A process for the preparation of tetrahydropyrroles by aminization of tetrahydrofuran

Abstract

The application discloses a method for preparing tetrahydropyrrole by tetrahydrofuran ammination, which comprises the following steps: reacting raw materials containing tetrahydrofuran and ammonia with a catalyst to obtain a tetrahydropyrrole product; and the catalyst is a ZSM-5 / ZSM-11 eutectic molecular sieve catalyst. The shaped ZSM-5 / ZSM-11 eutectic molecular sieve catalyst is adopted, so that the selectivity and yield of the tetrahydropyrrole product can be improved, the reaction device can be simplified, and industrial production can be realized.

Description

Technical Field

[0001] The present application relates to a method for preparing tetrahydropyrrole by amination of tetrahydrofuran, belonging to the field of preparation of tetrahydropyrrole. Background Art

[0002] Tetrahydropyrrole is an important fine chemical intermediate with widespread applications in organic synthesis, pharmaceuticals, pesticides, coatings, and daily chemicals. It can be used to synthesize dozens of drugs, including buflomedil, dextromorphamide tartrate, procyclidine, procyclidine, and carmatelin. It can also be used to synthesize insecticides such as dicamba. Tetrahydropyrrole reacts with aldehydes and ketones to produce enamine compounds. Tetrahydropyrrole is a key solvent in the fine chemical and pharmaceutical industries. It is an organic template for the synthesis of molecular sieves such as ZSM-5, ZSM-35, and ZSM-48. Furthermore, it can be used as a desulfurization agent, additive, and other fine chemical raw materials.

[0003] Tetrahydropyrrole can be synthesized from raw materials such as 1,4-butanediol, 1,4-succinonitrile, 1,4-butanediamine, and tetrahydrofuran. Among them, the synthesis of tetrahydropyrrole by catalytic amination of 1,4-butanediol and tetrahydrofuran has the advantages of simple reaction process, low raw material cost, and high atom utilization rate, and has high industrial application value.

[0004] However, existing catalysts are all powdered catalysts, which place high demands on the reactor during the preparation of tetrahydropyrrole, making it difficult to achieve industrialization. Summary of the Invention

[0005] The present application provides a method for preparing tetrahydropyrrole by amination of tetrahydrofuran, which uses a formed ZSM-5 / ZSM-11 eutectic molecular sieve catalyst. While maintaining high tetrahydropyrrole selectivity and yield, the process of preparing tetrahydropyrrole by amination of tetrahydrofuran can be industrialized.

[0006] According to one aspect of the present application, there is provided a method for preparing tetrahydropyrrole by amination of tetrahydrofuran, comprising the following steps:

[0007] The raw material containing tetrahydrofuran and ammonia is contacted with a catalyst to react to obtain a tetrahydropyrrole product;

[0008] The catalyst is a ZSM-5 / ZSM-11 eutectic molecular sieve catalyst.

[0009] Optionally, the reaction pressure is 0-3 MPa; the reaction temperature is 150-450°C.

[0010] In this application, "0 MPa" means a normal pressure state.

[0011] Optionally, the reaction pressure is selected from any value or range between two values selected from 0 MPa, 0.5 MPa, 1.0 MPa, 1.5 MPa, 2.0 MPa, 2.5 MPa, 2.8 MPa, 3.0 MPa.

[0012] Optionally, the reaction temperature is selected from any value or range between two values selected from 150℃, 200℃, 220℃, 260℃, 310℃, 320℃, 360℃, 380℃, 400℃, 450℃.

[0013] Optionally, the space velocity of the tetrahydrofuran is 0.02-2.0h -1 .

[0014] Optionally, the space velocity of the tetrahydrofuran is selected from any value or range between two values selected from 0.02h -1 , 0.08h -1 , 0.5h -1 , 1.0h -1 , 1.5h -1 , 1.8h -1 , 2.0h -1 .

[0015] Optionally, the molar ratio of ammonia to tetrahydrofuran in the raw material is 2-20.

[0016] Optionally, the molar ratio of ammonia to tetrahydrofuran in the raw material is selected from any value or range between two values selected from 2, 4, 6, 8, 10, 14, 18, 20.

[0017] Optionally, the preparation method of the ZSM-5 / ZSM-11 eutectic molecular sieve catalyst comprises the following steps:

[0018] Mixing the mixed raw material containing eutectic molecular sieve raw powder, binder and sesbania powder with an acid solution, molding, calcining I, ion exchange, calcining II, to obtain the ZSM-5 / ZSM-11 eutectic molecular sieve catalyst.

[0019] Optionally, the content of ZSM-5 molecular sieve in the ZSM-5 / ZSM-11 eutectic molecular sieve catalyst is 0-99.5wt%, and the content of ZSM-11 molecular sieve is 0.5-100wt%.

[0020] Optionally, the molar ratio of silicon dioxide to aluminum oxide in the eutectic molecular sieve raw powder is 15-500.

[0021] Optionally, the mass ratio of the eutectic molecular sieve raw powder to the binder is 0.05-19:1.

[0022] Optionally, the mass of the sesbania powder accounts for 0.1 to 15.0 wt % of the total mass of the eutectic molecular sieve raw powder and the adhesive.

[0023] Optionally, the mass of the acid solution accounts for 10 to 70 wt % of the total mass of the eutectic molecular sieve raw powder and the adhesive.

[0024] Optionally, the concentration of the acid solution is 1 to 8 wt%.

[0025] Optionally, the adhesive is pseudo-boehmite.

[0026] Optionally, the acid solution is a nitric acid solution.

[0027] Optionally, the forming method is extrusion or ball rolling.

[0028] Optionally, the calcination conditions are as follows: in an oxygen-containing atmosphere, heating the temperature to 440-600° C. at a heating rate of 0.5-3.0° C. / min, and keeping the temperature for 3-24 h.

[0029] Optionally, the calcination II conditions are: in an oxygen-containing atmosphere, heating the temperature to 420-550° C. at a heating rate of 0.5-3.0° C. / min, and keeping the temperature for 1-5 hours.

[0030] Optionally, the ion exchange conditions are: temperature 50-95° C., time 0.5-24 h.

[0031] Optionally, the ion exchange solution is selected from at least one of oxalic acid, hydrochloric acid, ammonium chloride, and ammonium nitrate.

[0032] As a specific preparation method of a ZSM-5 / ZSM-11 eutectic molecular sieve catalyst, the method comprises the following steps:

[0033] 1) The raw materials containing ZSM-5 / ZSM-11 eutectic molecular sieve powder, pseudo-boehmite, and sesbania powder are fully mixed with dilute nitric acid and formed, wherein the content of each component is:

[0034] a) The mass ratio of ZSM-5 / ZSM-11 eutectic molecular sieve powder to pseudo-boehmite is (0.05-19):1;

[0035] b) the mass of sesbania powder is 0.1 to 15.0 wt% of the total mass of ZSM-5 / ZSM-11 eutectic molecular sieve powder and binder;

[0036] c) the mass of the dilute nitric acid solution is 10 to 70 wt% of the total mass of the ZSM-5 / ZSM-11 eutectic molecular sieve powder and the binder;

[0037] d) the concentration of the dilute nitric acid solution is 1 to 8 wt%;

[0038] e) The content of ZSM-5 molecular sieve in the ZSM-5 / ZSM-11 eutectic molecular sieve is 0% to 99.5%, the content of ZSM-11 molecular sieve is 0.5% to 100%, and the sum of the content of ZSM-5 molecular sieve and the content of ZSM-11 molecular sieve is 100%.

[0039] f) The molar ratio of silicon dioxide to aluminum oxide in the ZSM-5 / ZSM-11 eutectic molecular sieve raw powder is 15 to 500.

[0040] 2) slowly raising the temperature (0.5-3°C / min) to 440-600°C under flowing air and maintaining it for 3-24 hours to remove the organic template;

[0041] 3) The calcined sample is exchanged with oxalic acid, hydrochloric acid, ammonium chloride or ammonium nitrate solution and then dried at 60-130°C for 6-12 hours;

[0042] 4) The exchanged sample is slowly heated (0.5-3° C. / min) to 420-550° C. under a flowing air atmosphere and maintained for 1-5 hours to obtain a hydrogenated ZSM-5 / ZSM-11 eutectic molecular sieve catalyst.

[0043] The beneficial effects of this application include:

[0044] 1) The method for preparing tetrahydropyrrole by amination of tetrahydrofuran provided in the present application uses a formed ZSM-5 / ZSM-11 eutectic molecular sieve catalyst, which can not only improve the selectivity and yield of the tetrahydropyrrole product but also simplify the reaction apparatus and realize industrial production.

[0045] 2) The method for preparing tetrahydropyrrole by amination of tetrahydrofuran provided in the present application uses a formed ZSM-5 / ZSM-11 eutectic molecular sieve catalyst and can achieve high tetrahydropyrrole selectivity and yield within the reaction range of 150 to 450°C.

[0046] 3) The method for preparing tetrahydropyrrole by amination of tetrahydrofuran provided in the present application uses a low-cost catalyst, readily available raw materials, and is simple to operate. DETAILED DESCRIPTION

[0047] The present application is described in detail below with reference to embodiments, but the present application is not limited to these embodiments.

[0048] Unless otherwise specified, the raw materials in the examples of this application were purchased through commercial channels.

[0049] The analysis method in the examples of this application is as follows:

[0050] tetrahydrofuran conversion = (moles of carbon of tetrahydrofuran in reactant - moles of carbon of tetrahydrofuran in product) / moles of carbon of tetrahydrofuran in reactant x 100%

[0051] tetrahydrofuran conversion = (moles of carbon of tetrahydrofuran in reactant - moles of carbon of tetrahydrofuran in product) / moles of carbon of tetrahydrofuran in reactant x 100%

[0052] tetrahydrofuran conversion = (moles of carbon of tetrahydrofuran in reactant - moles of carbon of tetrahydrofuran in product) / moles of carbon of tetrahydrofuran in reactant x 100%

[0053] In the embodiments of the present application, the tetrahydrofuran conversion, the tetrahydrofuran selectivity and the tetrahydrofuran yield are all calculated based on the carbon moles.

[0054] Example 1

[0055] 11.36 g of ZSM-5 / ZSM-11 eutectic molecular sieve (dry basis 88%, ZSM-5 content 95%, molar ratio of silica to alumina 400), 116.13 g of pseudoboehmite (dry basis 77.5%), 12.00 g of sesbania powder, 20.00 g of dilute nitric acid solution with a mass concentration of 6.5 wt% were thoroughly mixed, and molding was performed by extrusion. Drying was performed at 80°C for 12 h. Then, temperature was raised to 580°C at 1.5°C / min, and maintained for 4 h, so as to remove the organic template. Ion exchange was performed with 0.8 mol / L of ammonium nitrate solution, and repeated three times. After drying at 120°C, temperature was raised to 530°C at 1.5°C / min, and maintained for 4 h. Thus, a columnar catalyst with a ZSM-5 / ZSM-11 eutectic molecular sieve content of 10% was obtained, and was recorded as catalyst A.

[0056] Example 2

[0057] 51.14 g of ZSM-5 / ZSM-11 eutectic molecular sieve (dry basis 88%, ZSM-5 content 55%, molar ratio of silica to alumina 25), 70.97 g of pseudoboehmite (dry basis 77.5%), 8.00 g of sesbania powder, 60.00 g of dilute nitric acid solution with a mass concentration of 2.0 wt% were thoroughly mixed, and molding was performed by rolling. Drying was performed at 90°C for 8 h. Then, temperature was raised to 460°C at 2.5°C / min, and maintained for 20 h, so as to remove the organic template. Ion exchange was performed with 0.8 mol / L of oxalic acid solution, and repeated three times. After drying at 80°C, temperature was raised to 450°C at 2.5°C / min, and maintained for 2 h. Thus, a spherical catalyst with a ZSM-5 / ZSM-11 eutectic molecular sieve content of 45% was obtained, and was recorded as catalyst B.

[0058] Example 3

[0059] 102.27g of ZSM-5 / ZSM-11 eutectic molecular sieve (88% dry basis, 10% ZSM-5 content, 60 silica to alumina molar ratio), 12.90g of pseudo-boehmite (77.5% dry basis), 1.50g of sesbania powder, and 45.00g of a 4.0wt% dilute nitric acid solution were thoroughly mixed and formed into strips by extrusion. The strips were dried at 120°C for 8h. The temperature was then increased to 530°C at a rate of 2.0°C / min and held for 6h to remove the organic template. Ion exchange was performed using a 0.8mol / L ammonium chloride solution, repeated three times. After drying at 80°C, the temperature was increased to 510°C at a rate of 2.0°C / min and held for 3h. This resulted in a columnar catalyst containing 90% ZSM-5 / ZSM-11 eutectic molecular sieve, designated Catalyst C.

[0060] Example 4

[0061] The catalytic performance of the prepared catalyst in the amination of tetrahydrofuran to tetrahydropyrrole was evaluated in a fixed-bed reactor. The reactor diameter was 13 mm, the catalyst loading was 3 g, the reaction pressure was 0.0-3.0 MPa (0.0 MPa represents atmospheric pressure), the reaction temperature was 160-450°C, and the tetrahydrofuran space velocity was 0.02-2.0 h-1. -1 , the ammonia / tetrahydrofuran molar ratio is 2 to 20.

[0062] The reaction results are shown in Table 1.

[0063] Table 1 Catalytic performance of the catalyst of the present invention in the amination reaction of tetrahydrofuran to tetrahydropyrrole

[0064]

[0065]

[0066] The above descriptions are merely a few embodiments of the present application and do not constitute any form of limitation to the present application. Although the present application discloses the preferred embodiments as above, they are not intended to limit the present application. Any technical personnel familiar with the present profession, without departing from the scope of the technical solution of the present application, using the technical content disclosed above to make slight changes or modifications are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims

1. A method for preparing tetrahydropyrrole by amination of tetrahydrofuran, characterized in that: The following steps are involved: The raw material containing tetrahydrofuran and ammonia is contacted with a catalyst to react to obtain a tetrahydropyrrole product; The catalyst is a ZSM-5 / ZSM-11 eutectic molecular sieve catalyst; The preparation method of the ZSM-5 / ZSM-11 eutectic molecular sieve catalyst comprises the following steps: The mixed raw material containing eutectic molecular sieve raw powder, adhesive, and sesbania powder is mixed with an acid solution, formed, calcined I, ion-exchanged, and calcined II to obtain the ZSM-5 / ZSM-11 eutectic molecular sieve catalyst; The content of ZSM-5 molecular sieve in the ZSM-5 / ZSM-11 eutectic molecular sieve catalyst is 0-99.5 wt %, and the content of ZSM-11 molecular sieve is 0.5-100 wt %.

2. The method according to claim 1, characterized in that The molar ratio of silicon dioxide to aluminum oxide in the eutectic molecular sieve raw powder is 15-500.

3. The method according to claim 1, characterized in that The mass ratio of the eutectic molecular sieve raw powder to the adhesive is 0.05~19:

1.

4. The method according to claim 1, wherein The mass of the sesbania powder accounts for 0.1-15.0 wt % of the total mass of the eutectic molecular sieve raw powder and the binder.

5. The method according to claim 1, wherein The mass of the acid solution accounts for 10-70 wt % of the total mass of the eutectic molecular sieve raw powder and the adhesive.

6. The method according to claim 1, characterized in that The concentration of the acid solution is 1-8 wt %.

7. The method according to claim 1, characterized in that The adhesive is pseudo-boehmite.

8. The method according to claim 1, characterized in that The acid solution is a nitric acid solution.

9. The method according to claim 1, characterized in that The forming method is extrusion or ball rolling.

10. The method according to claim 1, characterized in that The calcination conditions are as follows: in an oxygen-containing atmosphere, heating the temperature to 440-600° C. at a heating rate of 0.5-3.0° C. / min and keeping the temperature for 3-24 hours.

11. The method according to claim 1, wherein The calcination II conditions are as follows: in an oxygen-containing atmosphere, heating the temperature to 420-550° C. at a heating rate of 0.5-3.0° C. / min, and keeping the temperature for 1-5 hours.

12. The method according to claim 1, characterized in that The ion exchange conditions are: temperature 50-95° C., time 0.5-24 h.

13. The method according to claim 1, wherein The exchange solution for the ion exchange is selected from at least one of oxalic acid, hydrochloric acid, ammonium chloride and ammonium nitrate.

14. The method according to claim 1, wherein The reaction pressure is 0-3.0 MPa, wherein 0 MPa is normal pressure; The reaction temperature is 150-450°C.

15. The method according to claim 1, wherein The space velocity of the tetrahydrofuran is 0.02~2.0h -1 .

16. The method according to claim 1, wherein The molar ratio of ammonia to tetrahydrofuran in the raw material is 2-20.

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