A method for preparing ethyl 3-methoxypropionate by ester exchange method

Abstract

The present application relates to a method for preparing ethyl 3-methoxypropionate by transesterification. The method comprises: in the presence of a catalyst, methyl 3-methoxypropionate is contacted with ethanol and reacted to obtain ethyl 3-methoxypropionate; the catalyst comprises amino acid titanium, and the amino acid titanium is selected from at least one of glycine titanium, alanine titanium, proline titanium, isoleucine titanium, leucine titanium, phenylalanine titanium and glutamate titanium. The method described in the present application uses a catalyst with excellent performance, and the catalyst has high catalytic activity and good selectivity, so that the amount of catalyst used in the reaction process is small, and the conversion rate of methyl 3-methoxypropionate and the selectivity of ethyl 3-methoxypropionate after the reaction can reach more than 95%; at the same time, the method also has the advantages of low raw material toxicity, low pollution, mild reaction conditions, and no corrosion of the catalyst.

Description

Technical Field

[0001] The present application relates to the technical field of organic chemical industry, and in particular to a method for preparing ethyl 3-methoxypropionate by using an ester exchange method. Background Art

[0002] At present, the high boiling point solvents on the market include propylene carbonate and ethylene carbonate, both of which have boiling points of more than 240 degrees. However, they are polar solvents and have poor solubility in many high-temperature resins, paints, inks, and ceramic raw materials. When the amount added is small, the viscosity of the paint and the viscosity of the ceramic raw materials cannot be reduced well. Only when a large amount is added can the viscosity requirements be met. The market needs some high-boiling point solvents with low polarity and good solubility. Therefore, a solvent with low toxicity, 3-methoxyethyl propionate, has been developed. Its boiling point is similar to that of propylene carbonate and ethylene carbonate. It has good solubility in many high-temperature resins, paints, inks, and ceramic raw materials, and can meet the requirements with a small amount of addition. Therefore, the use of 3-methoxyethyl propionate can effectively solve the problem that propylene carbonate and ethylene carbonate have poor solubility in many high-temperature resins, paints, inks, and ceramic raw materials, which in turn causes poor leveling of the ceramic surface, poor leveling of the paint and ink film, and low gloss. In addition, some coil paint production lines need to increase their production capacity and require a baking time of several minutes and a baking temperature of more than 200 degrees. When only propylene carbonate, ethylene carbonate and other solvents with low boiling points are used, the leveling performance is poor and the gloss is not high, which does not meet the requirements. The use of ethyl 3-methoxypropionate can also solve this problem.

[0003] At present, the synthesis method of ethyl 3-methoxypropionate can adopt the transesterification method: under the action of a catalyst, methyl 3-methoxypropionate and ethanol undergo transesterification to prepare ethyl 3-methoxypropionate. This method has the advantages of cheap and easy-to-obtain raw materials, low toxicity, low pollution, mild reaction conditions, and the by-product methanol can be recycled and reused in the preparation of methyl 3-methoxypropionate.

[0004] Catalysts for transesterification reactions reported in the literature include alkaline catalysts, molecular sieves, and ionic liquids. However, when the above catalysts are used to synthesize ethyl 3-methoxypropionate by transesterification with methyl 3-methoxypropionate and ethanol as raw materials, there are problems such as low conversion rate of methyl 3-methoxypropionate, long reaction time, and low selectivity of ethyl 3-methoxypropionate.

[0005] Therefore, it is necessary to provide a new method for preparing ethyl 3-methoxypropionate by ester exchange method. Summary of the invention

[0006] In order to solve the outstanding problems existing in the prior art in the process of preparing ethyl 3-methoxypropionate, such as large amount of catalyst, long reaction time, low raw material conversion rate, low selectivity of product ethyl 3-methoxypropionate, etc., the present application provides a new method for preparing ethyl 3-methoxypropionate by ester exchange method, which has the advantages of low raw material toxicity, low pollution, mild reaction conditions, small amount of catalyst, high conversion rate of raw material methyl 3-methoxypropionate (abbreviated as MMP) and high selectivity of product ethyl 3-methoxypropionate (abbreviated as MEP).

[0007] To this end, the present application provides a method for preparing ethyl 3-methoxypropionate by using an ester exchange method, the method comprising: in the presence of a catalyst, methyl 3-methoxypropionate is contacted with ethanol and reacted to obtain ethyl 3-methoxypropionate;

[0008] The catalyst comprises amino acid titanium, and the amino acid titanium is selected from at least one of glycine titanium, alanine titanium, proline titanium, isoleucine titanium, leucine titanium, phenylalanine titanium and glutamate titanium.

[0009] In the present application, the reaction formula of the method is shown in the following formula (1):

[0010]

[0011] Formula (1)

[0012] In the process of preparing ethyl 3-methoxypropionate by transesterification, the type of catalyst used has a significant impact on the reaction results. When no catalyst is used or the activity of the catalyst used is low, the conversion rate of methyl 3-methoxypropionate in the raw material after the reaction is low; when the selectivity of the catalyst used is poor, side reactions will occur during the reaction, resulting in a large amount of by-products, which in turn leads to a low selectivity of ethyl 3-methoxypropionate in the product after the reaction.

[0013] The method described in the present application uses a specific catalyst, which includes amino acid titanium (at least one of glycine titanium, alanine titanium, proline titanium, isoleucine titanium, leucine titanium, phenylalanine titanium and glutamate titanium). The inventors of the present application creatively discovered that when using the above catalyst to prepare ethyl 3-methoxypropionate, it has the advantages of high catalytic activity and good selectivity, thereby making the conversion rate of methyl 3-methoxypropionate and the selectivity of ethyl 3-methoxypropionate as high as 95% or more, achieving unexpected technical effects.

[0014] In some preferred embodiments, the amino acid titanium is selected from at least two of glycinate titanium, leucine titanium and phenylalanine titanium. For example, the amino acid titanium can be a mixture of glycinate titanium and leucine titanium, a mixture of glycinate titanium and phenylalanine titanium, a mixture of leucine titanium and phenylalanine titanium, or a mixture of glycinate titanium, leucine titanium and phenylalanine titanium.

[0015] In some more preferred embodiments, the amino acid titanium is a mixture of glycine titanium, leucine titanium and phenylalanine titanium.

[0016] In the present application, when the amino acid titanium in the catalyst is a mixture of glycine titanium and leucine titanium, a mixture of glycine titanium and phenylalanine titanium, or a mixture of leucine titanium and phenylalanine titanium, especially a mixture of glycine titanium, leucine titanium and phenylalanine titanium, the catalyst can have better catalytic activity and selectivity, thereby making the conversion rate of the raw materials and the selectivity of the products after the reaction better.

[0017] In some specific embodiments, the mass ratio of glycinate titanium, leucine titanium and phenylalanate titanium in the mixture of glycinate titanium, leucine titanium and phenylalanate titanium is 1:(0.3-0.8):(0.3-0.8).

[0018] In some specific embodiments, the mass ratio of glycinate titanium, leucine titanium and phenylalanine titanium in the mixture of glycinate titanium, leucine titanium and phenylalanine titanium can be 1:0.3:0.3, 1:0.3:0.5, 1:0.3:0.8, 1:0.5:0.3, 1:0.5:0.5, 1:0.5:0.8, 1:0.8:0.3, 1:0.8:0.5 or 1:0.8:0.8, etc. In some preferred embodiments, the mass ratio of glycinate titanium, leucine titanium and phenylalanine titanium in the mixture of glycinate titanium, leucine titanium and phenylalanine titanium is 1:0.5:0.5.

[0019] The present application can further improve the catalytic performance of the catalyst by controlling the mass ratio of glycinate titanium, leucine titanium and phenylalanate titanium in the mixture of glycinate titanium, leucine titanium and phenylalanate titanium within the above range.

[0020] In some embodiments, the catalyst further includes aluminum titanate.

[0021] The inventors of the present application have discovered through research that when the catalyst also includes aluminum titanate, the amino acid titanium in the catalyst can act synergistically with the aluminum titanate, thereby further improving the catalytic performance of the catalyst.

[0022] In some specific embodiments, the mass ratio of aluminum titanate to amino acid titanium is (0.1-0.5): 1. In some specific embodiments, the mass ratio of aluminum titanate to amino acid titanium can be, for example, 0.1: 1, 0.2: 1, 0.3: 1, 0.4: 1 or 0.5: 1. In some preferred embodiments, the mass ratio of aluminum titanate to amino acid titanium is 0.3: 1.

[0023] The present application controls the mass ratio of the aluminum titanate to the amino acid titanium within the above range, so that the catalytic performance of the catalyst can be optimized, thereby optimizing the conversion rate of methyl 3-methoxypropionate in the raw material and the selectivity of ethyl 3-methoxypropionate in the product after the reaction.

[0024] In some embodiments, the amount of the catalyst is 0.01 to 0.5 wt % of the mass of methyl 3-methoxypropionate. In some preferred embodiments, the amount of the catalyst is 0.1 to 0.3 wt % of the mass of methyl 3-methoxypropionate.

[0025] In the present application, the catalyst has high catalytic activity and a small amount of catalyst is used. When the amount of the catalyst is only 0.01 to 0.5 wt % of the mass of methyl 3-methoxypropionate, a good catalytic effect can be achieved.

[0026] In some embodiments, the molar ratio of ethanol to methyl 3-methoxypropionate is (1-5): 1. In some preferred embodiments, the molar ratio of ethanol to methyl 3-methoxypropionate is (2-4): 1.

[0027] In the present application, the transesterification reaction process of the method is a reversible reaction. Therefore, in order to make the reaction proceed in the direction of generating ethyl 3-methoxypropionate as much as possible, the ethanol in the raw material should be excessive, and when the molar ratio of ethanol in the raw material to methyl 3-methoxypropionate is (2 to 4): 1, the effect of generating ethyl 3-methoxypropionate by the reaction is optimal. In addition, in order to make the reaction proceed in the direction of generating ethyl 3-methoxypropionate, the by-product methanol can be separated from the reaction system in time.

[0028] In some embodiments, the reaction temperature is 60-100° C. In some preferred embodiments, the reaction temperature is 75-85° C.

[0029] In the present application, the reaction temperature is low, the reaction conditions are mild, and the preparation process is safer and energy-saving.

[0030] In some embodiments, the reaction time is 1 to 8 hours. In some preferred embodiments, the reaction time is 3 to 6 hours.

[0031] The present invention can improve the conversion rate of raw materials and the selectivity of products after the reaction by controlling the reaction conditions (temperature and time) within the above range.

[0032] The beneficial technical effects of the present application are as follows: the method described in the present application uses a catalyst with excellent performance, the catalyst has high catalytic activity and good selectivity, so that the amount of catalyst used in the reaction process is small, and the conversion rate of methyl 3-methoxypropionate and the selectivity of ethyl 3-methoxypropionate after the reaction can reach more than 95%, achieving unexpected technical effects. At the same time, the method also has the advantages of low raw material toxicity, low pollution, mild reaction conditions, and no corrosion of the catalyst, so it can be well applied to the preparation of ethyl 3-methoxypropionate, and has excellent application prospects. DETAILED DESCRIPTION

[0033] In order to make the present application easier to understand, the present application will be further described in detail below in conjunction with the examples, which are merely illustrative and are not intended to limit the scope of application of the present application. The raw materials or components used in the present application can be obtained through commercial routes or conventional methods unless otherwise specified.

[0034] Example 1: Preparation of ethyl 3-methoxypropionate

[0035] 11.8 g of methyl 3-methoxypropionate (0.1 mol), 18.4 g of ethanol (0.4 mol), and 0.024 g of glycinate titanium were added to a 100 mL two-mouth round-bottom flask equipped with a condenser, stirred evenly, and the round-bottom flask was heated to 85° C. for 5 hours to obtain a reaction product containing ethyl 3-methoxypropionate; the amount of glycinate titanium catalyst used in the reaction process was 0.2 wt % of the mass of methyl 3-methoxypropionate, and the molar ratio of ethanol to methyl 3-methoxypropionate was 4:1. The reaction product was detected by gas chromatography-mass spectrometry, and the results are shown in Table 1.

[0036] Example 2: Preparation of ethyl 3-methoxypropionate

[0037] 11.8 g of methyl 3-methoxypropionate (0.1 mol), 13.8 g of ethanol (0.3 mol), and 0.012 g of titanium alanate were added to a 100 mL two-mouth round-bottom flask equipped with a condenser, stirred evenly, and the round-bottom flask was heated to 80 ° C for 4 hours to obtain a reaction product containing ethyl 3-methoxypropionate; the amount of titanium alanate catalyst used in the reaction process was 0.1 wt% of the mass of methyl 3-methoxypropionate, and the molar ratio of ethanol to methyl 3-methoxypropionate was 3: 1. The reaction product was detected by gas chromatography-mass spectrometry, and the results are shown in Table 1.

[0038] Example 3: Preparation of ethyl 3-methoxypropionate

[0039] 11.8 g of methyl 3-methoxypropionate (0.1 mol), 9.2 g of ethanol (0.2 mol), and 0.024 g of proline titanium were added to a 100 mL two-mouth round-bottom flask equipped with a condenser, stirred evenly, and the round-bottom flask was heated to 75° C. for 6 hours to obtain a reaction product containing ethyl 3-methoxypropionate; the amount of catalyst proline titanium used in the reaction process was 0.2 wt% of the mass of methyl 3-methoxypropionate, and the molar ratio of ethanol to methyl 3-methoxypropionate was 2:1. The reaction product was detected by gas chromatography-mass spectrometry, and the results are shown in Table 1.

[0040] Example 4: Preparation of ethyl 3-methoxypropionate

[0041] 11.8 g of methyl 3-methoxypropionate (0.1 mol), 23 g of ethanol (0.5 mol), and 0.006 g of titanium isoleucine were added to a 100 mL two-mouth round-bottom flask equipped with a condenser, stirred evenly, and the round-bottom flask was heated to 90° C. for 3 hours to obtain a reaction product containing ethyl 3-methoxypropionate; the amount of titanium isoleucine catalyst used in the reaction process was 0.05wt% of the mass of methyl 3-methoxypropionate, and the molar ratio of ethanol to methyl 3-methoxypropionate was 5:1. The reaction product was detected by gas chromatography-mass spectrometry, and the results are shown in Table 1.

[0042] Example 5: Preparation of ethyl 3-methoxypropionate

[0043] 11.8 g of methyl 3-methoxypropionate (0.1 mol), 18.4 g of ethanol (0.4 mol), and 0.036 g of leucine titanium were added to a 100 mL two-mouth round-bottom flask equipped with a condenser, stirred evenly, and the round-bottom flask was heated to 95° C. for 2 hours to obtain a reaction product containing ethyl 3-methoxypropionate; the amount of catalyst leucine titanium used in the reaction process was 0.3 wt % of the mass of methyl 3-methoxypropionate, and the molar ratio of ethanol to methyl 3-methoxypropionate was 4:1. The reaction product was detected by gas chromatography-mass spectrometry, and the results are shown in Table 1.

[0044] Example 6: Preparation of ethyl 3-methoxypropionate

[0045] 11.8 g of methyl 3-methoxypropionate (0.1 mol), 18.4 g of ethanol (0.4 mol), and 0.06 g of phenylalanine titanium were added to a 100 mL two-mouth round-bottom flask equipped with a condenser, stirred evenly, and the round-bottom flask was heated to 60° C. for 8 hours to obtain a reaction product containing ethyl 3-methoxypropionate; the amount of phenylalanine titanium catalyst used in the reaction process was 0.5wt% of the mass of methyl 3-methoxypropionate, and the molar ratio of ethanol to methyl 3-methoxypropionate was 4:1. The reaction product was detected by gas chromatography-mass spectrometry, and the results are shown in Table 1.

[0046] Example 7: Preparation of ethyl 3-methoxypropionate

[0047] 11.8 g of methyl 3-methoxypropionate (0.1 mol), 4.6 g of ethanol (0.1 mol), and 0.024 g of titanium glutamate were added to a 100 mL two-mouth round-bottom flask equipped with a condenser, stirred evenly, and the round-bottom flask was heated to 100 ° C for 1 hour to obtain a reaction product containing ethyl 3-methoxypropionate; the amount of the catalyst titanium glutamate used in the reaction process was 0.2wt% of the mass of methyl 3-methoxypropionate, and the molar ratio of ethanol to methyl 3-methoxypropionate was 1:1. The reaction product was detected by gas chromatography-mass spectrometry, and the results are shown in Table 1.

[0048] Example 8: Preparation of ethyl 3-methoxypropionate

[0049] The preparation process is basically the same as that of Example 1, except that the catalyst is 0.016 g of glycinate titanium and 0.008 g of leucine titanium, and the mass ratio of glycinate titanium to leucine titanium in the catalyst is 1:0.5; the amount of the catalyst used in the reaction process is 0.2 wt % of the mass of 3-methoxypropionic acid methyl ester. The reaction product is detected by gas chromatography-mass spectrometry, and the results are shown in Table 1.

[0050] Example 9: Preparation of ethyl 3-methoxypropionate

[0051] The preparation process is basically the same as that of Example 1, except that the catalyst is 0.016 g of titanium glycinate and 0.008 g of titanium phenylalanate, and the mass ratio of titanium glycinate to titanium phenylalanate in the catalyst is 1:0.5; the amount of the catalyst used in the reaction process is 0.2 wt % of the mass of methyl 3-methoxypropionate. The reaction product is detected by gas chromatography-mass spectrometry, and the results are shown in Table 1.

[0052] Example 10: Preparation of ethyl 3-methoxypropionate

[0053] The preparation process is basically the same as that of Example 1, except that the catalyst is 0.012 g of titanium glycinate, 0.006 g of titanium leucine and 0.006 g of titanium phenylalanine, and the mass ratio of titanium glycinate, titanium leucine and titanium phenylalanine in the catalyst is 1:0.5:0.5; the amount of the catalyst used in the reaction process is 0.2 wt % of the mass of methyl 3-methoxypropionate. The reaction product is detected by gas chromatography-mass spectrometry, and the results are shown in Table 1.

[0054] Example 11: Preparation of ethyl 3-methoxypropionate

[0055] The preparation process is basically the same as that of Example 1, except that the catalyst is 0.013 g of glycinate titanium, 0.004 g of leucine titanium and 0.007 g of phenylalanine titanium, and the mass ratio of glycinate titanium, leucine titanium and phenylalanine titanium in the catalyst is 1:0.3:0.5; the amount of the catalyst used in the reaction process is 0.2 wt % of the mass of 3-methoxypropionic acid methyl ester. The reaction product is detected by gas chromatography-mass spectrometry, and the results are shown in Table 1.

[0056] Example 12: Preparation of ethyl 3-methoxypropionate

[0057] The preparation process is basically the same as that of Example 1, except that the catalyst is 0.01 g of glycinate titanium, 0.008 g of leucine titanium and 0.005 g of phenylalanine titanium, and the mass ratio of glycinate titanium, leucine titanium and phenylalanine titanium in the catalyst is 1:0.8:0.5; the amount of the catalyst used in the reaction process is 0.2 wt % of the mass of 3-methoxypropionic acid methyl ester. The reaction product is detected by gas chromatography-mass spectrometry, and the results are shown in Table 1.

[0058] Example 13: Preparation of ethyl 3-methoxypropionate

[0059] The preparation process is basically the same as that of Example 1, except that the catalyst is 0.013 g of glycinate titanium, 0.007 g of leucine titanium and 0.004 g of phenylalanine titanium, and the mass ratio of glycinate titanium, leucine titanium and phenylalanine titanium in the catalyst is 1:0.5:0.3; the amount of the catalyst used in the reaction process is 0.2 wt % of the mass of 3-methoxypropionic acid methyl ester. The reaction product is detected by gas chromatography-mass spectrometry, and the results are shown in Table 1.

[0060] Example 14: Preparation of ethyl 3-methoxypropionate

[0061] The preparation process is basically the same as that of Example 1, except that the catalyst is 0.01 g of glycinate titanium, 0.005 g of leucine titanium and 0.008 g of phenylalanine titanium, and the mass ratio of glycinate titanium, leucine titanium and phenylalanine titanium in the catalyst is 1:0.5:0.8; the amount of the catalyst used in the reaction process is 0.2 wt % of the mass of 3-methoxypropionic acid methyl ester. The reaction product is detected by gas chromatography-mass spectrometry, and the results are shown in Table 1.

[0062] Example 15: Preparation of ethyl 3-methoxypropionate

[0063] The preparation process is basically the same as that of Example 1, except that the catalyst is 0.022 g of amino acid titanium (0.011 g of glycine titanium, 0.0055 g of leucine titanium and 0.0055 g of phenylalanine titanium) and 0.002 g of aluminum titanate, the mass ratio of aluminum titanate to amino acid titanium in the catalyst is 0.1:1, and the mass ratio of glycine titanium, leucine titanium and phenylalanine titanium in the amino acid titanium is 1:0.5:0.5; the amount of the catalyst used in the reaction process is 0.2 wt % of the mass of methyl 3-methoxypropionate. The reaction product is detected by gas chromatography-mass spectrometry, and the results are shown in Table 1.

[0064] Example 16: Preparation of ethyl 3-methoxypropionate

[0065] The preparation process is basically the same as that of Example 1, except that the catalyst is 0.018 g of amino acid titanium (0.009 g of glycine titanium, 0.0045 g of leucine titanium and 0.0045 g of phenylalanine titanium) and 0.006 g of aluminum titanate, the mass ratio of aluminum titanate to amino acid titanium in the catalyst is 0.3:1, and the mass ratio of glycine titanium, leucine titanium and phenylalanine titanium in the amino acid titanium is 1:0.5:0.5; the amount of the catalyst used in the reaction process is 0.2 wt % of the mass of methyl 3-methoxypropionate. The reaction product is detected by gas chromatography-mass spectrometry, and the results are shown in Table 1.

[0066] Example 17: Preparation of ethyl 3-methoxypropionate

[0067] The preparation process is basically the same as that of Example 1, except that the catalyst is 0.016 g of amino acid titanium (0.008 g of glycine titanium, 0.004 g of leucine titanium and 0.004 g of phenylalanine titanium) and 0.008 g of aluminum titanate, the mass ratio of aluminum titanate to amino acid titanium in the catalyst is 0.5:1, and the mass ratio of glycine titanium, leucine titanium and phenylalanine titanium in the amino acid titanium is 1:0.5:0.5; the amount of the catalyst used in the reaction process is 0.2 wt % of the mass of methyl 3-methoxypropionate. The reaction product is detected by gas chromatography-mass spectrometry, and the results are shown in Table 1.

[0068] Example 18: Preparation of ethyl 3-methoxypropionate

[0069] The preparation process is basically the same as that of Example 16, except that the amount of ethanol added to the raw material is 4.6 g ethanol (0.1 mol); the molar ratio of ethanol to methyl 3-methoxypropionate during the reaction is 1: 1. The reaction product is detected by gas chromatography-mass spectrometry, and the results are shown in Table 1.

[0070] Example 19: Preparation of ethyl 3-methoxypropionate

[0071] The preparation process is basically the same as that of Example 16, except that the reaction temperature is 60° C. The reaction product is detected by gas chromatography-mass spectrometry, and the results are shown in Table 1.

[0072] Example 20: Preparation of ethyl 3-methoxypropionate

[0073] The preparation process is basically the same as that of Example 16, except that the reaction time is 2 hours. The reaction product is detected by gas chromatography-mass spectrometry, and the results are shown in Table 1.

[0074] Comparative Example 1: Preparation of ethyl 3-methoxypropionate

[0075] The preparation process is basically the same as that of Example 1, except that no catalyst is added during the preparation process. The reaction product is detected by gas chromatography-mass spectrometry, and the results are shown in Table 1.

[0076] Comparative Example 2: Preparation of ethyl 3-methoxypropionate

[0077] The preparation process is basically the same as that of Example 1, except that the catalyst added during the preparation process is 0.024 g of titanium valine. The reaction product is detected by gas chromatography-mass spectrometry, and the results are shown in Table 1.

[0078] Comparative Example 3: Preparation of ethyl 3-methoxypropionate

[0079] The preparation process is basically the same as that of Example 1, except that the catalyst added during the preparation process is 0.024 g of histidine titanium. The reaction product is detected by gas chromatography-mass spectrometry, and the results are shown in Table 1.

[0080] Comparative Example 4: Preparation of ethyl 3-methoxypropionate

[0081] The preparation process is basically the same as that of Example 1, except that the catalyst added during the preparation process is 0.024 g of titanium threonate. The reaction product is detected by gas chromatography-mass spectrometry, and the results are shown in Table 1.

[0082] Table 1

[0083]

[0084]

[0085] From the test results of Table 1, it can be seen that compared with Comparative Examples 1-4, the conversion rate of methyl 3-methoxypropionate after the reaction of Examples 1-20 of the present application is more than 70%, and the selectivity of ethyl 3-methoxypropionate is more than 78%, achieving good results. Specifically, compared with Example 1, no catalyst is added in Comparative Example 1, and under the same reaction conditions, the conversion rate of methyl 3-methoxypropionate and the selectivity of ethyl 3-methoxypropionate are much lower than the results of Example 1. According to the test results of Comparative Examples 2-5, when valine titanium, histidine titanium or threonine titanium are used as catalysts, under the same reaction conditions, the conversion rate of methyl 3-methoxypropionate and the selectivity of ethyl 3-methoxypropionate are also much lower than the results of Example 1, indicating that the specific type of catalyst has a great influence on the reaction results described in the present application.

[0086] From the test results of Examples 1 and 8-14, it can be seen that when the amino acid titanium in the catalyst is selected from at least two of glycine titanium, leucine titanium and phenylalanine titanium, especially when it contains glycine titanium, leucine titanium and phenylalanine titanium at the same time, it helps to improve the conversion rate of methyl 3-methoxypropionate and the selectivity of ethyl 3-methoxypropionate after the reaction; and when the mass ratio of glycine titanium, leucine titanium and phenylalanine titanium in the amino acid titanium is 1:0.5:0.5, the conversion rate of methyl 3-methoxypropionate and the selectivity of ethyl 3-methoxypropionate can be further improved.

[0087] From the test results of Examples 10 and 15-17, it can be seen that when the catalyst further includes aluminum titanate, it helps to improve the conversion rate of methyl 3-methoxypropionate and the selectivity of ethyl 3-methoxypropionate after the reaction; and when the mass ratio of aluminum titanate to amino acid titanium in the catalyst is 0.3:1, the conversion rate of methyl 3-methoxypropionate can reach 95% and the selectivity of ethyl 3-methoxypropionate can reach 98%, achieving excellent results.

[0088] It should be noted that the embodiments described above are only used to explain the present application and do not constitute any limitation to the present application. The present application is described with reference to typical embodiments, but it should be understood that the words used therein are descriptive and explanatory words, rather than restrictive words. The present application may be modified as specified within the scope of the claims of the present application, and the present invention may be revised without departing from the scope and spirit of the present application. Although the present application described therein relates to specific methods, materials and embodiments, it does not mean that the present application is limited to the specific examples disclosed therein. On the contrary, the present application can be extended to all other methods and applications with the same functions.

Claims

1. A method for preparing ethyl 3-methoxypropionate by transesterification, characterized in that: The method comprises: in the presence of a catalyst, methyl 3-methoxypropionate is contacted with ethanol and reacted to obtain ethyl 3-methoxypropionate; The catalyst comprises amino acid titanium and aluminum titanate, wherein the amino acid titanium is selected from at least one of glycine titanium, alanine titanium, proline titanium, isoleucine titanium, leucine titanium, phenylalanine titanium and glutamate titanium.

2. The method according to claim 1, characterized in that The amino acid titanium is selected from at least two of glycine titanium, leucine titanium and phenylalanine titanium.

3. The method according to claim 2, characterized in that The amino acid titanium is a mixture of glycine titanium, leucine titanium and phenylalanine titanium.

4. The method according to claim 3, characterized in that The mass ratio of glycinate titanium, leucine titanium and phenylalanate titanium in the mixture of glycinate titanium, leucine titanium and phenylalanate titanium is 1: (0.3-0.8): (0.3-0.8).

5. The method according to claim 4, characterized in that The mass ratio of glycinate titanium, leucine titanium and phenylalanate titanium in the mixture of glycinate titanium, leucine titanium and phenylalanate titanium is 1:0.5:0.

5.

6. The method according to claim 1, characterized in that The mass ratio of the aluminum titanate to the amino acid titanium is (0.1-0.5):

1.

7. The method according to claim 6, characterized in that The mass ratio of the aluminum titanate to the amino acid titanium is 0.3:

1.

8. The method according to any one of claims 1 to 4, characterized in that: The amount of the catalyst used is 0.01-0.5 wt % of the mass of methyl 3-methoxypropionate.

9. The method according to claim 8, characterized in that The amount of the catalyst used is 0.1-0.3 wt % of the mass of methyl 3-methoxypropionate.

10. The method according to any one of claims 1 to 4, characterized in that: The molar ratio of ethanol to methyl 3-methoxypropionate is (1-5):

1.

11. The method according to claim 10, characterized in that The molar ratio of ethanol to methyl 3-methoxypropionate is (2-4):

1.

12. The method according to any one of claims 1 to 4, characterized in that: The reaction temperature is 60-100°C.

13. The method according to claim 12, characterized in that The reaction temperature is 75-85°C.

14. The method according to any one of claims 1 to 4, characterized in that: The reaction time is 1 to 8 hours.

15. The method according to claim 14, characterized in that The reaction time is 3 to 6 hours.

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