Synthesis method of phenyl formate compound

Abstract

The invention provides a synthesis method of a phenyl formate compound, which comprises the following steps: mixing 3, 5-heptanediol and a solvent, and cooling to 0-8 DEG C to obtain a first mixture; dropwise adding benzoyl chloride into the first mixture, and sequentially carrying out heat preservation at 20-30 DEG C for 1-2 hours, heat preservation at 60-65 DEG C for 2-3 hours, heat preservation at 65-75 DEG C for 2-3 hours and heat preservation at 75-80 DEG C for 2-3 hours; cooling to 30-40 DEG C, and dropwise adding methanol; a second mixture is prepared; carrying out heat preservation on the second mixture at 75-85 DEG C for 3-4 hours to obtain a third mixture; extracting the third mixture, and rectifying; the rectification temperature is 165 DEG C to 180 DEG C. The phenyl formate compound prepared by the synthesis method disclosed by the invention is high in yield and high in purity.

Description

Technical Field

[0001] The present application relates to the technical field of chemical synthesis, and in particular to a method for synthesizing phenylformate compounds. Background Art

[0002] The development of the polyolefin industry is an important indicator of the development of a country's petrochemical industry. The key to polyolefin technology lies in catalysts. The improvement of polyolefin resin performance is closely related to the development of polyolefin catalysts.

[0003] 3.5-Heptanediol dibenzoate is a synthetic intermediate of polyolefin catalysts and is used in the synthesis of polyolefin catalysts. This product can greatly improve the performance of polyolefin catalysts, eliminate plasticizers in downstream products, and has high added value.

[0004] The related technology uses the following method to synthesize 3,5-heptanediol dibenzoate, specifically: the first step, in the presence of a solvent and an alkaline catalyst, ethyl propionate and methyl ethyl ketone are subjected to an acylation reaction to generate 3,5-heptanedione, and in particular, after the reaction is stopped, a chelation purification method is used to obtain a 3,5-heptanedione product; the second step, in the presence of a solvent and an alkaline catalyst, a reagent capable of undergoing a 4-substitution reaction with 3,5-heptanedione is contacted with it to obtain 4-substituted 3,5-heptanedione; the third step, in the presence of a solvent or in the absence of a solvent, a reducing agent is used to reduce the substituted 3,5-heptanedione under alkaline conditions to obtain 3,5-heptanediol; the fourth step, the reduced product 3,5-heptanediol is reacted with a carbonyl-containing compound under certain conditions in a solvent to obtain the product heptanediol dibenzoate. The above method needs to be purified by a chelation method, and the production cost is high; and the yield of the purity of the product is low, which is not conducive to large-scale industrial production.

[0005] Application Contents

[0006] The present application is made in view of the above problems, and its purpose is to provide a method for synthesizing phenylformate compounds, wherein the phenylformate compounds prepared by the method have high purity.

[0007] Specifically, the present application discloses a method for synthesizing phenylformate compounds, comprising the following steps:

[0008] Mixing 3,5-heptanediol and a solvent and cooling the mixture to 0°C to 8°C to obtain a first mixture;

[0009] Then, benzoyl chloride is added dropwise to the first mixture, and the mixture is kept at 20°C to 30°C for 1h to 4h, 60°C to 65°C for 2h to 3h, 65°C to 75°C for 2h to 3h, and 75°C to 80°C for 2h to 3h in sequence; the mixture is then cooled to 30°C to 40°C and methanol is added dropwise to obtain a second mixture;

[0010] The second mixture is kept at 75° C. to 85° C. for 3 h to 4 h to obtain a third mixture;

[0011] extracting and then distilling the third mixture;

[0012] The distillation temperature is 165℃~180℃.

[0013] According to one of the technical solutions of the synthesis method of the present application, at least the following beneficial effects are achieved:

[0014] In the present application, during the preparation of the first mixture, precise control is performed, and the mixture is first kept warm for a period of time at a low temperature stage to allow the reactants to be fully mixed, which is beneficial to the subsequent full reaction of the reactants. After the low temperature stage, the present application performs step-by-step heat preservation and heating to make the temperature distribution inside the reaction system uniform, thereby reducing the occurrence of side reactions and further improving the purity of the product.

[0015] According to some embodiments of the present application, the method for preparing 3,5-heptanediol comprises the following steps:

[0016] After mixing 3,5-heptanedione and methanol, add alkali and potassium borohydride at 0°C to 6°C under a protective atmosphere, and keep the mixture at 0°C to 6°C for 1h to 2h after the addition is complete; and then keep the mixture at 18°C ​​to 25°C for 3h to 4h;

[0017] Then add glycerol, dissolve at 80℃~90℃ for 3h~4h, and perform vacuum distillation to collect 3,5-heptanediol.

[0018] According to some embodiments of the present application, the temperature of the vacuum distillation is 80°C to 120°C.

[0019] According to some embodiments of the present application, the pressure of the vacuum distillation is -0.092MPa to -0.1MPa.

[0020] According to some embodiments of the present application, the method for preparing 3,5-heptanedione comprises the following steps:

[0021] Under a protective atmosphere, sodium hydride is added dropwise to tetrahydrofuran at 20°C to 30°C to prepare a sodium hydride mixture;

[0022] Then, the tetrahydrofuran and methanol mixture is added dropwise to the sodium hydride mixture at 30°C to 40°C;

[0023] Then, the mixture of butanone and ethyl propionate was added dropwise at 40°C to 45°C, and after the addition was completed, the mixture was kept at 50°C to 55°C for 6h to 7h;

[0024] Then, water is added dropwise at 0°C to 5°C, and hydrochloric acid is added dropwise after the addition is complete. After the addition of hydrochloric acid is complete, the liquids are separated; and the organic phase is collected;

[0025] The organic phase was distilled under atmospheric pressure and then under reduced pressure.

[0026] According to some embodiments of the present application, the temperature of the atmospheric distillation is 80°C to 150°C.

[0027] According to some embodiments of the present application, the temperature of the vacuum distillation is 80°C to 120°C.

[0028] According to some embodiments of the present application, the pressure of the vacuum distillation is -0.09 MPa to -0.098 MPa.

[0029] According to some embodiments of the present application, the solvent includes at least one of pyridine, methanol and toluene.

[0030] According to some embodiments of the present application, the molar ratio of the sodium hydride to the butyl propionate is 1:2-3.

[0031] According to some embodiments of the present application, the molar ratio of butanone to butyl propionate is 1:2-3.

[0032] According to some embodiments of the present application, the molar ratio of 3,5-heptanedione to potassium borohydride is 1:0.5 to 1.5.

[0033] According to some embodiments of the present application, the molar ratio of 3,5-heptanediol to benzoyl chloride is 1:2-3.

[0034] According to some embodiments of the present application, in the preparation process of 3,5-heptanedione, the emulsion layer is collected after liquid separation; the emulsion layer is filtered to collect the organic phase.

[0035] According to some embodiments of the present application, a filter medium is selected during the emulsification layer filtration process.

[0036] According to some embodiments of the present application, the filter medium includes at least one of diatomaceous earth and modified diatomaceous earth.

[0037] In this application, by selecting the filter medium,

[0038] According to some embodiments of the present application, the modified diatomaceous earth includes alkali-treated diatomaceous earth or molecular sieve-modified diatomaceous earth.

[0039] According to some embodiments of the present application, the method for preparing alkali-treated diatomaceous earth comprises the following steps:

[0040] Mix diatomaceous earth and alkaline solution and heat them with water.

[0041] According to some embodiments of the present application, the alkaline solution includes silicate and a strong base.

[0042] According to some embodiments of the present application, the molar concentration of silicate in the alkaline solution is 0.5 mol / L to 1.5 mol / L.

[0043] According to some embodiments of the present application, the molar concentration of the strong base in the alkaline solution is 1.5 mol / L to 2.5 mol / L.

[0044] According to some embodiments of the present application, the hydrothermal temperature is 130°C to 150°C.

[0045] According to some embodiments of the present application, the hydrothermal time is 20 h to 30 h.

[0046] According to some embodiments of the present application, the mass volume ratio of the diatomaceous earth and the alkaline solution is 1 g: 1 mL to 3 mL.

[0047] According to some embodiments of the present application, the method for preparing the molecular sieve modified diatomaceous earth comprises the following steps:

[0048] The alkali-treated diatomaceous earth and the molecular sieve precursor liquid are mixed and then subjected to hydrothermal reaction, solid-liquid separation, solid phase collection, and calcination.

[0049] According to some embodiments of the present application, the hydrothermal temperature is 170°C to 200°C.

[0050] According to some embodiments of the present application, the hydrothermal time is 40 h to 60 h.

[0051] According to some embodiments of the present application, the calcination temperature is 500°C to 600°C.

[0052] According to some embodiments of the present application, the calcination time is 4 h to 6 h.

[0053] According to some embodiments of the present application, a reciprocating vacuum pump and a Roots pump are used in series in the reduced pressure distillation of the present application to achieve control of the vacuum degree. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] In order to more clearly illustrate the embodiments of the present drawings or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present drawings. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0055] Figure 1This is a liquid chromatogram of the product (3,5-heptanediol dibenzoate) obtained in Example 1.

[0056] Figure 2 This is the detection spectrum of heptanedione obtained in Example 1.

[0057] Figure 3 This is the detection spectrum of heptanediol obtained in Example 1.

[0058] The purpose, features and advantages of this figure will be further described in conjunction with the embodiments with reference to the accompanying drawings. DETAILED DESCRIPTION

[0059] In order to make the purpose, technical solutions and advantages of the present application clearer, the present application is described and illustrated below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not intended to limit the present application. Based on the embodiments provided in the present application, all other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of the present application.

[0060] Obviously, the following descriptions are only some examples or embodiments of the present application. For ordinary technicians in this field, the present application can also be applied to other similar scenarios without creative work. In addition, it can also be understood that although the efforts made in this development process may be complicated and lengthy, for ordinary technicians in the field related to the content disclosed in this application, some changes in design, manufacturing or production based on the technical content disclosed in this application are just conventional technical means, and should not be understood as insufficient content disclosed in this application.

[0061] However, unnecessary detailed descriptions may be omitted. For example, detailed descriptions of well-known matters and repeated descriptions of substantially the same structures may be omitted. This is to avoid the following description from becoming unnecessarily lengthy and to facilitate understanding by those skilled in the art. In addition, the following description is provided for those skilled in the art to fully understand the present application and is not intended to limit the subject matter described in the claims.

[0062] Unless otherwise specified, all embodiments and optional embodiments of the present application can be combined with each other to form a new technical solution.

[0063] Unless otherwise specified, all technical features and optional technical features of this application can be combined with each other to form a new technical solution.

[0064] "Scope" disclosed in the present application is limited in the form of lower limit and upper limit, and a given range is limited by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundary of a special range. The scope limited in this way can be including end values ​​or not including end values, and can be arbitrarily combined, that is, any lower limit can be combined with any upper limit to form a scope. For example, if the scope of 60-120 and 80-110 is listed for a specific parameter, it is understood that the scope of 60-110 and 80-120 is also expected. In addition, if the minimum range values ​​1 and 2 are listed, and if the maximum range values ​​3, 4 and 5 are listed, the following scope can be all expected: 1-3, 1-4, 1-5, 2-3, 2-4 and 2-5. In the present application, unless otherwise specified, the numerical range "ab" represents the abbreviation of any real number combination between a and b, wherein a and b are real numbers. For example, the numerical range "0-5" means that all real numbers between "0-5" are listed in this document, and "0-5" is just an abbreviation of these numerical combinations. In addition, when a parameter is expressed as an integer ≥ 2, it is equivalent to disclosing that the parameter is, for example, an integer of 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0065] If there is no special explanation, all steps of the present application can be performed sequentially or randomly, preferably sequentially. For example, the method includes steps (a) and (b), which means that the method may include steps (a) and (b) performed sequentially, or may include steps (b) and (a) performed sequentially. For example, the method may further include step (c), which means that step (c) may be added to the method in any order. For example, the method may include steps (a), (b) and (c), or may include steps (a), (c) and (b), or may include steps (c), (a) and (b), etc.

[0066] If there is no special explanation, the "include" and "comprising" mentioned in this application are open-ended or closed-ended. For example, the "include" and "comprising" may mean that other components not listed may also be included or only the listed components may be included or only the listed components may be included.

[0067] If not specifically stated, in this application, the term "or" is inclusive. For example, the phrase "A or B" means "A, B, or both A and B". More specifically, any of the following conditions satisfies the condition "A or B": A is true (or exists) and B is false (or does not exist); A is false (or does not exist) and B is true (or exists); or both A and B are true (or exist).

[0068] Some of the equipment selected in the implementation scheme of this application are shown in Table 1:

[0069] Table 1

[0070]

[0071]

[0072] Note: Normal temperature is 25℃ and normal pressure is 101.325kPa.

[0073] The main equations for each step in 3,5-heptanediol dibenzoate are as follows:

[0074] 3,5-Heptanedione chemical formula:

[0075]

[0076] 3.5-Heptanediol chemical formula:

[0077]

[0078] 3,5-Heptanediol dibenzoate chemical formula:

[0079]

[0080] The composition (mass fraction) of the diatomaceous earth selected in the implementation mode of the present application is as follows:

[0081] SiO2, 86.23%; Al2O3, 2.65%; Fe2O3, 1.85%; K2O, 1.66%; MgO, 1.95%; CaO, 1.59%; Na2O, 1.58%; TiO2, 0.98% and the balance is loss on ignition.

[0082] Example 1

[0083] This embodiment is a method for synthesizing a phenylformate compound, which consists of the following steps:

[0084] S1. Synthesis of 3,5-heptanedione:

[0085] S01, Gas protection:

[0086] Turn on the water pump, draw the vacuum in R201 to 0.09Mpa, close the vacuum valve, turn on the argon gas until the vacuum gauge returns to zero, repeat twice, and then continue to pass argon gas until the hydrochloric acid (mass fraction is 14%, mass is 375kg) is dripped.

[0087] S02, feeding:

[0088] Open the R201 manhole cover, pass argon gas, put in sodium hydride (mass fraction 60%, mass 120kg), and close the manhole cover;

[0089] Tetrahydrofuran (THF, 90% of the total amount (219.78*0.9kg)) was pumped into the tetrahydrofuran high-level tank V203, and R201 was slowly added. After the addition, stirring was started and steam was turned on to slowly raise the temperature to 38°C.

[0090] Mix methanol (2.5 kg) and part of tetrahydrofuran (the remaining 10% (219.78*0.1 kg)) and pump them into the tetrahydrofuran high-level tank V203. When the temperature of R201 is 38°C, slowly add them dropwise into the R201 tank. Keep the temperature at 40°C and stir for 0.5 h.

[0091] Butanone (180 kg) and ethyl propionate (640 kg) were pumped into the premixing kettle V201 in advance and stirred for 1 hour. After the methanol was added, they were pumped into the ketone-ester mixed liquid high-level tank V202.

[0092] After the stirring is completed, the mixture of butanone and ethyl propionate is added dropwise to R201, and the temperature of R201 is controlled between 40℃ and 45℃. After the addition is completed, the R201 tank is kept at 40℃ to 45℃ for 1h.

[0093] Then turn on the steam to raise the temperature of the R201 tank to 55℃, and keep it between 50℃ and 55℃ for 6 hours; after the insulation is completed, turn on the circulating water to cool the R201 tank to about 40℃, and then turn on the ice brine (ice sodium chloride solution) to cool it down to 0℃.

[0094] Add water (700 kg) to the water high-level tank V204 in advance. When the temperature in R201 drops to about 0°C, turn on the argon gas and start adding dropwise. Control the temperature below 5°C during the addition. After adding the water, stir between 0°C and 5°C for 1 hour, stop the argon gas, turn on the vacuum pump, and transfer the material in R201 to the neutralization kettle R202.

[0095] Dilute hydrochloric acid (mass fraction of 14%) is pumped from the aluminum sol to the hydrochloric acid high-level tank V206. Turn on the R202 chilled water and argon gas and slowly add the dilute hydrochloric acid to the neutralization kettle R202 at below 10°C. At the same time, measure the pH value of the material in R202. Stop adding when the pH value of the organic phase is between 6 and 7. Turn on the circulating water and raise the temperature to about 20°C and stir for 0.5h.

[0096] Place the neutralization kettle R202 at rest for 1 hour, and separate the liquids; the lower aqueous phase is transferred to the receiving tank V231, and the middle emulsified layer is placed in the ketone filtration tank V234, and vacuum filtered into the receiving tank V231. During the filtration, a layer of diatomaceous earth is placed on the filter paper to collect the organic phase; after the organic phase is qualified, it is vacuum transferred to the ketone intermediate tank V207;

[0097] The organic phase is placed in the distillation kettle R203 from V207 for distillation;

[0098] Distillation is divided into atmospheric distillation and vacuum distillation;

[0099] Atmospheric distillation:

[0100] The oil temperature is initially set to 80°C, and the vertical cooling water flow rate at the top of the tower is set to 2500L / h; reflux for 2 hours. Then close the cooling water valve, discharge the cooling water in the distillation tower through the low-point zero discharge, and start distilling the low-boiling water to the light component receiving tank V208;

[0101] Finally, the oil temperature rises to 120°C and is no longer raised. The distillation time is 22 hours.

[0102] After distillation, set the oil temperature to 0℃, set the vertical cooling water flow rate at the top of the tower to 2500L / h, and naturally cool down to the tank temperature below 80℃ before vacuum distillation;

[0103] Vacuum distillation: Open the oil pump at level one and slowly pull the vacuum to -0.08mpa~-0.096mpa;

[0104] Set the oil temperature, the initial setting is 80℃, the oil temperature will increase by 10℃ each time in the early stage, and the oil temperature will increase by 5℃ each time when it exceeds 120℃; the oil temperature setting frequency is determined according to the discharge situation, 80℃, 1h; 90℃, 3h; 100℃, 2h; 110℃, 2h; 120℃, 2h; 130℃, 2h; 140℃ until the end.

[0105] When there is product being steamed out, change the receiver to the front distillation tank V209 to steam the front distillation and increase the sampling density;

[0106] When the sample product content exceeds 85%, change the receiver to product tank V210 to steam the product. When the air temperature and tank temperature rise at the same time, the discharge becomes smaller. When the sample product content is <85%, change the receiver to front distillation tank V209 and distill until the product content is <10%. After the distillation is completed, keep vacuum stirring in the tank to cool down naturally.

[0107] S2, 3,5-heptanediol synthesis:

[0108] S01, 3,5-heptanedione (mass fraction 98%, test results see Figure 2 , the amount is 160kg) and methanol (102kg) are sucked into the ketone alcohol high-level tank V211, water (330kg) and methanol (102kg) are sucked into the hydrogenation reactor R211, stirring is turned on and chilled water is turned on for cooling;

[0109] S02, turn on the water pump, draw the vacuum in R211 to -0.09Mpa, close the vacuum valve and start filling with argon until the vacuum gauge returns to zero, and continue to pass argon;

[0110] S03, open the R211 manhole cover, add potassium borohydride (mass fraction 96%, dosage 51kg) and sodium hydroxide (dosage 1.41kg), and close the manhole cover;

[0111] S04. When the temperature inside R211 drops to 0°C, slowly add a mixture of methanol and 3,5-heptanedione, and control the temperature between 0°C and 5°C.

[0112] S05. After dripping, keep warm at 0-6℃ for 1h, then drain the jacket chilled water and start circulating water to raise the temperature to 20℃ and keep warm for 2h.

[0113] S06, start the water pump to evacuate R211 to -0.08mpa~-0.096mpa, start the R211 steam to slowly increase the temperature and decompress and distill to the solvent receiving tank V212. When white solid precipitates in the kettle, stop distillation, cool down to 40℃, suck in glycerol (855.8kg), then start the steam to increase the temperature to 80℃, keep it at about 80℃ and stir for 3h;

[0114] S07, cooling to 50°C and transferring the material to alcohol distillation tank R212;

[0115] Vacuum distillation: Open the oil pump and slowly pull the vacuum to -0.08mpa~-0.096mpa. The initial oil is set at 80℃. The receiving tank is V214. Methanol and water are discharged first (condensed water is fully opened and refluxed for 0.5h and then half-opened. When the temperature is below 40℃, it is all water). When the oil temperature is set to about 180℃ and the tank temperature is 100℃, the temperature rises sharply. At this time, the water and methanol in V214 are discharged first, and then the pre-distillation is started. Samples are taken to measure the product content. If the product content is >80%, change the product receiver V213 and evaporate the product (3,5-heptanediol, the final test results of the product are shown in Figure 3 , purity 99.8%);

[0116] End the distillation when the temperature first drops and then rises.

[0117] S3, 3,5-heptanediol dibenzoate synthesis:

[0118] S01. Suck 3,5-heptanediol (mass fraction is 99.8%, dosage is 261.06kg), pyridine (468.1kg), and toluene (total dosage is 901.9kg, and 20kg is left) into the esterification reactor R221, and suck benzoyl chloride (777.3kg) into the esterification high-level tank V221, and turn on the chilled water to cool down to 0°C.

[0119] S02, add benzoyl chloride at 0℃~8℃, and heat the circulating water to 20℃ and keep warm for 3h;

[0120] Turn on the steam and raise the temperature to 60℃~65℃, keep warm for 3h, 65℃~75℃, keep warm for 2h, 75℃~80℃, keep warm for 2h;

[0121] S03, cool down to 30-40℃, absorb methanol into methanol high level tank V222, add into R221, raise temperature to 80℃ and keep warm for 3h.

[0122] S04, turn on the circulating water to cool down to 40℃, turn on the vacuum and transfer to the extraction drying kettle R222.

[0123] S05, R222 open chilled water to cool to 10℃, wash once: put water from extraction water high tank V223 into R222, stir for 0.5h, drain jacket chilled water;

[0124] After standing for 1.5 hours, separate the liquids, the aqueous phase (lower layer) is transferred to a waste water bucket (ton barrel) for the recovery of pyridine, and the organic phase (upper layer) is left in the tank;

[0125] Secondary water washing: add water from V223 to the kettle, stir for 0.5h, let stand for 1h, separate the liquids, the water phase (lower layer) is separated into a waste water bucket for the recovery of pyridine, and the organic phase (upper layer) is left in the kettle;

[0126] Three water washes: Inhale 10% dilute soda ash solution into the kettle and stir for 0.5h, let it stand for 1h, separate the liquids, and separate the water phase (lower layer) into a waste water bucket and discharge it after inspection; the organic phase (upper layer) remains in the kettle;

[0127] Four water washes: add water from V223 to the kettle, stir for 0.5h, let stand for 1h, separate the liquids, and separate the water phase (lower layer) into a waste water bucket and discharge it after inspection; the organic phase (upper layer) remains in the kettle;

[0128] Five water washes: add water from V223 to the kettle, stir for 0.5h, let stand for 1.5h, separate the liquids, and transfer the aqueous phase (lower layer) to the waste water bucket and discharge it after inspection; the organic phase (upper layer) remains in the kettle.

[0129] S06. Open the manhole cover, add anhydrous sodium sulfate into R222, stir for 20 minutes, filter through V224, rinse the tank bottom and filter cake with toluene, aspirate the filtrate to the desolventizing kettle R223, distill to 80°C under reduced pressure with a water vacuum pump, and remove the solvent to the receiving tank V225 (the mother liquor is guaranteed to enter the distillation tank once); cool down and transfer to the ester distillation kettle R224.

[0130] S07, distillation: open the oil pump level 1, pull the vacuum to -0.09MPa~-0.098MPa, set the initial oil temperature to 80℃, slowly increase the temperature to produce toluene, and the receiving tank is V226;

[0131] When the kettle temperature reaches 120℃, take samples for measurement. If the toluene content is <30%, turn on the second-level oil pump, slowly pull the vacuum to -0.09MPa~-0.098MPa, and start steaming 3,5-heptanediol dibenzoate. When the tank temperature reaches 150℃, the air temperature will reach about 135℃. When the air temperature drops and the discharge becomes smaller, turn on the third-level oil pump, slowly pull the vacuum to -0.09MPa~-0.098MPa, raise the tank temperature to 180℃, and stop steaming until no more material is discharged.

[0132] After the distillation is completed, close the vacuum valve and discharge valve of the receiving tank V226, create a vacuum in the distillation tank R224, and pass argon gas into the distillation tank R224 until the vacuum gauge returns to zero.

[0133] The finished product kettle R225 is passed with cooling water in advance and the water pump is turned on to evacuate to -0.09MPa~-0.098MPa. When the distillation tank R224 is filled with argon, open the valve and suck it into the finished product kettle R225. During the material transfer, the argon is always on and the distillation tank feeding valve is half open.

[0134] The product is cooled to room temperature (25°C) in the finished product kettle R225 under vacuum conditions, discharged into barrels, and weighed for sampling.

[0135] Example 2

[0136] This embodiment is a method for synthesizing a phenylformate compound, which differs from Embodiment 1 in that:

[0137] In this embodiment, diatomaceous earth is replaced by modified diatomaceous earth, and the preparation method of modified diatomaceous earth is as follows:

[0138] Diatomaceous earth and alkaline solution (a mixed solution of 1 mol / L sodium silicate and 2 mol / L sodium hydroxide, the volume mass ratio of the alkaline solution to diatomaceous earth is 2 mL: 1 g) are mixed (at 60°C, the stirring speed is 60 r / min, and the mixing time is 3 h); after the mixing is completed, the mixture is reacted in a high-pressure reactor (the reaction temperature is 140°C, and the reaction time is 24 h). After the reaction is completed, the solid-liquid separation is carried out, the solid phase is collected, and dried to obtain modified diatomaceous earth.

[0139] Example 3

[0140] This embodiment is a method for synthesizing a phenylformate compound, which differs from Embodiment 2 in that:

[0141] The preparation method of modified diatomaceous earth in this embodiment is as follows:.

[0142] S1, diatomaceous earth and alkaline solution (mixed solution of 1 mol / L sodium silicate and 2 mol / L sodium hydroxide, the volume mass ratio of alkaline solution to diatomaceous earth is 2 mL: 1 g) are mixed (at 60°C, the stirring speed is 60 r / min, and the mixing time is 3 h); after the mixing is completed, the reaction is carried out in a high-pressure reactor (the reaction temperature is 140°C, and the reaction time is 24 h). After the reaction is completed, the solid-liquid separation is carried out, the solid phase is collected, and it is dried to obtain alkali-treated diatomaceous earth;

[0143] S2. Mix alkali-treated diatomaceous earth and molecular sieve precursor liquid (the mass volume ratio of alkali-treated diatomaceous earth and molecular sieve precursor liquid is 1g:5mL, and the molar ratio of tetrapropylammonium hydroxide, tetraethyl orthosilicate and water in the precursor liquid is 2:32.5:2349) and then perform hydrothermal reaction (hydrothermal temperature is 180°C for 48h). After the reaction is completed, separate the solid and liquid, collect the solid phase, and dry it at 60°C for 10h; after drying, calcine (calcination temperature is 540°C, calcination time is 5h); after calcination, grind until D50 is 100μm to obtain modified diatomaceous earth.

[0144] Example 4

[0145] This embodiment is a method for synthesizing a phenylformate compound, which differs from Embodiment 2 in that:

[0146] The preparation method of modified diatomite in this embodiment is as follows:

[0147] S1, diatomaceous earth and alkaline solution (mixed solution of 1 mol / L sodium silicate and 2 mol / L sodium hydroxide, the volume mass ratio of alkaline solution to diatomaceous earth is 2 mL: 1 g) are mixed (at 60°C, the stirring speed is 60 r / min, and the mixing time is 3 h); after the mixing is completed, the reaction is carried out in a high-pressure reactor (the reaction temperature is 140°C, and the reaction time is 24 h). After the reaction is completed, the solid-liquid separation is carried out, the solid phase is collected, and it is dried to obtain alkali-treated diatomaceous earth;

[0148] S2. Mix alkali-treated diatomaceous earth and molecular sieve precursor liquid (the mass volume ratio of alkali-treated diatomaceous earth and molecular sieve precursor liquid is 1g:8mL, and the molar ratio of tetrapropylammonium hydroxide, tetraethyl orthosilicate and water in the precursor liquid is 2:32.5:2349) and then perform hydrothermal reaction (hydrothermal temperature is 180°C for 48h). After the reaction is completed, separate the solid and liquid, collect the solid phase, and dry it at 60°C for 10h; after drying, calcine (calcination temperature is 540°C, calcination time is 5h); after calcination, grind until D50 is 100μm to obtain modified diatomaceous earth.

[0149] Example 5

[0150] This embodiment is a method for synthesizing a phenylformate compound, which differs from Embodiment 2 in that:

[0151] The preparation method of modified diatomite in this embodiment is as follows:

[0152] S1, diatomaceous earth and alkaline solution (mixed solution of 1 mol / L sodium silicate and 2 mol / L sodium hydroxide, the volume mass ratio of alkaline solution to diatomaceous earth is 2 mL: 1 g) are mixed (at 60°C, the stirring speed is 60 r / min, and the mixing time is 3 h); after the mixing is completed, the reaction is carried out in a high-pressure reactor (the reaction temperature is 140°C, and the reaction time is 24 h). After the reaction is completed, the solid-liquid separation is carried out, the solid phase is collected, and it is dried to obtain alkali-treated diatomaceous earth;

[0153] S2. Mix alkali-treated diatomaceous earth and molecular sieve precursor liquid (the mass volume ratio of alkali-treated diatomaceous earth and molecular sieve precursor liquid is 1g:10mL, and the molar ratio of tetrapropylammonium hydroxide, tetraethyl orthosilicate and water in the precursor liquid is 2:32.5:2349) and then perform hydrothermal reaction (hydrothermal temperature is 180°C for 48h). After the reaction is completed, separate the solid and liquid, collect the solid phase, and dry it at 60°C for 10h; after drying, calcine (calcination temperature is 540°C, calcination time is 5h); after calcination, grind until D50 is 100μm to obtain modified diatomaceous earth.

[0154] Comparative Example 1

[0155] This comparative example is a method for synthesizing a phenylformate compound, which differs from Example 1 in that:

[0156] S2. Step S06 in the synthesis of 3,5-heptanediol. The specific operation of step S06 is as follows:

[0157] S06. Turn on the water pump to draw the vacuum to the maximum, turn on the R211 steam to slowly increase the temperature and reduce the pressure to distill to the solvent receiving tank V212. When white solid precipitates in the kettle, stop distillation and cool down to 80℃.

[0158] The performance test method in the implementation mode of this application is as follows:

[0159] The test method for the ester and meso content is as follows: Q / SH 361 839. The test results are shown in Table 1.

[0160] The product testing method is as follows:

[0161] The HPLC test conditions are as follows:

[0162] Chromatographic column: Vertex C18; flow rate: 1.5 mL / min; temperature: 30 °C;

[0163] Mobile phase: methanol and water in a volume ratio of 85:15;

[0164] Injection volume: 5 μL;

[0165] The detection wavelength is: 229nm.

[0166] In the figure, the peak with a retention time of 4.057 min is the meso peak (3,5-heptanediol dibenzoate); the peak with a retention time of 4.543 min is the racemic peak (3,5-heptanediol dibenzoate);

[0167] Table 1

[0168] - Ester content (%) Content of racemate (%) Example 1 99.87 65.39 Example 2 99.88 65.52 Example 3 99.90 65.58 Example 4 99.92 65.81 Example 5 99.95 65.94 Comparative Example 1 97.32 62.23

[0169] In the present application, during the preparation of the first mixture, precise control is performed, and the mixture is first kept warm for a period of time at a low temperature stage to allow the reactants to be fully mixed, which is beneficial to the subsequent full reaction of the reactants. After the low temperature stage, the present application performs step-by-step heat preservation and heating to make the temperature distribution inside the reaction system uniform, thereby reducing the occurrence of side reactions and further improving the purity of the product.

[0170] It should be noted that the present application is not limited to the above-mentioned embodiments. The above-mentioned embodiments are only examples, and the embodiments having the same structure as the technical idea and exerting the same effect within the scope of the technical solution of the present application are all included in the technical scope of the present application. In addition, without departing from the scope of the main purpose of the present application, various modifications that can be thought of by those skilled in the art to the embodiments and other methods of combining some of the constituent elements in the embodiments are also included in the scope of the present application.

Claims

1. A method for synthesizing a phenylformate compound, characterized in that: The following steps are involved: Mixing 3,5-heptanediol and a solvent and cooling the mixture to 0°C to 8°C to obtain a first mixture; Then, benzoyl chloride is added dropwise to the first mixture, and the mixture is kept at 20°C to 30°C for 1h to 4h, 60°C to 65°C for 2h to 3h, 65°C to 75°C for 2h to 3h, and 75°C to 80°C for 2h to 3h in sequence; the mixture is then cooled to 30°C to 40°C and methanol is added dropwise to obtain a second mixture; The second mixture is kept at 75° C. to 85° C. for 3 h to 4 h to obtain a third mixture; extracting and then distilling the third mixture; The distillation temperature is 165℃~180℃.

2. The synthetic method of phenylformate compounds according to claim 1, characterized in that: The preparation method of 3,5-heptanediol comprises the following steps: After mixing 3,5-heptanedione and methanol, add alkali and potassium borohydride at 0°C to 6°C under a protective atmosphere, and keep the mixture at 0°C to 6°C for 1h to 2h after the addition is complete; and then keep the mixture at 18°C ​​to 25°C for 3h to 4h; Then add glycerol, dissolve at 80℃~90℃ for 3h~4h, and perform vacuum distillation to collect 3,5-heptanediol.

3. The synthetic method of phenylformate compounds according to claim 2, characterized in that, The temperature of the vacuum distillation is 80°C to 180°C; And / or, the pressure of the vacuum distillation is -0.092MPa to -0.1MPa.

4. The synthetic method of phenylformate compounds according to claim 1, characterized in that: The preparation method of 3,5-heptanedione comprises the following steps: Under a protective atmosphere, sodium hydride is added dropwise to tetrahydrofuran at 20°C to 30°C to prepare a sodium hydride mixture; Then, the tetrahydrofuran and methanol mixture is added dropwise to the sodium hydride mixture at 30°C to 40°C; Then, the mixture of butanone and ethyl propionate was added dropwise at 40°C to 45°C, and after the addition was completed, the mixture was kept at 50°C to 55°C for 6h to 7h; Then, water is added dropwise at 0°C to 5°C, and hydrochloric acid is added dropwise after the addition is complete. After the hydrochloric acid is added, the liquids are separated; and the organic phase is collected; The organic phase was distilled under atmospheric pressure and then under reduced pressure.

5. The method for synthesizing phenylformate compounds according to claim 4, characterized in that: The temperature of the atmospheric distillation is 80°C to 140°C.

6. The method for synthesizing phenylformate compounds according to claim 4, characterized in that: The temperature of the vacuum distillation is 80°C to 145°C; And / or, the pressure of the vacuum distillation is -0.09 MPa to -0.098 MPa.

7. The method for synthesizing phenylformate compounds according to claim 1, characterized in that: The solvent includes at least one of pyridine, methanol and toluene.

8. The method for synthesizing a phenylformate compound according to any one of claims 1 to 7, characterized in that: The molar ratio of the sodium hydride to the butyl propionate is 1:2-3; And / or, the molar ratio of butanone to butyl propionate is 1:2-3.

9. The method for synthesizing a phenylformate compound according to any one of claims 1 to 7, characterized in that: The molar ratio of the 3,5-heptanedione to potassium borohydride is 1:0.5-1.

5.

10. The method for synthesizing phenylformate compounds according to any one of claims 1 to 7, characterized in that: The molar ratio of the 3,5-heptanediol to the benzoyl chloride is 1:2-3.

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