uses palladium on carbon or Raney nickel as a catalyst and is carried out under hydrogen pressure.

7. The method according to claim 6, characterized in that, The reaction temperature in step (2) is from room temperature to 100°C, the hydrogen pressure is 1-10 atm, and the reaction time is 1-12 hours.