CN107245066B - A method for selectively preparing furfurylamine or tetrahydrofurfurylamine - Google Patents

Abstract

The invention discloses a kind of methods that selectivity prepares chaff amine or tetrahydrofurfuryl amine, and using furfuryl alcohol as raw material, using metallic nickel as catalyst, under the conditions of no hydrogen, chaff amine is prepared through reduction amination；Under hydrogen atmosphere, tetrahydrofurfuryl amine is prepared through reduction amination.The present invention provides a kind of methods that selectivity prepares chaff amine or tetrahydrofurfuryl amine, using furfuryl alcohol as raw material, using heterogeneous catalysis, under identical raw material, catalyst system and essentially identical process conditions, change the selectivity of product by introducing hydrogen.

Description

A method for selectively preparing furfurylamine or tetrahydrofurfurylamine

technical field

The invention relates to the field of organic synthesis, in particular to a method for selectively preparing furfurylamine or tetrahydrofurfurylamine.

Background technique

Furfurylamine is also called 2-furylmethylamine, the chemical formula is C ₅ H ₇ NO, and the structural formula is Furfuryl amine is an important organic synthesis intermediate and chemical product. Furfuryl amine and its derivatives are widely used in the pharmaceutical industry. The high-efficiency diuretic drug "furosemide" has strong diuretic effect and quick effect, and is an essential drug for the treatment of severe edema; in addition, furfurylamine is also used as a corrosion inhibitor, flux, etc.

Like general primary amines, furfurylamine can be prepared by reductive amination of furfural under the action of a metal catalyst. However, due to the active nature of furfural, the mixture of primary amines, secondary amines and tertiary amines is usually obtained from the reaction. The selectivity is low, and furfuryl alcohol is used as the raw material, and the selectivity of the target product furfurylamine is high. However, there are few reports on the preparation of furfurylamine by reductive amination of furfuryl alcohol, and only homogeneous metal complex catalysts are used for this reaction.

For example, the U.S. patent with the publication number WO 2010018570 uses Ru-acridine complex as a catalyst to catalyze the reaction of furfuryl alcohol with _NH3 to prepare furfurylamine, furfuryl alcohol 10mmol, ammonia pressure 7.5atm, solvent toluene 3ml, reflux reaction for 12h, furfuryl alcohol conversion rate Reach 100%, product furfuryl amine yield reaches 94.8%.

Another example is the U.S. Patent Publication No. WO 2012076560, which uses Ru ₃ (CO) ₁₂ and pyrrole ligand as a catalyst to catalyze the reaction of furfuryl alcohol and NH ₃ to prepare furfurylamine. The reaction is carried out under an argon atmosphere. The raw materials furfuryl alcohol 0.098g, carbonyl ruthenium 0.0128 g, pyrrole ligand 0.0204g, solvent 2-methyl-2-butanol 1ml into a 50ml reactor, 20bar argon pressure purged the reactor three times, then added 0.6g of ammonia, reacted at 150°C for 20 hours, converted The yield reaches 99%, and the yield of furfurylamine reaches 71%.

However, because the homogeneous system is expensive and difficult to separate, it is of great practical value to develop a heterogeneous catalytic reaction system.

Tetrahydrofurfurylamine, also known as 2-tetrahydrofurfurylamine, has a molecular formula of C ₅ H ₁₁ NO and a structural formula of Tetrahydrofurfurylamine is used as an important intermediate in the synthesis of chemical products such as drugs, rubber and perfume. At present, the preparation of tetrahydrofurfurylamine is mainly based on furfural as raw material. First, furfurylamine is prepared by reductive ammoniation and then further hydrogenated or hydrogenated to prepare tetrahydrofurfuryl alcohol and then ammoniated. In addition, there is also catalytic hydrogenation of 2-cyanofuran. Methods.

For example, the Japanese patent whose publication number is JP 60178877 uses the hydrogenation product tetrahydrofurfuryl alcohol of furfural as a raw material, and uses Ni catalyst to catalyze the reductive amination of tetrahydrofurfuryl alcohol to prepare tetrahydrofurfuryl amine. Add 10.2g tetrahydrofurfuryl alcohol in a 50ml reactor, g liquefied ammonia, 1.0 g of Ni catalyst, reacted for 5 hours at 200 ° C under a pressure of 100 kg/cm ² , the conversion rate of tetrahydrofurfuryl alcohol was 15.4%, and the selectivity of tetrahydrofurfuryl amine was 98.3%.

Another example is that the Japanese patent with the publication number JP 2008143832 adopts 2-cyanofuran hydrogenation to prepare tetrahydrofurfurylamine. In a 500ml reactor, add 30g of raw materials, 120g of solvent 2-(dimethylamine) ethanol, and 5wt% of Rh /Al ₂ O ₃ catalyst 0.3g, 5wt%Pd/Al ₂ O ₃ catalyst 1.5g, nitrogen purging and then 2MPa H ₂ was introduced, and reacted at 60°C for 9 hours. Then, the reaction temperature was raised to 110° C., and the reaction was continued for 5 hours, the conversion rate of raw materials reached 100%, and the yield of tetrahydrofurfurylamine reached 92%.

Also have the report that directly prepares tetrahydrofurfuryl amine by furfural, as the U.S. patent that publication number is US 4598159 prepares tetrahydrofurfuryl amine with Raney nickel catalyzed furfural reductive amination, reaction is carried out in the reactor of 50cc, adds 0.5g Raney Nickel catalyst, solvent dioxane 5.0g, liquid ammonia 1.1g, add 10.12g tetrahydrofurfurylamine, react at 150°C for 6 hours, the conversion rate reaches 100%, and the tetrahydrofurfurylamine yield reaches 89%. In the reaction, tetrahydrofurfurylamine is used as a solvent, and by-products of secondary and tertiary amines are inevitably introduced.

Although both furfurylamine and tetrahydrofurfurylamine can be prepared with furfural as raw material, the preparation of tetrahydrofurfurylamine is usually to synthesize tetrahydrofurfurylamine or tetrahydrofurfuryl alcohol through furfural, and then further hydrogenation or ammoniation, two-step The reaction conditions and catalytic systems are often different, and the direct preparation of tetrahydrofurfurylamine by reductive amination of furfural requires adding the product tetrahydrofurfurylamine as a solvent, and the selectivity of primary amines is not high.

Contents of the invention

The invention provides a method for selectively preparing furfurylamine or tetrahydrofurfurylamine, using furfuryl alcohol as a raw material, adopting a heterogeneous catalyst, under the same raw material, catalytic system and basically the same process conditions, changing by introducing hydrogen Product selectivity.

The specific technical scheme is as follows:

A method for selectively preparing furfuryl amine or tetrahydrofurfuryl amine, using furfuryl alcohol as raw material and metal nickel as a catalyst to prepare furfuryl amine through reductive ammoniation reaction under hydrogen-free conditions; chemical reaction to prepare tetrahydrofurfurylamine.

The technical core of the present invention is to use metal nickel as a catalyst to catalyze the reductive amination reaction of furfuryl alcohol under ammonia gas to prepare furfuryl amine. After the hydrogen gas is introduced, the selectivity of the reaction changes, and the target product is changed from furfuryl amine to tetrahydrofurfuryl amine. , the process conditions of the two reactions are basically the same, but they can selectively control the formation of different products.

Specifically:

Mix furfuryl alcohol, catalyst and organic solvent, feed ammonia gas, or ammonia/hydrogen blend gas until the pressure in the reactor reaches 0.1-2.0MPa, then heat to 120-220°C, after reduction amination reaction, After post-treatment, the said furfurylamine or tetrahydrofurfurylamine can be selectively obtained.

As preferably, the organic solvent is selected from tetrahydrofuran, dioxane, methanol or ethanol;

The mass ratio of the furfuryl alcohol to the catalyst is 1:0.05-0.8;

The volume-mass ratio of the organic solvent to furfuryl alcohol is 15-50 mL/g.

If furfurylamine is used as the target product, it is preferable to feed ammonia gas until the pressure in the reactor reaches 0.1-0.4 MPa, and then heat to 140-200° C. to carry out reductive amination reaction.

More preferably, ammonia gas is introduced until the pressure in the reactor reaches 0.3-0.4 MPa, then heated to 160-180° C., and reacted for 48-60 hours to prepare furfurylamine. Under optimal process conditions, the conversion rate of furfuryl alcohol and the selectivity of the target product furfurylamine can be improved.

If tetrahydrofurfurylamine is used as the target product, as a preference, first feed ammonia gas until the pressure in the reactor reaches 0.1-0.4 MPa, then feed hydrogen gas until the pressure in the reactor reaches 0.5-2.0 MPa, and heat to 140-200 °C for reductive amination reaction.

More preferably, first feed ammonia gas until the pressure in the reactor reaches 0.3-0.4 MPa, then feed hydrogen gas until the pressure in the reactor reaches 0.8-1.5 MPa, heat to 160-180 °C, and react for 48-60 hours to prepare tetrahydro Furfurylamine. Under optimal process conditions, the conversion rate of furfuryl alcohol and the selectivity of the target product tetrahydrofurfurylamine can be improved.

Under the above reaction conditions, it is further preferred that:

Described organic solvent is selected from tetrahydrofuran;

The feeding mass of furfuryl alcohol and catalyst is 1:0.5;

The volume to mass ratio of the organic solvent to furfuryl alcohol is 30mL/g.

As preferably, described aftertreatment is:

The reaction liquid is filtered, and the catalyst can be recovered after the filter cake is washed; the filtrate is distilled under reduced pressure to obtain the final product.

Compared with prior art, the present invention has following advantage:

1. The present invention uses furfuryl alcohol as a raw material. Under the action of a metal nickel catalyst, the selectivity of the product is changed by introducing hydrogen. After adding hydrogen, the target product is converted from furfuryl amine to tetrahydrofurfuryl amine. The process conditions of the two reactions are basically The same, but can achieve selective control of the formation of different products;

2. The present invention uses furfuryl alcohol as a raw material, which is easy to obtain and low in cost;

3. The present invention adopts the heterogeneous catalyst—metal nickel, which can realize the recovery and utilization of the catalyst.

Description of drawings

Fig. 1 is the schematic diagram of the method for selectively preparing furfurylamine or tetrahydrofurfurylamine from furfuryl alcohol in the present invention.

Detailed ways

The present invention is further described below in conjunction with specific embodiment, but protection scope of the present invention is not limited thereto:

Example 1

(1) Preparation of furfurylamine

Add 0.5g of furfuryl alcohol into a 25ml reactor, then add 15ml of THF solvent, 0.25g of Raney nickel catalyst, close the reactor, blow nitrogen to purge to replace the air in the reactor, and then pass ammonia to make the pressure of the reactor reach 0.35MPa , stirred and balanced at room temperature for 20 minutes, raised the temperature to 160°C, and reacted for 24 hours. After the reaction, the reactor was cooled to room temperature, and samples were taken for gas chromatography detection. The conversion rate of furfuryl alcohol was 24.0%, and the selectivity of furfurylamine was 92.5%.

(2) Preparation of Tetrahydrofurfurylamine

Add 0.5g of furfuryl alcohol into a 25ml reactor, then add 15ml of THF solvent, 0.25g of Raney nickel catalyst, close the reactor, blow nitrogen to purge to replace the air in the reactor, and then pass ammonia to make the pressure of the reactor reach 0.35MPa , Stir and balance at room temperature for 20 minutes, then pass hydrogen to make the pressure of the reactor reach 1.0MPa, heat up to 160 ° C, and react for 24 hours. After the reaction is completed, the reactor is cooled to room temperature, and samples are taken for gas chromatography detection. The conversion rate of furfuryl alcohol is 27.5%. The selectivity of tetrahydrofurfurylamine is 40%.

Example 2

(1) Preparation of furfurylamine

Add 0.5g of furfuryl alcohol into a 25ml reactor, then add 15ml of THF solvent, 0.25g of Raney nickel catalyst, close the reactor, blow nitrogen to purge to replace the air in the reactor, and then pass ammonia to make the pressure of the reactor reach 0.35MPa , stirred and balanced at room temperature for 20 minutes, heated to 180°C, and reacted for 24 hours. After the reaction, the reactor was cooled to room temperature, and samples were taken for gas chromatography detection. The conversion rate of furfuryl alcohol was 52.0%, and the selectivity of furfurylamine was 91.7%.

(2) Preparation of Tetrahydrofurfurylamine

Add 0.5g of furfuryl alcohol into a 25ml reactor, then add 15ml of THF solvent, 0.25g of Raney nickel catalyst, close the reactor, blow nitrogen to purge to replace the air in the reactor, and then pass ammonia to make the pressure of the reactor reach 0.35MPa , Stir and balance at room temperature for 20 minutes, then pass hydrogen to make the pressure of the reactor reach 1.0MPa, heat up to 180°C, and react for 24 hours. After the reaction is completed, cool the reactor to room temperature, and take samples for gas chromatography detection. The conversion rate of furfuryl alcohol is 67.8%. The selectivity of tetrahydrofurfurylamine is 68.1%.

Example 3

(1) Preparation of furfurylamine

Add 0.5g of furfuryl alcohol into a 25ml reactor, then add 15ml of THF solvent, 0.25g of Raney nickel catalyst, close the reactor, blow nitrogen to purge to replace the air in the reactor, and then pass ammonia to make the pressure of the reactor reach 0.35MPa , Stir and balance at room temperature for 20 minutes, heat up to 200°C, and react for 24 hours. After the reaction, the reactor is cooled to room temperature, and samples are taken for gas chromatography detection. The conversion rate of furfuryl alcohol is 52.8%, and the selectivity of furfurylamine is 57.6%.

(2) Preparation of Tetrahydrofurfurylamine

Add 0.5g of furfuryl alcohol into a 25ml reactor, then add 15ml of THF solvent, 0.25g of Raney nickel catalyst, close the reactor, blow nitrogen to purge to replace the air in the reactor, and then pass ammonia to make the pressure of the reactor reach 0.35MPa , Stir and balance at room temperature for 20 minutes, then pass hydrogen to make the pressure of the reactor reach 1.0MPa, heat up to 200 ° C, and react for 24 hours. After the reaction is completed, the reactor is cooled to room temperature, and samples are taken for gas chromatography detection. The conversion rate of furfuryl alcohol is 98.5%. The selectivity of tetrahydrofurfurylamine is 66.4%.

Example 4

Preparation of Tetrahydrofurfurylamine

Add 0.5g of furfuryl alcohol into a 25ml reactor, then add 15ml of THF solvent, 0.25g of Raney nickel catalyst, close the reactor, blow nitrogen to purge to replace the air in the reactor, and then pass ammonia to make the pressure of the reactor reach 0.35MPa , Stir and balance at room temperature for 20 minutes, then pass hydrogen to make the pressure of the reactor reach 0.5MPa, heat up to 160°C, and react for 24 hours. After the reaction, cool the reactor to room temperature, take samples for gas chromatography detection, and the conversion rate of furfuryl alcohol is 27.8%. The selectivity of tetrahydrofurfurylamine is 27.0%.

Example 5

Preparation of Tetrahydrofurfurylamine

Add 0.5g of furfuryl alcohol into a 25ml reactor, then add 15ml of THF solvent, 0.25g of Raney nickel catalyst, close the reactor, blow nitrogen to purge to replace the air in the reactor, and then pass ammonia to make the pressure of the reactor reach 0.35MPa , Stir and balance at room temperature for 20 minutes, then pass hydrogen to make the pressure of the reactor reach 2.0 MPa, heat up to 160 ° C, and react for 24 hours. After the reaction is completed, the reactor is cooled to room temperature, and samples are taken for gas chromatography detection. The conversion rate of furfuryl alcohol is 69.3%. The selectivity of tetrahydrofurfurylamine is 10.8%.

Example 6

(1) Preparation of furfurylamine

Add 0.5g of furfuryl alcohol into a 25ml reactor, then add 15ml of THF solvent, 0.25g of Raney nickel catalyst, close the reactor, blow nitrogen to purge to replace the air in the reactor, and then pass ammonia to make the pressure of the reactor reach 0.35MPa , stirred and balanced at room temperature for 20 minutes, raised the temperature to 180°C, and reacted for 60 hours. After the reaction, the reactor was cooled to room temperature, and samples were taken for gas chromatography detection. The conversion rate of furfuryl alcohol was 81.8%, and the selectivity of furfurylamine was 96.3%.

(2) Preparation of Tetrahydrofurfurylamine

Add 0.5g of furfuryl alcohol into a 25ml reactor, then add 15ml of THF solvent, 0.25g of Raney nickel catalyst, close the reactor, blow nitrogen to purge to replace the air in the reactor, and then pass ammonia to make the pressure of the reactor reach 0.35MPa , Stir and balance at room temperature for 20 minutes, then pass hydrogen to make the pressure of the reactor reach 1.0MPa, raise the temperature to 180°C, and react for 48 hours. After the reaction, cool the reactor to room temperature, take samples for gas chromatography detection, and the conversion rate of furfuryl alcohol is 98.2%. The selectivity of tetrahydrofurfurylamine is 95.7%.

Examples 7-11

The reaction conditions for preparing tetrahydrofurfurylamine are the same as those in Example 2, except that the Raney nickel catalyst used is a recycled catalyst, and the reaction time is 24 hours. The number of catalyst reuses and the obtained test results are listed in Table 1 below, respectively.

Examples 12-13

The reaction conditions for preparing furfurylamine are the same as those in Example 2, except that the reaction time is 48 hours, and the Raney nickel catalyst used is a recycled catalyst. The number of catalyst reuses and the obtained test results are listed in Table 1 below, respectively.

Table 1

Example Catalyst repetitions Furfuryl alcohol conversion rate (%) Tetrahydrofurfurylamine selectivity (%) Furfurylamine selectivity (%) 7 1 66.2 68.1 - 8 2 67.6 69.1 - 9 3 64.5 67.6 - 10 4 64.4 67.6 - 11 5 63.9 69.0 - 12 1 78.5 - 97.5 13 2 53.4 - 98.7

As can be seen from Table 1, in the reaction of preparing tetrahydrofurfurylamine by reductive amination of furfuryl alcohol under the condition of 1MPa H , the Raney nickel catalyst was reused ₅ times, and the activity remained basically unchanged, while the reductive amination of furfurylamine was prepared under the condition of no hydrogen. In the reaction, the activity of the Raney nickel catalyst dropped significantly after being used once, and the characterization showed that in the reaction without hydrogen, the Raney nickel catalyst reacted with NH ₃ to form Ni ₃ N, which led to a decrease in catalyst activity.

Comparative example 1-5

The reaction conditions for preparing furfurylamine are the same as those in Example 1, except that the catalyst Raney nickel is replaced by Pd/C, Pt/C, Ru/C, Rh/C, and Raney Co respectively. The test results are respectively listed in Table 2 below.

Comparative example 6-10

The reaction conditions for preparing tetrahydrofurfurylamine are the same as in Example 1, except that the catalyst Raney nickel is replaced by Pd/C, Pt/C, Ru/C, Rh/C, and Raney Co respectively. The test results are respectively listed in Table 2 below.

Table 2

By comparing the examples of the present invention with the comparative examples, it can be seen that in the process of selectively catalyzing furfuryl alcohol to prepare furfurylamine or tetrahydrofurfurylamine, Raney nickel shows higher activity than Raney cobalt and noble metals, and noble metals are more active in reductive amination Under these conditions, the surface active sites are more likely to be occupied by NH ₃ adsorption, resulting in the catalyst being basically inactive.

Claims (9)

1. a method for selectively preparing furfurylamine or tetrahydrofurfurylamine is characterized in that, taking furfuryl alcohol as raw material, using metal nickel as a catalyst, under hydrogen-free conditions, prepares furfurylamine through reductive amination reaction; Under certain conditions, tetrahydrofurfurylamine was prepared by reductive amination reaction. 2. the method for selectively preparing furfurylamine or tetrahydrofurfurylamine according to claim 1 is characterized in that, specifically: Mix furfuryl alcohol, catalyst and organic solvent, feed ammonia gas, or ammonia/hydrogen blend gas until the pressure in the reactor reaches 0.1-2.0MPa, then heat to 120-220°C, after reduction amination reaction, After post-treatment, the said furfurylamine or tetrahydrofurfurylamine can be selectively obtained. 3. the method for selectively preparing furfurylamine or tetrahydrofurfurylamine according to claim 2, is characterized in that, described organic solvent is selected from tetrahydrofuran (THF), dioxane, methyl alcohol or ethanol; The mass ratio of the furfuryl alcohol to the catalyst is 1:0.05-0.8; The volume-mass ratio of the organic solvent to furfuryl alcohol is 15-50 mL/g. 4. The method for selectively preparing furfurylamine or tetrahydrofurfurylamine according to claim 2, characterized in that ammonia gas is introduced until the pressure in the reactor reaches 0.1 to 0.4 MPa, and then heated to 140 to 200° C. Selective preparation of furfurylamine by reductive amination reaction. 5. The method for selectively preparing furfurylamine or tetrahydrofurfurylamine according to claim 4, characterized in that, the ammonia gas is introduced until the pressure in the reactor reaches 0.3-0.4MPa, and then heated to 160-180°C, and the reaction After 48-60 hours, furfurylamine was prepared. 6. The method for selectively preparing furfurylamine or tetrahydrofurfurylamine according to claim 2, characterized in that, first feed ammonia gas until the pressure in the reactor reaches 0.1-0.4MPa, and then feed hydrogen gas into the reactor The pressure reaches 0.5-2.0MPa, heating to 140-200°C, and selective preparation of tetrahydrofurfurylamine through reductive amination reaction. 7. The method for selectively preparing furfurylamine or tetrahydrofurfurylamine according to claim 6, characterized in that, first feed ammonia until the pressure in the reactor reaches 0.3-0.4MPa, and then feed hydrogen into the reactor The pressure reaches 0.8-1.5MPa, heating to 160-180°C, and reacting for 48-60 hours to prepare tetrahydrofurfurylamine. 8. the method for selectively preparing furfurylamine or tetrahydrofurfurylamine according to claim 5 or 7, is characterized in that, described organic solvent is selected from tetrahydrofuran; The feeding mass of furfuryl alcohol and catalyst is 1:0.5; The volume to mass ratio of the organic solvent to furfuryl alcohol is 30mL/g. 9. the method for selectively preparing furfurylamine or tetrahydrofurfurylamine according to claim 2, is characterized in that, described aftertreatment is: The reaction liquid is filtered, and the catalyst can be recovered after the filter cake is washed; the filtrate is distilled under reduced pressure to obtain the final product.