Composite catalyst, preparation method thereof and synthesis method of p-methoxycinnamate compound

Abstract

The invention provides a composite catalyst and a preparation method thereof, and a synthesis method of a p-methoxy cinnamate compound. The composite catalyst comprises a carrier modified by a modifier, and a metal salt and a choline substance loaded on the carrier. In the presence of the composite catalyst provided by the invention, a Claison-Schmidt condensation reaction of an aromatic aldehyde compound and an acetate compound is catalyzed to obtain the p-methoxycinnamate. The composite catalyst provided by the invention has the advantages of high reaction activity and selectivity, stable catalyst structure, difficult loss of active components, realization of cyclic application of the catalyst, no need of frequent replacement of the catalyst, simple operation, facilitation of continuous industrial production, substantial increase of the equipment utilization rate, and realization of industrial production. By using the composite catalyst provided by the invention, the p-methoxy cinnamate compound can be prepared under relatively mild reaction conditions, and the composite catalyst has no corrosion to equipment, does not generate waste water and waste salt, and is green and environment-friendly.

Description

Technical Field

[0001] The present invention belongs to the field of organic synthesis, and particularly relates to a composite catalyst, a preparation method thereof, and a method for synthesizing p-methoxycinnamate compounds. Background Art

[0002] Most p-methoxycinnamates such as methyl p-methoxycinnamate, ethyl p-methoxycinnamate, isoamyl p-methoxycinnamate, and isooctyl p-methoxycinnamate are good absorbers in the UVB region, have no irritation to the skin, and have good safety. They are ideal sunscreen agents and are usually applied to products such as cosmetics, textiles, and polymers. Among them, isoamyl p-methoxycinnamate and isooctyl p-methoxycinnamate are the most commonly used.

[0003] Isooctyl p-methoxycinnamate, with the English name Octylmethoxycinnamate, abbreviated as OMC, is one of the most commonly used sunscreen agents in the world. It has an excellent ultraviolet absorption curve in the range of 280 - 310 nm, high absorption rate, good safety, extremely low toxicity, and good solubility in oily raw materials. Therefore, it is widely used in fields such as daily chemical industry, plastics, rubber, and coatings. As an oil-soluble liquid UVB absorber, it can be compounded with various sunscreen agents.

[0004] Isoamyl p-methoxycinnamate, with the English name Isoamyl p-methoxycinnamate, abbreviated as IMC, is present in small amounts in the roots of Kaempferia galanga. The synthetic product is similar to the natural equivalent. It has good compatibility with common cosmetic components, is easily biodegradable, and has environmental compatibility. It is commonly used in sunscreen products in EU countries.

[0005] Taking the synthesis of isooctyl p-methoxycinnamate as an example, there are many domestic and foreign synthesis methods for isooctyl p-methoxycinnamate at present. According to the main raw materials, they are mainly divided into the following four types: p-methoxystyrene method, p-methoxyaniline method, p-methoxyhalobenzene method, and p-methoxybenzaldehyde method.

[0006] Preparation using p-methoxybenzaldehyde as a raw material through the Knoevenagel reaction: Using p-methoxybenzaldehyde and malonic acid and its derivatives as raw materials, under the action of a catalyst such as pyridine, p-methoxycinnamic acid is first prepared. After the reaction, it is necessary to wash with acid water to remove the catalyst piperidine. These operations will undoubtedly generate a large amount of wastewater, which will seriously pollute the environment. Then, it is esterified with isooctanol to obtain OMC; however, malonic acid and its derivatives are relatively expensive, and the catalysts used such as pyridine have a strong odor and high toxicity, which limit the possibility of applying this method to industrial production.

[0007] Prepared from p-methoxybenzaldehyde by Claison-Schmidt reaction: Using p-methoxybenzaldehyde and methyl acetate as raw materials, a strong base such as sodium methoxide is used as a catalyst for the reaction, and then acidified with hydrochloric acid or sulfuric acid to obtain methyl p-methoxycinnamate. Then, under the action of a catalyst such as sodium carbonate, it undergoes a transesterification reaction with isooctanol to obtain OMC. After the reaction is completed, a large amount of water is required to wash the material, and the resulting high-salt, high-COD wastewater brings pressure to environmental protection treatment and causes pollution to the surrounding environment.

[0008] Alternatively, methyl acetate and isooctanol first undergo a transesterification reaction under the catalysis of p-toluenesulfonic acid to form isooctyl acetate. Then, under the catalysis of liquid sodium methoxide, it undergoes a condensation reaction with p-methoxybenzaldehyde to form isooctyl p-methoxycinnamate. Among them, the amount of liquid sodium methoxide (concentration 25 - 31%) is 25 - 65 wt% of the amount of p-methoxybenzaldehyde. After the condensation reaction is completed, a certain amount of glacial acetic acid is added to neutralize the remaining sodium methoxide in the reaction system. After the reaction is completed, a large amount of waste salts of sodium p-toluenesulfonate and sodium acetate are generated, which not only brings great environmental protection pressure, but also the catalyst cannot be recycled and reused, and the economy is poor.

[0009] Therefore, in the prior art, the method for condensing p-methoxybenzaldehyde and isooctyl acetate to prepare isooctyl p-methoxycinnamate mostly uses sodium alkoxide or potassium alkoxide as a catalyst, and there are problems such as low yield, poor selectivity, many side reactions, inability to recycle the catalyst, and large amount of wastewater. Therefore, there is a large room for improvement. Therefore, some effective strategies need to be adopted to improve the yield of p-methoxycinnamate esters, make the reaction proceed under mild reaction conditions, reduce wastewater and waste salts, and reduce the environmental protection pressure of production. Summary of the Invention

[0010] Aiming at the deficiencies of the prior art, the purpose of the present invention is to provide a composite catalyst, a preparation method thereof, and a preparation method of p-methoxycinnamate compounds.

[0011] To achieve the purpose of this invention, the following technical solutions are adopted by the present invention:

[0012] On the one hand, the present invention provides a composite catalyst, and the composite catalyst includes a carrier modified by a modifier and a metal salt and a choline substance supported on the carrier.

[0013] The composite catalyst of the present invention has high reaction activity and selectivity, the catalyst structure is stable, the active components are not easily lost, the catalyst can be recycled and reused, there is no need to frequently replace the catalyst, the operation is simple, which is beneficial to continuous industrial production, significantly improves the equipment utilization rate, can be used to catalyze the Claison-Schmidt condensation reaction to prepare p-methoxycinnamate compounds, makes the reaction proceed under relatively mild conditions, does not corrode the equipment, and does not produce wastewater and waste salts, which is green and environmentally friendly.

[0014] Preferably, the modifier is an organosiloxane.

[0015] Preferably, the modifier is selected from one or a combination of at least two of vinyl pentamethyldisiloxane, hexaethyldisiloxane, 1,1,1,3,5,5,5-heptamethyltrisiloxane, polyphenylmethylsiloxane, polymethylhydrosiloxane, hexamethyldisiloxane, hexamethoxydisiloxane, pentamethyldisiloxane, dodecamethylpentasiloxane, decamethyltetrasiloxane, hexamethylcyclotrisiloxane, octamethyltrisiloxane, and polydimethylsiloxane.

[0016] The organosiloxane can reduce the surface tension of the resin carrier, enabling the carrier and the active component to form good contact, strengthening the binding strength between the active component and the carrier, inhibiting the aggregation of the active component, reducing the loss of the active component during the reaction process, slowing down the deactivation of the catalyst, realizing the recycling of the catalyst, and further reducing the production cost without the need to frequently replace the catalyst.

[0017] Preferably, the carrier is a macroporous adsorption resin, preferably one or a combination of at least two of D3520, D141, S-8, HPD300, HZ801, XAD16N, or DM11.

[0018] Preferably, the mass ratio of the modifier to the carrier is 1 to 5:1, such as 1:1, 1.5:1, 2:1, 2.5:1, 3:1, 3.5:1, 4:1, 4.5:1, or 5:1, etc., and preferably 2 to 4:1.

[0019] Preferably, the mass ratio of the metal salt to the carrier is 0.01 to 0.09:1, such as 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, preferably 0.03 to 0.07:1, and more preferably 0.03 to 0.05:1.

[0020] Preferably, the metal salt is any one or a combination of at least two of zinc (Zn), iron (Fe), copper (Cu), cobalt (Co), nickel (Ni) hydrochlorides or hydrates of the hydrochlorides.

[0021] Preferably, the choline substance is one or a combination of at least two of choline chloride, β-methylcholine chloride, benzoylcholine chloride, butyrylcholine chloride, chlorocholine chloride, choline phosphate, or acetylcholine chloride.

[0022] The choline-based substance and the active metal ions can form a deep eutectic complex similar to the properties of ionic liquids through coordination bonds, and at the same time have acid-base active centers, playing a role in synergistic catalysis. In addition, the oxygen atoms with coordination activity in the organosiloxane can be bonded and assembled with the active metal atoms through coordination bonds to form a three-dimensional stereoscopic multinuclear metal complex with a definite molecular structure, which has characteristics such as porosity and low density, providing more high-activity sites for the reaction, and making the catalyst have high catalytic activity and selectivity.

[0023] Therefore, the macroporous resin carrier, modifier, active metal component and choline-based substance in the catalyst provided by the present invention act synergistically, rather than being the superposition of the effects of single components. Therefore, the components of the catalyst of the present invention should not be viewed separately, but should be regarded as a complete whole, and not all random combinations can achieve the best experimental results.

[0024] Preferably, the molar ratio of the metal salt to the choline-based substance is 1:1 to 5, such as 1:1, 1:1.2, 1:1.5, 1:1.8, 1:2, 1:2.5, 1:2.8, 1:3, 1:3.5, 1:3.8, 1:4, 1:4.5, 1:4.8, 1:5, etc., preferably 1:1 to 4, more preferably 1:2 to 3.

[0025] On the other hand, the present invention provides a preparation method of the composite catalyst as described above, and the preparation method includes the following steps:

[0026] (1) The modifier and the carrier are mixed and reacted in a first solvent to obtain a carrier modified by the modifier;

[0027] (2) The metal salt and the choline-based substance are mixed in a second solvent to obtain a mixed solution;

[0028] (3) The carrier modified by the modifier obtained in step (1) is added to the mixed solution obtained in step (2), stirred, adsorbed, filtered, the solvent is removed, and dried to obtain the composite catalyst.

[0029] Preferably, the temperature of the reaction in step (1) is 60°C to 120°C, such as 60°C, 65°C, 70°C, 75°C, 80°C, 85°C, 90°C, 95°C, 100°C, 110°C or 120°C, preferably 80°C to 100°C.

[0030] Preferably, the reaction time in step (1) is 1 to 5 hours, such as 1 hour, 2 hours, 3 hours, 4 hours or 5 hours, preferably 2 to 3 hours.

[0031] Preferably, the first solvent in step (1) is selected from one or a combination of at least two of water, ethanol, methanol or isopropanol.

[0032] In step (1), the modifier and the carrier are stirred and dispersed evenly in the first solvent, and then filtered to obtain the carrier modified by the modifier.

[0033] Preferably, the second solvent in step (2) is selected from one or a combination of at least two of water, ethanol, methanol or isopropanol.

[0034] In the present invention, a metal salt and a choline-based substance are stirred and mixed in the second solvent to obtain a mixed solution.

[0035] Preferably, the mixing in step (2) is carried out at a temperature of 60 °C to 120 °C (such as 60 °C, 65 °C, 70 °C, 75 °C, 80 °C, 85 °C, 90 °C, 95 °C, 100 °C, 110 °C or 120 °C), preferably 80 °C to 120 °C; the mixing time is 2 to 5 hours (such as 2 hours, 3 hours, 4 hours or 5 hours), preferably 2 to 4 hours.

[0036] Preferably, the stirring in step (3) is carried out at a temperature of 30 to 60 °C (such as 30 °C, 35 °C, 40 °C, 45 °C, 50 °C, 55 °C or 60 °C), preferably 30 to 50 °C; the stirring time is 2 to 6 hours (such as 2 hours, 3 hours, 4 hours, 5 hours or 6 hours), preferably 4 to 6 hours.

[0037] On the other hand, the present invention provides a method for preparing a p-methoxycinnamate compound, the preparation method comprising the following steps: in the presence of a catalyst, catalyzing a Claison-Schmidt condensation reaction between a p-arylaldehyde compound and an ester compound to obtain a p-methoxycinnamate, and the catalyst is the composite catalyst as described above.

[0038] The present invention uses a composite catalyst to prepare p-methoxycinnamate compounds, enabling the reaction to proceed under relatively mild conditions, capable of producing products in high yields, and having no corrosion to equipment, no generation of waste water and waste salts, being green and environmentally friendly; the reaction general formula in the present invention is as follows:

[0039]

[0040] Wherein R1 is selected from hydrogen or methoxy, and R2 is selected from hydrogen, a C1-C10 (such as C1, C2, C3, C4, C5, C6, C7, C8, C9 or C10) straight-chain or branched-chain alkyl group.

[0041] Preferably, the p-arylaldehyde compound is benzaldehyde and / or p-methoxybenzaldehyde.

[0042] Preferably, the ester compound is one or a combination of at least two of methyl acetate, ethyl acetate, butyl acetate, isooctyl acetate, isopentyl acetate or diethyl malonate.

[0043] Preferably, the mass ratio of the composite catalyst to the aromatic aldehyde compound is 0.03-0.09:1, such as 0.03:1, 0.04:1, 0.05:1, 0.06:1, 0.07:1, 0.08:1 or 0.09:1, preferably 0.05-0.09:1.

[0044] Preferably, the molar ratio of the aromatic aldehyde compound to the ester compound is 1:1-3, such as 1:1, 1:1.5, 1:2, 1:2.5, 1:3, preferably 1:1-2, more preferably 1:1.2-1.6.

[0045] Preferably, the temperature of the condensation reaction is 40°C-80°C, such as 40°C, 45°C, 48°C, 50°C, 55°C, 60°C, 65°C, 70°C, 75°C or 80°C, preferably 40°C-60°C.

[0046] Preferably, the time of the condensation reaction is 1-5 hours, such as 1 hour, 2 hours, 3 hours, 4 hours or 5 hours, preferably 2-4 hours.

[0047] In the present invention, the Claison-Schmidt condensation reaction is carried out with or without a solvent. If a solvent is used, low-toxic or non-toxic solvents such as water, ethanol, isopropanol, methanol, etc. can be selected, and water is preferred.

[0048] Compared with the prior art, the present invention has the following beneficial effects:

[0049] (1) The composite catalyst provided by the present invention has high reaction activity and selectivity, the catalyst structure is stable, the active components are not easily lost, the catalyst can be recycled, there is no need to frequently replace the catalyst, the operation is simple, which is beneficial to continuous industrial production, and significantly improves the equipment utilization rate.

[0050] (2) Using the composite catalyst provided by the present invention can make the preparation of p-methoxycinnamic acid ester compounds react under relatively mild reaction conditions, without corrosion of equipment, without generation of waste water and waste salt, and is green and environmentally friendly. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 It is the electron microscope photograph of Catalyst 1;

[0052] Figure 2 It is the comparison of the mass spectrum (Figure A) of the product obtained in Application Example 1 with the standard spectrum (Figure B) of this substance in the mass spectrum library;

[0053] Figure 3 It is the gas chromatogram of the product obtained in Application Example 1. DETAILED DESCRIPTION OF THE INVENTION

[0054] The technical solution of the present invention will be further described below through specific embodiments. Those skilled in the art should understand that the embodiments are only for helping to understand the present invention and should not be regarded as specific limitations on the present invention.

[0055] Catalyst Preparation Example 1

[0056] (1) Add polydimethylsiloxane (30 g) and support HPD300 (10 g) to 30 mL of purified water. The mass ratio of the two is 3:1. Start stirring, heat up to 100 °C, keep stirring for 3 hours, then cool to room temperature and filter to obtain the modified support.

[0057] (2) At room temperature, add ZnCl2 (1.042 g, 7.64 mmol) and choline chloride (3.202 g) to 40 mL of purified water. The mass ratio of ZnCl2 and choline chloride is 1:3. Start stirring and heat up to 100 °C, keep stirring for 3 hours to obtain a mixed solution.

[0058] (3) Add the modified support in (1) to the mixed solution in (2), cool down to 40 °C, and keep stirring for 5 hours. Filter while it is hot, and dry the filter cake to constant weight to obtain Catalyst 1.

[0059] Characterize Catalyst 1 using a scanning electron microscope (instrument model: JEOL JSM - 6701F). As Figure 1 shown, from the electron microscope photo magnified 10,000 times, it can be seen that the active components are distributed on the surface and pores of the support, with nearly uniform dispersion, exposing more active sites, and the catalyst shows high activity and selectivity.

[0060] Catalyst Preparation Examples 2 - 11

[0061] Examples 2 - 11 respectively provide a preparation method of a composite catalyst. The difference compared with Example 1 is only that the ZnCl2 metal salt in Example 1 is successively replaced with FeCl3 (1.452 g, 8.95 mmol), FeCl3·6H2O (2.420 g, 8.95 mmol), FeCl2 (1.135 g, 8.95 mmol), CuCl2 (1.058 g, 7.87 mmol), CuCl2·2H2O (1.341 g, 7.87 mmol), CuCl (0.779 g, 7.87 mmol), CoCl2·6H2O (2.019 g, 8.48 mmol), CoCl2 (1.102 g, 8.48 mmol), NiCl2 (1.104 g, 8.52 mmol), NiCl2·6H2O (2.025 g, 8.52 mmol), while keeping the types and dosages of choline chloride, support, and modifier unchanged.

[0062] Examples 12 to 15

[0063] Examples 12 to 15 respectively provide a method for preparing a composite catalyst, which is only different from Example 1 in that the mass ratios of the active metal element to the carrier are 0.01:1, 0.03:1, 0.07:1, and 0.09:1 in sequence, and the addition amounts of the metal salt and choline chloride are adjusted as shown in Table 1.

[0064] Table 1

[0065]

[0066] Examples 16 to 21

[0067] Examples 16 to 21 respectively provide a method for preparing a composite catalyst, which is only different from Example 1 in that choline chloride in Example 1 is sequentially replaced by β-methylcholine chloride (3.524 g), benzoylcholine chloride (5.589 g), butyrylcholine chloride (4.809 g), chlorocholine chloride (3.625 g), choline phosphate (5.036 g), and acetylcholine chloride (4.166 g), and the types and amounts of the metal salt, the carrier, and the modifier are kept unchanged.

[0068] Examples 22 to 25

[0069] Examples 22 to 25 respectively provide a composite catalyst, which is only different from Example 1 in that the addition amount of choline chloride is adjusted as shown in Table 2, so that the mass ratios of choline chloride to the metal salt are 1:1, 2:1, 4:1, and 5:1 in sequence.

[0070] Table 2

[0071]

[0072] Examples 26 to 29

[0073] Examples 26 to 29 respectively provide a composite catalyst, which is only different from Example 1 in that the addition amount of the modifier is adjusted as shown in Table 3, so that the mass ratios of the modifier to the carrier are 1:1, 2:1, 4:1, and 5:1 in sequence.

[0074] Table 3

[0075]

[0076] Examples 30 to 41

[0077] The present embodiments 30 to 41 provide a composite catalyst, which is different from the embodiment 1 only in that the modifier in the embodiment 1 is replaced by vinyl pentamethyl disiloxane, hexaethyl disiloxane, 1,1,1,3,5,5,5-heptamethyl trisiloxane, polyphenylmethyl siloxane (CAS No.: 9005-12-3 ; Aladdin), polymethylhydrogensiloxane (CAS No.: 63148-57-2 ; Aladdin), hexamethyldisiloxane, pentamethyldisiloxane, hexamethoxydisiloxane, dodecamethylpentasiloxane, decamethyltetrasiloxane, hexamethylcyclotrisiloxane, octamethyltrisiloxane, and keep the quality of the modifier unchanged.

[0078] Embodiments 42 to 57

[0079] The present Examples 42 to 57 respectively provide a method for preparing a composite catalyst, which differs from Example 1 only in adjusting the temperature and time of the reaction of the metal salt and choline chloride, the temperature and time of the reaction of the carrier and the modifier, and adjusting the temperature and time of the carrier for adsorption and stirring, as shown in Table 4.

[0080] Table 4

[0081]

[0082] Embodiments 58 to 63

[0083] The present Examples 58 to 63 provide a composite catalyst respectively, and the only difference compared with Example 1 is that the carrier in Example 1 is replaced with D3520, D141, S-8, HZ801, XAD16N, and DM11 respectively, while keeping the mass of the carrier unchanged.

[0084] Comparative Example 1

[0085] This comparative example provides a method for preparing a composite catalyst. The difference between the preparation method and Example 1 is that choline chloride is not added. The preparation method comprises the following steps:

[0086] Add polydimethylsiloxane (30 g) and carrier HPD300 (10 g) to 30 mL of purified water in a mass ratio of 3:1, start stirring, heat to 100°C, keep stirring for 3 hours, cool to room temperature, and filter to obtain the modified carrier. Then, add ZnCl2 (1.042 g, 7.64 mmol), cool to 40°C, keep stirring for 5 hours, filter while hot, and dry the filter cake to constant weight to obtain the catalyst of Comparative Example 1.

[0087] Comparative Example 2

[0088] This comparative example provides a method for preparing a composite catalyst. The difference between this preparation method and that of Example 1 is that no modifier is added. The preparation method includes the following steps:

[0089] At room temperature, ZnCl2 (1.042 g, 7.64 mmol) and choline chloride (3.202 g) are added to 40 mL of purified water. The mass ratio of ZnCl2 to choline chloride is 1:3. Stirring is started and the temperature is raised to 100 °C. After maintaining the temperature and stirring for 3 hours, the support HPD300 (10 g) is added. The temperature is lowered to 40 °C and maintained with stirring for 5 hours. The mixture is filtered while it is hot, and the filter cake is dried to a constant weight to obtain the catalyst of Comparative Example 2.

[0090] Comparative Example 3

[0091] At room temperature, ZnCl2 (1.042 g, 7.64 mmol) and choline chloride (3.202 g) are added to 40 mL of purified water. The mass ratio of ZnCl2 to choline chloride is 1:3. Stirring is started and the temperature is raised to 100 °C. After maintaining the temperature and stirring for 3 hours, polydimethylsiloxane (30 g) is added. Stirring is continued at 100 °C for 3 hours to obtain a mixed solution. Excess water is removed to obtain a viscous liquid to obtain the catalyst of Comparative Example 3.

[0092] Comparative Example 4

[0093] Polydimethylsiloxane (30 g) and the support HPD300 (10 g) with a mass ratio of 3:1 are added to 30 mL of purified water. Stirring is started and the temperature is raised to 100 °C. After maintaining the temperature and stirring for 3 hours, the mixture is cooled to room temperature, and then choline chloride (3.202 g) is added. Stirring is continued at 100 °C for 3 hours, the temperature is lowered to 40 °C, and maintained with stirring for 5 hours. The mixture is filtered while it is hot, and the filter cake is dried to a constant weight to obtain the catalyst of Comparative Example 4.

[0094] Comparative Example 5

[0095] (1) Polydimethylsiloxane (30 g) and silicon dioxide (10 g) with a mass ratio of 3:1 are added to 30 mL of purified water. Stirring is started and the temperature is raised to 100 °C. After maintaining the temperature and stirring for 3 hours, the mixture is cooled to room temperature and then filtered to obtain a modified support.

[0096] (2) At room temperature, ZnCl2 (1.042 g, 7.64 mmol) and choline chloride (3.202 g) are added to 40 mL of purified water. The mass ratio of ZnCl2 to choline chloride is 1:3. Stirring is started and the temperature is raised to 100 °C. After maintaining the temperature and stirring for 3 hours, a mixed solution is obtained.

[0097] Add the modified carrier in (1) to the mixed solution in (2), cool down to 40 °C, keep warm and stir for 5 hours, filter while it is hot, and dry the filter cake to constant weight to obtain the catalyst of Comparative Example 5.

[0098] Application Example 1

[0099] In a 500 mL four-necked flask, add catalyst 1 (1.0 g, catalyst concentration 1.0%) and octyl acetate (151.84 g, 0.8814 mol) in sequence. After heating to 60 °C, start to dropwise add p-methoxybenzaldehyde (100 g, 0.7345 mol) and finish the dropping within 1 hour. After the addition of p-methoxybenzaldehyde is completed, keep the temperature and react for 3 hours. Sampling is carried out through the bottom pipe of the reaction kettle, and the reaction solution is detected and analyzed by GC. The conversion rate of the raw material p-methoxybenzaldehyde is 97.10%, and the product isooctyl p-methoxycinnamate OMC is obtained, and the selectivity of the reaction is 98.30%.

[0100] Then, pure isooctyl p-methoxycinnamate OMC 203.08 g with a purity > 99.5% and a yield of 95.21% is obtained through rectification and purification.

[0101] Mass spectrometry diagram:

[0102] Mass spectrometry: Agilent 5977C;

[0103] Detection conditions: Column type DB~17 (30 m × 0.32 mm × 0.25 μm); Injector: 250 °C; Detector: 300 °C; Column temperature: Keep at 70 °C for 2 min, rise to 250 °C at 40 °C / min and keep for 20 min, total running time 26.5 min.

[0104] Figure 2 The mass spectrometry diagram (Diagram A) of isooctyl p-methoxycinnamate obtained in Application Example 1 is compared with the standard spectrum diagram (Diagram B) with the number 150019. It can be seen that it is completely consistent with the standard spectrum diagram, proving that the target product isooctyl p-methoxycinnamate is generated in the reaction product, and the corresponding molecular weight is 290.1.

[0105] Figure 3 The gas chromatography diagram of isooctyl p-methoxycinnamate obtained in Application Example 1, with a content of 99.51%, meeting the standard. The gas phase detection conditions are:

[0106] Gas chromatograph: Fuli 9790;

[0107] Detection conditions: Column type DB~17 (30 m × 0.32 mm × 0.25 μm); Injector: 250 °C; Detector: 300 °C; Column temperature: Keep at 70 °C for 2 min, rise to 250 °C at 40 °C / min and keep for 20 min, total running time 26.5 min.

[0108] Application Examples 2 - 5

[0109] The differences between Application Examples 2 - 5 and Application Example 1 are only that the dosages of Catalyst 1 are changed to 3.0%, 5.0%, 7.0%, and 9.0% successively, and the corresponding catalyst dosages are 3.0 g, 5.0 g, 7.0 g, and 9.0 g respectively. Other conditions are the same as those in Application Example 1. The results are shown in Table 5.

[0110] Taking the process of preparing isooctyl p - methoxycinnamate provided in Application Example 4 as an example, after the reaction is completed, the reaction solution is filtered and separated. The recovered catalyst is obtained by washing the filtered catalyst with deionized water 2 - 3 times. Then, the method of preparing pseudo - isooctyl p - methoxycinnamate provided in Application Example 4 is carried out again with the recovered catalyst for catalyst reuse. The first use of the catalyst is regarded as 1 time of reuse, the second use is regarded as 2 times of reuse, and so on. The conversion rate of p - methoxybenzaldehyde and the selectivity of isooctyl p - methoxycinnamate are calculated. The results are shown in Table 6.

[0111] Application Examples 6 - 12

[0112] The differences between Application Examples 6 - 12 and Application Example 4 are only that the molar ratios of isooctyl acetate to p - methoxybenzaldehyde are 1.0:1, 1.4:1, 1.6:1, 1.8:1, 2.0:1, 2.5:1, and 3.0:1 successively, and the corresponding molar amounts of isooctyl acetate are 0.7345 mol, 1.0283 mol, 1.1752 mol, 1.3221 mol, 1.4690 mol, 1.8362 mol, and 2.2035 mol respectively. Other conditions are the same as those in Application Example 4. The results are shown in Table 5.

[0113] Application Examples 13 - 16

[0114] The differences between Application Examples 13 - 16 and Application Example 4 are only that the types of acetate esters are changed successively to methyl acetate (65.29 g, 0.8814 mol), ethyl acetate (77.66 g, 0.8814 mol), butyl acetate (102.38 g, 0.8814 mol), and isoamyl acetate (114.74 g, 0.8814 mol). Other conditions are the same as those in Application Example 4. The results are shown in Table 5.

[0115] Application Examples 17 - 21

[0116] The differences between Application Examples 17 - 21 and Application Example 4 are only that the reaction temperature and reaction time are changed. Other conditions are the same as those in Application Example 4. The reaction temperatures of Application Examples 17 and 18 are 40°C and 80°C successively, and other conditions are the same as those in Application Example 4. The reaction times of Application Examples 19, 20, and 21 are 2 hours, 4 hours, and 5 hours successively, and other conditions are the same as those in Application Example 4. The results are shown in Table 5.

[0117] Application Examples 22 - 83

[0118] Each of Application Examples 22 - 83 provides an application of a composite catalyst. The composite catalyst is successively the composite catalyst provided in the above Examples 2 - 63, and is used for preparing isooctyl p - methoxycinnamate. The preparation method includes:

[0119] After heating the catalyst (7.0 g, catalyst concentration 7.0%) and octyl acetate (151.84 g, 0.8814 mol) to 60°C, p - methoxybenzaldehyde (100 g, 0.7345 mol) is added dropwise and the addition is completed within 1 hour. After the addition of p - methoxybenzaldehyde is completed, the reaction is kept at a constant temperature for 3 hours. After the reaction ends, the reaction solution is detected and analyzed by GC, and the conversion rate of p - methoxybenzaldehyde and the selectivity of isooctyl p - methoxycinnamate are calculated. The results are shown in Table 5.

[0120] Application Comparative Examples 1 - 5

[0121] Each of Application Comparative Examples 1 - 5 provides an application of a composite catalyst. The difference from Application Example 4 is only that the composite catalyst is successively the composite catalyst provided in the above Comparative Examples 1 - 5. After the reaction ends, the reaction solution is analyzed by a gas chromatograph, and the conversion rate of p - methoxybenzaldehyde and the selectivity of isooctyl p - methoxycinnamate are calculated. The results are shown in Table 5.

[0122] Table 5

[0123]

[0124]

[0125]

[0126]

[0127]

[0128] Table 6

[0129]

[0130] Application Example 84

[0131] The difference between Application Example 84 and Application Example 4 is only that water is used as the solvent in the reaction system, with a dosage of 100 g and a ratio to p-methoxybenzaldehyde of 1:1. Other conditions are the same as those in Application Example 4. The reaction solution was analyzed by GC. The conversion rate of the raw material p-methoxybenzaldehyde was 97.30%, and the product isooctyl p-methoxycinnamate OMC was obtained with a selectivity of 98.80%. Subsequently, 204.53 g of pure isooctyl p-methoxycinnamate OMC with a purity > 99.5% and a yield of 95.89% was obtained through rectification and purification.

[0132] The applicant declares that the present invention uses the above embodiments to illustrate the composite catalyst of the present invention and the synthesis method of p-methoxycinnamate compounds, but the present invention is not limited to the above embodiments, that is, it does not mean that the present invention must rely on the above embodiments to be implemented. Those skilled in the art should understand that any improvement to the present invention, the equivalent substitution of the raw materials selected for the present invention, the addition of auxiliary components, the selection of specific methods, etc., all fall within the protection scope and the disclosure scope of the present invention.

Claims

1. A composite catalyst, characterized in that: The composite catalyst comprises a carrier modified by a modifier and a metal salt and a choline substance supported by the carrier.

2. The composite catalyst according to claim 1, characterized in that The modifier is an organosiloxane; The carrier is a macroporous adsorption resin.

3. The composite catalyst according to claim 1, characterized in that The modifier is selected from one or a combination of at least two of vinyl pentamethyl disiloxane, hexaethyl disiloxane, 1,1,1,3,5,5,5-heptamethyl trisiloxane, polyphenylmethylsiloxane, polymethyl hydrogen siloxane, hexamethyl disiloxane, hexamethoxy disiloxane, pentamethyl disiloxane, dodecamethyl pentasiloxane, decamethyl tetrasiloxane, hexamethyl cyclotrisiloxane, octamethyl trisiloxane, and polydimethyl siloxane; The vector is one or a combination of at least two of D3520, D141, S-8, HPD300, HZ801, XAD16N or DM11; The mass ratio of the modifier to the carrier is 1-5:1; The mass ratio of the metal salt to the carrier is 0.01-0.09:1; The metal salt is any one or a combination of at least two of a hydrochloride containing zinc, iron, copper, cobalt, or nickel, or a hydrate of the hydrochloride; The choline substance is one or a combination of at least two of choline chloride, β-methylcholine chloride, benzoylcholine chloride, butyrylcholine chloride, choline chloride, phosphorylcholine or acetylcholine chloride; The molar ratio of the metal salt to the choline substance is 1:1-5.

4. The composite catalyst according to claim 3, characterized in that The mass ratio of the modifier to the carrier is 2-4:1; the mass ratio of the metal salt to the carrier is 0.03-0.07:1; and the molar ratio of the metal salt to the choline substance is 1:1-4.

5. The composite catalyst according to claim 3 or 4, characterized in that The mass ratio of the metal salt to the carrier is 0.03-0.05:1; the molar ratio of the metal salt to the choline substance is 1:2-3.

6. The method for preparing the composite catalyst according to any one of claims 1 to 5, characterized in that: The preparation method comprises the following steps: (1) The modifying agent and the carrier are mixed and reacted in a first solvent to obtain a carrier modified by the modifying agent; (2) mixing the metal salt and the choline substance in a second solvent to obtain a mixed solution; (3) adding the carrier modified by the modifying agent obtained in step (1) to the mixed solution obtained in step (2), stirring, adsorbing, filtering, removing the solvent, and drying to obtain the composite catalyst.

7. The preparation method according to claim 6, characterized in that: The reaction temperature in step (1) is 60°C to 120°C; The reaction time of step (1) is 1 to 5 hours; Step (1) the first solvent is selected from one or a combination of at least two of water, ethanol, methanol or isopropanol; Step (2) the second solvent is selected from one or a combination of at least two of water, ethanol, methanol or isopropanol; The mixing in step (2) is carried out at a temperature of 60°C to 120°C and the mixing time is 2 to 5 hours; The stirring in step (3) is carried out at a temperature of 30 to 60° C. and the stirring time is 2 to 6 hours.

8. The preparation method according to claim 6, characterized in that: The reaction temperature of step (1) is 80°C to 100°C, and the reaction time of step (1) is 2 to 3 hours; The mixing in step (2) is carried out at a temperature of 80°C to 120°C and the mixing time is 2 to 4 hours; The stirring in step (3) is carried out at a temperature of 30-50° C., and the stirring time is 4-6 hours.

9. A method for preparing a p-methoxycinnamate compound, characterized in that: The preparation method comprises the following steps: in the presence of a catalyst, catalyzing a Claison-Schmidt condensation reaction of an aromatic aldehyde compound and an ester compound to obtain p-methoxycinnamate, wherein the catalyst is a composite catalyst as described in any one of claims 1 to 5.

10. The preparation method according to claim 9, characterized in that: The aromatic aldehyde compound is benzaldehyde and / or p-methoxybenzaldehyde; The ester compound is one or a combination of at least two of methyl acetate, ethyl acetate, butyl acetate, isooctyl acetate, isopentyl acetate or diethyl malonate; The mass ratio of the composite catalyst to the aromatic aldehyde compound is 0.03-0.09:1; The molar ratio of the aromatic aldehyde compound to the ester compound is 1:1-3; The temperature of the condensation reaction is 40°C to 80°C; The condensation reaction time is 1 to 5 hours; The Claison-Schmidt condensation reaction is carried out with or without a solvent; The solvent is selected from any one of water, ethanol, isopropanol or methanol, or a combination of at least two of them.

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