Composite catalyst, preparation method thereof and application of composite catalyst in production of methyl cis-dihydrojasmonate

Abstract

The invention relates to a composite catalyst, a preparation method thereof and application of the composite catalyst in production of methyl cis-dihydrojasmonate. The composite catalyst comprises a carrier and an active component loaded on the carrier, the active component comprises a complex formed by active metal and an organic ligand; the active metal comprises main active metal and auxiliary metal; the organic ligand comprises a pyridine carboxamide compound. The composite catalyst provided by the invention is used for a synthesis process of methyl cis-dihydrojasmonate, the selectivity is high, the operation is simple, and the obtained methyl cis-dihydrojasmonate has excellent fragrance.

Description

Technical Field

[0001] This invention relates to the field of catalytic hydrogenation technology, specifically to a composite catalyst, its preparation method, and its application in the production of methyl cis-dihydrojasmonate. Background Technology

[0002] Methyl cis-dihydrojasmonate is a colorless to pale yellow liquid with a strong and elegant jasmine fragrance and a pleasant lemony aroma. It has a low aroma threshold and its aroma intensity is far superior to that of ordinary methyl dihydrojasmonate. This compound can be prepared using a variety of methods, providing multiple options for industrial production.

[0003] For example, US Patent 3978108 discloses the hydrogenation of dehydrojasmonic acid methyl ester in alcohol or ester solvents using a catalyst Pd / C to prepare cis-dihydrojasmonic acid methyl ester. To increase the content of the cis product, this method incorporates a large amount of organoaluminum compounds, which not only complicates post-processing but also makes the Pd / C catalyst difficult to recover and reuse. Furthermore, the added solvent can undergo transesterification with dehydrojasmonic acid methyl ester and its hydrogenation product, dihydrojasmonic acid methyl ester. Although this does not affect the proportion of the cis product, it reduces the yield of the target product.

[0004] Patent EP399788 discloses a method of adding a small amount of carbonate to ordinary methyl dihydrojasmonate, isomerizing it into approximately 10% cis-methyl dihydrojasmonate under nitrogen protection and high temperature, and then preparing methyl dihydrojasmonate with a cis content of 20-50% by distillation. However, this method cannot obtain a high-content methyl dihydrojasmonate product.

[0005] Patent CN100999466A discloses the process of hydrogenating palladium on carbon, platinum on carbon, or Raney nickel with a halogen curing agent containing soluble silver salts to obtain methyl dihydrojasmonate with a cis content of over 80%. However, it does not mention the treatment of the cured silver halide and the re-application of the catalyst. If silver salts deposit on the catalyst, it will inevitably affect the selectivity and lifespan of the re-application catalyst.

[0006] Patent CN117964485A discloses a method for selectively catalytically hydrogenating carbon-carbon double bonds to methyl cis-(1R,2S)-dihydrojasmonic acid using dehydrojasmonic acid methyl ester (3-oxo-2-pentyl-1-cyclopentene-1-acetate) as a raw material, under the action of an asymmetric catalytic hydrogenation catalyst, chiral ligands, and additives, in a solvent and a hydrogen atmosphere at a certain pressure, to produce methyl cis-(1R,2S)-dihydrojasmonic acid. The crude product is then purified by distillation to obtain the final product. This method uses a strong organic acid as an additive, posing risks of equipment corrosion and environmental pollution.

[0007] Patent CN115477581B discloses a method for preparing highly cis dihydrojasmonic acid methyl ester from dehydrojasmonic acid methyl ester. The method involves three steps: reduction of the ketone group, reduction of the double bond, and oxidation of the hydroxyl group in dehydrojasmonic acid methyl ester. This method is relatively complex and involves many reaction steps, making it difficult to scale up industrial production.

[0008] Therefore, given the problems of existing methods such as complex preparation processes, long synthetic routes, poor atom economy, and the content of methyl cis-dihydrojasmonate not meeting customer requirements, it is of great significance to develop a simple and efficient process for synthesizing methyl cis-dihydrojasmonate. Summary of the Invention

[0009] To address the shortcomings of existing technologies, the present invention aims to provide a composite catalyst, its preparation method, and its application in the production of methyl cis-dihydrojasmonate. Compared with existing technologies, the composite catalyst provided by the present invention, when used in the synthesis process of methyl cis-dihydrojasmonate, not only exhibits high selectivity and simple operation, but also produces methyl cis-dihydrojasmonate with excellent aroma.

[0010] To achieve this objective, the present invention adopts the following technical solution:

[0011] In a first aspect, the present invention provides a composite catalyst, the composite catalyst comprising a support and an active component supported on the support;

[0012] The active ingredient includes a complex formed by an active metal and an organic ligand;

[0013] The active metal includes a main active metal and an auxiliary metal;

[0014] The organic ligands include pyridine carboxamide compounds.

[0015] The composite catalyst provided by this invention comprises a main active metal, a promoter metal, an organic ligand, and a support. The main active metals, barium and molybdenum, possess characteristics such as low cost, low toxicity, and strong coordination. The coordination between the main active metal and promoter metals such as Ir, Ru, and Pd via metallic bonds enhances the catalytic activity of the catalyst, increases the reaction conversion rate, and significantly reduces the amount of precious metals used, thus lowering the application cost of the catalyst. Furthermore, the nitrogen atoms in the pyridine carboxamide organic ligands in the catalyst form complexes with the active metals through coordination bonds and adsorb onto the surface of the support, reducing the loss of active components during catalysis and enabling catalyst recycling, further reducing the cost of catalyst use and minimizing environmental pollution caused by heavy metal ion loss. The -NH- and -C=O groups in the pyridine carboxamide organic ligands act as hydrogen bond acceptors and substrates, undergoing hydrogenation reactions through hydrogen bonding, greatly improving the selectivity for the product methyl dihydrojasmonate. In addition, the support surface used in this invention has a large degree of coordination unsaturation and high metal dispersibility, thereby achieving a high degree of dispersion of active metal complexes on its surface; and the Lewis acid sites on its surface effectively reduce the carbon surface area of ​​the catalyst, which is conducive to the recycling of the catalyst.

[0016] Therefore, by using the composite catalyst provided by this invention to selectively hydrogenate methyl jasmonate to synthesize methyl cis-dihydrojasmonate, a methyl cis-dihydrojasmonate with a mass percentage of 75-85% can be obtained after the reaction (the client requires that the content of methyl cis-dihydrojasmonate in the product should not be too high or too low, and the mass percentage is generally required to be 75-85%), without the need for distillation to adjust the content.

[0017] Preferably, the main active metal includes barium and / or molybdenum.

[0018] Preferably, the auxiliary metal includes any one or a combination of at least two of iridium, ruthenium, or palladium.

[0019] Preferably, the mass ratio of the main active metal to the auxiliary metal is 1:(0.1-0.9), for example, it can be 1:0.1, 1:0.2, 1:0.3, 1:0.4, 1:0.5, 1:0.6, 1:0.7, 1:0.8 or 1:0.9, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable, preferably 1:(0.3-0.7).

[0020] In this invention, by optimizing the mass ratio of the main active metal to the auxiliary metal, the amount of precious metal auxiliary agent used can be effectively reduced, thereby lowering the catalyst cost.

[0021] Preferably, the mass ratio of the main active metal to the carrier is (0.01-0.09):1, for example, it can be 0.01:1, 0.02:1, 0.03:1, 0.04:1, 0.05:1, 0.06:1, 0.07:1, 0.08:1 or 0.09:1, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable, preferably (0.03-0.07):1.

[0022] In this invention, by optimizing the mass ratio of the main active metal to the carrier, the specific surface area of ​​the carrier can be effectively utilized, avoiding the agglomeration of metal ions on the carrier surface due to excessive active metal, thus preventing the waste of active metal.

[0023] Preferably, the organic ligand comprises any one or a combination of at least two of 4-pyridinecarboxamide, 2-pyridinecarboxamide, 3-pyridinecarboxamide, 2,6-pyridinedicarboxamide, 4-fluoropyridinecarboxamide, 5-bromopyridinecarboxamide, 5-amino-3-pyridinecarboxamide, 3-methyl-2-pyridinecarboxamide, or 3,5-dichloropyridinecarboxamide.

[0024] Preferably, the molar ratio of the active metal to the organic ligand is 1:(2-8), for example, it can be 1:2, 1:3, 1:4, 1:5, 1:6, 1:7 or 1:8, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable, preferably 1:(2-6).

[0025] In this invention, by optimizing the molar ratio of active metal to organic ligand, efficient coordination of active metal and organic ligand can be achieved, avoiding waste of raw materials.

[0026] Preferably, the carrier comprises a metal oxide.

[0027] Preferably, the support comprises any one or a combination of at least two of SiO2-Al2O3 composite oxide, ZrO2-WO3 composite oxide, Nb2O5, TiO3-SiO2 composite oxide, or Al2O3.

[0028] In a second aspect, the present invention provides a method for preparing a composite catalyst as described in the first aspect of the present invention, the method comprising the following steps:

[0029] (1) Mix the main active metal precursor, the auxiliary metal precursor and the organic ligand, and carry out a complexation reaction to obtain a mixed solution;

[0030] (2) The mixed solution obtained in step (1) and the support are mixed and then adsorption reaction is carried out. After that, solid-liquid separation, washing and drying are carried out in sequence to obtain the composite catalyst.

[0031] The preparation method provided by this invention mainly includes steps such as mixing, complexation, adsorption, solid-liquid separation, washing and drying. The preparation method is simple, the conditions are mild, the reaction conditions are controllable, and it is easy to scale up for production.

[0032] In this invention, the solid-liquid separation method can be a conventional method in the art, such as filtration and centrifugation. In this invention, the mixing in step (1) can be done by mixing two materials first and then adding a third material, or by mixing all three materials simultaneously. In this invention, the mixed solution in step (2) is generally cooled to room temperature (10-40℃) before the carrier is added.

[0033] In this invention, the primary active metal precursor can be a primary active metal salt, specifically, for example, a hydrochloride, nitrate, potassium salt, sodium salt, ammonium salt, or hydrate of the aforementioned substances containing barium and / or molybdenum, and further for example, BaCl2·2H2O, BaCl2, Ba(NO3)2, (NH4)2Mo4O 13 Any one or a combination of at least two of the following: ·2H2O, Na2MoO4, Na2MoO4·2H2O, or K2MoO4.

[0034] In this invention, the auxiliary metal precursor can be an auxiliary metal salt, specifically, for example, it can be a hydrochloride, nitrate, acetylacetone salt, ammonium salt, or hydrate of the aforementioned substances of the auxiliary metal, and further for example, it can be any one or a combination of at least two of IrCl3·3H2O, RuCl3, Ru(OAc)3, PdCl2, Pd(acac)2, Pd(NO3)2·2H2O, or Pd(NO3)2.

[0035] Preferably, the temperature of the complexation reaction in step (1) is 80-120℃, for example, it can be 80℃, 82℃, 84℃, 86℃, 88℃, 90℃, 92℃, 94℃, 96℃, 98℃, 100℃, 102℃, 105℃, 108℃, 110℃, 112℃, 115℃, 118℃ or 120℃, but is not limited to the listed values, and other unlisted values ​​within the range are also applicable.

[0036] Preferably, the complexation reaction time is 2-4 hours, for example, 2 hours, 2.2 hours, 2.5 hours, 2.8 hours, 3 hours, 3.2 hours, 3.5 hours, 3.8 hours or 4 hours, but not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0037] Preferably, the temperature of the adsorption reaction in step (2) is 30-60℃, for example, it can be 30℃, 32℃, 35℃, 38℃, 40℃, 42℃, 45℃, 48℃, 50℃, 52℃, 55℃, 58℃ or 60℃, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0038] Preferably, the adsorption reaction time is 2-6 hours, for example, 2 hours, 2.5 hours, 3 hours, 3.5 hours, 4 hours, 4.5 hours, 5 hours, 5.5 hours or 6 hours, but not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0039] As a preferred embodiment of the second aspect of the present invention, the preparation method includes the following steps:

[0040] (1) Mix the main active metal precursor and the auxiliary metal precursor, stir and disperse, then add the organic ligand, and heat to 80-120℃ for complexation reaction for 2-4 hours to obtain a mixed solution;

[0041] (2) Cool the mixed solution obtained in step (1), then add the support, and then heat it to 30-60℃ for adsorption reaction for 2-6 hours. Then, perform solid-liquid separation, washing and drying in sequence to obtain the composite catalyst.

[0042] Thirdly, the present invention provides an application of the composite catalyst as described in the first aspect of the present invention, wherein the composite catalyst is used for the selective hydrogenation reaction of dehydrojasmonic acid methyl ester to prepare cis-dihydrojasmonic acid methyl ester.

[0043] Preferably, the mass ratio of the composite catalyst to methyl dehydrojasmonate is (0.01-0.09):1, for example, it can be 0.01:1, 0.02:1, 0.03:1, 0.04:1, 0.05:1, 0.06:1, 0.07:1, 0.08:1 or 0.09:1, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable, preferably (0.03-0.07):1.

[0044] Preferably, the hydrogen pressure for the selective hydrogenation reaction is 1-4 MPa, for example, it can be 1 MPa, 1.5 MPa, 2 MPa, 2.5 MPa, 3 MPa, 3.5 MPa or 4 MPa, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0045] Preferably, the temperature of the selective hydrogenation reaction is 60-120°C, for example, it can be 60°C, 65°C, 70°C, 75°C, 80°C, 85°C, 90°C, 95°C, 100°C, 105°C, 110°C, 115°C or 120°C, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable, with 60-80°C being the preferred temperature.

[0046] Preferably, the selective hydrogenation reaction time is 2-6 hours, for example, 2 hours, 3 hours, 4 hours, 5 hours or 6 hours, but not limited to the listed values. Other unlisted values ​​within the range are also applicable, with 2-4 hours being the preferred time.

[0047] Preferably, the selective hydrogenation reaction is carried out under solvent-containing or solvent-free conditions, and more preferably under solvent-free conditions.

[0048] Preferably, the solvent includes any one or a combination of at least two of ethanol, methanol, isopropanol, butanol or water.

[0049] Preferably, the mass ratio of the solvent to methyl dehydrojasmonate is (1-3):1, for example, it can be 1:1, 1.5:1, 2:1, 2.5:1 or 3:1, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0050] In this invention, the selective hydrogenation reaction can be intermittent or continuous, and can be freely switched and adjusted according to actual production needs. Intermittent reaction is preferred.

[0051] Compared with the prior art, the present invention has the following beneficial effects:

[0052] (1) The composite catalyst provided by the present invention has high reactivity and selectivity, stable catalyst structure, and active components are not easily lost. It can realize the recycling of catalysts, without the need for frequent catalyst replacement. It is simple to operate, conducive to continuous industrial production, and can significantly improve the utilization rate of equipment.

[0053] (2) The composite catalyst provided by the present invention can be reacted under solvent-free conditions, eliminating solvent interference, such as a small amount of transesterification side reaction in the reaction, and the post-processing operation reduces the solvent separation steps, which is beneficial to reducing production costs.

[0054] (3) The composite catalyst provided by the present invention is used to synthesize methyl cis-dihydrojasmonate. It has high selectivity and yield for the product methyl cis-dihydrojasmonate, and the content of the cis-form is in the range of 75-85%. The content of the product meets the needs of the customer. No additional post-processing work such as distillation and blending is required, which simplifies the production process, saves energy consumption and improves production efficiency. Attached Figure Description

[0055] Figure 1 This is the gas phase spectrum of methyl dihydrojasmonate obtained in Application Example 1 of this invention;

[0056] Figure 2 This is the mass spectrum of methyl dihydrojasmonate obtained in Application Example 1 of this invention;

[0057] Figure 3 This is the standard spectrum of methyl dihydrojasmonate. Detailed Implementation

[0058] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the invention and should not be considered as specific limitations thereof. Unless otherwise defined, the technical terms used in the following embodiments have the same meaning as commonly understood by those skilled in the art. Unless otherwise specified, the experimental reagents used in the following embodiments are conventional biochemical reagents; the experimental methods, unless otherwise specified, are conventional methods.

[0059] Example 1

[0060] This embodiment provides a composite catalyst, which includes a support and an active component loaded on the support. The active component includes a complex formed by an active metal and an organic ligand. The active metal includes Ba, the auxiliary metal includes Pd, the organic ligand includes 3,5-dichloropyridine carboxamide, and the support includes a ZrO2-WO3 support. The mass ratio of the main active metal to the auxiliary metal is 1:0.5, the mass ratio of the main active metal to the support is 0.07:1, and the molar ratio of the active metal to the organic ligand is 1:6.

[0061] This embodiment also provides a method for preparing the above-mentioned composite catalyst, the preparation method comprising the following steps:

[0062] (1) At room temperature (25℃), 1.245g of the main active metal salt BaCl2·2H2O (5.098mmol) and 0.8765g of the auxiliary metal salt Pd(NO3)2·2H2O (3.289mmol) were added to 30mL of purified water. After stirring and dispersing, 9.61g of the organic ligand 3,5-dichloropyridinecarboxamide (0.05mol) was added. The temperature was raised to 100℃ and kept warm for 2h to carry out the complexation reaction, and a mixed solution was obtained.

[0063] (2) Cool the mixed solution obtained in step (1) to room temperature, then add 10.0g of ZrO2-WO3 support, then heat to 40℃ and keep warm for 4h for adsorption reaction, then filter while hot, then wash, and dry the filter cake to constant weight to obtain the composite catalyst, denoted as catalyst 1.

[0064] Example 2-3

[0065] Examples 2-3 provide a method for preparing a composite catalyst. The only difference from Example 1 is that the BaCl2·2H2O metal salt in Example 1 is replaced with Ba(NO3)2 (1.332g, 5.098mmol) and BaCl2 (1.062g, 5.098mmol) respectively, while keeping the types and amounts of the auxiliary metal salt, organic ligand, and support unchanged. The resulting catalysts are referred to as catalysts 2-3 respectively.

[0066] Examples 4-8

[0067] Examples 4-8 provide composite catalysts, which differ from Example 1 only in that the mass ratio of the main active metal to the support is 0.01:1, 0.03:1, 0.05:1, 0.09:1, and 0.1:1, respectively, and are referred to as catalysts 4-8.

[0068] Examples 4-8 also provide a method for preparing the above-mentioned composite catalyst. The difference from Example 1 is only that the amount of main active metal salt, auxiliary metal salt and organic ligand added is adjusted, the mass ratio of main active metal to auxiliary metal and the molar ratio of active metal to organic ligand are kept constant, and only the mass ratio of main active metal to support is changed sequentially, as shown in Table 1.

[0069] Table 1

[0070]

[0071] Examples 9-14

[0072] Examples 9-14 provide a composite catalyst, which differs from Example 1 only in that the mass ratio of the auxiliary metal to the main active metal is 0.1:1, 0.3:1, 0.7:1, 0.9:1, 0.05:1, and 1:1, respectively, and are referred to as catalysts 9-14.

[0073] Examples 9-14 also provide a method for preparing the above-mentioned composite catalyst. The difference from Example 1 is only that the amount of additive metal salt and organic ligand added is adjusted, the molar ratio of active metal to organic ligand and the mass ratio of main active metal to support are kept unchanged, and only the mass ratio of additive metal to main active metal is changed sequentially, as shown in Table 2.

[0074] Table 2

[0075]

[0076] Examples 15-19

[0077] Examples 15-19 provide a method for preparing a composite catalyst, the only difference from Example 1 being that the BaCl2·2H2O metal salt in Example 1 is replaced with (NH4)2Mo4O in turn. 13 ·2H2O (1.211g, 1.824mmol), H 24 Mo7N6O 24 The catalysts obtained by using 4H2O (1.288g, 1.042mmol), Na2MoO4 (1.502g, 7.296mmol), Na2MoO4·2H2O (1.765g, 7.296mmol), and K2MoO4 (1.737g, 7.296mmol) while keeping the types and amounts of auxiliary metal salts and supports constant, are shown in Table 3. These catalysts are denoted as catalysts 15-19.

[0078] Table 3

[0079]

[0080] Examples 20-24

[0081] Examples 20-24 provide a method for preparing a composite catalyst. The only difference from Example 1 is that the auxiliary metal salts Pd(NO3)2·2H2O in Example 1 are replaced sequentially with PdCl2 (0.5833g, 3.289mmol), Pd(acac)2 (1.0021g, 3.289mmol), IrCl3·3H2O (0.6421g, 1.821mmol), RuCl3 (0.7181g, 3.462mmol), and Ru(OAc)3 (0.9631g, 3.462mmol), while keeping the type and amount of the main active metal salt and the support unchanged. As shown in Table 4, the resulting catalysts are designated as catalysts 20-24.

[0082] Table 4

[0083]

[0084]

[0085] Examples 25-28

[0086] Examples 25-28 provide a composite catalyst, which differs from Example 1 only in that the support ZrO2-WO3 in Example 1 is replaced with SiO2-Al2O3, Nb2O5, TiO3-SiO2, and Al2O3 in sequence, while keeping the mass of the support unchanged. These are referred to as catalysts 25-28.

[0087] Examples 25-28 provide a method for preparing the above-mentioned composite catalyst. The only difference from Example 1 is that the support in Example 1 is replaced sequentially with SiO2-Al2O3, Nb2O5, TiO3-SiO2, and Al2O3, while keeping the mass of the support unchanged.

[0088] Examples 29-33

[0089] Examples 29-33 provide a composite catalyst, which differs from Example 1 only in that the molar ratios of the organic ligand 3,5-dichloropyridine carboxamide and the active metal are 2.0:1, 4.0:1, 8.0:1, 1:1, and 9:1, respectively, and are referred to as catalysts 29-33.

[0090] Examples 29-33 also provide a method for preparing the above-mentioned composite catalyst, the only difference from Example 1 is the adjustment of the amount of 3,5-dichloropyridine carboxamide added, as shown in Table 5.

[0091] Table 5

[0092]

[0093] Examples 34-40

[0094] Examples 34-40 provide a composite catalyst, which differs from Example 1 only in that the 3,5-dichloropyridine carboxamide in Example 1 is replaced in equal molar amounts with 4-pyridine carboxamide, 2-pyridine carboxamide, 3-pyridine carboxamide, 2,6-pyridinedicarboxamide, 4-fluoropyridine carboxamide, 5-bromopyridine carboxamide, and 5-amino-3-pyridine carboxamide, respectively, and are referred to as catalysts 34-40.

[0095] Examples 34-40 provide a method for preparing the above-mentioned composite catalyst. The only difference from Example 1 is that the 3,5-dichloropyridine carboxamide in Example 1 is replaced by 4-pyridine carboxamide (6.15 g, 0.05 mol), 2-pyridine carboxamide (6.15 g, 0.05 mol), 3-pyridine carboxamide (6.15 g, 0.05 mol), 2,6-pyridinedicarboxamide (8.31 g, 0.05 mol), 4-fluoropyridine carboxamide (7.05 g, 0.05 mol), 5-bromopyridine carboxamide (10.12 g, 0.05 mol), and 5-amino-3-pyridine carboxamide (6.90 g, 0.05 mol), while keeping the type and amount of active metal salt and support unchanged.

[0096] Examples 41-49

[0097] Examples 41-49 provide a method for preparing a composite catalyst. The difference from Example 1 is only in adjusting the temperature and time of the complexation reaction and the temperature and time of the adsorption reaction, as shown in Table 6. The obtained catalysts are referred to as catalysts 41-49.

[0098] Table 6

[0099]

[0100]

[0101] Comparative Example 1

[0102] This comparative example provides a method for preparing a composite catalyst. The only difference from Example 1 is that the auxiliary metal salt Pd(NO3)2·2H2O is not added in the mixing of step (1), and it is replaced with an equimolar amount of the main active metal salt BaCl2·2H2O, so as to ensure that the total molar amount of active metal remains unchanged. The resulting catalyst is referred to as comparative catalyst 1.

[0103] Comparative Example 2

[0104] This comparative example provides a method for preparing a composite catalyst. The only difference from Example 1 is that the main active metal salt BaCl2·2H2O is not added in the mixing in step (1), and it is replaced with an equimolar amount of auxiliary metal salt Pd(NO3)2·2H2O, so as to ensure that the total molar amount of active metal remains unchanged. The resulting catalyst is referred to as comparative catalyst 2.

[0105] Comparative Example 3

[0106] This comparative example provides a method for preparing a composite catalyst. The only difference from Example 1 is that the organic ligand 3,5-dichloropyridine carboxamide is not added in the mixing in step (1). The resulting catalyst is referred to as comparative catalyst 3.

[0107] Application Example 1

[0108] This application example provides a method for synthesizing methyl cis-dihydrojasmonic acid, characterized in that the synthesis method includes the following steps:

[0109] In a 500 mL high-pressure reactor, catalyst 2 (5.0 g, with a mass ratio of composite catalyst to methyl dehydrojasmonate of 0.05:1), methyl dehydrojasmonate of 100 g (0.45 mol), and solvent water (150 g) were added sequentially and mixed thoroughly. The mixture was then purged with nitrogen three times and then with hydrogen three times. After that, hydrogen was introduced to maintain the pressure inside the reactor at 2.0 MPa. The temperature was raised to 80 °C and maintained for reaction. After the reaction was completed, the reaction solution was analyzed by gas chromatography, and the conversion rate of the raw material methyl dehydrojasmonate of 98.51% and the selectivity for the product methyl dihydrojasmonate of 99.22% were calculated.

[0110] Subsequently, the purified product, methyl dihydrojasmonate, was obtained by distillation with a mass of 98.14 g. The yield of methyl dihydrojasmonate was calculated to be 97.27%, and the content of cis-form was determined to be 85%.

[0111] Taking application example 1 as an example, the gas phase spectrum of the obtained product, methyl dihydrojasmonate, is as follows: Figure 1 As shown, the mass spectrum and standard spectrum are as follows: Figure 2 and Figure 3 As shown.

[0112] Taking the synthesis method of methyl cis-dihydrojasmonate provided in this application example as an example, the reaction solution after the reaction is completed is filtered and separated. The catalyst obtained by filtration is washed three times with ethanol to obtain the recovered catalyst. The synthesis method of methyl cis-dihydrojasmonate provided in Application Example 1 is performed using the recovered catalyst, and the catalyst reuse is performed. The first use of the catalyst is called reuse 1, the second use of the catalyst is called reuse 2, and so on. The above conversion, selectivity and yield are shown in Table 7.

[0113] Table 7

[0114]

[0115]

[0116] As can be seen from Table 7, the composite catalyst provided by the present invention can still maintain high selectivity, conversion rate and yield after multiple cycles of use.

[0117] Application Example 2-6

[0118] Application Examples 2-6 provide a method for synthesizing methyl cis-dihydrojasmonate, which differs from Application Example 1 only in that the solvent water is replaced by equal masses of ethanol, methanol, isopropanol, butanol or no solvent is added.

[0119] Application Example 7-8

[0120] Application Examples 7-8 provide a method for synthesizing methyl cis-dihydrojasmonate, which differs from Application Example 1 only in that the amount of water used as solvent is replaced with 100g and 300g respectively.

[0121] Application Example 9-11

[0122] Application Examples 9-11 provide a method for synthesizing methyl cis-dihydrojasmonate, which differs from Application Example 1 only in that the amount of catalyst is adjusted to 1g, 7g, and 9g respectively, i.e., the mass ratio of the composite catalyst to methyl dehydrojasmonate is 0.01:1, 0.07:1, and 0.09:1 respectively.

[0123] Application Example 12-14

[0124] Application Examples 12-14 provide a method for synthesizing methyl cis-dihydrojasmonate, which differs from Application Example 1 only in that the hydrogen pressure of the selective hydrogenation reaction is changed to 1.0 MPa, 3.0 MPa, and 4.0 MPa respectively.

[0125] Application Examples 15-16

[0126] Application Examples 15-16 provide a method for synthesizing methyl cis-dihydrojasmonic acid, which differs from Application Example 1 only in that the selective hydrogenation reaction time is changed to 2 h and 6 h respectively.

[0127] Application Example 17-19

[0128] Application Examples 17-19 provide a method for synthesizing methyl cis-dihydrojasmonate, which differs from Application Example 1 only in that the selective hydrogenation reaction temperatures are changed to 60°C, 100°C, and 120°C respectively.

[0129] Application Example 20

[0130] Application Example 20 provides a method for synthesizing methyl cis-dihydrojasmonate, which differs from Application Example 1 only in that it uses catalyst 1 provided in Example 1.

[0131] Application Example 21-67

[0132] Application Examples 21-67 provide a method for synthesizing methyl cis-dihydrojasmonic acid, which differs from Application Example 1 only in that the catalysts 3-49 provided in Examples 3-49 are used in sequence.

[0133] Application Comparative Examples 1-3

[0134] Comparative Examples 1-3 of this application provide a method for synthesizing methyl cis-dihydrojasmonate, the only difference from Application Example 1 being that the comparative catalysts 1-3 provided in Comparative Examples 1-3 are used in turn.

[0135] The conversion rate of dehydrojasmonic acid methyl ester, the selectivity for the product dihydrojasmonic acid methyl ester, and the yield of dihydrojasmonic acid methyl ester in the above examples and comparative examples are shown in Table 8.

[0136] Table 8

[0137]

[0138]

[0139]

[0140] As can be seen from the data in Table 8:

[0141] (1) Application Examples 1-19 use the catalyst provided in Example 2. It can be seen that under different solvent types (or no solvent added), different solvent amounts, different mass ratios of composite catalyst to dehydrojasmonic acid methyl ester, and by changing the hydrogen pressure, time and temperature of the selective hydrogenation reaction, the yield of the product dihydrojasmonic acid methyl ester is high, reaching more than 95.75%.

[0142] (2) Application Examples 20, 1, and 21 use the catalysts provided in Examples 1-3 respectively. It can be seen that when the metal salt BaCl2·2H2O is replaced with Ba(NO3)2 and BaCl2 respectively, the target product yield can be achieved at a high level of over 97.09%.

[0143] (3) Application Examples 22-26 use the catalysts provided in Examples 4-8 respectively. It can be seen that when the mass ratio of the main active metal to the support is 0.01:1, 0.03:1, 0.05:1, 0.09:1 and 0.1:1 respectively, a high target product yield of more than 96.15% can be achieved. The present invention further preferably controls the mass ratio of the main active metal to the support to be (0.01-0.09):1, and even more preferably to be (0.03-0.07):1, which can control the amount of main active metal and the catalyst cost while ensuring a high target product yield.

[0144] (4) Application Examples 27-32 use the catalysts provided in Examples 9-14 respectively. It can be seen that when the mass ratio of the auxiliary metal to the main active metal is 0.1:1, 0.3:1, 0.7:1, 0.9:1, 0.05:1 and 1:1 respectively, a high target product yield of more than 95.62% can be achieved. The present invention further preferably controls the mass ratio of the main active metal to the auxiliary metal to be 1:(0.1-0.9), and even more preferably controls it to be 1:(0.3-0.7), which can control the amount of active metal and control the catalyst cost while ensuring a high target product yield.

[0145] (5) Application Examples 33-37 use the catalysts provided in Examples 15-19 respectively. It can be seen that when the BaCl2·2H2O metal salt is replaced with (NH4)2Mo4O 13 ·2H2O, H 24 Mo7N6O 24 When using ·4H2O, Na2MoO4, Na2MoO4·2H2O, and K2MoO4, a high yield of the target product can be achieved, reaching over 94.24%.

[0146] (6) Application Examples 38-42 used the catalysts provided in Examples 20-24 respectively. It can be seen that when the Pd(NO3)2·2H2O auxiliary metal salt was replaced with PdCl2, Pd(acac)2, IrCl3·3H2O, RuCl3, and Ru(OAc)3 respectively, a high yield of the target product could be achieved, reaching more than 97.04%.

[0147] (7) Application Examples 43-46 use the catalysts provided in Examples 25-28. It can be seen that when the support is replaced with SiO2-Al2O3, Nb2O5, TiO3-SiO2, and Al2O3 respectively, a high yield of the target product can be achieved, reaching more than 96.36%.

[0148] (8) Application Examples 47-51 use the catalysts provided in Examples 29-33 respectively. It can be seen that when the molar ratio of the organic ligand 3,5-dichloropyridine carboxamide to the active metal is 2.0:1, 4.0:1, 8.0:1, 1:1 and 9:1 respectively, a high yield of the target product can be achieved, reaching more than 96.50%. The present invention further preferably controls the molar ratio of the active metal to the organic ligand to be 1:(2-8), which can further improve the yield of the target product, save the amount of organic ligand, and reduce the cost of the catalyst.

[0149] (9) Application Examples 52-58 used the catalysts provided in Examples 34-40 respectively. It can be seen that when the organic ligand is replaced by 4-pyridinecarboxamide, 2-pyridinecarboxamide, 3-pyridinecarboxamide, 2,6-pyridinedicarboxamide, 4-fluoropyridinecarboxamide, 5-bromopyridinecarboxamide, and 5-amino-3-pyridinecarboxamide respectively, a high yield of the target product can be achieved, reaching more than 91.83%.

[0150] (10) Application Examples 59-67 used the catalysts provided in Examples 41-49 respectively. It can be seen that when the temperature and time of the complexation reaction and the temperature and time of the adsorption reaction are adjusted, a high yield of the target product can be achieved, reaching more than 95.85%.

[0151] (11) As can be seen from Application Comparative Examples 1-3, when only the main active metal or no organic ligand is used as the active ingredient, the yield of the target product decreases significantly. When only the auxiliary metal is used as the active ingredient, although a good catalytic effect can be achieved, the amount of precious metal is very high, and the catalyst cost increases significantly. It can be seen that the composite catalyst provided by the present invention uses the complex formed by the active metal and the organic ligand as the active ingredient and controls the active metal to include both the main active metal and the auxiliary metal, which can achieve good selectivity, a high yield of the target product methyl dihydrojasmonate, and a low catalyst cost. Furthermore, according to the data from Application Example 1, the content of cis-form in the product is 85%, which meets the client's requirements and does not require additional separation operations.

[0152] In summary, the composite catalyst provided by this invention for the synthesis of methyl dihydrojasmonate not only has high selectivity, simple operation, and low cost, but also ensures that the content of the cis-form in the obtained methyl dihydrojasmonate meets the client's requirements without the need for additional separation operations.

[0153] The applicant declares that the above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A composite catalyst, characterized in that, The composite catalyst includes a support and an active component supported on the support; The active ingredient includes a complex formed by an active metal and an organic ligand; The active metal includes a main active metal and an auxiliary metal; The organic ligands include pyridine carboxamide compounds.

2. The composite catalyst according to claim 1, characterized in that, The main active metal includes barium and / or molybdenum; Preferably, the auxiliary metal includes any one or a combination of at least two of iridium, ruthenium, or palladium; Preferably, the mass ratio of the main active metal to the auxiliary metal is 1:(0.1-0.9), more preferably 1:(0.3-0.7); Preferably, the mass ratio of the main active metal to the carrier is (0.01-0.09):1, and more preferably (0.03-0.07):

1.

3. The composite catalyst according to claim 1 or 2, characterized in that, The organic ligands include any one or a combination of at least two of 4-pyridinecarboxamide, 2-pyridinecarboxamide, 3-pyridinecarboxamide, 2,6-pyridinedicarboxamide, 4-fluoropyridinecarboxamide, 5-bromopyridinecarboxamide, 5-amino-3-pyridinecarboxamide, 3-methyl-2-pyridinecarboxamide, or 3,5-dichloropyridinecarboxamide.

4. The composite catalyst according to any one of claims 1-3, characterized in that, The molar ratio of the active metal to the organic ligand is 1:(2-8), preferably 1:(2-6).

5. The composite catalyst according to any one of claims 1-4, characterized in that, The carrier includes metal oxides; Preferably, the support comprises any one or a combination of at least two of SiO2-Al2O3 composite oxide, ZrO2-WO3 composite oxide, Nb2O5, TiO3-SiO2 composite oxide, or Al2O3.

6. A method for preparing the composite catalyst according to any one of claims 1-5, characterized in that, The preparation method includes the following steps: (1) Mix the main active metal precursor, the auxiliary metal precursor and the organic ligand, and carry out a complexation reaction to obtain a mixed solution; (2) The mixed solution obtained in step (1) and the support are mixed and then adsorption reaction is carried out. After that, solid-liquid separation, washing and drying are carried out in sequence to obtain the composite catalyst.

7. The preparation method according to claim 6, characterized in that, The temperature of the complexation reaction in step (1) is 80-120℃; Preferably, the complexation reaction takes 2-4 hours.

8. The preparation method according to claim 6 or 7, characterized in that, The temperature of the adsorption reaction in step (2) is 30-60℃; Preferably, the adsorption reaction takes 2-6 hours.

9. The application of a composite catalyst as described in any one of claims 1-5, characterized in that, The composite catalyst is used for the selective hydrogenation of dehydrojasmonic acid methyl ester to prepare cis-dihydrojasmonic acid methyl ester.

10. The application according to claim 9, characterized in that, The mass ratio of the composite catalyst to methyl dehydrojasmonate is (0.01-0.09):1, preferably (0.03-0.07):1; Preferably, the selective hydrogenation reaction is carried out under solvent-containing or solvent-free conditions; Preferably, the solvent includes any one or a combination of at least two of ethanol, methanol, isopropanol, butanol or water; Preferably, the mass ratio of the solvent to methyl dehydrojasmonate is (1-3):1.

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