Preparation method of anisyl propanal
The reaction of methoxybenzene and halogenated alkyl produces anisylpropionaldehyde, which solves the problems of high cost and low yield in the prior art, and achieves simple and low cost high yield preparation.
Patent Information
- Application Number
- CN202310383468.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2023-04-11
- Publication Date
- 2025-07-08
- Estimated Expiration
- 2043-04-11
AI Technical Summary
The existing preparation methods for anisylpropionaldehyde have problems such as excessive polycondensation, high cost of precious metal catalysts, difficulty in obtaining raw materials and low synthesis energy efficiency, resulting in high cost and low yield.
Methoxybenzene and halogenated alkyl are reacted under the action of Lewis acid to form the first intermediate, and then eliminate the reaction in an alcohol solution of strong base, and then hydroformylated with the synthesis gas under the action of a catalyst to form anisylpropionaldehyde.
The operation steps are simple, the raw materials are easy to obtain, the cost is low, the yield of anise propionaldehyde is high, the reaction process is stable and there are few impurities.
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Figure CN116693377B_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of spices, and particularly to a method for preparing anisyl propionaldehyde. Background Art
[0002] Anisyl propionaldehyde, also known as khusimol, with the chemical name 2-methyl-3-(p-methoxyphenyl) propionaldehyde, is an important synthetic spice. It has a strong floral fragrance, accompanied by the fragrance of fennel, and can be compatible with many types of fragrances. Therefore, it is widely used in cosmetics, food, and various daily chemical products.
[0003] There are several traditional methods for preparing anisyl propionaldehyde. The first one: Condense p-methoxybenzaldehyde with propionaldehyde, and then use a noble metal as a catalyst to continue hydrogenation to obtain anisyl propionaldehyde. However, in this method, excessive polycondensation is likely to occur during the condensation process, and the aldehyde group needs to be protected from oxidation during the hydrogenation process. The second one: Condense p-methoxybenzaldehyde with propionaldehyde to obtain enal, then protect the aldehyde group of the enal, use a noble metal as a catalyst to continue hydrogenation, and then remove the protecting group to obtain anisyl propionaldehyde. Although this method can protect the aldehyde group from oxidation, the synthesis process is complex, the synthesis energy efficiency is high, and the unit consumption is high. The third one: Use p-methoxyhalobenzene as the raw material and react with methyl allyl alcohol to prepare anisyl propionaldehyde. Although this method has a simple process, the raw materials are difficult to obtain, the raw material cost is high, and it is difficult to find a catalyst with good catalytic effect. The fourth one: React hydrohalic acid with anisyl alcohol to obtain anisyl halide, and then react with allyl methyl ether under the action of a solvent and a catalyst to obtain anisyl propionaldehyde. The yield of anisyl propionaldehyde in this method is low, resulting in high costs. Summary of the Invention
[0004] Based on this, it is necessary to provide a method for preparing anisyl propionaldehyde aiming at the above problems. This preparation method has simple operation steps, easily available raw materials, low cost, and high yield of anisyl propionaldehyde.
[0005] A method for preparing anisyl propionaldehyde includes the following steps:
[0006] React methoxybenzene with a haloalkane shown in the structural formula (1) under the action of a Lewis acid to obtain a first intermediate shown in the structural formula (2);
[0007] Place the first intermediate in an alcoholic solution of a strong base for an elimination reaction to obtain a second intermediate shown in the structural formula (3);
[0008] React the second intermediate with syngas under the action of a catalyst for hydroformylation reaction to obtain anisyl propionaldehyde, wherein the syngas is a mixed gas of hydrogen and carbon monoxide;
[0009]
[0010] Among them, R is a halogen element.
[0011] In one embodiment, the haloalkane is selected from at least one of 1,1-dichloropropane and 1,1-dibromopropane.
[0012] In one embodiment, the molar ratio of the haloalkane to the methoxybenzene is 1:1 - 1.5:1.
[0013] In one embodiment, in the step of reacting methoxybenzene with the haloalkane having the structural formula as shown in formula (1) under the action of a Lewis acid, the haloalkane is added to the methoxybenzene in a batchwise manner for reaction.
[0014] In one embodiment, in the step of adding the haloalkane to the methoxybenzene in a batchwise manner for reaction, the addition time is 2 h - 10 h.
[0015] In one embodiment, in the step of reacting methoxybenzene with the haloalkane having the structural formula as shown in formula (1) under the action of a Lewis acid, the reaction temperature is -25°C - 10°C.
[0016] In one embodiment, the strong base is selected from at least one of sodium hydroxide and potassium hydroxide;
[0017] And / or, the mass ratio of the strong base to the first intermediate is 2:9 - 6:9.
[0018] In one embodiment, in the step of carrying out an elimination reaction by placing the first intermediate in an alcoholic solution of a strong base, the reaction temperature is 70°C - 100°C.
[0019] In one embodiment, in the step of carrying out a hydroformylation reaction on the second intermediate and syngas under the action of a catalyst, the pressure of the syngas is 3 MPa - 6 MPa;
[0020] And / or, the volume ratio of hydrogen to carbon monoxide is 2:1 - 2:4.
[0021] In one embodiment, in the step of carrying out a hydroformylation reaction on the second intermediate and syngas under the action of a catalyst, the reaction temperature is 140°C - 180°C.
[0022] In the method for preparing anisyl propionaldehyde of the present invention, methoxybenzene is used as a raw material, and anisyl propionaldehyde is formed through three-step reactions. The operation steps are simple, the raw materials are easily obtained, and the cost is low.
[0023] In addition, in the three-step reaction, a specific first intermediate is generated by restricting the type of alkyl halide, and the elimination reaction and hydroformylation reaction pathways are clear. Therefore, the reaction process is stable. At the same time, the mechanisms of the elimination reaction and hydroformylation reaction are mature, the catalytic efficiency of the catalyst is high, and the impurities generated are few, resulting in a high yield of anisyl propionaldehyde. Detailed implementation manners
[0024] To facilitate the understanding of the present invention, the present invention will be described more comprehensively below with reference to related embodiments. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, these embodiments are provided to make the understanding of the disclosure of the present invention more thorough and comprehensive.
[0025] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present invention belongs. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.
[0026] The preparation method of anisyl propionaldehyde provided by the present invention includes the following steps:
[0027] S1, reacting methoxybenzene with an alkyl halide having a structural formula as shown in formula (1) under the action of a Lewis acid to obtain a first intermediate having a structural formula as shown in formula (2), and the reaction equation is as follows:
[0028]
[0029] In formula (1), R is a halogen element, and the halogen element is preferably chlorine, bromine, iodine, etc. Optionally, the alkyl halide is selected from at least one of 1,1-dichloropropane and 1,1-dibromopropane, and preferably 1,1-dichloropropane.
[0030] In step S1, due to the limitation of the type of alkyl halide, a first intermediate having a structural formula as shown in formula (2) can be stably generated.
[0031] In order to better generate the first intermediate having a structural formula as shown in formula (2), in one embodiment, the molar ratio of the alkyl halide to the methoxybenzene is 1:1 - 1.5:1, and preferably 1.2:1.
[0032] In order to make the reaction between the alkyl halide and methoxybenzene more sufficient, in one embodiment, the alkyl halide is added to the methoxybenzene in a batchwise manner for reaction, the addition time is 2h - 10h, preferably 3h - 6h, and the batchwise addition method is preferably dropwise addition.
[0033] In order to better avoid the occurrence of side reactions, in one embodiment, in the step of reacting methoxybenzene with a haloalkane having the structural formula shown in Formula (1), the reaction temperature is -25°C to 10°C, preferably -15°C to 0°C.
[0034] Optionally, the Lewis acid is selected from at least one of aluminum trichloride, zinc chloride, copper chloride, and chromium chloride, and preferably a mixture of aluminum trichloride and zinc chloride.
[0035] S2. Place the first intermediate in an alcoholic solution of a strong base for an elimination reaction to obtain a second intermediate having the structural formula shown in Formula (3). The reaction equation is as follows:
[0036]
[0037] Among them, the strong base includes at least one of sodium hydroxide and potassium hydroxide, and preferably sodium hydroxide; the alcohol includes at least one of methanol, ethanol, isopropanol, and cyclohexanol, and preferably ethanol.
[0038] In order to better generate the second intermediate having the structural formula shown in Formula (3), in one embodiment, the mass ratio of the strong base to the first intermediate is 2:9 - 6:9, preferably 3:9 - 5:9.
[0039] In order to make the reaction more complete, in one embodiment, in the step of placing the first intermediate in an alcoholic solution of a strong base for an elimination reaction, the reaction temperature is 70°C to 100°C, preferably 80°C to 90°C. At this temperature, the reaction process can be better controlled.
[0040] S3. React the second intermediate with syngas under the action of a catalyst to obtain anisyl propionaldehyde. Among them, the syngas is a mixed gas of hydrogen and carbon monoxide. The reaction equation is as follows:
[0041]
[0042] The catalyst for the hydroformylation reaction can be a rhodium catalyst, a cobalt catalyst, or a ruthenium catalyst, etc. In one embodiment, the catalyst is selected from at least one of dodecacarbonyltriruthenium, octacarbonyldicobalt, and tetracarbonylhydrocobalt.
[0043] In order to better maintain the stability of the reaction, in one embodiment, in the step of reacting the second intermediate with syngas under the action of a catalyst, the pressure of the syngas is 3 MPa - 6 MPa, preferably 4 MPa - 5 MPa.
[0044] In order to better generate anisyl propionaldehyde, in one embodiment, the volume ratio of hydrogen to carbon monoxide is 2:1 - 2:4, preferably 2:1.6 - 2:2.5.
[0045] In one embodiment, in the step of subjecting the second intermediate to hydroformylation reaction with syngas under the action of a catalyst, the reaction temperature is 140°C - 180°C, preferably 150°C - 170°C.
[0046] It should be noted that the crude product of anisyl propionaldehyde is obtained after subjecting the second intermediate to hydroformylation reaction with syngas under the action of a catalyst, and the crude product of anisyl propionaldehyde is obtained to anisyl propionaldehyde by means of vacuum distillation and the like.
[0047] In the method for preparing anisyl propionaldehyde of the present invention, methoxybenzene is used as a raw material, and anisyl propionaldehyde is formed through three-step reactions. The operation steps are simple, the raw materials are easily available and the cost is low.
[0048] In addition, in the three-step reactions, a specific first intermediate is formed by restricting the type of haloalkane, and the elimination reaction and the hydroformylation reaction pathways are clear. Therefore, the reaction process is stable. At the same time, the elimination reaction and the hydroformylation reaction mechanisms are mature, the catalytic efficiency of the catalyst is high, and the impurities generated are few, resulting in a high yield of anisyl propionaldehyde.
[0049] Hereinafter, the method for preparing anisyl propionaldehyde will be further described through the following specific examples.
[0050] Example 1
[0051] After putting 216 g of methoxybenzene into the reaction kettle and starting stirring, 60 g of a mixture of aluminum trichloride and zinc chloride was added, and the temperature was lowered to -5°C. 230 g of 1,1-dichloropropane was uniformly added dropwise to the reaction kettle over 3 h. After the addition was completed, the reaction continued for 2 h. Samples were taken during the reaction for gas chromatography analysis. When the mass content of methoxybenzene ≤ 0.5%, the reaction was stopped. After filtration and static stratification, the oil layer was retained, washed with sodium carbonate until neutral and then washed with water again. After static stratification, the oil layer was retained to obtain a first intermediate with a crude product content of 87.24%. After vacuum distillation, 308.91 g of a first intermediate with a content of 96.75% was obtained.
[0052] After putting 184 g of the first intermediate obtained above into the reaction kettle and starting stirring, 135 g of an ethanol solution of sodium hydroxide with a mass fraction of 30% was added. After stirring evenly, the temperature was controlled at 80°C and the reaction was refluxed for 2 h. Samples were taken during the reaction for gas chromatography analysis. When the mass content of the first intermediate ≤ 0.5%, the reaction was stopped. After recovering ethanol, 200 g of water was added for washing. After static stratification, it was washed again with 200 g of water, and then dried with a desiccant to obtain 139 g of a second intermediate with a content of 91.26%.
[0053] 74 g of the second intermediate obtained above was charged into a hydrogenation autoclave, and then 1.5 g of dodecacarbonyltriruthenium was added. After closing the hydrogenation autoclave, nitrogen was introduced until the pressure reached 1.5 MPa and then discharged. This was repeated three times. Then, syngas was introduced until the pressure reached 4 MPa. The volume ratio of hydrogen to carbon monoxide in the syngas was 1:1. After heating to 140 °C, heating was stopped, and hydroformylation reaction was carried out. When the pressure in the hydrogenation autoclave decreased to 2 MPa, syngas was introduced again until the pressure reached 4 MPa. This was repeated 2 times until the pressure no longer decreased. After continuing the reaction for half an hour, the reaction was stopped to obtain a crude product of anisyl propionaldehyde with a content of 92.18%. After vacuum distillation, 77.50 g of anisyl propionaldehyde with a content of 99.19% was obtained.
[0054] Example 2
[0055] 216 g of methoxybenzene was charged into a reaction kettle and stirring was started. Then, a mixture of 30 g of aluminum trichloride and zinc chloride was added. The temperature was lowered to -25 °C, and 226 g of 1,1-dichloropropane was added dropwise to the reaction kettle at a uniform rate over 2 h. After the addition was completed, the reaction continued for 2 h. Samples were taken during the reaction for gas chromatography analysis. When the mass content of methoxybenzene ≤ 0.5%, the reaction was stopped. After filtration and standing for liquid separation, the oil layer was retained. The oil layer was washed with sodium carbonate until neutral and then washed with water again. After standing for liquid separation, the oil layer was retained to obtain a crude product of the first intermediate with a content of 85.14%. After vacuum distillation, 298.25 g of the first intermediate with a content of 95.92% was obtained.
[0056] 184 g of the first intermediate obtained above was charged into a reaction kettle and stirring was started. Then, 408 g of an ethanol solution of sodium hydroxide with a mass fraction of 30% was added. After stirring evenly, the temperature was controlled at 70 °C and the reflux reaction was carried out for 2 h. Samples were taken during the reaction for gas chromatography analysis. When the mass content of the first intermediate ≤ 0.5%, the reaction was stopped. After recovering ethanol, 200 g of water was added for washing. After standing for liquid separation, it was washed again with 200 g of water, and then dried with a desiccant to obtain 136.31 g of the second intermediate with a content of 91.98%.
[0057] 74 g of the second intermediate obtained above was charged into a hydrogenation autoclave, and then 1.5 g of dodecacarbonyltriruthenium was added. After closing the hydrogenation autoclave, nitrogen was introduced until the pressure reached 1.5 MPa and then discharged. This was repeated three times. Then, syngas was introduced until the pressure reached 3 MPa. The volume ratio of hydrogen to carbon monoxide in the syngas was 1:2. After heating to 150 °C, heating was stopped, and hydroformylation reaction was carried out. When the pressure in the hydrogenation autoclave decreased to 2 MPa, syngas was introduced again until the pressure reached 3 MPa. This was repeated 2 times until the pressure no longer decreased. After continuing the reaction for half an hour, the reaction was stopped to obtain a crude product of anisyl propionaldehyde with a content of 85.45%. After vacuum distillation, 69.27 g of anisyl propionaldehyde with a content of 98.87% was obtained.
[0058] Example 3
[0059] After adding 216 g of anisole into the reaction kettle, start stirring, then add 30 g of aluminum trichloride, cool down to 5 °C, and slowly dropwise add 339 g of 1,1-dichloropropane into the reaction kettle over 8 h. After the addition is complete, continue the reaction for 2 h. During the reaction, take samples for gas chromatography analysis. When the mass content of anisole ≤ 0.5%, stop the reaction. After filtration and static stratification, retain the oil layer. Wash the oil layer with sodium carbonate until neutral and then wash it with water again. After static stratification, retain the oil layer to obtain a first intermediate with a crude product content of 87.42%. After vacuum distillation, 302.89 g of the first intermediate with a content of 95.59% is obtained.
[0060] After adding 184 g of the first intermediate obtained above into the reaction kettle, start stirring, then add 140 g of an ethanol solution of sodium hydroxide with a mass fraction of 30%. After stirring evenly, control the temperature at 90 °C and reflux for 2 h. During the reaction, take samples for gas chromatography analysis. When the mass content of the first intermediate ≤ 0.5%, stop the reaction. After recovering ethanol, add 200 g of water for washing. After static stratification, wash it with 200 g of water again, and then dry it with a desiccant to obtain 134.27 g of a second intermediate with a content of 92.14%.
[0061] Add 74 g of the second intermediate obtained above into the hydrogenation kettle, then add 1.5 g of dodecacarbonyltriruthenium. After closing the hydrogenation kettle, introduce nitrogen to 1.5 MPa and then discharge it. Repeat this three times. Then introduce syngas to 5 MPa. The volume ratio of hydrogen to carbon monoxide in the syngas is 2:1. After heating up to 140 °C, stop heating and carry out hydroformylation reaction. When the pressure in the hydrogenation kettle drops to 2 MPa, introduce syngas to 5 MPa again. Repeat this 2 times until the pressure no longer drops. Continue the reaction for half an hour and then stop the reaction to obtain a crude product of anisyl propionaldehyde with a content of 82.74%. After vacuum distillation, 67.33 g of anisyl propionaldehyde with a content of 98.44% is obtained.
[0062] Example 4
[0063] After adding 216 g of anisole into the reaction kettle, start stirring, then add 30 g of copper chloride, cool down to 0 °C, and slowly dropwise add 270 g of 1,1-dichloropropane into the reaction kettle over 6 h. After the addition is complete, continue the reaction for 2 h. During the reaction, take samples for gas chromatography analysis. When the mass content of anisole ≤ 0.5%, stop the reaction. After filtration and static stratification, retain the oil layer. Wash the oil layer with sodium carbonate until neutral and then wash it with water again. After static stratification, retain the oil layer to obtain a first intermediate with a crude product content of 91.63%. After vacuum distillation, 311.60 g of the first intermediate with a content of 98.33% is obtained.
[0064] After adding 184 g of the first intermediate obtained above into the reaction kettle, start stirring, and then add 204 g of an ethanol solution of sodium hydroxide with a mass fraction of 30%. After stirring evenly, control the temperature at 100 °C and reflux for 2 h. During the reaction, take samples for gas chromatography analysis. When the mass content of the first intermediate ≤ 0.5%, stop the reaction. After recovering ethanol, add 200 g of water for washing. After standing and separating the layers, wash again with 200 g of water, and then dry with a desiccant to obtain 140.52 g of the second intermediate with a content of 95.81%.
[0065] Add 74 g of the second intermediate obtained above into the hydrogenation kettle, and then add 1.5 g of dicobalt octacarbonyl. After closing the hydrogenation kettle, introduce nitrogen to 1.5 MPa and then discharge it. Repeat three times. Then introduce syngas to 6 MPa. The volume ratio of hydrogen to carbon monoxide in the syngas is 2:1. After heating to 180 °C, stop heating and carry out hydroformylation reaction. When the pressure in the hydrogenation kettle drops to 2 MPa, introduce syngas to 6 MPa again. Repeat 2 times until the pressure no longer drops. Continue the reaction for half an hour and then stop the reaction to obtain a crude product of anisyl propionaldehyde with a content of 83.15%. After vacuum distillation, 67.78 g of anisyl propionaldehyde with a content of 98.29% is obtained.
[0066] Example 5
[0067] Add 216 g of methoxybenzene into the reaction kettle and start stirring. Then add a mixture of 30 g of aluminum trichloride and zinc chloride, cool down to -15 °C, and slowly drop 402 g of 1,1-dibromopropane into the reaction kettle. The dropping time is 10 h. After the dropping is completed, continue the reaction for 2 h. During the reaction, take samples for gas chromatography analysis. When the mass content of methoxybenzene ≤ 0.5%, stop the reaction. After filtration and standing to separate the layers, retain the oil layer. Wash the oil layer with sodium carbonate until neutral and then wash with water again. After standing and separating the layers, retain the oil layer to obtain a crude product of the first intermediate with a content of 83.99%. After vacuum distillation, 292.11 g of the first intermediate with a content of 95.23% is obtained.
[0068] Add 184 g of the first intermediate obtained above into the reaction kettle and start stirring. Then add 340 g of a methanol solution of sodium hydroxide with a mass fraction of 30%. After stirring evenly, control the temperature at 100 °C and reflux for 2 h. During the reaction, take samples for gas chromatography analysis. When the mass content of the first intermediate ≤ 0.5%, stop the reaction. After recovering methanol, add 200 g of water for washing. After standing and separating the layers, wash again with 200 g of water, and then dry with a desiccant to obtain 139.78 g of the second intermediate with a content of 94.61%.
[0069] 74 g of the second intermediate obtained above was charged into a hydrogenation autoclave, and then 1.5 g of dodecacarbonyltriruthenium was added. After closing the hydrogenation autoclave, nitrogen was introduced until the pressure reached 1.5 MPa and then discharged. This was repeated three times. Then, syngas was introduced until the pressure reached 6 MPa. The volume ratio of hydrogen to carbon monoxide in the syngas was 1:2. After heating to 180 °C, heating was stopped, and hydroformylation reaction was carried out. When the pressure in the hydrogenation autoclave decreased to 2 MPa, syngas was introduced again until the pressure reached 6 MPa. This was repeated 2 times until the pressure no longer decreased. After continuing the reaction for half an hour, the reaction was stopped to obtain a crude product of anisyl propionaldehyde with a content of 80.54%. After vacuum distillation, 64.52 g of anisyl propionaldehyde with a content of 98.16% was obtained.
[0070] Example 6
[0071] 240 g of 1,1-dichloropropane was charged into a reaction kettle and stirring was started. Then, a mixture of 30 g of aluminum trichloride and zinc chloride was added. The temperature was lowered to -5 °C, and 216 g of methoxybenzene was added dropwise to the reaction kettle at a constant rate over 3 h. After the addition was completed, the reaction continued for 2 h. Samples were taken during the reaction for gas chromatography analysis. When the mass content of methoxybenzene ≤ 0.5%, the reaction was stopped. After filtration and static separation, the oil layer was retained. The oil layer was washed with sodium carbonate until neutral and then washed with water again. After static separation, the oil layer was retained to obtain a crude product of the first intermediate with a content of 64.21%. After vacuum distillation, 228.23 g of the first intermediate with a content of 93.22% was obtained.
[0072] Example 7
[0073] 216 g of methoxybenzene was charged into a reaction kettle and stirring was started. Then, a mixture of 30 g of aluminum trichloride and zinc chloride was added. The temperature was lowered to -5 °C, and 120 g of 1,1-dichloropropane was added to the reaction kettle. The reaction was carried out for 2 h. Samples were taken during the reaction for gas chromatography analysis. When the mass content of methoxybenzene ≤ 0.5%, the reaction was stopped. After filtration and static separation, the oil layer was retained. The oil layer was washed with sodium carbonate until neutral and then washed with water again. After static separation, the oil layer was retained to obtain a crude product of the first intermediate with a content of 43.21%. After vacuum distillation, 155.34 g of the first intermediate with a content of 92.15% was obtained.
[0074] As can be seen from Example 4 and other examples, when the molar ratio of the haloalkane to methoxybenzene is 1.2:1, the content of the first intermediate obtained is higher. As can be seen from Example 4, 5 and other examples, when the mass ratio of the strong base to the first intermediate is 3:9 - 5:9, the content of the second intermediate obtained is higher. As can be seen from Examples 1 - 5 and Examples 6, 7, when the haloalkane is added dropwise to methoxybenzene, the content of the first intermediate obtained is higher.
[0075] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity in description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as falling within the scope described in this specification.
[0076] The above-described embodiments merely represent several implementation manners of the present invention. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention patent shall be subject to the appended claims.
Claims
1. A method for preparing anisyl propanal, characterized in that, It includes the following steps: React methoxybenzene with a halogenoalkane having the structural formula shown in Formula (1) under the action of a Lewis acid to obtain a first intermediate having the structural formula shown in Formula (2); Subject the first intermediate to an elimination reaction in an alcoholic solution of a strong base to obtain a second intermediate having the structural formula shown in Formula (3); Subject the second intermediate to hydroformylation reaction with syngas under the action of a catalyst to obtain anisyl propionaldehyde, wherein the syngas is a mixed gas of hydrogen and carbon monoxide, and the catalyst is selected from a rhodium catalyst, a cobalt catalyst or a ruthenium catalyst; 、 、 ， Wherein, R is a halogen element.
2. The preparation method of anisyl propionaldehyde according to claim 1, characterized in that, The halogenoalkane is selected from at least one of 1,1-dichloropropane and 1,1-dibromopropane.
3. The method for preparing anisyl propanal according to claim 1, wherein The molar ratio of the halogenoalkane to the methoxybenzene is 1:1 - 1.5:
1.
4. The preparation method of anisyl propionaldehyde according to claim 1, characterized in that, In the step of reacting methoxybenzene with a halogenoalkane having the structural formula shown in Formula (1) under the action of a Lewis acid, the halogenoalkane is added to the methoxybenzene in a batchwise manner for reaction.
5. The preparation method of anisyl propionaldehyde according to claim 4, wherein In the step of adding the halogenoalkane to the methoxybenzene in a batchwise manner for reaction, the addition time is 2 h - 10 h.
6. The preparation method of anisyl propanal according to claim 1, characterized in that, In the step of reacting methoxybenzene with a halogenoalkane having the structural formula shown in Formula (1) under the action of a Lewis acid, the reaction temperature is -25°C - 10°C.
7. The preparation method of anisyl propionaldehyde according to claim 1, characterized in that, The strong base is selected from at least one of sodium hydroxide and potassium hydroxide; And / or, the mass ratio of the strong base to the first intermediate is 2:9 - 6:
9.
8. The method for preparing anisyl propionaldehyde according to claim 1, wherein In the step of subjecting the first intermediate to an elimination reaction in an alcoholic solution of a strong base, the reaction temperature is 70°C - 100°C.
9. The preparation method of anisyl propionaldehyde according to claim 1, characterized in that, In the step of subjecting the second intermediate to hydroformylation reaction with syngas under the action of a catalyst, the pressure of the syngas is 3 MPa - 6 MPa; And / or, the volume ratio of the hydrogen to the carbon monoxide is 2:1 - 2:
4.
10. The preparation method of anisyl propionaldehyde according to claim 1, characterized in that, In the step of subjecting the second intermediate to hydroformylation reaction with syngas under the action of a catalyst, the reaction temperature is 140°C - 180°C.