Method for synthesizing benzoyl formate compound

Abstract

The invention provides a method for synthesizing a benzoyl formate compound. The method comprises the following steps: carrying out carbonyl insertion reaction on benzyl chloride in the presence of a first catalyst, alkali, carbon monoxide and alcohol to obtain a phenylacetate compound; the phenylacetate compound is subjected to an oxidation reaction in the presence of a second catalyst and an oxygen-containing atmosphere to obtain the benzoyl formate compound, the initial raw material used in the method is benzyl chloride with low price, and the raw material cost can be greatly reduced; an oxygen-containing atmosphere such as oxygen is used as an oxidizing agent in the process of generating the benzoyl formate compound by using the phenylacetate compound, so that high-toxicity and high-pollution compounds such as potassium permanganate, sodium cyanide and bromine can be prevented from being used; the post-treatment cost of the process can be greatly reduced, and the safety in the production process can be improved.

Description

Technical Field

[0001] This application relates to the field of fine chemical technology, and particularly relates to a method for synthesizing benzoyl formate compounds. Background Art

[0002] Benzoyl formate compounds (such as methyl benzoylformate) are intermediates of the pesticide herbicide metribuzin. In recent years, due to their advantages of high efficiency and low toxicity, the usage amount of metribuzin in the field of sugar beet weeding has gradually increased, and it has gradually developed into a large-tonnage herbicide. As the main intermediate of metribuzin, methyl benzoylformate is expensive, and effectively controlling its cost plays an important role in reducing the production cost of metribuzin. In addition, methyl benzoylformate is a highly efficient and non-yellowing free radical (I) type liquid photoinitiator, and the usage amount of methyl benzoylformate in this field is also increasing continuously. Therefore, it is necessary to explore the synthesis route of methyl benzoylformate.

[0003] In the prior art, methods for preparing benzoyl formate compounds (such as methyl benzoylformate), classified by different starting materials, mainly include the following categories:

[0004] 1. Using benzaldehyde as the starting material, there are two such methods. The first is to react benzaldehyde with chloroform under alkaline conditions, and then oxidize the resulting product with potassium permanganate to obtain benzoyl formic acid; the second is to treat benzaldehyde with sodium bisulfite and sodium cyanide to obtain benzoyl nitrile, then hydrolyze benzoyl nitrile and oxidize it with potassium permanganate to obtain benzoyl formic acid, and finally esterify it to obtain benzoyl formate. Both of these methods use benzaldehyde as the raw material, which is relatively expensive and the total yield is low; in addition, the large-scale use of potassium permanganate and sodium cyanide also poses great risks.

[0005] 2. Using acetophenone as the starting material, reacting with chlorine to replace two hydrogen atoms on the methyl group, then hydrolyzing it with alkali and acid in sequence, and finally oxidizing it with potassium permanganate to obtain benzoyl formic acid. After reacting benzoyl formic acid with methanol, methyl benzoylformate is obtained. The process route of this method is relatively long, and the dichlorination at the ortho position of the carbonyl group with chlorine is difficult to control the reaction end point. In addition, using potassium permanganate as the oxidant will produce a large amount of sewage, causing huge pollution.

[0006] 3. Using styrene as the starting material, under alkaline conditions, preparing benzoyl formic acid by oxidation with potassium permanganate, and then performing methylation. This route has fewer steps and is simple. Currently, most industrial production uses this method. However, the reaction of oxidizing styrene to benzoic acid with potassium permanganate cannot be well controlled, and the problem of potassium permanganate pollution still exists.

[0007] 4. Using benzonitrile as a raw material, reacting under the action of concentrated sulfuric acid and a catalyst to obtain an intermediate product, and reacting the intermediate product with methanol to obtain methyl benzoylformate. Although this route has fewer steps and is simple, its raw material benzonitrile requires the use of highly toxic cyanide in synthesis, which is difficult to obtain. At the same time, highly toxic gas hydrocyanic acid will be released during the synthesis of methyl benzoylformate, which is very dangerous and not suitable for industrial production.

[0008] 5. Using methyl phenylacetate as a raw material, using a phase transfer catalyst, peroxide as an oxidant and bromine as a catalyst in an aqueous phase to synthesize methyl benzoylformate. This route has fewer steps and is easy to operate, but the raw materials methyl phenylacetate and bromine are relatively expensive. At the same time, bromine is highly toxic and has great industrial risks, so it is not suitable for industrial production either. Summary of the Invention

[0009] In view of some problems existing in the prior art, the present application provides a new method for synthesizing benzoylformate compounds. The method has fewer steps, is easy to operate, environmentally friendly, and has low cost, and is more suitable for industrialization.

[0010] The specific technical solution of the present application is as follows:

[0011] 1. A method for synthesizing benzoylformate compounds, which includes:

[0012] Performing carbonyl insertion reaction on benzyl chloride in the presence of a first catalyst, a base, carbon monoxide and an alcohol to obtain a phenylacetate compound;

[0013] Performing an oxidation reaction on the phenylacetate compound in the presence of a second catalyst and an oxygen-containing atmosphere to obtain a benzoylformate compound.

[0014] 2. The method according to item 1, wherein the first catalyst comprises a first catalyst A and a first catalyst B;

[0015] Preferably, the first catalyst A is a palladium-based catalyst, and preferably the palladium-based catalyst is selected from one or more of palladium(II) chloride, palladium(II) acetate, bis(triphenylphosphine)palladium(II) chloride, [1,1'-bis(diphenylphosphino)ferrocene] palladium(II) dichloride and bis(acetonitrile)palladium(II) dichloride, and more preferably palladium(II) chloride;

[0016] Preferably, the first catalyst B is a halide salt, and preferably the halide salt is selected from one or more of tetrabutylammonium iodide, tetrabutylammonium bromide, tetrabutylammonium chloride, potassium iodide, sodium iodide and cuprous iodide, and more preferably tetrabutylammonium iodide.

[0017] 3. The method according to item 1 or 2, wherein the alcohol is selected from one of methanol, ethanol, propanol, butanol and pentanol; and / or

[0018] The oxygen-containing atmosphere is oxygen or air.

[0019] 4. The method according to any one of items 1 to 3, wherein the base is selected from one or more of potassium carbonate, potassium phosphate, monopotassium phosphate, sodium acetate, disodium hydrogen phosphate, triethylamine and triethylenediamine, preferably disodium hydrogen phosphate.

[0020] 5. The method according to any one of items 2 to 4, wherein in the step of producing the phenylacetate compound, the reaction pressure is 1.2 - 2.0 MPa, preferably 1.4 - 1.7 MPa; and / or

[0021] The reaction temperature is 110 - 140 °C, preferably 110 - 120 °C; and / or

[0022] The reaction time is more than 1 h, preferably 6 - 10 h, more preferably 7 - 8 h; and / or

[0023] The molar ratio of the benzyl chloride to the first catalyst A is 1:0.01 - 0.1; preferably 0.025 - 0.05 and / or

[0024] The molar ratio of the benzyl chloride to the first catalyst B is 1:0.05 - 0.5, preferably 1:0.1 - 0.5.

[0025] 6. The method according to any one of items 1 to 5, wherein in the step of generating the phenylacetate compound, it further includes: carrying out an insertion carbonylation reaction of benzyl chloride in the presence of a first catalyst, a base, carbon monoxide and an alcohol and in a first solvent, preferably, after the insertion carbonylation reaction, obtaining the phenylacetate compound under negative pressure conditions.

[0026] 7. The method according to item 6, wherein the first solvent is selected from solvents of alcohols, ethers, benzenes, nitriles or esters, preferably selected from one or more of ethanol, tetrahydrofuran, acetonitrile, anisole, o - dimethoxybenzene, p - dimethoxybenzene, toluene and 1,4 - dioxane, more preferably anisole; and / or

[0027] The volume ratio of the amount of substance of the benzyl chloride to the volume of the first solvent is greater than 1 mol:1 L, preferably 1 mol:(1.0 - 1.5 L), more preferably 1 mol:(1.2 - 1.4 L); and / or

[0028] The pressure of the negative pressure is less than -0.09 MPa, preferably less than -0.095 MPa.

[0029] 8. The method according to any one of items 1 to 7, wherein the second catalyst comprises a second catalyst A and a second catalyst B;

[0030] Preferably, the second catalyst A is selected from one or both of acetate and manganese dioxide, preferably the acetate is cobalt acetate, manganese acetate, nickel acetate, chromium acetate, zinc acetate or copper acetate, and more preferably cobalt acetate;

[0031] Preferably, the second catalyst B is selected from one or more of the following:

[0032]

[0033] Preferably, it is

[0034] 9. The method according to item 8, wherein, in the step of generating the benzoylformate compound, the reaction pressure is 1.2 - 1.8 MPa, preferably 1.2 - 1.5 MPa; and / or

[0035] the reaction temperature is 110 - 150 °C, preferably 130 - 140 °C; and / or

[0036] the reaction time is more than 1 h, preferably 6 - 10 h, and more preferably 6 - 8 h; and / or

[0037] the molar ratio of the phenylacetate compound to the second catalyst A is 1:0.025 - 0.1; preferably 1:0.025 - 0.05 and / or

[0038] the molar ratio of the phenylacetate compound to the second catalyst B is 1:0.05 - 0.5, preferably 1:0.05 - 0.2, and more preferably 1:0.05 - 0.15.

[0039] 10. The method according to any one of items 1 to 8, wherein, in the step of generating the benzoylformate compound, the method further comprises: oxidizing the methyl phenylacetate in the presence of a second catalyst and an oxygen-containing atmosphere and adding a second solvent to obtain the benzoylformate compound; preferably, after the oxidation reaction, the benzoylformate compound is obtained under negative pressure conditions.

[0040] 11. The method according to item 9, wherein the second solvent is an organic solvent, and the organic solvent is preferably one or two of acetic acid, trifluoroacetic acid, hexafluoroisopropanol, N,N-dimethylformamide and acetonitrile, and more preferably acetic acid; and / or

[0041] The molar amount of the phenylacetate compound and the volume of the second solvent are greater than 1 mol: 0.5 L, preferably 1 mol: (0.6 - 0.8 L); and / or

[0042] The pressure of the negative pressure is less than -0.09 MPa, preferably less than -0.095 MPa.

[0043] Effect of the invention

[0044] The method described in the present application is a two-step reaction with simple steps. It only needs to distill off the solvent and the product at different temperatures under negative pressure, which is suitable for industrial production;

[0045] The starting material used in the method described in the present application is benzyl chloride with relatively low price, which can greatly reduce the raw material cost;

[0046] In the process of using the phenylacetate compound to generate the benzoylformate compound in the method described in the present application, an oxygen-containing atmosphere such as oxygen is used as an oxidant, which can avoid using highly toxic and highly polluting compounds such as potassium permanganate, sodium cyanide, and bromine, and can greatly reduce the post-treatment cost of the process and improve the safety during the production process. Detailed implementation mode

[0047] The following describes the present application in detail in combination with the described implementation modes. Although specific embodiments of the present application are shown, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present application and to fully convey the scope of the present application to those skilled in the art.

[0048] It should be noted that certain terms are used in the specification and claims to refer to specific components. Those skilled in the art should understand that technicians may use different terms to refer to the same component. The specification and claims do not use the difference in terms as a way to distinguish components, but use the difference in the functions of components as the criterion for distinction. As used throughout the specification and claims, the terms "comprising" or "including" are open-ended terms and should be interpreted as "including but not limited to". The subsequent description of the specification is for the purpose of implementing the preferred implementation mode of the present application, but the description is for the general principle of the specification and is not used to limit the scope of the present application. The scope of protection of the present application shall be determined by the terms defined in the appended claims.

[0049] The present application provides a method for synthesizing benzoylformate compounds, which includes:

[0050] Performing a carbonyl insertion reaction on benzyl chloride in the presence of a first catalyst, a base, carbon monoxide, and an alcohol to obtain methyl phenylacetate;

[0051] The phenylacetate compound is subjected to an oxidation reaction in the presence of a second catalyst and an oxygen-containing atmosphere to obtain a benzoylformate compound.

[0052] In this application, benzyl chloride is used to synthesize pesticide intermediate benzoylformate compounds such as methyl benzoylformate. Since the raw material benzyl chloride is relatively inexpensive, this greatly reduces the production cost.

[0053] In some embodiments, the first catalyst comprises a first catalyst A and a first catalyst B;

[0054] Preferably, the first catalyst A is a palladium-based catalyst. Preferably, the palladium-based catalyst is selected from one or more of palladium(II) chloride, palladium(II) acetate, bis(triphenylphosphine)palladium(II) chloride, [1,1'-bis(diphenylphosphino)ferrocene] palladium(II) dichloride, and bis(acetonitrile)palladium(II) dichloride, and more preferably palladium(II) chloride;

[0055] Preferably, the first catalyst B is a halide salt. Preferably, the halide salt is selected from one or more of tetrabutylammonium iodide, tetrabutylammonium bromide, tetrabutylammonium chloride, potassium iodide, sodium iodide, and copper(I) iodide, and more preferably tetrabutylammonium iodide. In some embodiments, the base is selected from one or more of potassium carbonate, potassium phosphate, potassium hydrogen phosphate, sodium acetate, disodium hydrogen phosphate, triethylamine, and triethylenediamine, and preferably disodium hydrogen phosphate. In some embodiments, the alcohol is selected from one of methanol, ethanol, propanol, butanol, and pentanol; and / or

[0056] The oxygen-containing atmosphere is oxygen or air.

[0057] When the alcohol is selected from one of methanol, ethanol, propanol, butanol, and pentanol, the obtained benzoylformate compounds can be methyl benzoylformate, ethyl benzoylformate, propyl benzoylformate, butyl benzoylformate, pentyl benzoylformate, etc.

[0058] Among them, when methanol is used for the reaction, the obtained product is methyl benzoylformate, and its reaction equation is as follows:

[0059]

[0060] In some embodiments, in the step of producing the phenylacetate compound, the reaction pressure is 1.2 - 2.0 MPa, preferably 1.4 - 1.7 MPa; and / or

[0061] The reaction temperature is 110 - 140 °C, preferably 110 - 120 °C; and / or

[0062] The reaction time is more than 1 hour, preferably 6 - 10 h, more preferably 7 - 8 h; and / or

[0063] The molar ratio of the benzyl chloride to the first catalyst A is 1:0.01 - 0.1, preferably 1:0.025 - 0.05; and / or

[0064] The molar ratio of the benzyl chloride to the first catalyst B is 1:0.05 - 0.5, preferably 1:0.1 - 0.5.

[0065] For example, the reaction pressure can be 1.2 MPa, 1.3 MPa, 1.4 MPa, 1.5 MPa, 1.6 MPa, 1.7 MPa, 1.8 MPa, 1.9 MPa, 2.0 MPa, etc.

[0066] The reaction temperature is 110 °C, 111 °C, 112 °C, 113 °C, 114 °C, 115 °C, 116 °C, 117 °C, 118 °C, 119 °C, 120 °C, 121 °C, 122 °C, 123 °C, 124 °C, 125 °C, 126 °C, 127 °C, 128 °C, 129 °C, 130 °C, 131 °C, 132 °C, 133 °C, 134 °C, 135 °C, 136 °C, 137 °C, 138 °C, 139 °C, 140 °C, etc.

[0067] The molar ratio (n 氯苄 :n 第一催化剂A ) of the benzyl chloride to the first catalyst A can be 1:0.001, 1:0.015, 1:0.02, 1:0.025, 1:0.03, 1:0.035, 1:0.04, 1:0.045, 1:0.05, 1:0.06, 1:0.07, 1:0.08, 1:0.09, 1:0.1, etc.

[0068] The molar ratio (n 氯苄 :n 第一催化剂B ) of the benzyl chloride to the first catalyst B can be 1:0.05, 1:0.1, 1:0.2, 1:0.3, 1:0.4, 1:0.5, etc.

[0069] In the process of synthesizing phenylacetate compounds, for the reaction time, the present application does not impose any restrictions, and it can be conventionally selected as needed. As long as the kettle pressure no longer drops, it indicates the end of the reaction. Therefore, the reaction time can be more than 1 h, preferably 6 - 10 h, more preferably 6 - 8 h.

[0070] The reaction time can be 1 h, 2 h, 3 h, 4 h, 5 h, 6 h, 7 h, 8 h, 9 h, 10 h, 11 h, etc.

[0071] In some embodiments, the step of generating phenylacetate compounds further includes: carrying out a carbonyl insertion reaction on benzyl chloride in the presence of a first catalyst, a base, carbon monoxide and an alcohol in a first solvent. Preferably, after the carbonyl insertion reaction, the phenylacetate compounds are obtained under negative pressure conditions.

[0072] In this application, the phenylacetate compounds are obtained by negative pressure operation, which is only operated according to the boiling points of different components, with simple operation and suitable for industrial production.

[0073] In some embodiments, the first solvent is selected from solvents such as alcohols, ethers, benzenes, nitriles or esters, preferably selected from one or more of ethanol, tetrahydrofuran, acetonitrile, anisole, o-dimethoxybenzene, p-dimethoxybenzene, toluene and 1,4-dioxane, and more preferably anisole; and / or

[0074] The molar amount of the benzyl chloride and the volume ratio of the first solvent are greater than 1 mol:1 L, preferably 1 mol:(1.0 - 1.5 L), and more preferably 1 mol:(1.2 - 1.4 L); and / or

[0075] The pressure of the negative pressure is less than -0.09 MPa, preferably less than -0.095 MPa.

[0076] For example, the molar amount of the benzyl chloride and the volume ratio (n 氯苄 :v 第一溶剂 ) can be 1 mol:1.0 L, 1 mol:1.1 L, 1 mol:1.2 L, 1 mol:1.25 L, 1 mol:1.3 L, 1 mol:1.35 L, 1 mol:1.4 L, 1 mol:1.5 L, 1 mol:1.6 L, 1 mol:1.7 L, 1 mol:1.8 L, 1 mol:1.9 L, 1 mol:2.0 L, etc.

[0077] The pressure of the negative pressure can be -0.091 MPa, -0.092 MPa, -0.093 MPa, -0.094 MPa, -0.095 MPa, -0.096 MPa, -0.097 MPa, -0.098 MPa, -0.099 MPa, etc.

[0078] In some embodiments, the second catalyst includes a second catalyst A and a second catalyst B;

[0079] Preferably, the second catalyst A is selected from one or two of acetates and manganese dioxide. Preferably, the acetate is cobalt acetate, manganese acetate, nickel acetate, chromium acetate, zinc acetate or copper acetate, and more preferably cobalt acetate;

[0080] Preferably, the second catalyst B is selected from one or more of the following:

[0081]

[0082] Preferably i.e., C4. In some embodiments, in the step of generating the benzoylformate compound, the reaction pressure is 1.2 - 1.8 MPa, preferably 1.2 - 1.5 MPa; and / or

[0083] the reaction temperature is 110 - 150 °C, preferably 130 - 140 °C; and / or

[0084] the molar ratio of the phenylacetate compound to the second catalyst A is 1:0.025 - 0.1; preferably 1:0.025 - 0.5; and / or

[0085] the molar ratio of the phenylacetate compound to the second catalyst B is 1:0.05 - 0.5, preferably 1:0.05 - 0.2, and more preferably 1:0.05 - 0.15.

[0086] For example, the reaction pressure can be 1.2 MPa, 1.3 MPa, 1.4 MPa, 1.5 MPa, 1.6 MPa, 1.7 MPa, 1.8 MPa, etc.

[0087] The reaction temperature can be 110 °C, 115 °C, 120 °C, 125 °C, 130 °C, 131 °C, 132 °C, 133 °C, 134 °C, 135 °C, 136 °C, 137 °C, 138 °C, 139 °C, 140 °C, 145 °C, 150 °C, etc.

[0088] The molar ratio (n 苯乙酸酯类化合物 :n 第二催化剂A ) of the phenylacetate compound to the second catalyst A can be 1:0.025, 1:0.03, 1:0.035, 1:0.04, 1:0.045, 1:0.05, 1:0.06, 1:0.07, 1:0.08, 1:0.09, 1:0.1, etc.;

[0089] The molar ratio (n 苯乙酸酯类化合物 :n 第二催化剂B ) of the phenylacetate compound to the second catalyst B can be 1:0.05, 1:0.1, 1:0.15, 1:0.2, 1:0.25, 1:0.3, 1:0.35, 1:0.4, 1:0.45, 1:0.5, etc.

[0090] In the process of synthesizing benzoyl formate compounds, the present application does not impose any restrictions on the reaction time, which can be conventionally selected as needed. As long as the kettle pressure no longer drops, it indicates the end of the reaction. Therefore, the reaction time can be 1 h or more, preferably 6 - 10 h, and more preferably 6 - 8 h;

[0091] For example, the reaction time can be 1 h, 1.5 h, 2 h, 2.5 h, 3 h, 3.5 h, 4 h, 4.5 h, 5 h, 5.5 h, 6 h, 6.5 h, 7 h, 7.5 h, 8 h, 8.5 h, 9 h, 9.5 h, 10 h, etc.

[0092] In some embodiments, the second solvent is an organic solvent, and the organic solvent is preferably one or two selected from acetic acid, trifluoroacetic acid, hexafluoroisopropanol, N,N - dimethylformamide, and acetonitrile, and more preferably acetic acid; and / or

[0093] The molar ratio of the phenylacetate compound to the volume of the second solvent is greater than 1 mol:0.5 L, preferably 1 mol:(0.6 - 0.8 L); and / or

[0094] The pressure of the negative pressure is less than -0.09 MPa, preferably less than -0.095 MPa.

[0095] For example, the molar ratio of the phenylacetate compound to the volume of the second solvent (n 苯乙酸酯类化合物 :v 第二溶剂 ) can be 1 mol:0.5 L, 1 mol:0.6 L, 1 mol:0.7 L, 1 mol:0.8 L, 1 mol:0.9 L, 1 mol:1.0 L, 1 mol:1.1 L, 1 mol:1.2 L, 1 mol:1.3 L, etc.

[0096] The present application uses the above - mentioned method to prepare benzoyl formate compounds. The method is simple and easy to operate. And in the process of using phenylacetate compounds to prepare benzoyl formate compounds, using an oxygen - containing atmosphere as an oxidant for oxidation can avoid using highly toxic and / or highly polluting compounds, and using an oxygen - containing atmosphere for oxidation can reduce the later - stage process treatment cost and improve the safety in the production process.

[0097] The present application uses benzyl chloride as a raw material. Since the benzyl chloride raw material is relatively cheap, this can greatly reduce the production cost of benzoyl formate compounds such as methyl benzoylformate.

[0098] For example, in the process of preparing benzoyl formate compounds such as methyl benzoylformate, using different raw materials as follows (see Table 1), their costs are significantly different. The cost of using benzyl chloride is only 9.5 yuan / kg.

[0099] Table 1 Costs of Preparing Benzoylformate Compounds Using Different Raw Materials

[0100] Benzaldehyde Acetophenone Styrene Benzoyl cyanide Methyl phenylacetate Benzyl chloride Unit consumption (kg / kg) 2.22 1.51 1.43 1.05 1.14 1.06 Unit price (yuan / kg) 14.6 14.5 8.3 75 49.5 9 Cost (yuan / kg) 32.4 21.9 11.9 78.8 56.4 9.5

[0101] In the post - treatment step of each step of the method described in this application, under negative pressure conditions only, phenylacetate compounds and benzoylformate compounds can be separately obtained according to different temperatures. The method is simple and suitable for industrial production.

[0102] Examples

[0103] This application generally and / or specifically describes the materials and test methods used in the experiments. In the following examples, unless otherwise specifically stated, % represents wt%, that is, weight percentage. Reagents or instruments without indicating the manufacturer can be obtained as conventional reagent products through commercial purchase.

[0104] Example 1 Preparation of Methyl Benzoylformate

[0105] (1) Carbonylation Reaction

[0106] Check a 2L high - pressure reactor equipped with a stirrer, a thermocouple, and a hydrogenation device. After confirming that everything is normal, add benzyl chloride (127 g, 1 mol), anisole (1.2 L), palladium(II) chloride (4.4 g, 0.025 mol), tetrabutylammonium iodide (110 g, 0.3 mol), disodium hydrogen phosphate (216 g, 1.5 mol), and methanol (35 g, 1.1 mol) into the high - pressure reactor together. After purging with carbon monoxide three times, finally fill the system with carbon monoxide, and then stir and react at 1.6 MPa and 110 - 120 °C until the reactor pressure no longer drops. Then cool down to room temperature, open the reactor, and pump out the liquid. Under a negative pressure of - 0.095 MPa, first distill anisole at 70 - 80 °C until no solvent is evaporated from the system. The anisole distilled out is directly used for the next batch of feeding. Subsequently, raise the temperature to 130 - 140 °C to distill out the product methyl phenylacetate until no more product is distilled out. The remaining reactor residue is directly used for the next batch of feeding. The content of methyl phenylacetate obtained is 99.2%, and the yield is 97.7%.

[0107] (2) Oxidation Reaction

[0108] Check a 2L high - pressure reactor equipped with a stirrer, a thermocouple, and a hydrogenation device. After confirming that everything is normal, add the methyl phenylacetate (150 g, 1 mol) obtained in the previous step, cobalt acetate (8.8 g, 0.035 mol), The catalyst (25.5 g, 0.1 mol) and acetic acid (600 mL) were added together into an autoclave. After purging with oxygen three times, the system was finally filled with oxygen. Then, the reaction was carried out with stirring at 1.5 MPa and 130 - 140 °C until the pressure in the autoclave no longer decreased. The reaction time was... Then, the temperature was lowered to room temperature, the autoclave was opened, and the material was pumped out. Under a negative pressure of -0.095 MPa, acetic acid was first distilled out at 70 - 80 °C until no solvent was distilled out from the system. The distilled acetic acid was directly used for the next batch of feeding. Subsequently, the temperature was raised to 140 - 150 °C to distill out the product methyl benzoylformate until no more product was distilled out. The obtained methyl benzoylformate had a content of 98.3% and a yield of 96.1%.

[0109] Preparation of Methyl Benzoylformate in Example 2

[0110] The difference between Example 2 and Example 1 was that the first catalyst A used in the carbonyl insertion reaction was palladium(II) acetate, and the others were the same as in Example 1. The obtained methyl phenylacetate had a content of 98.7% and a yield of 67.2%, and the methyl benzoylformate had a content of 98.1% and a yield of 95.5%.

[0111] Preparation of Methyl Benzoylformate in Example 3

[0112] The difference between Example 3 and Example 1 was that the first catalyst B used in the carbonyl insertion reaction was sodium iodide, and the others were the same as in Example 1. The obtained methyl phenylacetate had a content of 95.4% and a yield of 46.3%, and the methyl benzoylformate had a content of 96.9% and a yield of 95.3%.

[0113] Preparation of Methyl Benzoylformate in Example 4

[0114] The difference between Example 4 and Example 1 was that the second catalyst A used in the oxidation reaction was manganese dioxide, and the others were the same as in Example 1. The obtained methyl phenylacetate had a content of 99.2% and a yield of 97.7%, and the methyl benzoylformate had a content of 97.2% and a yield of 78.3%.

[0115] Preparation of Methyl Benzoylformate in Example 5

[0116] The difference between Example 5 and Example 1 was that the second catalyst B used in the carbonyl insertion reaction was i.e., C3, and the others were the same as in Example 1. The obtained methyl phenylacetate had a content of 99.1% and a yield of 97.5%, and the methyl benzoylformate had a content of 97.6% and a yield of 61.1%.

[0117] Preparation of Methyl Benzoylformate in Example 6

[0118] Example 6 is different from Example 1 in that in the step of preparing methyl phenylacetate, the negative pressure is -0.09 MPa, and the others are the same as in Example 1. The content of methyl phenylacetate is 98.9%, the yield is 95.4%, the content of methyl benzoylformate is 97.8%, and the yield is 95.6%.

[0119] Preparation of Methyl Benzoylformate in Example 7

[0120] Example 7 is different from Example 1 in that in the step of preparing methyl benzoylformate, the negative pressure is -0.09 MPa, and the others are the same as in Example 1. The content of methyl phenylacetate is 99.0%, the yield is 98.1%, the content of methyl benzoylformate is 97.2%, and the yield is 93.7%.

[0121] Preparation of Ethyl Benzoylformate in Example 8

[0122] Example 8 is different from Example 1 in that ethanol is used instead of methanol to prepare ethyl benzoylformate, and the others are the same as in Example 1. The content of ethyl phenylacetate is 99.0%, the yield is 95.9%, the content of ethyl benzoylformate is 97.3%, and the yield is 94.1%.

[0123] Preparation of Propyl Benzoylformate in Example 9

[0124] Example 9 is different from Example 1 in that propanol is used instead of methanol to prepare propyl benzoylformate, and the others are the same as in Example 1. The content of propyl phenylacetate is 98.6%, the yield is 91.2%, the content of propyl benzoylformate is 97.8%, and the yield is 92.9%.

[0125] Table 2 Catalysts Used in Examples, as well as the Molar Ratios of Raw Materials and Catalysts

[0126]

[0127] In summary, the present application uses the above-mentioned method to synthesize benzoylformate compounds. The raw material used is chlorobenzene, which can greatly reduce the cost. An oxygen-containing atmosphere is used in the oxidation process, the process treatment is simple and the operation is relatively safe; and in the separation process, negative pressure operation is adopted, and the required components can be separated only according to the different boiling points of different components, and the operation is simple.

[0128] The above are only the preferred embodiments of the present application, and are not intended to limit the present application in other forms. Any person skilled in the art may use the technical content disclosed above to make changes or modifications into equivalent embodiments with equivalent changes. However, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present application without departing from the technical solution content of the present application still fall within the protection scope of the technical solution of the present application.

Claims

1. A method for synthesizing benzoylformate compounds, which comprises: Performing a carbonylation reaction on benzyl chloride in the presence of a first catalyst, a base, carbon monoxide, and an alcohol to obtain phenylacetate compounds; Performing an oxidation reaction on the phenylacetate compounds in the presence of a second catalyst and an oxygen-containing atmosphere to obtain benzoylformate compounds.

2. The method according to claim 1, wherein The first catalyst comprises a first catalyst A and a first catalyst B; Preferably, the first catalyst A is a palladium-based catalyst, and preferably the palladium-based catalyst is selected from one or more of palladium(II) chloride, palladium(II) acetate, bis(triphenylphosphine)palladium(II) chloride, [1,1'-bis(diphenylphosphino)ferrocene] palladium(II) dichloride, and bis(acetonitrile)palladium(II) dichloride, and more preferably palladium(II) chloride; Preferably, the first catalyst B is a halide salt, and preferably the halide salt is selected from one or more of tetrabutylammonium iodide, tetrabutylammonium bromide, tetrabutylammonium chloride, potassium iodide, sodium iodide, and copper(I) iodide, and more preferably tetrabutylammonium iodide; 3. The method according to claim 1 or 2, wherein The alcohol is selected from one of methanol, ethanol, propanol, butanol, and pentanol; and / or The oxygen-containing atmosphere is oxygen or air.

4. The method according to any one of claims 1 to 3, wherein, The base is selected from one or more of potassium carbonate, potassium phosphate, potassium hydrogen phosphate, sodium acetate, disodium hydrogen phosphate, triethylamine, and triethylenediamine, and preferably disodium hydrogen phosphate; 5. The method according to any one of claims 2 to 4, wherein, In the step of producing phenylacetate compounds, the reaction pressure is 1.2 - 2.0 MPa, preferably 1.4 - 1.7 MPa; and / or The reaction temperature is 110 - 140 °C, preferably 110 - 120 °C; and / or The molar ratio of the benzyl chloride to the first catalyst A is 1:0.01 - 0.1; preferably 0.025 - 0.05 and / or The molar ratio of the benzyl chloride to the first catalyst B is 1:0.05 - 0.5, preferably 1:0.1 - 0.

5.

6. The method according to any one of claims 1 to 5, wherein, In the step of generating phenylacetate compounds, it further comprises: performing a carbonylation reaction on benzyl chloride in the presence of a first catalyst, a base, carbon monoxide, and an alcohol and in a first solvent, and preferably, after the carbonylation reaction, obtaining phenylacetate compounds under negative pressure conditions.

7. The method according to claim 6, wherein, The first solvent is selected from solvents of alcohols, ethers, benzenes, nitriles, or esters, preferably selected from one or more of ethanol, tetrahydrofuran, acetonitrile, anisole, o-dimethoxybenzene, p-dimethoxybenzene, toluene, and 1,4-dioxane, and more preferably anisole; and / or The volume ratio of the amount of substance of the benzyl chloride to the first solvent is greater than 1 mol:1 L, preferably 1 mol:(1.0 - 1.5 L), and more preferably 1 mol:(1.2 - 1.4 L); and / or The pressure of the negative pressure is less than -0.09 MPa, preferably less than -0.095 MPa.

8. The method according to any one of claims 1 to 7, wherein The second catalyst comprises a second catalyst A and a second catalyst B; Preferably, the second catalyst A is selected from one or two of acetates and manganese dioxide, and preferably the acetate is cobalt acetate, manganese acetate, nickel acetate, chromium acetate, zinc acetate, or copper acetate, and more preferably cobalt acetate; Preferably, the second catalyst B is selected from one or more of the following: Preferably 9. The method according to claim 8, wherein In the step of producing benzoyl formate compounds, the reaction pressure is 1.2 - 1.8 MPa, preferably 1.2 - 1.5 MPa; and / or The reaction temperature is 110 - 150 °C, preferably 130 - 140 °C; and / or The molar ratio of the phenylacetate compound to the second catalyst A is 1:0.025 - 0.1; preferably 1:0.025 - 0.05 and / or The molar ratio of the phenylacetate compound to the second catalyst B is 1:0.05 - 0.5, preferably 1:0.05 - 0.2, and more preferably 1:0.05 - 0.

15.

10. The method according to any one of claims 1 to 8, wherein In the step of producing benzoyl formate compounds, the method further includes: oxidizing methyl phenylacetate in the presence of a second catalyst and an oxygen-containing atmosphere and adding a second solvent to obtain benzoyl formate compounds; preferably, after the oxidation reaction, benzoyl formate compounds are obtained under negative pressure conditions.

11. The method according to claim 9, wherein, The second solvent is an organic solvent, and the organic solvent is preferably one or two of acetic acid, trifluoroacetic acid, hexafluoroisopropanol, N,N-dimethylformamide, and acetonitrile, and more preferably acetic acid; and / or The volume ratio of the amount of substance of the phenylacetate compound to the second solvent is greater than 1 mol:0.5 L, preferably 1 mol:(0.6 - 0.8 L); and / or The pressure of the negative pressure is less than -0.09 MPa, preferably less than -0.095 MPa.

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