Preparation method of piperonyl propionaldehyde

Abstract

The present invention relates to the technical field of compound synthesis, and in particular to a method for preparing piperonyl propionaldehyde. The method for preparing piperonyl propionaldehyde comprises: mixing a catalyst 1, 1,2-methylenedioxybenzene, and methacrolein diacetyl acetal to react to form an intermediate; mixing the intermediate, an alcoholysis reagent, and a catalyst 2 to perform an alcoholysis reaction; wherein the catalyst 2 is selected from at least two of the following metal ion salt compounds or oxides: Fe 3+ 、Al 3+ 、Zn 2+ 、Mn 4+ Cr 3+ 、Ce 4+ 、Ba 2+ Mg 2+ 、Sr 2+ and Ca 2+ The preparation method can significantly shorten the batch time and realize the continuous production of piperonyl propionaldehyde. It also has the advantages of small equipment occupation, short batch time, high efficiency, mild reaction conditions, and small amount of three wastes, which significantly reduces costs.

Description

Technical Field

[0001] The present invention relates to the technical field of compound synthesis, and in particular to a method for preparing piperonyl propionaldehyde. Background Art

[0002] Piperonyl propionaldehyde, chemically known as 2-methyl-3-(3,4-methylenedioxyphenyl) propionaldehyde, is a spice with the aroma of fresh watermelon, light lily of the valley and jasmine-like fennel. It can be widely used in the formulation of various new floral, forest and sea breeze-type fragrances such as jasmine and rabbit ear flowers, with long-lasting fragrance.

[0003] Piperonyl propionaldehyde is usually prepared from piperonal, which undergoes an aldol condensation reaction with propionaldehyde to obtain piperonyl propionaldehyde, and finally catalytic reduction is performed to obtain crude piperonyl propionaldehyde. However, this route has a low conversion rate, many impurities, and high cost.

[0004] Patent CN 103304536 A uses piperonyl cyclopentane and methacrolein diacetyl acetal as raw materials, using boron trifluoride as a catalyst to prepare piperonyl propionaldehyde. The reactor temperature is controlled between -10 and 15°C, and the pumping time is 4 to 10 hours. This patent involves synthesis, fractionation, and refining reactors, requiring extensive equipment, resulting in high levels of waste, long batch times, low efficiency, and low equipment utilization.

[0005] Patent CN 104650027 A describes alcoholysis of piperonyl propionaldehyde monoester by adding alcohol at a temperature of 0-80°C. After the alcoholysis is complete, the piperonyl propionaldehyde product is obtained through steps including water washing and distillation. This patent involves both an alcoholysis reactor and a crude product refining reactor, requiring extensive equipment, resulting in high levels of three wastes and low equipment efficiency.

[0006] In view of this, the present invention is proposed. Summary of the Invention

[0007] The present invention aims to provide a method for preparing piperonyl propionaldehyde. The method provided in the embodiments of the present invention can significantly shorten batching time, enabling continuous production of piperonyl propionaldehyde. The method also has the advantages of reduced equipment footprint, short batching time, high efficiency, mild reaction conditions, and low levels of three wastes, thereby significantly reducing costs.

[0008] The present invention is achieved in that:

[0009] In a first aspect, the present invention provides a method for preparing piperonyl propionaldehyde, comprising: mixing a catalyst (1,1,2-methylenedioxybenzene) and methacrolein diacetyl acetal to react to form an intermediate;

[0010] Mixing the intermediate, an alcoholysis reagent, and a catalyst-2 to carry out an alcoholysis reaction;

[0011] Wherein, the catalyst-1 is selected from a combination of at least two of the following fluorides: tris(pentafluorophenyl)borane, boron trifluoride complex and trifluoroacetic acid;

[0012] The catalyst-2 is selected from at least two of the following metal ion salt compounds or the following metal ion oxides: Fe 3+ 、Al 3+ 、Zn 2+ 、Mn 4+ Cr 3+ 、Ce 4+ 、Ba 2+ Mg 2+ 、Sr 2+ and Ca 2+ .

[0013] In an optional embodiment, the catalyst-1 is selected from at least two of tris(pentafluorophenyl)borane, boron trifluoride complex and trifluoroacetic acid;

[0014] Preferably, the catalyst-1 is selected from any one of the following compositions: (1) tris(pentafluorophenyl)borane and a boron trifluoride complex, wherein the mass percentage of the tris(pentafluorophenyl)borane is 15-60%, and the mass percentage of the boron trifluoride complex is 40-85%;

[0015] (2) tris(pentafluorophenyl)borane and trifluoroacetic acid, wherein the mass percentage of the tris(pentafluorophenyl)borane is 15-60%, and the mass percentage of the trifluoroacetic acid is 40-85%;

[0016] (3) a boron trifluoride complex and trifluoroacetic acid, wherein the mass percentage of the boron trifluoride complex is 15-60%, and the mass percentage of the trifluoroacetic acid is 40-85%;

[0017] (4) tris(pentafluorophenyl)borane, a boron trifluoride complex, and trifluoroacetic acid, wherein the mass percentage of the boron trifluoride complex is 5-63%; the mass percentage of the trifluoroacetic acid is 10-30%; and the mass ratio of the tris(pentafluorophenyl)borane is 25-80%;

[0018] In an optional embodiment, the amount of the catalyst-1 is 0.01-30 wt% of the mass of the methacrolein diacetyl acetal; preferably 0.1-5 wt%.

[0019] In an optional embodiment, the molar ratio of the methacrolein diacetyl acetal to the 1,2-methylenedioxybenzene is 1:(1-5).

[0020] In an optional embodiment, the step of forming the intermediate comprises: adding the methacrolein diacetyl acetal to a mixture of the catalyst-1 and the 1,2-methylenedioxybenzene at 10-60° C., and reacting the mixture for 5 minutes to 4 hours.

[0021] In an optional embodiment, the methacrolein diacetyl acetal is added to the mixed material by pumping;

[0022] Preferably, the pumping flow rate of the methacrolein diacetyl acetal is 0.0001m 3 / h-3m 3 In an optional embodiment, the catalyst-2 is selected from at least four of the following metal ion salt compounds or the following metal ion oxides: Fe 3+ 、Al 3+ 、Zn 2+ 、Mn 4+ Cr 3+ 、Ce 4+ 、Ba 2+ Mg 2+ 、Sr 2+ and Ca 2+ ;

[0023] Preferably, the mass content of the following metal ions in the catalyst-2 is as follows: Al 3+ The content is 20.00wt%-80.00wt%, Mn 4+ The content is 0.01wt%-60.00wt%, Cr 3+ Content is 0.01wt%-50.00wt%, Ce 4+ The content is 0.01wt%-50.00wt%, Fe 3+ The content is 0.01wt%-50.00wt%, Zn 2+ The content is 0.01wt%-50.00wt%, Ba 2+ The content is 0.01wt%-60.00wt%, Mg 2+ The content is 0.01wt%-60.00wt%, Sr 2+ The content is 0.01wt%-60.00wt%, Ca 2+ The content is 0.01wt%-60.00wt%;

[0024] Preferably, the mass content of the following metal ions in the catalyst-2 is as follows: Al 3+ The content is 25.00wt%-60.00wt%, Mn 4+ The content is 0.1wt%-30.00wt%, Cr 3+Content is 0.01wt%-40.00wt%, Ce 4+ The content is 1.00wt%-40.00wt%, Fe 3+ The content is 10.00wt%-30.00wt%, Zn 2+ The content is 10.00wt%-40.00wt%, Ba 2+ The content is 0.01wt%-40.00wt%, Mg 2+ The content is 0.1wt%-45.00wt%, Sr 2+ The content is 0.01wt%-50.00wt%, Ca 2+ The content is 0.01wt%-50.00wt%;

[0025] Preferably, the particle size of the catalyst-2 is 1 mesh to 100 mesh.

[0026] In an optional embodiment, the amount of the catalyst-2 is 0.1%-10% of the mass of the methacrolein diacetyl acetal.

[0027] In an optional embodiment, the method comprises: pumping the intermediate and the alcoholysis reagent into a fixed bed containing the catalyst-2 to carry out an alcoholysis reaction;

[0028] Preferably, the intermediate and the alcoholysis reagent reside in the fixed bed for a time period of 5 minutes to 4 hours, preferably 5 minutes to 60 minutes.

[0029] In an optional embodiment, the method comprises: refining the crude piperonyl propionaldehyde formed by the alcoholysis reaction;

[0030] Preferably, the refining includes vacuum distillation, rectification and molecular distillation.

[0031] The present invention has the following beneficial effects: the preparation method provided by the embodiment of the present invention realizes the continuous preparation of piperonyl propionaldehyde, greatly reduces the amount of three wastes and shortens the reaction time. The technology proposed by the present invention can prepare piperonyl propionaldehyde with a content of ≥95% and a yield of ≥90%, which is suitable for large-scale industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0033] Figure 1A schematic structural diagram of an apparatus for preparing piperonyl propionaldehyde provided in an embodiment of the present invention.

[0034] Icons: 1-transfer pump; 2-high-level tank; 3-intermediate synthesis kettle; 4-first molecular distillation equipment; 5-transfer pump; 6-fixed bed reactor; 7-second molecular distillation equipment. DETAILED DESCRIPTION

[0035] To make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are described clearly and completely below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer are used. Where the manufacturer of the reagents or instruments is not specified, they are all conventional products that can be purchased commercially.

[0036] The present invention provides a method for preparing piperonyl propionaldehyde, and the synthesis path is as follows:

[0037]

[0038] The specific steps include:

[0039] S1. Formation of intermediates:

[0040] Add catalyst-1 and 1,2-methylenedioxybenzene into the reactor, control the reactor temperature at 10-60°C, pump in the methacrolein diacetyl acetal within 5 minutes to 4 hours under normal pressure, and keep the reaction warm for 5 minutes to 4 hours.

[0041] Among them, the pumping flow rate of methacrolein diacetyl acetal is 0.0001m 3 / h-3m 3 / h. The molar ratio of methacrolein diacetyl acetal to the 1,2-methylenedioxybenzene is 1:(1-5). For example, it is any value between 1:(1-5), such as 1:1, 1:2, 1:3, 1:4, and 1:5. The amount of catalyst-1 is 0.01-30 wt% of the mass of the methacrolein diacetyl acetal; preferably 0.1-5 wt%, and preferably 0.9-4.5 wt%. For example, it is any value between 0.01-30 wt%, such as 0.01 wt%, 0.005 wt%, 0.1 wt%, 0.5 wt%, 0.9 wt%, 1 wt%, 3 wt%, 4.5 wt%, 5 wt%, 10 wt%, 15 wt%, 20 wt%, 25 wt%, and 30 wt%.

[0042] Furthermore, the catalyst-1 is selected from fluorides, and the catalyst-1 is selected from at least two of tris(pentafluorophenyl)borane, boron trifluoride complex and trifluoroacetic acid.

[0043] Specifically, catalyst-1 is selected from any one of the following compositions: (1) tri(pentafluorophenyl)borane and a boron trifluoride complex, wherein the mass percentage of tri(pentafluorophenyl)borane is 15-60%, for example, any value between 15-60% such as 15%, 20%, 30%, 40%, 50%, 60%, etc.; the mass percentage of the boron trifluoride complex is 40-85%, for example, any value between 40-85% such as 40%, 50%, 60%, 70%, 80% and 85%.

[0044] (2) tris(pentafluorophenyl)borane and trifluoroacetic acid, wherein the mass percentage of tris(pentafluorophenyl)borane is 15-60%, for example, any value between 15% and 60%, such as 15%, 20%, 30%, 40%, 50%, 60%, etc.; the mass percentage of trifluoroacetic acid is 40-85%, for example, any value between 40% and 85%, such as 40%, 50%, 60%, 70%, 80%, and 85%.

[0045] (3) a boron trifluoride complex and trifluoroacetic acid, wherein the mass percentage of the boron trifluoride complex is 15-60%, for example, any value between 15% and 60%, such as 15%, 20%, 30%, 40%, 50%, and 60%; and the mass percentage of the trifluoroacetic acid is 40-85%, for example, any value between 40% and 85%, such as 40%, 50%, 60%, 70%, 80%, and 85%.

[0046] (4) tris(pentafluorophenyl)borane, boron trifluoride complex and trifluoroacetic acid, the mass percentage of the boron trifluoride complex is 5-63%; for example, any value between 5-63%, such as 5%, 15%, 20%, 30%, 40%, 50%, 60% and 63%; the mass percentage of the trifluoroacetic acid is 10-30%; for example, any value between 10-30%, such as 10%, 15%, 20%, 25% and 30%; the mass ratio of the tris(pentafluorophenyl)borane is 25-80%; for example, any value between 25-80%, such as 25%, 35%, 40%, 45%, 50%, 60%, 70% and 80%.

[0047] After the reaction is completed, the reaction system is passed through a molecular distillation device to obtain an intermediate.

[0048] S2, alcoholysis reaction;

[0049] The intermediate and alcoholysis reagent are pumped into a fixed bed reactor, and alcoholysis is carried out under the action of catalyst-2 to obtain crude piperonyl propionaldehyde.

[0050] Wherein, catalyst-2 is selected from at least two of the following metal ion salt compounds or the following metal ion oxides: Fe 3+ 、Al3+ 、Zn 2+ 、Mn 4+ Cr 3+ 、Ce 4+ 、Ba 2+ Mg 2+ 、Sr 2+ and Ca 2+ Preferably, at least four of the salt compounds of the above-mentioned metal ions or the oxides of the following metal ions are selected, and the most preferred is exactly four.

[0051] Specifically, the mass contents of the following metal ions in the catalyst-2 are as follows: Al 3+ The content is 20.00wt%-80.00wt%, Mn 4+ The content is 0.01wt%-60.00wt%, Cr 3+ Content is 0.01wt%-50.00wt%, Ce 4+ The content is 0.01wt%-50.00wt%, Fe 3+ The content is 0.01wt%-50.00wt%, Zn 2+ The content is 0.01wt%-50.00wt%, Ba 2+ The content is 0.01wt%-60.00wt%, Mg 2+ The content is 0.01wt%-60.00wt%, Sr 2+ The content is 0.01wt%-60.00wt%, Ca 2+ The content is 0.01wt%-60.00wt%;

[0052] Preferably, the mass content of the following metal ions in the catalyst-2 is as follows: Al 3+ The content is 25.00wt%-60.00wt%, Mn 4+ The content is 0.1wt%-30.00wt%, Cr 3+ Content is 0.01wt%-40.00wt%, Ce 4+ The content is 1.00wt%-40.00wt%, Fe 3+ The content is 10.00wt%-30.00wt%, Zn 2+ The content is 10.00wt%-40.00wt%, Ba 2+ The content is 0.01wt%-40.00wt%, Mg 2+ The content is 0.1wt%-45.00wt%, Sr 2+ The content is 0.01wt%-50.00wt%, Ca 2+ The content is 0.01wt%-50.00wt%.

[0053] For example, Al 3+ The content is any value between 20.00-80.00wt%, such as 20.00wt%, 25.00wt%, 30wt%, 40wt%, 50wt%, 60wt%, 70wt% and 80wt%.

[0054] Mn 4+ The content is any value between 0.01-60wt%, such as 0.01wt%, 0.1wt%, 1wt%, 10wt%, 20wt%, 30wt%, 40wt%, 50wt% and 60wt%.

[0055] Cr 3+ The content is any value between 0.01-50wt%, such as 0.01wt%, 0.1wt%, 0.5wt%, 1wt%, 10wt%, 20wt%, 30wt%, 40wt% and 50wt%.

[0056] Ce 4+ The content is any value between 0.01-50wt%, such as 0.01wt%, 0.1wt%, 0.5wt%, 1wt%, 10wt%, 20wt%, 30wt%, 40wt% and 50wt%.

[0057] Fe 3+ The content is any value between 0.01-50wt%, such as 0.01wt%, 0.1wt%, 0.5wt%, 1wt%, 10wt%, 20wt%, 30wt%, 40wt% and 50wt%.

[0058] Zn 2+ The content is any value between 0.01-50wt%, such as 0.01wt%, 0.1wt%, 0.5wt%, 1wt%, 10wt%, 20wt%, 30wt%, 40wt% and 50wt%.

[0059] Ba 2+ The content is any value between 0.01-60wt%, such as 0.01wt%, 0.1wt%, 1wt%, 10wt%, 20wt%, 30wt%, 40wt%, 50wt% and 60wt%.

[0060] Mg 2+ The content is any value between 0.01-60wt%, such as 0.01wt%, 0.1wt%, 1wt%, 10wt%, 20wt%, 30wt%, 40wt%, 50wt% and 60wt%.

[0061] Sr 2+The content is any value between 0.01-60wt%, such as 0.01wt%, 0.1wt%, 1wt%, 10wt%, 20wt%, 30wt%, 40wt%, 50wt% and 60wt%.

[0062] Ca 2+ The content is any value between 0.01-60wt%, such as 0.01wt%, 0.1wt%, 1wt%, 10wt%, 20wt%, 30wt%, 40wt%, 50wt% and 60wt%.

[0063] It should be noted that the above-mentioned salt substances can be metal chlorides, such as ferric chloride, aluminum chloride, and magnesium chloride, or sulfates, such as calcium sulfate, magnesium sulfate, and zinc sulfate. The oxides are oxides of the corresponding metals, such as aluminum oxide, iron oxide, calcium oxide, and magnesium oxide.

[0064] The particle size of catalyst-2 is 1 mesh to 100 mesh, preferably 10-80 mesh, and more preferably 20-50 mesh.

[0065] The amount of catalyst-2 used is 1-10% of the mass of the methacrolein diacetyl acetal, for example, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9% and 10%, etc., any value between 1-10%.

[0066] The alcoholysis reagent is an alcohol substance commonly used in the art, including but not limited to methanol, ethanol, propylene glycol, propanol and other alcohol substances.

[0067] The intermediate and the alcoholysis reagent are retained in the fixed bed for 5 minutes to 4 hours, preferably 5 minutes to 60 minutes. The fixed bed reaction temperature is 30-150°C.

[0068] S3, post-processing;

[0069] The crude piperonyl propionaldehyde formed by the alcoholysis reaction is refined; specifically, the crude piperonyl propionaldehyde is pumped into a molecular distillation device for refining to obtain a high-content piperonyl propionaldehyde finished product.

[0070] The device structure for implementing the above preparation method in the embodiment of the present invention is shown in FIG. Figure 1Specifically, the delivery pump 1 pumps the raw material catalyst-1 and 1,2-methylenedioxybenzene into the intermediate synthesis kettle 3, and the methacrolein diacetyl acetal is delivered to the high-level tank 2 by the delivery pump 1 and then pumped into the intermediate synthesis kettle 3, or it can be directly pumped into the intermediate synthesis kettle 3. After the intermediate synthesis reaction is completed, the reaction system is purified by the first molecular distillation equipment 4 to obtain the piperonyl propionaldehyde intermediate. The piperonyl propionaldehyde intermediate is pumped into the fixed bed reactor 6 containing the catalyst-2 at a constant flow rate by the delivery pump 5 for alcoholysis. After the alcoholysis is completed, it enters the second molecular distillation equipment 7 under the action of vacuum for purification to obtain the piperonyl propionaldehyde finished product.

[0071] The features and performance of the present invention are further described in detail below with reference to the embodiments.

[0072] Example 1

[0073] This embodiment provides a method for preparing piperonyl propionaldehyde, comprising:

[0074] 56.8 kg of 1,2-methylenedioxybenzene and 1.2 kg of catalyst-1 were mixed, and then 80.0 kg of methacrolein diacetyl acetal was added through a pump. During the addition process, the kettle temperature was maintained at 10-50 ° C, and the flow rate was controlled so that the materials were pumped in within 1 hour. After the addition of the materials, the temperature was kept at this temperature for 3 hours. After the insulation was completed, methanol and piperonyl propionaldehyde intermediate purified by molecular distillation equipment were mixed through a pump and 0.0023 m 3 / h was pumped into a fixed bed containing 10.5 kg of catalyst-2 (the particle size of catalyst-2 was 30 mesh) for alcoholysis. The crude product after alcoholysis was further refined by molecular distillation equipment. After purification, the material could obtain a finished product with a content of 96.7% piperonyl propionaldehyde, and the yield of the finished piperonyl propionaldehyde was 87.2%.

[0075] Example 2

[0076] This embodiment provides a method for preparing piperonyl propionaldehyde, comprising:

[0077] Mix 57.8 kg of 1,2-methylenedioxybenzene and 1.0 kg of catalyst-1, and add 80.3 kg of methacrolein diacetyl acetal by pump. During the feeding process, the kettle temperature is maintained at 22-35 ° C. The whole process is completed within 3 hours. After the addition of the materials, the temperature is kept at 2.5 hours. After the insulation is completed, the propanol and the piperonyl propionaldehyde intermediate purified by the molecular distillation equipment are mixed by pump and 0.0019m 3 / h was pumped into a fixed bed containing 11.2 kg of catalyst-2 (the particle size of catalyst-2 was 30 mesh) for alcoholysis. After the alcoholysis, the material was pumped into the molecular distillation equipment again to refine the crude product. After refining, a finished product with a content of 98.7% piperonyl propionaldehyde was obtained, and the yield of the finished piperonyl propionaldehyde was 90.3%.

[0078] Example 3

[0079] This embodiment provides a method for preparing piperonyl propionaldehyde, comprising:

[0080] 120.0 kg of 1,2-methylenedioxybenzene and 3.0 kg of catalyst-1 were mixed, and then 160.0 kg of methacrolein diacetyl acetal was added by pump within 3 hours. The kettle temperature was maintained at 30-40 ° C during the feeding process. After the materials were added and kept warm for 3 hours, the intermediate was purified by molecular distillation equipment. Then, ethanol and the purified intermediate were mixed by pump and 0.0019 m 3 / h was pumped into a fixed bed containing 9.8 kg of catalyst-2 (the particle size of catalyst-2 was 10 mesh) for alcoholysis. After the alcoholysis was completed, the material was pumped into a molecular distillation device for purification. After purification, the crude piperonyl propionaldehyde product could be obtained to obtain a piperonyl propionaldehyde product with a content of 99.0%, and the yield of the piperonyl propionaldehyde product was 90.1%.

[0081] Example 4

[0082] This embodiment provides a method for preparing piperonyl propionaldehyde, comprising:

[0083] 28.0 kg of 1,2-methylenedioxybenzene and 1.0 kg of catalyst-1 were mixed, and then 39.0 kg of methacrolein diacetyl acetal was added via a pump within 3 hours. During the process, the kettle temperature was controlled at 22-35 ° C. After the addition of the materials, the temperature was kept at this temperature for 2.5 hours. The above intermediate was purified by molecular distillation and mixed with ethylene glycol and 0.0016 m 3 / h was pumped into a fixed bed containing 10.4 kg of catalyst-2 (the particle size of catalyst-2 was 30 mesh) for alcoholysis. The material after alcoholysis was further refined by molecular distillation equipment. After refining, a finished product with a piperonyl propionaldehyde content of 98.5% was obtained, and the yield of the finished piperonyl propionaldehyde was 78.6%.

[0084] Example 5

[0085] This embodiment provides a method for preparing piperonyl propionaldehyde, comprising:

[0086] 42.0 kg of 1,2-methylenedioxybenzene and 1.2 kg of catalyst-1 were mixed, and then 28.0 kg of methacrolein diacetyl acetal was pumped into the mixture within 3 hours. After the addition of the materials, the mixture was kept warm for 2.3 hours, and the kettle temperature was maintained at 30-40 ° C. The synthesized intermediate was purified by molecular distillation and mixed with methanol and 0.0016 m 3 / h was pumped into a fixed bed containing 9.8 kg of catalyst-2 (the particle size of catalyst-2 was 30 mesh) for alcoholysis. The material after alcoholysis was pumped into a molecular distillation device again for purification and refining to obtain a finished product with a content of 95.7% piperonyl propionaldehyde, and the yield of the finished piperonyl propionaldehyde was 88.3%.

[0087] Example 6

[0088] This embodiment provides a method for preparing piperonyl propionaldehyde, comprising:

[0089] 54.6 kg of 1,2-methylenedioxybenzene and 1.5 kg of catalyst-1 were mixed, and then 40.0 kg of methacrolein diacetyl acetal was added. The pump flow was controlled to ensure that the methacrolein diacetyl acetal was pumped in within 1 hour. The kettle temperature was controlled at 30-40 ° C during the pumping process and kept warm for 2.3 hours after the pumping was completed. The intermediate was then purified by molecular distillation. Isopropyl alcohol and the purified piperonyl propionaldehyde intermediate were pumped into the mixture at 0.0017 m 3 / h was pumped into a fixed bed containing 9.9 kg of catalyst-2 (the particle size of catalyst-2 was 40 mesh) for alcoholysis. The material after the alcoholysis was pumped into a molecular distillation device for purification. After purification, the crude piperonyl propionaldehyde product could be obtained to obtain a piperonyl propionaldehyde product with a content of 96.0%, and the yield of the piperonyl propionaldehyde product was 80.7%.

[0090] Example 7

[0091] This embodiment provides a method for preparing piperonyl propionaldehyde, comprising:

[0092] Mix 28.0 kg of 1,2-methylenedioxybenzene and 1.0 kg of catalyst-1, and pump 39.0 kg of methacrolein diacetyl acetal into the mixture within 2.8 hours. During the pumping process, the kettle temperature was controlled at 22-35 ° C. After the addition of the materials, the kettle was kept warm for 2.5 hours. Then, methanol and the purified piperonyl propionaldehyde intermediate were pumped into the mixture at a rate of 0.0017 m 3 / h was pumped into a fixed bed containing 10.3 kg of catalyst-2 (the particle size of catalyst-2 was 30 mesh) for alcoholysis. The material after alcoholysis was purified by molecular distillation equipment. After refining, a finished product with a piperonyl propionaldehyde content of 89.3% was obtained, and the yield of the finished piperonyl propionaldehyde was 18.6%.

[0093] Example 8

[0094] This embodiment provides a method for preparing piperonyl propionaldehyde, comprising:

[0095] 57.8 kg of 1,2-methylenedioxybenzene and 1.0 kg of catalyst-1 were mixed, and then 80.3 kg of methacrolein diacetyl acetal was pumped into the mixture within 3 hours. The kettle temperature was maintained at 22-35 °C during the addition process. After the addition of the materials, the kettle temperature was kept at 2.5 hours. Methanol and piperonyl propionaldehyde intermediate purified by molecular distillation were then pumped into the mixture at a rate of 0.0019 m 3 / h through a fixed bed containing 11.5 kg of catalyst-2 (catalyst-2 with a particle size of 30 mesh) for alcoholysis. The material after alcoholysis is further refined by molecular distillation equipment to obtain a finished product with a content of 84.1% piperonyl propionaldehyde, and the yield of the finished piperonyl propionaldehyde is 33.3%.

[0096] Comparative Example 1-Comparative Example 6

[0097] Comparative Examples 1-6 prepared piperonyl propionaldehyde according to the preparation method provided in Example 3, except that the composition of Catalyst-1 or Catalyst-2 used was different, as shown in Table 1. The compositions of Catalyst-1 and Catalyst-2 used in Examples 1-6 are shown in Table 1.

[0098] Table 1 Composition of the catalyst in Examples 1-6

[0099]

[0100]

[0101] Note: Ba in Table 1 above 2+ SourceBaO, Mg 2+ Source MgO, Ca 2+ SourceCaO,Al 3+ SourceAl2O3, Zn 2+ Source ZnO, Sr 2+ Source SrO, Ce 4+ Source CeO2, Cr 3+ Source Cr2O3, Mn 4+ Source: MnO2, Fe 3+ Source: Fe2O3.

[0102] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A method for preparing piperonyl propionaldehyde, characterized in that: include: The catalyst-1,1,2-methylenedioxybenzene and methacrolein diacetyl acetal are mixed and reacted to form an intermediate; Mixing the intermediate, an alcoholysis reagent, and a catalyst-2 to carry out an alcoholysis reaction; Wherein, the catalyst-1 is selected from a combination of at least two of the following fluorides: tris(pentafluorophenyl)borane, boron trifluoride complex and trifluoroacetic acid; The catalyst-2 is selected from at least four of the following metal ion salt compounds or the following metal ion oxides: Fe 3+ 、Al 3+ 、Zn 2+ 、Mn 4+ Cr 3+ 、Ce 4+ 、Ba 2+ Mg 2+ 、Sr 2+ and Ca 2+ .

2. The method for preparing piperonyl propionaldehyde according to claim 1, wherein The catalyst-1 is selected from at least two of tris(pentafluorophenyl)borane, a boron trifluoride complex and trifluoroacetic acid.

3. The method for preparing piperonyl propionaldehyde according to claim 2, wherein The catalyst-1 is selected from any one of the following compositions: (1) tris(pentafluorophenyl)borane and a boron trifluoride complex, wherein the mass percentage of tris(pentafluorophenyl)borane is 15-60%, and the mass percentage of the boron trifluoride complex is 40-85%; (2) tris(pentafluorophenyl)borane and trifluoroacetic acid, wherein the mass percentage of tris(pentafluorophenyl)borane is 15-60%, and the mass percentage of trifluoroacetic acid is 40-85%; (3) a boron trifluoride complex and trifluoroacetic acid, wherein the mass percentage of the boron trifluoride complex is 15-60%, and the mass percentage of the trifluoroacetic acid is 40-85%; (4) tris(pentafluorophenyl)borane, boron trifluoride complex and trifluoroacetic acid, wherein the mass percentage of the boron trifluoride complex is 5-63%; the mass percentage of the trifluoroacetic acid is 10-30%; and the mass ratio of the tris(pentafluorophenyl)borane is 25-80%.

4. The method for preparing piperonyl propionaldehyde according to claim 1, wherein The amount of the catalyst-1 used is 0.01-30 wt % of the mass of the methacrolein diacetyl acetal.

5. The method for preparing piperonyl propionaldehyde according to claim 1, wherein The amount of the catalyst-1 used is 0.1-5 wt % of the mass of the methacrolein diacetyl acetal.

6. The method for preparing piperonyl propionaldehyde according to claim 1, wherein The molar ratio of the methacrolein diacetyl acetal to the 1,2-methylenedioxybenzene is 1:(1-5).

7. The method for preparing piperonyl propionaldehyde according to any one of claims 1 to 6, characterized in that: The step of forming the intermediate comprises: adding the methacrolein diacetyl acetal to a mixture of the catalyst-1 and the 1,2-methylenedioxybenzene at 10-60° C., and carrying out the reaction by heat preservation for 5 minutes to 4 hours.

8. The method for preparing piperonyl propionaldehyde according to claim 7, wherein: The methacrolein diacetyl acetal is added to the mixed material by pumping; The flow rate of the methacrolein diacetyl acetal pump is 0.0001m 3 / h-3 m 3 / h.

9. The method for preparing piperonyl propionaldehyde according to claim 1, wherein The catalyst-2 is selected from the following four metal ion salt compounds or metal ion oxides: Fe 3+ 、A l3+ 、Zn 2+ 、Mn 4+ Cr 3+ 、Ce 4 + 、Ba 2+ Mg 2+ 、Sr 2+ and Ca 2+ .

10. The method for preparing piperonyl propionaldehyde according to claim 1, wherein: The mass contents of the following metal ions in the catalyst-2 are as follows: Al 3+ The content is 20.00wt%-80.00wt%, Mn 4+ The content is 0.01wt%-60.00wt%, Cr 3+ Content is 0.01wt%-50.00wt%, Ce 4+ The content is 0.01wt%-50.00wt%, Fe 3+ The content is 0.01wt%-50.00wt%, Zn 2+ The content is 0.01wt%-50.00wt%, Ba 2+ The content is 0.01wt%-60.00wt%, Mg 2+ The content is 0.01wt%-60.00wt%, Sr 2+ The content is 0.01wt%-60.00wt%, Ca 2+ The content is 0.01wt%-60.00wt%.

11. The method for preparing piperonyl propionaldehyde according to claim 1, wherein: The mass contents of the following metal ions in the catalyst-2 are as follows: Al 3+ The content is 25.00wt%-60.00wt%, Mn 4+ The content is 0.1wt%-30.00wt%, Cr 3+ Content is 0.01wt%-40.00wt%, Ce 4+ The content is 1.00wt%-40.00wt%, Fe 3+ The content is 10.00wt%-30.00wt%, Zn 2+ The content is 10.00wt%-40.00wt%, Ba 2+ The content is 0.01wt%-40.00wt%, Mg 2+ The content is 0.1wt%-45.00wt%, Sr 2+ The content is 0.01wt%-50.00wt%, Ca 2+ The content is 0.01wt%-50.00wt%.

12. The method for preparing piperonyl propionaldehyde according to claim 1, wherein: The particle size of the catalyst-2 is 1 mesh to 100 mesh.

13. The method for preparing piperonyl propionaldehyde according to claim 1, wherein: The amount of the catalyst-2 used is 1-10% of the mass of the methacrolein diacetyl acetal.

14. The method for preparing piperonyl propionaldehyde according to any one of claims 9 to 13, characterized in that: include: The intermediate and the alcoholysis reagent are pumped into a fixed bed containing the catalyst-2 to carry out an alcoholysis reaction.

15. The method for preparing piperonyl propionaldehyde according to claim 14, characterized in that: The intermediate and the alcoholysis reagent stay in the fixed bed for 5 minutes to 4 hours.

16. The method for preparing piperonyl propionaldehyde according to claim 14, characterized in that: The intermediate and the alcoholysis reagent stay in the fixed bed for 5 minutes to 60 minutes.

17. The method for preparing piperonyl propionaldehyde according to claim 1, wherein: include: The crude piperonyl propionaldehyde formed by the alcoholysis reaction is purified.

18. The method for preparing piperonyl propionaldehyde according to claim 17, characterized in that: Refining includes molecular distillation.

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