Preparation method of n-borneol

Abstract

The invention relates to a preparation method of n-borneol. Specifically, the invention provides a preparation method of n-borneol, and the method comprises the following steps: (1) mixing a solvent and isoborneol, heating and dissolving to obtain a solution containing raw materials, pumping the solution containing the raw materials into a dehydrogenation fixed bed reactor filled with a catalyst, and carrying out a dehydrogenation reaction; (2) feeding the material subjected to the dehydrogenation reaction in the step (1) into a gas-liquid separator, discharging hydrogen from an emptying port in the gas-liquid separator, pumping reaction liquid into a hydrogenation fixed bed reactor filled with a catalyst, and simultaneously introducing hydrogen into the hydrogenation fixed bed reactor for hydrogenation reaction; and (3) feeding the material subjected to the hydrogenation reaction in the step (2) into a gas-liquid separator, discharging hydrogen from an emptying port of the gas-liquid separator, and feeding the reaction liquid into a crystallization kettle for crystallization to obtain the n-borneol. The preparation method of the n-borneol is high in production efficiency and beneficial to industrial production.

Description

Technical Field

[0001] The invention relates to the field of chemical industry, and in particular to a method for preparing borneol. Background Art

[0002] Borneol, also known as borneol, is a colorless, transparent or white, translucent, flaky, crispy crystal. It tastes pungent, bitter, and slightly cold. It enters the heart, liver, and lung meridians. It has a refreshing fragrance and has the effects of invigorating the mind, clearing away heat and dispersing toxins, improving eyesight and removing cataracts. It is mainly used to treat high fever and coma caused by febrile disease, stroke, phlegm, convulsions, epilepsy, obstruction of the clear orifices caused by heat and dampness, throat paralysis and deafness, mouth sores and swollen teeth, sores, carbuncles, malnutrition and hemorrhoids, red and swollen eyes, and cataracts covering the eyes.

[0003] However, the existing synthesis methods of borneol often have many disadvantages. For example, the prior art often uses α-pinene as a raw material for esterification. Acid borneol ester is then saponified and crystallized to prepare borneol. However, the process route of this method is relatively complicated, the yield is low, and the first step of esterification has a large exothermic heat, high risk, and relatively high requirements for operating conditions, which is not conducive to industrial production, thereby limiting the application value of borneol. Therefore, how to effectively achieve the effective preparation of borneol has become a research hotspot.

[0004] Therefore, there is a need in the art to develop a method for effectively preparing borneol. Summary of the invention

[0005] The object of the present invention is to provide a method for effectively preparing borneol, wherein the borneol prepared by the method has an excellent yield and is conducive to industrial production.

[0006] In a first aspect of the present invention, a method for preparing borneol is provided, wherein the method comprises:

[0007] (1) mixing a solvent and isoborneol, heating and dissolving the mixture to obtain a solution containing a raw material, and injecting the solution containing the raw material into a dehydrogenation fixed bed reactor containing a catalyst to perform a dehydrogenation reaction;

[0008] (2) the material after the dehydrogenation reaction in step (1) enters a gas-liquid separator, hydrogen is discharged from the vent in the gas-liquid separator, the reaction liquid is pumped into a hydrogenation fixed bed reactor containing a catalyst, and hydrogen is added to the hydrogenation fixed bed reactor to carry out a hydrogenation reaction;

[0009] (3) The material after the hydrogenation reaction in step (2) enters a gas-liquid separator, hydrogen is discharged from the vent of the gas-liquid separator, and the reaction liquid enters a crystallization kettle for crystallization to obtain borneol.

[0010] Preferably, in step (1), the solvent comprises p-menthane and / or p-cymene.

[0011] Preferably, in step (1), the solvent comprises p-menthane.

[0012] Preferably, in the step (1), the mass ratio of the solvent to the isoborneol is (5-9):(1-5), preferably (6-8):(2-4), more preferably (6.5-7.5), (2.5-3.5), more preferably (6.8-7.2):(2.8-3.2), and optimally 7:3.

[0013] Preferably, in step (1), the solution containing the raw material is stirred for 0.1-0.6 h. -1 (Preferably 0.1-0.4h -1 , preferably 0.1-0.3h -1 , optimally 0.2h -1 ) is injected into the dehydrogenation fixed bed reactor filled with catalyst.

[0014] Preferably, in step (1), the solution containing the raw material is pumped from the bottom or top into a dehydrogenation fixed bed reactor containing a catalyst.

[0015] Preferably, in step (1), the temperature of the dehydrogenation reaction is 150-190°C, preferably 160-180°C, more preferably 165-175°C, and most preferably 170°C.

[0016] Preferably, in step (1), the dehydrogenation reaction is carried out under normal pressure.

[0017] Preferably, in the dehydrogenation fixed bed reactor containing a catalyst in step (1), the catalyst comprises supported CuO and / or CoO3.

[0018] Preferably, in the dehydrogenation fixed bed reactor containing a catalyst in step (1), the catalyst comprises supported CuO.

[0019] Preferably, in step (2), the material after the dehydrogenation reaction in step (1) enters the gas-liquid separator through the outlet of the dehydrogenation fixed bed reactor.

[0020] Preferably, in step (2), the reaction solution is stirred for 0.1-0.8 h. -1 (Preferably 0.1-0.5h -1 , preferably 0.2-0.4h -1 , optimally 0.3h -1 ) is injected into a hydrogenation fixed bed reactor containing a catalyst.

[0021] Preferably, in the hydrogenation fixed bed reactor containing a catalyst in step (2), the catalyst comprises supported Cr, Co and / or Ni, preferably supported Co.

[0022] Preferably, in step (2), the temperature of the hydrogenation reaction is 110-150°C, preferably 120-140°C, more preferably 125-135°C, and most preferably 130°C.

[0023] Preferably, in step (2), the pressure of the hydrogenation reaction is 4-6 MPa, preferably 4.5-5.5 MPa, more preferably 4.8-5.2 MPa, and most preferably 5 MPa.

[0024] Preferably, in step (3), the reaction liquid is pumped into the crystallization kettle from the bottom of the gas-liquid separator.

[0025] Preferably, in step (3), the crystallization temperature is 8-25°C, preferably 10-20°C, more preferably 13-17°C, and most preferably 15°C.

[0026] Preferably, the method comprises:

[0027] (1) Add p-menthane and isoborneol in a mass ratio of 7:3 into a raw material dissolving kettle, heat to 100°C for dissolution, and after the dissolution is completed, heat the solution for 0.2 h. -1 The gas was pumped into a dehydrogenation fixed bed reactor containing a supported copper oxide catalyst from the bottom at a space velocity of 1.5 % to carry out a dehydrogenation reaction at normal pressure and 170°C.

[0028] (2) After the dehydrogenation reaction is completed, the material enters the gas-liquid separator through the outlet of the dehydrogenation fixed bed reactor. In the gas-liquid separator, hydrogen is discharged from the vent. The reaction liquid is cooled to room temperature at 0.3h. -1 The space velocity is pumped from the bottom into the hydrogenation fixed bed reactor filled with loaded Co, and hydrogen is added from the bottom of the hydrogenation fixed bed reactor to carry out hydrogenation reaction at a pressure of 5 MPa and 130°C;

[0029] (3) After the hydrogenation reaction is completed, the material enters the gas-liquid separator through the outlet of the hydrogenation fixed bed reactor, and the hydrogen is discharged from the vent of the gas-liquid separator. The reaction liquid is pumped from the bottom of the gas-liquid separator into a crystallization kettle and cooled to 15°C for crystallization. The crystals are filtered and dried to obtain borneol.

[0030] It should be understood that within the scope of the present invention, the above-mentioned technical features of the present invention and the technical features specifically described below (such as embodiments) can be combined with each other to form new or preferred technical solutions. DETAILED DESCRIPTION

[0031] The invention develops a method for preparing borneol by continuous dehydrogenation and hydrogenation of isoborneol. The method comprises: taking isoborneol as a raw material, dissolving it in a solvent and continuously pumping it into a dehydrogenation fixed bed reactor by a pump to carry out dehydrogenation under normal pressure under the action of a catalyst, and then the material enters a hydrogenation fixed bed reactor for catalytic hydrogenation reaction to obtain borneol.

[0032] the term

[0033] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

[0034] As used herein, the terms "including", "comprising", and "containing" are used interchangeably and include not only open definitions, but also semi-closed and closed definitions, and the terms include "consisting of", "consisting essentially of".

[0035] As used herein, the structure of borneol is as follows:

[0036]

[0037]

[0038] As used herein, the structure of isoborneol is as follows:

[0039]

[0040] As used herein, the structure of p-menthane is as follows:

[0041]

[0042] As used herein, normal pressure refers to one standard atmosphere.

[0043] method

[0044] The present invention provides a method for preparing borneol, the method comprising:

[0045] (1) mixing a solvent and isoborneol, heating and dissolving the mixture to obtain a solution containing a raw material, and injecting the solution containing the raw material into a dehydrogenation fixed bed reactor containing a catalyst to perform a dehydrogenation reaction;

[0046] (2) the material after the dehydrogenation reaction in step (1) enters a gas-liquid separator, hydrogen is discharged from the vent in the gas-liquid separator, the reaction liquid is pumped into a hydrogenation fixed bed reactor containing a catalyst, and hydrogen is added to the hydrogenation fixed bed reactor to carry out a hydrogenation reaction;

[0047] (3) The material after the hydrogenation reaction in step (2) enters a gas-liquid separator, hydrogen is discharged from the vent of the gas-liquid separator, and the reaction liquid enters a crystallization kettle for crystallization to obtain borneol.

[0048] Specifically, the preparation method of borneol according to the present invention is as described above in the first aspect of the present invention.

[0049] The main technical effects of the present invention include:

[0050] The invention develops a method for preparing borneol. The borneol prepared by the method has excellent yield and is conducive to industrial production.

[0051] The present invention will be further described below in conjunction with specific examples. It should be understood that these examples are only used to illustrate the present invention and are not intended to limit the scope of the present invention.

[0052] Example

[0053] The structure of borneol is as follows:

[0054]

[0055] The structure of isoborneol is as follows:

[0056]

[0057] The structure of p-mentane is as follows:

[0058]

[0059] Normal pressure refers to one standard atmospheric pressure.

[0060] Example 1

[0061] This embodiment 1 provides a method for preparing borneol, wherein the borneol is prepared by the following method:

[0062] (1) Add p-menthane and isoborneol in a mass ratio of 7:3 into a raw material dissolving kettle, heat to 100°C for dissolution, and after the dissolution is completed, heat the solution for 0.2 h. -1 The gas was pumped from the bottom into a dehydrogenation fixed bed reactor filled with a supported copper oxide catalyst at an air velocity of 1.5 to 2.5 ℃, and the dehydrogenation reaction was carried out at normal pressure and 170°C.

[0063] (2) After the dehydrogenation reaction is completed, the material enters the gas-liquid separator through the outlet of the dehydrogenation fixed bed reactor. In the gas-liquid separator, hydrogen is discharged from the vent. The reaction liquid is cooled to room temperature at 0.3h. -1 The space velocity is pumped from the bottom into the hydrogenation fixed bed reactor filled with loaded Co, and hydrogen is added from the bottom of the hydrogenation fixed bed reactor at the same time, and the hydrogenation reaction is carried out at a pressure of 5 MPa and 130°C.

[0064] (3) After the hydrogenation reaction is completed, the material enters the gas-liquid separator through the outlet of the hydrogenation fixed bed reactor, and the hydrogen is discharged from the vent of the gas-liquid separator. The reaction liquid (the content of borneol in the reaction liquid is 61.53%, the content of isoborneol is 33.36%, and the content of camphor is 1.46%) is pumped from the bottom of the gas-liquid separator into a crystallization kettle and cooled to 15° C. for crystallization. The crystals are filtered and dried to obtain borneol.

[0065] Comparative Example 1

[0066] This comparative example 1 provides a method for preparing borneol, wherein the method is the same as that in Example 1, except that:

[0067] The catalyst in step (1) is replaced with a catalyst loaded with CoO3, and a dehydrogenation reaction is carried out at normal pressure and 180°C.

[0068] In step (2), the reaction liquid and hydrogen are added from the top of the hydrogenation fixed bed reactor at a space velocity of 0.2h -1 , the hydrogenation reaction was carried out at 8MPa pressure and 140℃.

[0069] It was determined that the content of borneol in the reaction solution in step (3) was 52.08%, the content of isoborneol was 42.91%, and the content of camphor was 2.18%.

[0070] Comparative Example 2

[0071] This comparative example 2 provides a method for preparing borneol, wherein the method is the same as that in Example 1, except that:

[0072] In step (2), the reaction liquid and hydrogen are added from the top of the hydrogenation fixed bed reactor at a space velocity of 0.1h -1 The hydrogenation catalyst is a supported Cr catalyst, and the hydrogenation reaction is carried out at a pressure of 7 MPa and 150°C.

[0073] It was determined that the borneol content in the reaction solution in step (3) was 53.82%, the isoborneol content was 40.53%, and the camphor content was 2.35%.

[0074] Comparative Example 3

[0075] This comparative example 2 provides a method for preparing borneol, wherein the method is the same as that in Example 1, except that:

[0076] The solution in step (1) was heated for 0.6 h. -1 The gas was injected from the top into a dehydrogenation fixed bed reactor filled with a supported CuO catalyst at an air velocity of 1.5 to 2.5 ℃, and the dehydrogenation reaction was carried out at normal pressure and 130°C.

[0077] In step (2), a hydrogenation reaction is carried out at a pressure of 5 MPa and 100° C., and the hydrogenation catalyst is a supported Ni catalyst.

[0078] It was determined that the content of borneol in the reaction solution in step (3) was 50.18%, the content of isoborneol was 43.69%, and the content of camphor was 2.56%.

[0079] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for preparing borneol, characterized in that: The method includes: (1) mixing a solvent and isoborneol, heating and dissolving the mixture to obtain a solution containing a raw material, and injecting the solution containing the raw material into a dehydrogenation fixed bed reactor containing a catalyst to perform a dehydrogenation reaction; (2) the material after the dehydrogenation reaction in step (1) enters a gas-liquid separator, hydrogen is discharged from the vent in the gas-liquid separator, the reaction liquid is pumped into a hydrogenation fixed bed reactor containing a catalyst, and hydrogen is added to the hydrogenation fixed bed reactor to carry out a hydrogenation reaction; (3) The material after the hydrogenation reaction in step (2) enters a gas-liquid separator, hydrogen is discharged from the vent of the gas-liquid separator, and the reaction liquid enters a crystallization kettle for crystallization to obtain borneol.

2. The method according to claim 1, characterized in that In the step (1), the solvent includes p-menthane and / or p-cymene.

3. The method according to claim 1, characterized in that In the step (1), the solution containing the raw material is heated for 0.1-0.6 h. -1 (Preferably 0.1-0.4h -1 , preferably 0.1-0.3h -1 , optimally 0.2h -1 ) is injected into the dehydrogenation fixed bed reactor filled with catalyst.

4. The method according to claim 1, characterized in that In the step (1), the temperature of the dehydrogenation reaction is 150-190°C, preferably 160-180°C, more preferably 165-175°C, and most preferably 170°C; and / or In the step (1), the dehydrogenation reaction is carried out under normal pressure.

5. The method according to claim 1, characterized in that In the dehydrogenation fixed bed reactor filled with catalyst in step (1), the catalyst comprises supported CuO and / or CoO3.

6. The method according to claim 1, characterized in that In the step (2), the reaction solution is stirred for 0.1-0.8 h. -1 (Preferably 0.1-0.5h -1 , preferably 0.2-0.4h -1 , optimally 0.3h -1 ) is injected into a hydrogenation fixed bed reactor containing a catalyst.

7. The method according to claim 1, characterized in that In the hydrogenation fixed bed reactor filled with catalyst in step (2), the catalyst comprises supported Cr, Co and / or Ni, preferably supported Co.

8. The method according to claim 1, characterized in that In step (2), the temperature of the hydrogenation reaction is 110-150°C, preferably 120-140°C, more preferably 125-135°C, and most preferably 130°C; and / or In the step (2), the pressure of the hydrogenation reaction is 4-6 MPa, preferably 4.5-5.5 MPa, more preferably 4.8-5.2 MPa, and most preferably 5 MPa.

9. The method according to claim 1, characterized in that In the step (3), the crystallization temperature is 8-25°C, preferably 10-20°C, more preferably 13-17°C, and most preferably 15°C.

10. The method according to claim 1, characterized in that The method includes: (1) Add p-menthane and isoborneol in a mass ratio of 7:3 into a raw material dissolving kettle, heat to 100°C for dissolution, and after the dissolution is completed, heat the solution for 0.2 h. -1 The gas was pumped into a dehydrogenation fixed bed reactor containing a supported copper oxide catalyst from the bottom at a space velocity of 1.5 % and a dehydrogenation reaction was carried out at normal pressure and 170°C. (2) After the dehydrogenation reaction is completed, the material enters the gas-liquid separator through the outlet of the dehydrogenation fixed bed reactor. In the gas-liquid separator, hydrogen is discharged from the vent. The reaction liquid is cooled to room temperature at 0.3h. -1 The space velocity is pumped from the bottom into the hydrogenation fixed bed reactor filled with loaded Co, and hydrogen is added from the bottom of the hydrogenation fixed bed reactor to carry out hydrogenation reaction at a pressure of 5 MPa and 130°C; (3) After the hydrogenation reaction is completed, the material enters the gas-liquid separator through the outlet of the hydrogenation fixed bed reactor, and the hydrogen is discharged from the vent of the gas-liquid separator. The reaction liquid is pumped from the bottom of the gas-liquid separator into a crystallization kettle and cooled to 15°C for crystallization. The crystals are filtered and dried to obtain borneol.

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