Method for continuous production of campholenic aldehyde by one-step method of pinene and application thereof

Abstract

The application relates to the field of organic synthesis and discloses a method for continuously producing camphene aldehyde from pinene by one-step method and application of the method, which comprises the following steps: continuously feeding an organic solution of alpha-pinene and neutral organic peroxide into a reactor in the presence of a main catalyst A and an auxiliary catalyst B to perform continuous contact reaction, wherein the main catalyst A is an oxidation catalyst, and the auxiliary catalyst B contains alkali metal and / or alkaline earth metal. According to the method, camphene aldehyde can be directly produced from pinene by one-step method of epoxidation and isomerization rearrangement reaction, and the selectivity and yield of the camphene aldehyde product are relatively high. The method avoids complicated operation steps such as rectification purification required by a two-segment reaction process, reduces the reaction process, and simultaneously adopts a continuous production process, so that production is efficient, convenient and stable.

Description

Technical Field

[0001] This invention relates to the field of organic synthesis, and more specifically to a one-step continuous method for producing borneol from pinene and its application. Background Technology

[0002] Turpentine oil, as an existing biomass natural resource, mainly consists of α-pinene and β-pinene, which can be catalytically converted into 2,3-epoxypinene and 2,10-epoxypinene, respectively. 2,3-epoxypinene can be further processed to produce important fragrance raw materials such as bornenaldehyde, carvacrol, and carvone. Bornenaldehyde is an important intermediate in the artificial synthesis of sandalwood fragrances, and through further processing, it can synthesize various classic sandalwood fragrances, such as Firmenich sandalwood, White Lehman sandalwood, and Javanese sandalwood.

[0003] Currently, the production of borneol from α-pinene requires a two-step process: first, preparing 2,3-epoxypinene, and then isomerizing and rearranging the pure 2,3-epoxypinene to obtain borneol. These two steps necessitate separate distillation to recover the solvent, product purification, and catalyst recovery. This two-step process involves numerous steps, high energy consumption, and the final product yield and purity are not ideal.

[0004] The production of epoxide pinane typically uses peracetic acid as an oxidant in a batch reactor and is purified by distillation. This process suffers from drawbacks such as high operational requirements, poor safety, equipment corrosion, complex post-processing, and low product yield. There are also reports attempting to prepare epoxide pinane by directly oxidizing pinene with hydrogen peroxide. For example, CN104119300 discloses a method for preparing 2,3-epoxide pinane using hydrogen peroxide to oxidize α-pinene. Hydrogen peroxide is added dropwise to a mixed solvent of α-pinene, acetonitrile, and NaHCO3 aqueous solution at 50–80 °C. After the reaction, the mixture is filtered, separated, the organic phase is extracted and recovered, and then the organic phase is distilled to obtain 2,3-epoxide pinane. This method is complex and difficult to achieve efficient and stable production.

[0005] The isomerization rearrangement of 2,3-epoxypine to produce borneol has been studied before. For example, US6515186B2 describes a method for preparing borneol by reactive distillation of 2,3-epoxypine, using zinc chloride, zinc bromide, or a mixture thereof as catalysts in toluene or benzene solvents. CN101885671A discloses a solvent-free gas-phase continuous synthesis method for borneol. This process involves passing heated and flash-vaporized epoxypine into a tubular reactor under vacuum conditions, where it reacts with a solid catalyst to synthesize borneol; however, the catalytic mechanism is not fully understood.

[0006] In publicly reported cases, the two-step synthesis of borneol from α-pinene in batch reactors remains an unresolved issue, and continuous production is not yet mature and has not been reported. Compared to batch reactors, fixed-bed continuous production offers advantages such as better operability, convenient material post-processing, and ease of scale-up, enabling large-scale and stable production of borneol. However, currently, there is still a lack of efficient, convenient, and scalable one-step continuous production methods for borneol from α-pinene. Summary of the Invention

[0007] The purpose of this invention is to overcome the difficulties in achieving one-step preparation of borneol from α-pinene in existing technologies, and the fact that the two-step synthesis of borneol from α-pinene cannot escape the batch reactor reaction. This invention provides a one-step continuous method for producing borneol from pinene. This method directly and continuously produces borneol from pinene through two steps of epoxidation and isomerization rearrangement, reducing reaction steps, resulting in a highly efficient and stable production process. The borneol product exhibits high selectivity and yield, and the catalyst is easy to separate and has a high recycling rate. It has the advantages of simple operation steps, low production cost, and ease of industrial-scale production.

[0008] To achieve the above objectives, the present invention provides a one-step continuous production method of borneol from pinene. The method includes: continuously feeding an organic solution of α-pinene and a neutral organic peroxide into a reactor for continuous contact reaction in the presence of a main catalyst A and a co-catalyst B. The main catalyst A is an oxidation catalyst, and the co-catalyst B contains an alkali metal and / or an alkaline earth metal.

[0009] A second aspect of the present invention provides the application of the method described herein in the synthesis of sandalwood fragrance.

[0010] The present invention provides a one-step continuous production method for penneadine aldehyde, which enables the direct one-step continuous production of penneadine aldehyde by the sequential epoxidation and isomerization rearrangement of penneadine in the same reaction system within a single reactor, with high selectivity and yield of the penneadine aldehyde product. This method avoids the cumbersome steps of distillation and purification required in two-stage reaction processes, reducing the number of reaction steps. Furthermore, the continuous production process ensures high efficiency, convenience, and stability. In addition, the catalyst is easy to separate and recover after the reaction, with a high recycling rate, offering advantages such as simple operation, low production cost, and ease of industrial-scale production. Detailed Implementation

[0011] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0012] This invention provides a one-step continuous production method of borneol from pinene. The method includes: continuously feeding an organic solution of α-pinene and a neutral organic peroxide into a reactor for continuous contact reaction in the presence of a main catalyst A and a co-catalyst B. The main catalyst A is an oxidation catalyst, and the co-catalyst B contains an alkali metal and / or an alkaline earth metal.

[0013] The method for one-step continuous production of borneol from pinene provided by this invention avoids the cumbersome operation steps such as distillation and purification required by two segmented reaction processes, reduces reaction steps, and adopts a continuous production process, which is efficient, convenient and stable.

[0014] In this invention, the mass ratio of the main catalyst A to the co-catalyst B can be selected within a wide range. The following is an illustrative description, but it does not limit the scope of the invention. According to a preferred embodiment of the invention, the mass ratio of the main catalyst A to the co-catalyst B is 0.1-10:1, preferably 0.5-2:1.

[0015] In this invention, the range of types of main catalyst A is relatively wide, and commonly used oxidation catalysts such as titanium-silicon oxidation catalysts can be applied to this invention.

[0016] The following is an illustrative description, but does not limit the scope of the invention. According to a preferred embodiment of the invention, the main catalyst A is one or more of mesoporous titanium silicate molecular sieves and modified mesoporous oxides.

[0017] According to a preferred embodiment of the present invention, the main catalyst A is one or more of Ti-MCM-41, Ti-MCM-48, Ti-SBA-15, Ti-HMS, Ti-MTS-9, mesoporous TS-1, mesoporous TS-2, mesoporous Ti-beta, mesoporous Ti-MWW, mesoporous Ti-ZSM-12, mesoporous Ti-ZSM-48, mesoporous Ti-MCM-68, mesoporous Ti-FER, mesoporous Ti-MOR, mesoporous Ti-UTD molecular sieve, mesoporous Ti-supported amorphous silica, and mesoporous titanium silica oxide, preferably one or more of Ti-HMS molecular sieve and mesoporous Ti-beta molecular sieve.

[0018] In this invention, there are no special requirements for the type of cocatalyst B. The following is an illustrative description, but it does not limit the scope of the invention. According to a preferred embodiment of the invention, the cocatalyst B is one or more of the following: alkali metal exchanged microporous molecular sieve, alkaline earth metal exchanged microporous molecular sieve, alkali metal exchanged resin, and alkaline earth metal exchanged resin.

[0019] In this invention, the form of the main catalyst A is selected and determined according to the requirements of the reactor. Commonly used continuous reactors, such as fixed-bed reactors, can use shaped catalysts. According to one embodiment of this invention, the main catalyst A is in a shaped form, and there are no special requirements for the morphology. For example, it can be selected from one or more of the following: flake, ring, sphere (granule), extruded strip, special strip, and amorphous.

[0020] In this invention, the characteristic parameters of the main catalyst A, such as Ti content, length, specific surface area, average pore size, diameter, and bulk density, are not particularly required and can be selected according to actual needs. For example, the Ti content of the main catalyst A can be 0.5-5 wt%, the length can be 1-10 mm, and the specific surface area can be 250-600 m². 2 / g, with an average pore size of 2-15nm, a diameter of 1-6mm, and a bulk density of 0.2-0.8.

[0021] In this invention, the co-catalyst only needs to contain alkali metals and / or alkaline earth metals to achieve the purpose of this invention. It can be arbitrarily attached to other materials for use in this invention. The attachment materials are, for example, molecular sieves, resins, etc.

[0022] According to a preferred embodiment of the present invention, the co-catalyst B is one or more selected from alkali metal-exchanged microporous molecular sieves, alkaline earth metal-exchanged microporous molecular sieves, alkali metal-exchanged resins, and alkaline earth metal-exchanged resins; preferably, the co-catalyst B is a 3A molecular sieve, a 4A molecular sieve, a 5A molecular sieve, a 10X molecular sieve, a 13X molecular sieve, a Na-Y molecular sieve, a Ca-Y molecular sieve, a MOR molecular sieve, a Na-ZSM-5 molecular sieve, a K-ZSM-5 molecular sieve, a Ca-ZSM-5 molecular sieve, or a Na-Be One or more of the following: ta molecular sieve, K-beta molecular sieve, Ca-beta molecular sieve, Na-SAPO-31 molecular sieve, K-SAPO-31 molecular sieve, Ca-SAPO-31 molecular sieve, Na-SAPO-34 molecular sieve, K-SAPO-34 molecular sieve, Ca-SAPO-34 molecular sieve, Na-type PS-based cation exchange resin, K-type PS-based cation exchange resin, and Ca-type PS-based cation exchange resin, preferably one or more of 4A molecular sieve and Na-type PS-based cation exchange resin.

[0023] In this invention, the content of alkali metals and / or alkaline earth metals in co-catalyst B can be selected within a wide range. The following is an illustrative description, but it does not limit the scope of the invention. According to a preferred embodiment of the invention, the content of alkali metals and / or alkaline earth metals in co-catalyst B is within 15 wt%, preferably 6-12 wt%, with the remainder being support material.

[0024] In this invention, the form of the co-catalyst B is selected and determined according to the requirements of the reactor. Commonly used continuous reactors, such as fixed-bed reactors, can use shaped catalysts. According to one embodiment of this invention, the co-catalyst B is in a shaped form, and there are no special requirements for the morphology. For example, it can be selected from one or more of the following: flake, ring, sphere (granule), extruded strip, special strip, and amorphous.

[0025] In this invention, the specific surface area, diameter, and bulk density of the co-catalyst B are not subject to special requirements and can be selected according to actual needs. For example, the specific surface area of ​​the co-catalyst B can be 500-900 m². 2 / g, with a diameter of 0.1-5mm and a bulk density of 0.3-1.2.

[0026] In this invention, there are no special requirements for the catalyst forming process, and it can be carried out in accordance with conventional methods in the field. For example, the main catalyst A and the co-catalyst B can be formed by one of the following methods: tablet forming, extrusion forming, oil forming, spray forming, and rotational forming.

[0027] According to a preferred embodiment of the present invention, the water content in the organic solution of the neutral organic peroxide is less than 10 wt%. The present invention, by performing oxidation in a system with lower aqueous content, enables the product, bornyl aldehyde, to exhibit higher selectivity (>70%).

[0028] In this invention, there are no special requirements for the type of neutral organic peroxide. Commonly used neutral organic peroxides are all applicable to this invention. The following is an illustrative description, but it does not limit the scope of this invention. According to a preferred embodiment of this invention, the neutral organic peroxide is one or more of tert-butanol hydroperoxide, cumene hydroperoxide, and ethylbenzene hydroperoxide, preferably one or more of cumene hydroperoxide and ethylbenzene hydroperoxide.

[0029] In this invention, the concentration of the neutral organic peroxide in the organic solution is not particularly required. It can be provided alone or as a solution. The following is an illustrative description, but it does not limit the scope of the invention. According to a preferred embodiment of the invention, the concentration of the neutral organic peroxide in the organic solution is 1-90 wt%.

[0030] In this invention, there are no special requirements for the type of organic solvent in the organic solution of the neutral organic peroxide. The following is an illustrative description, but it does not limit the scope of the invention. According to a preferred embodiment of the invention, the organic solvent in the organic solution of the neutral organic peroxide is one or more of acetonitrile, acetone, tetrahydrofuran, dimethyl sulfoxide, N,N-dimethylformamide, benzene, toluene, xylene, pentane, hexane, octane, cyclohexane, tert-butanol, n-butanol, methanol, ethanol, isopropanol, cyclohexanol, cumene, and ethylbenzene, preferably one or more of cumene and ethylbenzene.

[0031] According to a preferred embodiment of the present invention, the organic solution of the neutral organic peroxide is a cumene / isocumene hydroperoxide solution and / or an ethylbenzene / ethylbenzene hydroperoxide solution.

[0032] According to a preferred embodiment of the present invention, the concentration of the cumene hydrogen peroxide / cumene solution is 1-90 wt%, preferably 15-55 wt%, for example, it can be 15 wt%, 20 wt%, 25 wt%, 30 wt%, 35 wt%, 40 wt%, 45 wt%, 50 wt%, 55 wt%, etc.

[0033] According to a preferred embodiment of the present invention, the concentration of the hydrogen peroxide ethylbenzene / ethylbenzene solution is 1-45 wt%, preferably 10-40 wt%, for example, it can be 10 wt%, 15 wt%, 20 wt%, 25 wt%, 30 wt%, 35 wt%, 40 wt%, etc.

[0034] The aforementioned preferred technical solution enables highly selective continuous reaction production of borneol.

[0035] In this invention, the reactor has no special requirements, and commonly used continuous reactors can be used. According to a preferred embodiment of this invention, the reactor is a fixed-bed reactor, used for contact reaction to continuously produce borneol.

[0036] In the contact reaction of the present invention, the reaction temperature can be selected within a wide range. The following is an illustrative description, but it does not limit the scope of the present invention. According to a preferred embodiment of the present invention, the reaction temperature is 25-130°C, preferably 60-120°C, and for example, it can be 70°C, 80°C, 90°C, 100°C, 110°C, 120°C, etc.

[0037] In the contact reaction of this invention, the reaction pressure can be selected within a wide range. The following is an illustrative description, but it does not limit the scope of this invention. According to a preferred embodiment of this invention, the reaction pressure is 0.1-3 MPa, preferably 0.1-1.5 MPa, for example, it can be atmospheric pressure, 0.3 MPa, 0.5 MPa, 0.7 MPa, 0.9 MPa, 1.1 MPa, 1.3 MPa, 1.5 MPa, etc.

[0038] In the contact reaction of this invention, the liquid hourly space velocity (LISH) of α-pinene can be selected over a wide range. The following is an illustrative description, but it does not limit the scope of this invention. According to a preferred embodiment of this invention, the LISH of the α-pinene is 0.02-10 h⁻¹. -1 Preferably, it is 0.2-1.5h. -1 For example, it can be 0.3h -1 0.5h -1 0.7h -1 0.9h -1 1.1h -1 1.3h -1 1.5h -1 wait.

[0039] In the contact reaction of this invention, the liquid hourly space velocity (LISH) of the organic solution of the neutral organic peroxide can be selected within a wide range. The following is an illustrative description, but it does not limit the scope of this invention. According to a preferred embodiment of this invention, the LISH of the organic solution of the neutral organic peroxide is 0.01-5 h⁻¹. -1 Preferably 0.5-1h -1 For example, it can be 0.6h -1 0.7h -1 0.8h -1 0.9h -1 1h -1 wait.

[0040] In this invention, there are no special requirements for the reaction atmosphere of the contact reaction; various atmospheres are applicable to this invention. According to a preferred embodiment of this invention, the contact reaction is carried out in an oxygen-free environment, preferably in an inert atmosphere, such as in a nitrogen atmosphere.

[0041] In the contact reaction of this invention, there are no special requirements for the feeding method of the organic solutions of α-pinene and neutral organic peroxide. For example, the organic solutions of α-pinene and neutral organic peroxide can be fed into the reactor separately or mixed together.

[0042] In the contact reaction of this invention, there are no special requirements for the order in which the main catalyst A and the co-catalyst B are loaded into the reactor. For example, the main catalyst A and the co-catalyst B are mixed and then loaded into the reactor; or the main catalyst A bed is loaded first and then the co-catalyst B bed is loaded along the material flow direction; or the main catalyst A bed and the co-catalyst B bed are loaded alternately along the material flow direction.

[0043] In this invention, the one-step continuous production method of borneol from pinene further includes: distilling the reactants after the contact reaction to recover the raw materials and solvents, and purifying and collecting the borneol product.

[0044] Subsequent distillation separation and purification steps have no special requirements and can be carried out according to conventional methods in the field, which will not be elaborated here. This invention further purifies and collects the bornonyl aldehyde product and recovers α-pinene and organic solvents through distillation. Furthermore, the catalyst in this invention is easy to separate; it can be recovered and recycled simply by disassembling the catalyst packed in the fixed-bed reactor.

[0045] The method for one-step continuous production of borneol from pinene provided by this invention enables the direct one-step continuous production of borneol from pinene via epoxidation and isomerization rearrangement reactions in a fixed-bed reactor. This reduces the number of reaction steps and, by employing a continuous production process, ensures efficient, convenient, and stable production. Furthermore, the borneol product exhibits high selectivity and yield, and boasts advantages such as simple operation steps, low production costs, and ease of industrial-scale production.

[0046] This invention provides the application of the method described herein in the synthesis of sandalwood fragrance. The borneol obtained by this invention is an important intermediate in the synthesis of sandalwood fragrance and can be further used to synthesize a series of sandalwood fragrances.

[0047] In this invention, an Agilent 7890B gas chromatograph (GC, Agilent Technologies, USA) was used for quantification, equipped with a flame ionization detector (FID) and an HP-1 nonpolar capillary column. The test conditions for the gas chromatograph were as follows: Injection volume: 1 μL, via autosampler. Inlet temperature: 250℃, split ratio: 60:1 Column temperature: initial temperature 120℃, holding time 5 min. HP-1 chromatographic column, The detector is set at 250°C.

[0048] The formula for calculating the conversion rate of CHP or EBHP is: Conversion rate = (1- ) 100%.

[0049] The formula for calculating the conversion rate of 2,3-epoxypine is: 100%.

[0050] The formula for calculating the selectivity of borneol (based on the change in α-pinene reaction) is as follows: 100%.

[0051] Example 1 5g of shaped Ti-HMS molecular sieve catalyst (characteristic parameters: Ti content 2.6wt%, grayish-white strip shape, diameter 2mm, length 3-8mm, specific surface area 423m²) was used. 2 / g, average pore size 3nm, bulk density 0.45) and a co-catalyst in a 1:1 mass ratio to form a 4A molecular sieve catalyst (alkali metal content 10.5%, characteristic parameters: specific surface area 650m²). 2 (g, grayish-white spherical particles, 3 mm in diameter, bulk density 0.71) were mixed evenly and loaded into a fixed-bed reactor. The fixed-bed reactor was purged with nitrogen and the reaction pressure was maintained at 1.0 MPa. The first stream of α-pinene was introduced at a liquid hourly space velocity (LHSV) of 1.5 h⁻¹. -1 Simultaneously, a second stream, a 50 wt% solution of cumene hydroperoxide (CHP) / cumene, is introduced into the system at a liquid hourly space velocity (LISH) of 1 h⁻¹. -1 A fixed bed was heated to 70℃. Samples of the material flowing out of the reactor outlet were analyzed. The material then entered a distillation unit to separate and recover the raw materials and solvents, and to purify and collect the borneol aldehyde product. The liquid product was analyzed by gas chromatography, and the results are shown in Table 1.

[0052] Example 2 5g of shaped Ti-MCM-41 molecular sieve catalyst (characteristic parameters: Ti content 1.9wt%, grayish-white strip shape, diameter 2mm, length 3-8mm, specific surface area 335m²) was used. 2 / g, average pore size 4nm, bulk density 0.45) and a co-catalyst in a 1:1 mass ratio to form 13X molecular sieve catalyst (alkali metal content 9.1wt%, characteristic parameters: specific surface area 720m²). 2 (g, grayish-white spherical particles, 3 mm in diameter, bulk density 0.51) were mixed evenly and loaded into a fixed-bed reactor. The fixed-bed reactor was purged with nitrogen and the reaction pressure was maintained at 1.5 MPa. The first stream of α-pinene was introduced at a liquid hourly space velocity (LHSV) of 0.4 h⁻¹. -1 The fixed bed was heated to 70℃. A second stream, a 30wt% ethylbenzene hydrogen peroxide (EBHP) / ethylbenzene solution, was introduced into the system at a liquid hourly space velocity (LISH) of 0.6 h⁻¹. -1 The material flowing out of the reactor outlet was sampled and analyzed. The material flow entered the distillation unit to separate and recover the raw materials and solvents, and to purify and collect the borneol aldehyde product. The liquid product was analyzed by gas chromatography, and the results are shown in Table 1.

[0053] Example 3 5g of molded mesoporous Ti-beta molecular sieve catalyst (characteristic parameters: Ti content 2.9wt%, grayish-white spherical shape, diameter 4.7mm, specific surface area 512m²) was used. 2 A mixture of α-pinene (with an average pore size of 10 nm and a bulk density of 0.5 g) and Na-type PS-based cation exchange resin (alkali metal content 6.8 wt%, characteristic parameters: milky white to pale yellow spheres, diameter 0.3 mm, bulk density 0.9) at a mass ratio of 1:1 was thoroughly mixed and loaded into a fixed-bed reactor. The fixed-bed reactor was purged with nitrogen and the reaction pressure was maintained at 1.2 MPa. The first stream of α-pinene was introduced at a liquid hourly space velocity (LISH) of 1 h⁻¹. -1 The fixed bed was heated to 70°C. A second stream, a 40% concentration of cumene hydroperoxide (CHP) / cumene solution, was introduced into the system at a liquid hourly space velocity (LISH) of 1 h⁻¹. -1 The material flowing out of the reactor outlet was sampled and analyzed. The material flow entered the distillation unit to separate and recover the raw materials and solvents, and to purify and collect the borneol aldehyde product. The liquid product was analyzed by gas chromatography, and the results are shown in Table 1.

[0054] Example 4 The method was followed in Example 1, except that the mass ratio of the main catalyst A to the co-catalyst B was 2:1, and the results are shown in Table 1.

[0055] Example 5 The method of Example 2 was followed, except that the mass ratio of main catalyst A to co-catalyst B was 1.5:1, and the results are shown in Table 1.

[0056] Example 6 The method of Example 3 was followed, except that the mass ratio of main catalyst A to co-catalyst B was 3:1, and the results are shown in Table 1.

[0057] Comparative Example 1 The method was followed in Example 1, except that no shaped 4A molecular sieve catalyst was added. The results are shown in Table 1.

[0058] Comparative Example 2 The method of Example 1 was followed, except that no shaped Ti-HMS molecular sieve catalyst was added. The results are shown in Table 1.

[0059] Comparative Example 3 The method of Example 2 was followed, except that no shaped 13X molecular sieve catalyst was added. The results are shown in Table 1.

[0060] Table 1. Conversion rates of α-pinene and peroxides and selectivity of major and by-products based on product liquid composition. CHP / EBHP conversion rate 2,3-Epoxypine Conversion Borneol selectivity (calculated by the change in α-pinene reaction) Example 1 99.7% 99.0% 85.2% Example 2 98.3% 96.9% 71.0% Example 3 98.3% 98.2% 80.1% Example 4 99.5% 98.8% 80.2% Example 5 98.3% 96.5% 70.2% Example 6 98.1% 98.0% 78.1% Comparative Example 1 99.5% 99.2% 47.8% Comparative Example 2 13.4%（*） 0.1% 0.0% Comparative Example 3 98.9% 98.5% 37.5% *CHP / EBHP conversion due to peroxide self-decomposition The preferred embodiments of the present invention have been described above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various specific technical features in any suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A one-step continuous method for producing borneol from pinene, characterized in that, The method includes: continuously feeding an organic solution of α-pinene and a neutral organic peroxide into a reactor for continuous contact reaction in the presence of a main catalyst A and a co-catalyst B, wherein the main catalyst A is an oxidation catalyst and the co-catalyst B contains an alkali metal and / or an alkaline earth metal.

2. The method according to claim 1, wherein, The mass ratio of main catalyst A to co-catalyst B is 0.1-10:1, preferably 0.5-2:1, and more preferably 0.8-1.2:

1.

3. The method according to claim 1 or 2, wherein, The main catalyst A is one or more of mesoporous titanium silica molecular sieves and modified mesoporous oxides; preferably, the main catalyst A is one or more of Ti-MCM-41, Ti-MCM-48, Ti-SBA-15, Ti-HMS, Ti-MTS-9, mesoporous TS-1, mesoporous TS-2, mesoporous Ti-beta, mesoporous Ti-MWW, mesoporous Ti-ZSM-12, mesoporous Ti-ZSM-48, mesoporous Ti-MCM-68, mesoporous Ti-FER, mesoporous Ti-MOR, mesoporous Ti-UTD molecular sieves, mesoporous Ti-supported amorphous silica, and mesoporous titanium silica oxides, preferably one or more of Ti-HMS molecular sieves and mesoporous Ti-beta molecular sieves; and / or The main catalyst A is in a molded form; Preferably, The molding morphology is selected from one or more of the following: sheet-like, ring-like, spherical (granular), extruded strip, special strip, and amorphous.

4. The method according to any one of claims 1-3, wherein, The content of alkali metals and / or alkaline earth metals in co-catalyst B is less than 15 wt%, with the remainder being support material; and / or The co-catalyst B is one or more of the following: alkali metal exchanged microporous molecular sieve, alkaline earth metal exchanged microporous molecular sieve, alkali metal exchanged resin, and alkaline earth metal exchanged resin. Preferably, the co-catalyst B is one or more of the following: 3A molecular sieve, 4A molecular sieve, 5A molecular sieve, 10X molecular sieve, 13X molecular sieve, Na-Y molecular sieve, Ca-Y molecular sieve, MOR molecular sieve, Na-ZSM-5 molecular sieve, K-ZSM-5 molecular sieve, Ca-ZSM-5 molecular sieve, Na-beta molecular sieve, K-beta molecular sieve, Ca-beta molecular sieve, Na-SAPO-31 molecular sieve, K-SAPO-31 molecular sieve, Ca-SAPO-31 molecular sieve, Na-SAPO-34 molecular sieve, K-SAPO-34 molecular sieve, Ca-SAPO-34 molecular sieve, Na-type PS cation exchange resin, K-type PS cation exchange resin, and Ca-type PS cation exchange resin; more preferably, it is one or more of the following: 4A molecular sieve and Na-type PS cation exchange resin. and / or Catalyst B is in a molded form; Preferably, The molding morphology is selected from one or more of the following: sheet-like, ring-like, spherical (granular), extruded strip, special strip, and amorphous.

5. The method according to any one of claims 1-4, wherein, The neutral organic peroxide is one or more of tert-butanol hydroperoxide, cumene hydroperoxide, and ethylbenzene hydroperoxide, preferably one or more of cumene hydroperoxide and ethylbenzene hydroperoxide.

6. The method according to any one of claims 1-5, wherein, The concentration of neutral organic peroxides in organic solutions is 1-90 wt%; and / or The organic solvent in the organic solution of the neutral organic peroxide is one or more of acetonitrile, acetone, tetrahydrofuran, dimethyl sulfoxide, N,N-dimethylformamide, benzene, toluene, xylene, pentane, hexane, octane, cyclohexane, tert-butanol, n-butanol, methanol, ethanol, isopropanol, cyclohexanol, cumene, and ethylbenzene, preferably one or more of cumene and ethylbenzene.

7. The method according to any one of claims 1-6, wherein, The organic solutions of neutral organic peroxides are cumene / isocumene hydroperoxide solutions and / or ethylbenzene / ethylbenzene hydroperoxide solutions; Preferably, The concentration of the cumene hydroperoxide / cumene solution is 1-90 wt%, preferably 15-55 wt%. The concentration of the hydrogen peroxide / ethylbenzene solution is 1-45 wt%, preferably 10-40 wt%.

8. The method according to any one of claims 1-7, wherein, The conditions for a contact reaction include: The reactor is a fixed-bed reactor; and / or The temperature is 25-130℃, preferably 60-120℃; and / or The pressure is 0.1-3 MPa, preferably 0.1-1.5 MPa; and / or The liquid hourly space velocity (LISH) of α-pinene is 0.02–10 h⁻¹. -1 Preferably, it is 0.2-1.5h. -1 ; and / or The liquid hourly space velocity (LISH) of organic solutions containing neutral organic peroxides is 0.01–5 h⁻¹. -1 Preferably 0.5-1h -1 ; and / or The contact reaction is carried out in an oxygen-free environment, preferably under an inert atmosphere; and / or The organic solutions of α-pinene and neutral organic peroxides are either introduced into the reactor individually or mixed together; and / or The main catalyst A and the co-catalyst B are mixed and then loaded into the reactor; or the main catalyst A bed is loaded first along the material flow direction, and then the co-catalyst B bed is loaded; or the main catalyst A bed and the co-catalyst B bed are loaded alternately along the material flow direction.

9. The method according to any one of claims 1-8, wherein, The method also includes: distilling the post-contact reaction stream to recover the raw materials and solvents, and purifying and collecting the borneol product.

10. The application of the method according to any one of claims 1-9 in the synthesis of sandalwood fragrance.