Vinylethylene carbonate and synthesis method thereof

Abstract

The invention relates to the technical field of organic synthesis, in particular to a synthesis method of vinylethylene carbonate, which comprises the following steps: (1) dehydrating an aprotic solvent; (2) dissolving chloroethylene carbonate in the aprotic solvent under the protection of inert gas, cooling, adding vinyl magnesium bromide, reacting at-10 to 0 DEG C, and adding a quenching reagent for quenching reaction after the reaction is finished, so as to obtain a vinylethylene carbonate crude product; and (3) purifying the vinylethylene carbonate crude product to obtain a vinylethylene carbonate pure product. According to the synthesis method of vinylethylene carbonate, the aprotic solvent is adopted and can be used as an electrolyte solvent, so that the influence of the solvent on the product quality is reduced, and the product purity is improved; meanwhile, vinyl magnesium bromide is used for carrying out nucleophilic substitution reaction on chloroethylene carbonate under a low-temperature condition, so that the reaction rate is high; and the obtained product has high purity and high yield.

Description

Technical Field

[0001] The invention relates to the technical field of organic synthesis, and in particular to vinyl ethylene carbonate and a synthesis method thereof. Background Art

[0002] Vinyl ethylene carbonate (VEC) is a colorless transparent liquid at room temperature. It is a special carbonate compound and an important additive for lithium-ion battery electrolyte. The boiling point of vinyl ethylene carbonate is 237°C / 733mmHg (lit.) and the flash point is 206°F.

[0003] The main synthesis method of vinyl ethylene carbonate is the transesterification reaction method, which has been widely used in industry. The transesterification reaction method uses 3,4-dihydroxy-1-butene and dialkyl carbonate as raw materials to produce vinyl ethylene carbonate through transesterification reaction. The transesterification reaction method has the advantages of high yield and good purity, but the reaction time is long, the acid value of the raw materials is relatively high, the purification cost is high, and a large amount of solid waste and liquid waste will be generated. These problems make the ion exchange method not in line with the concept of green environmental protection. The synthesis method of vinyl ethylene carbonate also includes the epoxybutene and carbon dioxide addition method; this method is simple to operate and has a high yield, but the raw material epoxy compound is unstable, the source is difficult to obtain, and the activation of carbon dioxide requires a higher pressure and a more efficient catalyst. For the synthesis of vinyl ethylene carbonate by phosgene, this method is limited by the toxicity of phosgene. Due to the development of the concept of green environmental protection, the phosgene method has been abandoned.

[0004] Based on this, finding a green, environmentally friendly and efficient method for synthesizing high-purity vinyl ethylene carbonate is a technical problem in this field. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides a method for synthesizing vinyl ethylene carbonate which is green, environmentally friendly, high in yield and easy to separate and purify.

[0006] The present invention adopts the following technical solutions:

[0007] A method for synthesizing vinyl ethylene carbonate comprises the following steps:

[0008] (1) Dehydrating the aprotic solvent;

[0009] (2) under the protection of an inert gas, dissolving chloroethylene carbonate in the aprotic solvent, cooling, adding vinylmagnesium bromide to react at -10 to 0°C, and after the reaction is completed, adding a quenching agent to quench the reaction to obtain a crude product of vinyl ethylene carbonate;

[0010] (3) purifying the crude vinyl ethylene carbonate to obtain pure vinyl ethylene carbonate.

[0011] Furthermore, the aprotic solvent includes any one or more of an ether solvent, a benzene solvent, and a ketone solvent;

[0012] Preferably, the aprotic solvent is methyl tert-butyl ether.

[0013] Furthermore, the molar ratio of the chloroethylene carbonate to the vinyl magnesium bromide is 1:(1-1.2).

[0014] Furthermore, the concentration of the vinyl magnesium bromide in the aprotic solvent is 1 to 3 mol / L;

[0015] Preferably, the concentration of the vinyl magnesium bromide in the aprotic solvent is 1.8 to 2.2 mol / L.

[0016] Furthermore, the quenching reagent includes any one of ice water, saturated ammonium chloride aqueous solution, and glacial acetic acid;

[0017] Preferably, the quenching reagent is ice water.

[0018] Further, the synthesis method of vinyl ethylene carbonate of the present invention comprises the following steps:

[0019] (1) Dehydrating the aprotic solvent by molecular sieve drying or distillation;

[0020] (2) under the protection of inert gas, dissolving chloroethylene carbonate in the aprotic solvent, cooling at -20 to 0° C. for 10 to 20 min, adding vinyl magnesium bromide and reacting at -10 to 0° C. for 1 to 3 h, monitoring the reaction progress by LC-MC, and adding a quenching reagent after the reaction to quench the reaction, thereby obtaining a crude product of vinyl ethylene carbonate;

[0021] (3) extracting, drying, and filtering the crude vinyl ethylene carbonate product, recondensing and rectifying the solvent evaporated by vacuum distillation, and recovering the solvent to obtain pure vinyl ethylene carbonate product.

[0022] Furthermore, in step (3), ethyl acetate is used as an extractant for extraction, anhydrous sodium sulfate is used as a desiccant for drying, and a silica gel filter is used for filtration.

[0023] On the other hand, the present invention also provides vinyl ethylene carbonate synthesized by the above synthesis method.

[0024] The method for synthesizing vinyl ethylene carbonate of the present invention adopts a non-protonic solvent which can be used as an electrolyte solvent, thereby reducing the influence of the solvent on product quality and improving product purity; at the same time, vinyl magnesium bromide is used to carry out a nucleophilic substitution reaction on vinyl chlorocarbonate under low temperature conditions, and the reaction rate is fast; the obtained product has high purity and high yield. DETAILED DESCRIPTION

[0025] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work belong to the protection scope of the present invention.

[0026] A method for synthesizing vinyl ethylene carbonate comprises the following steps:

[0027] (1) Dehydrating the aprotic solvent;

[0028] (2) under the protection of an inert gas, dissolving chloroethylene carbonate in a solvent, cooling at -20 to 0° C. for 10 to 20 minutes, adding vinyl magnesium bromide and reacting at -10 to 0° C., and after the reaction is completed, adding a quenching reagent to quench the reaction to obtain a crude product of vinyl ethylene carbonate;

[0029] (3) The crude product is extracted, dried, filtered, and distilled under reduced pressure to obtain pure vinyl ethylene carbonate.

[0030] The method for synthesizing vinyl ethylene carbonate of the present invention adopts a non-protonic solvent which can be used as an electrolyte solvent, thereby reducing the influence of the solvent on product quality and improving product purity; at the same time, vinyl magnesium bromide is used to carry out a nucleophilic substitution reaction on vinyl chlorocarbonate under low temperature conditions, and the reaction rate is fast; the obtained product has high purity and high yield.

[0031] Specifically, as an embodiment of the present invention, the aprotic solvent includes any one or more of an ether solvent, a benzene solvent, and a ketone solvent; preferably, the aprotic solvent is methyl tert-butyl ether.

[0032] The present invention adopts aprotic solvent, which will not destroy the Grignard reagent vinyl magnesium bromide and is conducive to the occurrence of the reaction. At the same time, the aprotic solvent, especially methyl tert-butyl ether, also has good stability, and the solvate formed by it and the Grignard reagent is relatively stable in the system; the more stable the solvent is, the less the amount of solvent used is, the higher the reaction concentration is, and the more conducive it is to improving the reaction rate.

[0033] Specifically, as an embodiment of the present invention, the concentration of the vinyl magnesium bromide in the aprotic solvent is 1 to 3 mol / L. The use of aprotic solvents allows the nucleophilic substitution reaction involving the Grignard reagent to be carried out at a concentration of 1 to 3 mol / L, and this concentration range allows the reaction to proceed normally. When the concentration of vinyl magnesium bromide is higher than 3 mol / L, the Grignard reagent will attack the carbonyl group and the Grignard reagent will polymerize itself, reducing the yield; when the concentration of vinyl magnesium bromide is lower than 1 mol / L, the reaction rate will be greatly reduced, and it will take more than 12 hours for the raw materials to react completely. More specifically, the concentration of the vinyl magnesium bromide in the aprotic solvent is 1 mol / L, 1.2 mol / L, 1.3 mol / L, 1.5 mol / L, 1.6 mol / L, 1.8 mol / L, 1.9 mol / L, 2.0 mol / L, 2.1 mol / L, 2.2 mol / L, 2.4 mol / L, 2.5 mol / L, 2.7 mol / L, 2.8 mol / L, 3 mol / L; preferably, the concentration of the vinyl magnesium bromide in the aprotic solvent is 1.8-2.2 mol / L.

[0034] Specifically, as an embodiment of the present invention, the molar ratio of the chloroethylene carbonate to the vinyl magnesium bromide is 1:(1-1.2). Under the current solvent conditions, the above molar ratio can have a faster reaction rate. More specifically, the molar ratio of the chloroethylene carbonate to the vinyl magnesium bromide is 1:1, 1:1.02, 1:1.04, 1:1.05, 1:1.06, 1:1.08, 1:1.1, 1:1.12, 1:1.14, 1:1.15, 1:1.16, 1:1.18, 1:1.2.

[0035] Specifically, as an embodiment of the present invention, the quenching reagent includes any one of ice water, saturated ammonium chloride aqueous solution, and glacial acetic acid; preferably, the quenching reagent is ice water.

[0036] Specifically, as an embodiment of the present invention, in step (1), the solvent is dehydrated by using a molecular sieve drying method or a distillation method. Preferably, the solvent is dehydrated by using a distillation method.

[0037] Specifically, as an embodiment of the present invention, vinyl magnesium bromide is added in step (2) and the reaction is carried out for 1 to 3 hours; and the reaction progress is monitored by LC-MC.

[0038] Specifically, as an embodiment of the present invention, the solvent is evaporated by vacuum distillation in step (3), and then condensed and rectified to recover the solvent. The aprotic solvent used in the present invention is not easily soluble in water, and is convenient for recycling and distillation and reuse. This not only reduces costs but also reduces pollution to the environment, which is in line with the concept of green development.

[0039] Specifically, as an embodiment of the present invention, in step (3), ethyl acetate is used as the extraction agent, anhydrous sodium sulfate is used as the drying agent, and a silica gel filter is used for filtration.

[0040] Reaction equation of the present invention is:

[0041]

[0042] On the other hand, the present invention also provides vinyl ethylene carbonate synthesized by the above synthesis method.

[0043] The synthesis method of vinyl ethylene carbonate of the present invention will be further described below in conjunction with specific embodiments.

[0044] Example 1

[0045] A method for synthesizing vinyl ethylene carbonate comprises the following steps:

[0046] (1) Dehydrating methyl tert-butyl ether by distillation;

[0047] (2) Under nitrogen protection, 245.02 g (2 mol) of ethylene chlorocarbonate was dissolved in 1 L of methyl tert-butyl ether after distillation, and stirring was started. The mixture was cooled at -20°C for 20 min, and 262.52 g (2 mol) of vinyl magnesium bromide was added. The mixture was reacted at 0°C for 2 hours. The reaction was monitored by LC-MS. After the reaction was completed, ice water was added to quench the mixture, thereby obtaining a crude product of ethylene carbonate;

[0048] (3) The crude product is extracted, dried, and rapidly filtered through silica gel. The solvent after vacuum distillation is purified by distillation and then recycled to obtain pure vinyl ethylene carbonate.

[0049] The purity of vinyl ethylene carbonate obtained in this example is 99.96%, and the yield is 94.5%.

[0050] Example 2

[0051] A method for synthesizing vinyl ethylene carbonate comprises the following steps:

[0052] (1) Dehydrating methyl tert-butyl ether by distillation;

[0053] (2) Under nitrogen protection, 245.02 g (2 mol) of ethylene chlorocarbonate was dissolved in 1 L of methyl tert-butyl ether after distillation, and stirring was started. The mixture was cooled at -10°C for 15 min, and 303.21 g (2.31 mol) of vinyl magnesium bromide was added. The mixture was reacted at -5°C for 3 hours. The reaction was monitored by LC-MS. After the reaction was completed, ice water was added to quench the mixture, thereby obtaining a crude product of ethylene carbonate;

[0054] (3) The crude product is extracted, dried, and rapidly filtered through silica gel. The solvent after vacuum distillation is purified by distillation and then recycled to obtain pure vinyl ethylene carbonate.

[0055] The purity of vinyl ethylene carbonate obtained in this example is 99.90%, and the yield is 85.4%.

[0056] Example 3

[0057] A method for synthesizing vinyl ethylene carbonate comprises the following steps:

[0058] (1) Dehydrating methyl tert-butyl ether by distillation;

[0059] (2) Under nitrogen protection, 245.02 g (2 mol) of ethylene chlorocarbonate was dissolved in 1 L of methyl tert-butyl ether after distillation, and stirring was started. The mixture was cooled at 0° C. for 10 min, and 315.02 g (2.4 mol) of vinyl magnesium bromide was added. The mixture was reacted at 0° C. for 1 hour. The reaction was monitored by LC-MS. After the reaction was completed, ice water was added to quench the mixture, thereby obtaining a crude product of ethylene carbonate;

[0060] (3) The crude product is extracted, dried, and rapidly filtered through silica gel. The solvent after vacuum distillation is purified by distillation and then recycled to obtain pure vinyl ethylene carbonate.

[0061] The purity of vinyl ethylene carbonate obtained in this example is 99.85%, and the yield is 80.7%.

[0062] Example 4

[0063] A method for synthesizing vinyl ethylene carbonate comprises the following steps:

[0064] (1) Dehydrating methyl tert-butyl ether by molecular sieve drying method;

[0065] (2) Under nitrogen protection, 269.522 g (2.2 mol) of chloroethylene carbonate was dissolved in 1 L of dehydrated methyl tert-butyl ether, and the mixture was stirred and cooled at -15°C for 12 min. 262.52 g (2 mol) of vinyl magnesium bromide was added, and the mixture was reacted at -10°C for 1.5 hours. The reaction was monitored by LC-MS. After the reaction was completed, ice water was added to quench the mixture, and crude vinyl ethylene carbonate was obtained;

[0066] (3) The crude product is extracted, dried, and rapidly filtered through silica gel. The solvent after vacuum distillation is purified by distillation and then recycled to obtain pure vinyl ethylene carbonate.

[0067] The purity of vinyl ethylene carbonate obtained in this example is 94.20%, and the yield is 74.5%.

[0068] Example 5

[0069] A method for synthesizing vinyl ethylene carbonate comprises the following steps:

[0070] (1) Dehydrating methyl tert-butyl ether by distillation;

[0071] (2) Under nitrogen protection, 122.51 g (1 mol) of ethylene chlorocarbonate was dissolved in 1 L of methyl tert-butyl ether after distillation, and stirring was started. The mixture was cooled at -10°C for 15 min, and 131.25 g (1 mol) of vinyl magnesium bromide was added. The mixture was reacted at -5°C for 3 hours. The reaction was monitored by LC-MS. After the reaction was completed, ice water was added to quench the mixture, thereby obtaining a crude product of ethylene carbonate;

[0072] (3) The crude product is extracted, dried, and rapidly filtered through silica gel. The solvent after vacuum distillation is purified by distillation and then recycled to obtain pure vinyl ethylene carbonate.

[0073] The purity of vinyl ethylene carbonate obtained in this example is 95.90%, and the yield is 79.7%.

[0074] Example 6

[0075] A method for synthesizing vinyl ethylene carbonate comprises the following steps:

[0076] (1) Dehydrating methyl tert-butyl ether by distillation;

[0077] (2) Under nitrogen protection, 183.77 g (1.5 mol) of ethylene chlorocarbonate was dissolved in 1 L of methyl tert-butyl ether after distillation, and stirring was started. The mixture was cooled at -10°C for 15 min, and 196.88 g (1.5 mol) of vinyl magnesium bromide was added. The mixture was reacted at -5°C for 3 hours. The reaction was monitored by LC-MS. After the reaction was completed, ice water was added to quench the mixture, thereby obtaining a crude product of ethylene carbonate;

[0078] (3) The crude product is extracted, dried, and rapidly filtered through silica gel. The solvent after vacuum distillation is purified by distillation and then recycled to obtain pure vinyl ethylene carbonate.

[0079] The purity of vinyl ethylene carbonate obtained in this example is 96.80%, and the yield is 80.1%.

[0080] Example 7

[0081] A method for synthesizing vinyl ethylene carbonate comprises the following steps:

[0082] (1) Dehydrating methyl tert-butyl ether by distillation;

[0083] (2) Under nitrogen protection, 220.52 g (1.8 mol) of ethylene chlorocarbonate was dissolved in 1 L of methyl tert-butyl ether after distillation, and stirring was started. The mixture was cooled at -10°C for 15 min, and 236.25 g (1.8 mol) of vinyl magnesium bromide was added. The mixture was reacted at -5°C for 3 hours. The reaction was monitored by LC-MS. After the reaction was completed, ice water was added to quench the mixture, thereby obtaining a crude product of ethylene carbonate;

[0084] (3) The crude product is extracted, dried, and rapidly filtered through silica gel. The solvent after vacuum distillation is purified by distillation and then recycled to obtain pure vinyl ethylene carbonate.

[0085] The purity of vinyl ethylene carbonate obtained in this example is 99.80%, and the yield is 93.1%.

[0086] Example 8

[0087] A method for synthesizing vinyl ethylene carbonate comprises the following steps:

[0088] (1) Dehydrating methyl tert-butyl ether by distillation;

[0089] (2) Under nitrogen protection, 269.52 g (2.2 mol) of ethylene chlorocarbonate was dissolved in 1 L of methyl tert-butyl ether after distillation, and stirring was started. The mixture was cooled at -10°C for 15 min, and 288.75 g (2.2 mol) of vinyl magnesium bromide was added. The mixture was reacted at -5°C for 3 hours. The reaction was monitored by LC-MS. After the reaction was completed, ice water was added to quench the mixture, thereby obtaining a crude product of ethylene carbonate;

[0090] (3) The crude product is extracted, dried, and rapidly filtered through silica gel. The solvent after vacuum distillation is purified by distillation and then recycled to obtain pure vinyl ethylene carbonate.

[0091] The purity of vinyl ethylene carbonate obtained in this example is 99.95%, and the yield is 93.5%.

[0092] Example 9

[0093] A method for synthesizing vinyl ethylene carbonate comprises the following steps:

[0094] (1) Dehydrating methyl tert-butyl ether by distillation;

[0095] (2) Under nitrogen protection, 306.28 g (2.5 mol) of ethylene chlorocarbonate was dissolved in 1 L of methyl tert-butyl ether after distillation, and stirring was started. The mixture was cooled at -10°C for 15 min, and 328.13 g (2.5 mol) of vinyl magnesium bromide was added. The mixture was reacted at -5°C for 3 hours. The reaction was monitored by LC-MS. After the reaction was completed, ice water was added to quench the mixture, thereby obtaining a crude product of ethylene carbonate;

[0096] (3) The crude product is extracted, dried, and rapidly filtered through silica gel. The solvent after vacuum distillation is purified by distillation and then recycled to obtain pure vinyl ethylene carbonate.

[0097] The purity of vinyl ethylene carbonate obtained in this example is 97.80%, and the yield is 78.5%.

[0098] Example 10

[0099] A method for synthesizing vinyl ethylene carbonate comprises the following steps:

[0100] (1) Dehydrating methyl tert-butyl ether by distillation;

[0101] (2) Under nitrogen protection, 367.53 g (3 mol) of ethylene chlorocarbonate was dissolved in 1 L of methyl tert-butyl ether after distillation, and stirring was started. The mixture was cooled at -10°C for 15 min, and 393.75 g (3 mol) of vinyl magnesium bromide was added. The mixture was reacted at -5°C for 3 hours. The reaction was monitored by LC-MS. After the reaction was completed, ice water was added to quench the mixture, thereby obtaining a crude product of ethylene carbonate;

[0102] (3) The crude product is extracted, dried, and rapidly filtered through silica gel. The solvent after vacuum distillation is purified by distillation and then recycled to obtain pure vinyl ethylene carbonate.

[0103] The purity of vinyl ethylene carbonate obtained in this example is 97.20%, and the yield is 77.3%.

[0104] Embodiment 11

[0105] A method for synthesizing vinyl ethylene carbonate comprises the following steps:

[0106] (1) Dehydrating methyl tert-butyl ether by distillation;

[0107] (2) Under nitrogen protection, 98.01 g (0.8 mol) of ethylene chlorocarbonate was dissolved in 1 L of methyl tert-butyl ether after distillation, and stirring was started. The mixture was cooled at -10°C for 15 min, and 105 g (0.8 mol) of vinyl magnesium bromide was added. The mixture was reacted at -5°C for 3 hours. The reaction was monitored by LC-MS. After the reaction was completed, ice water was added to quench the mixture, thereby obtaining a crude product of ethylene carbonate;

[0108] (3) The crude product is extracted, dried, and rapidly filtered through silica gel. The solvent after vacuum distillation is purified by distillation and then recycled to obtain pure vinyl ethylene carbonate.

[0109] The purity of vinyl ethylene carbonate obtained in this example is 99.60%, and the yield is 58.5%.

[0110] Example 12

[0111] A method for synthesizing vinyl ethylene carbonate comprises the following steps:

[0112] (1) Dehydrating methyl tert-butyl ether by distillation;

[0113] (2) Under nitrogen protection, 98.01 g (0.8 mol) of ethylene chlorocarbonate was dissolved in 1 L of methyl tert-butyl ether after distillation, and stirring was started. The mixture was cooled at -10°C for 15 min, and 105 g (0.8 mol) of vinyl magnesium bromide was added. The mixture was reacted at -5°C for 12 hours. The reaction was monitored by LC-MS. After the reaction was completed, ice water was added to quench the mixture, thereby obtaining a crude product of ethylene carbonate;

[0114] (3) The crude product is extracted, dried, and rapidly filtered through silica gel. The solvent after vacuum distillation is purified by distillation and then recycled to obtain pure vinyl ethylene carbonate.

[0115] The purity of vinyl ethylene carbonate obtained in this example is 99.60%, and the yield is 90.5%.

[0116] Example 13

[0117] A method for synthesizing vinyl ethylene carbonate comprises the following steps:

[0118] (1) Dehydrating methyl tert-butyl ether by distillation;

[0119] (2) Under nitrogen protection, 392.03 g (3.2 mol) of ethylene chlorocarbonate was dissolved in 1 L of methyl tert-butyl ether after distillation, and stirring was started. The mixture was cooled at -10°C for 15 min, and 420 g (3.2 mol) of vinyl magnesium bromide was added. The mixture was reacted at -5°C for 3 hours. The reaction was monitored by LC-MS. After the reaction was completed, ice water was added to quench the mixture, thereby obtaining a crude product of ethylene carbonate;

[0120] (3) The crude product is extracted, dried, and rapidly filtered through silica gel. The solvent after vacuum distillation is purified by distillation and then recycled to obtain pure vinyl ethylene carbonate.

[0121] The purity of vinyl ethylene carbonate obtained in this example is 96.50%, and the yield is 65.4%.

[0122] Embodiment 14

[0123] This embodiment is basically the same as embodiment 1, the only difference being that tetrahydrofuran is used as solvent.

[0124] The purity of vinyl ethylene carbonate obtained in this example is 99.80%, and the yield is 90.5%.

[0125] Embodiment 15

[0126] This embodiment is basically the same as embodiment 1, the only difference being that benzene is used as the solvent.

[0127] The purity of vinyl ethylene carbonate obtained in this example is 99.92%, and the yield is 89.5%.

[0128] Example 16

[0129] This embodiment is basically the same as embodiment 1, the only difference being that acetone is used as the solvent.

[0130] The purity of vinyl ethylene carbonate obtained in this example is 99.83%, and the yield is 85.8%.

[0131] Comparative Example 1

[0132] This comparative example is basically the same as Example 11, the only difference being that methanol is used as the solvent.

[0133] The purity of vinyl ethylene carbonate obtained in this comparative example was 92.50%, and the yield was 42.5%.

[0134] Comparative Example 2

[0135] This comparative example is basically the same as comparative example 1, except that the reaction time is extended to 12 hours.

[0136] The purity of vinyl ethylene carbonate obtained in this comparative example was 92.90%, and the yield was 44.5%.

[0137] Comparative Example 3

[0138] This comparative example is basically the same as Example 1, except that the methyl tert-butyl ether is not subjected to dehydration treatment.

[0139] The purity of vinyl ethylene carbonate obtained in this comparative example was 98.5%, and the yield was 54.5%.

[0140] Comparative Example 4

[0141] This comparative example is basically the same as Example 1, except that the reaction temperature in step (2) is 5°C.

[0142] The purity of vinyl ethylene carbonate obtained in this comparative example was 99.80%, and the yield was 40.5%.

[0143] Comparative Example 5

[0144] This comparative example is basically the same as Example 1, except that the reaction temperature in step (2) is -15°C.

[0145] The purity of vinyl ethylene carbonate obtained in this comparative example was 99.96%, and the yield was 44.5%.

[0146] It can be seen from the test results of Examples 1-16 and Comparative Examples 1-5 that the method for synthesizing vinyl ethylene carbonate of the present invention uses a non-protonic solvent, which can be used as an electrolyte solvent, thereby reducing the influence of the solvent on product quality and improving product purity; at the same time, vinyl magnesium bromide is used to perform a nucleophilic substitution reaction on vinyl chlorocarbonate under low temperature conditions, and the reaction rate is fast; the obtained product has high purity and high yield. It can be further seen from the test results of Examples 1-4 that when the molar ratio of vinyl chlorocarbonate to vinyl magnesium bromide is 1:(1 to 1.2), the synthesis process has a faster reaction rate and a higher yield.

[0147] It can be seen from the test results of Example 2 and Examples 5-13 that when the concentration of vinyl magnesium bromide in the aprotic solvent is 1-3 mol / L, the vinyl ethylene carbonate product has a higher purity and yield; at the same time, when the concentration of vinyl magnesium bromide in the aprotic solvent is 1.8-2.2 mol / L, the purity and yield of the vinyl ethylene carbonate product are better. When the concentration of vinyl magnesium bromide is higher than 3 mol / L, vinyl magnesium bromide will attack the carbonyl group and vinyl magnesium bromide will polymerize itself, reducing the yield; when the concentration of vinyl magnesium bromide is lower than 1 mol / L, the reaction rate will decrease, resulting in a lower product yield at the same reaction time; but when the reaction time is extended, a higher product yield can still be obtained. It can be seen from the test results of Examples 11, 12 and Comparative Examples 1 and 2 that when a protic solvent is used, even if the reaction time is extended, the product yield is still low, which further illustrates the influence of the aprotic solvent selected by the present invention on the product yield.

[0148] It can be seen from the test results of Example 1 and Examples 14-16 that when different aprotic solvents are used, the yield and purity of the prepared vinyl ethylene carbonate are higher; at the same time, when methyl tert-butyl ether is selected as the solvent, the yield and purity are better.

[0149] It can be seen from the test results of Example 1 and Comparative Example 3 that the aprotic solvent after dehydration treatment is more stable, reducing its influence on product quality, and obtaining vinyl ethylene carbonate with higher yield and yield. It can be seen from the test results of Example 1 and Comparative Examples 4-5 that in a low temperature environment of -10 to 0°C, the yield of the product obtained by using vinyl magnesium bromide to carry out nucleophilic substitution reaction on vinyl chlorocarbonate is high; when the reaction temperature is too low or too high, it will affect the yield of vinyl ethylene carbonate.

[0150] The present invention is further described above with the aid of specific embodiments. However, it should be understood that the specific description here should not be construed as limiting the essence and scope of the present invention. Various modifications made to the above embodiments by ordinary technicians in the field after reading this specification are all within the scope of protection of the present invention.

Claims

1. A method for synthesizing vinyl ethylene carbonate, characterized in that: The following steps are involved: (1) Dehydrating the aprotic solvent; (2) under the protection of an inert gas, dissolving chloroethylene carbonate in the aprotic solvent, cooling, adding vinylmagnesium bromide to react at -10 to 0°C, and after the reaction is completed, adding a quenching agent to quench the reaction to obtain a crude product of vinyl ethylene carbonate; (3) purifying the crude vinyl ethylene carbonate to obtain pure vinyl ethylene carbonate.

2. The synthetic method of vinyl ethylene carbonate according to claim 1, characterized in that The aprotic solvent includes any one or more of ether solvents, benzene solvents, and ketone solvents.

3. The synthetic method of vinyl ethylene carbonate according to claim 1 or 2, characterized in that, The aprotic solvent is methyl tert-butyl ether.

4. The synthetic method of vinyl ethylene carbonate according to claim 1, characterized in that: The molar ratio of the chloroethylene carbonate to the vinyl magnesium bromide is 1:(1-1.2).

5. The synthetic method of vinyl ethylene carbonate according to claim 1, characterized in that, The concentration of the vinyl magnesium bromide in the aprotic solvent is 1 to 3 mol / L 。 6. The method for synthesizing vinyl ethylene carbonate according to claim 1 or 5, characterized in that: The concentration of the vinyl magnesium bromide in the aprotic solvent is 1.8 to 2.2 mol / L.

7. The method for synthesizing vinyl ethylene carbonate according to claim 1, characterized in that: The quenching reagent includes any one of ice water, saturated ammonium chloride aqueous solution, and glacial acetic acid.

8. The method for synthesizing vinyl ethylene carbonate according to claim 1 or 7, characterized in that: The quenching reagent is ice water.

9. The method for synthesizing vinyl ethylene carbonate according to claim 1, characterized in that: The following steps are involved: (1) Dehydrating the aprotic solvent by molecular sieve drying or distillation; (2) under the protection of inert gas, dissolving chloroethylene carbonate in the aprotic solvent, cooling at -20 to 0° C. for 10 to 20 min, adding vinyl magnesium bromide and reacting at -10 to 0° C. for 1 to 3 h, monitoring the reaction progress by LC-MC, and adding a quenching reagent after the reaction to quench the reaction, thereby obtaining a crude product of vinyl ethylene carbonate; (3) extracting, drying, and filtering the crude vinyl ethylene carbonate product, recondensing and rectifying the solvent evaporated by vacuum distillation, and recovering the solvent to obtain pure vinyl ethylene carbonate product.

10. Vinyl ethylene carbonate synthesized by the synthesis method described in any one of claims 1 to 9.

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