A synthetic method for preparing substituted aromatic formyl methyl carboxylate by friedel-crafts reaction

Abstract

The present application relates to a kind of synthetic methods for preparing substituted aromatic formyl formic acid methyl ester by Friedel-Crafts reaction. By oxalic acid, oxalyl chloride is prepared, then react with quantitative sodium methoxide in specific solvent and inhibitor conditions, can be stable, and intermediate oxalyl chloride monomethyl ester is obtained efficiently, oxalyl chloride monomethyl ester is reacted with substituted aryl compound under specific catalyst conditions to obtain a series of photoinitiator substituted aromatic formyl formic acid methyl ester. The series of products can be generally used in UV curing type coating and ink.

Description

Technical Field

[0001] This invention relates to the field of fine chemical materials, and particularly to the synthesis of a class of photoinitiator-substituted aromatic methylforminates. Oxaloyl chloride reacts with a measured amount of sodium methoxide under specific solvent and inhibitor conditions to stably and efficiently yield the intermediate oxaloyl chloride monomethyl ester. The oxaloyl chloride monomethyl ester then reacts with substituted aryl compounds under a specific catalyst to obtain a series of substituted aromatic methylforminates. This route is low-cost, safe, and environmentally friendly, representing an environmentally friendly production process. Background Technology

[0002] Methyl benzoylformate (MBF) is a free radical (I) type liquid photoinitiator with high initiation efficiency, good thermal stability, non-yellowing, and low odor. It is also an important raw material for preparing the macromolecular photoinitiator 754. Its structural formula is shown below. It has an α-keto ester structure, containing both carbonyl and ester groups, resulting in multiple reaction centers and exhibiting more unique chemical properties than ordinary compounds. It is mainly used in conjunction with mono- or polyfunctional vinyl monomers and oligomers in UV curing systems for unsaturated monomers, primarily in UV-curable coatings and inks. It is suitable for preparing thicker cured materials, producing coatings with good decorative effects and excellent weather resistance. This product can initiate the polymerization of acrylate and epoxy monomers, has a narrow absorption wavelength, and requires only a small dosage, making it an important additive for next-generation solvent-free film-forming, coating, and printing materials. Currently, the market is showing a year-on-year upward trend, with an annual growth rate exceeding 20%.

[0003]

[0004] Furthermore, the carbonyl carbon in methyl benzoate is a potential chiral carbon, from which many chiral compounds with important applications can be synthesized. It is an important intermediate in organic synthesis and is widely used in pesticides, pharmaceuticals, and other fields. For example, methyl benzoate is also an important intermediate for the pesticide benzoyl benzoate and for the drug placebo, which is used to treat gastric and duodenal ulcers.

[0005]

[0006] Currently, the main methods for synthesizing substituted methyl benzoylcarbamate are as follows:

[0007] 1. Obtained by direct esterification of substituted benzoylcarboxylic acid with methanol

[0008] The reaction equation is as follows:

[0009]

[0010] Patent CN11051143 reports a reaction using substituted benzoylformic acid and methanol as raw materials, undergoing esterification with concentrated sulfuric acid catalyst to obtain the product. While this route is simple, the raw materials are not readily available, and it is prone to a series of side reactions such as carbonization, oxidation, polymerization, isomerization, and addition, affecting the reaction yield and increasing the difficulty of product separation. This increases the separation cost of substituted benzoylformic acid methyl ester. Furthermore, the use of sulfuric acid generates a large amount of acidic water that is difficult to treat, posing a significant environmental burden and making it unsuitable for large-scale production.

[0011] 2. Preparation by oxidation of α-diazo esters

[0012] The reaction equation is as follows:

[0013]

[0014] Patent CN113149835 reports a synthetic method for rapidly generating substituted benzoylformate from α-diazo esters via iodine oxidation. This method is difficult to prepare diazo compounds, resulting in low yields and high costs for substituted benzoylformate, making large-scale production difficult.

[0015] 3. Preparation from benzoyl cyanide

[0016]

[0017] The equation is as follows:

[0018] Patent CN107473971 reports a method for preparing substituted benzoyl cyanate using substituted benzoyl cyanide. This method requires reacting substituted benzoyl chloride with highly toxic sodium cyanide to prepare substituted benzoyl cyanide. The reaction is risky, the waste is difficult to treat, and the environment is polluted, making it difficult to meet the requirements for large-scale production.

[0019] 4. Preparation from phenylethyl cyanide

[0020] The reaction equation is as follows:

[0021]

[0022] Patent CN109485566 reports a method for obtaining methyl substituted benzoylformate by chlorinating a substituted phenethyl cyanide, followed by hydrolysis and esterification. However, the raw material substituted phenethyl cyanide is not readily available, the preparation requires highly toxic sodium cyanide, and it involves a dangerous chlorination process, resulting in high production risks and significant risks for large-scale production. Summary of the Invention

[0023] The method described in the references first uses oxalic acid as a raw material, reacting it with phosphorus pentachloride to generate oxalyl chloride in a low cost and high yield, which serves as the initial raw material for this invention. This application discovers that using oxalyl chloride as a raw material, reacting it with a measured amount of sodium methoxide in a specific solvent and with an inhibitor, and controlling the reaction conditions, can generate high-purity and high-yield oxalyl chloride monomethyl ester. This monomethyl oxalyl chloride then undergoes a Friedel-Crafts reaction with a substituted aromatic compound under specific catalytic conditions to generate substituted aromatic formylformate methyl ester. Oxalic acid is readily available and inexpensive; phosphorus oxychloride and unreacted oxalic acid can be recycled. The synthesis of the key step, oxalyl chloride monomethyl ester, exhibits better selectivity than existing methods, with easily controllable process conditions, high yield, and suitability for large-scale production. The acylation reaction uses a specific catalyst to stably yield the corresponding target product. This route is safe and reasonable, with easily controllable process conditions and low overall cost, making it an economical and environmentally friendly synthetic route suitable for industrial production. The reaction process is as follows:

[0024]

[0025] In the above equation, R is a straight-chain or branched alkyl group containing 1-12 carbon atoms. This group can be 1-6 discontinuous oxygen atoms, nitrogen atoms, sulfur atoms, fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, silicon atoms, carbonyl groups, nitro groups, ester groups, double bonds, triple bonds, siloxy groups; R1 is a benzene-based aromatic compound or a heterocyclic compound such as pyridine, thiophene, N-methylpyrrole, N-ethylcarbazole, naphthalene, anthracene, biphenyl, etc.

[0026] To achieve the above-mentioned objectives, the technical solution of this invention is as follows:

[0027] 1. Preparation of oxalyl chloride monomethyl ester

[0028] Oxaloyl chloride monomethyl ester is prepared by esterification reaction of oxaloyl chloride and methanol at low temperature. The amount of sodium methoxide used is 0.5-2 equivalents, preferably 0.7-1.3 equivalents, and more preferably 0.8-1.0 equivalents. The reaction temperature is -20-50℃, preferably -10-20℃, and more preferably -5-5℃. The reaction time is 0.5-8 h, preferably 1-5 h, and more preferably 2-3 h.

[0029] The selected solvents include 1,2-dichloroethane, dichloromethane, trichloromethane, carbon tetrachloride, toluene, diethyl ether, acetone, tetrahydrofuran, cyclohexane, n-heptane, acetonitrile, and unsuitable solvents, among which dichloromethane is preferred.

[0030] The solvent selected for synthesizing oxaloyl chloride monomethyl ester has a water content of <0.2%, preferably <0.1%, and more preferably <0.05%.

[0031] The sodium methoxide selected for the synthesis of oxaloyl chloride monomethyl ester is solid sodium methoxide; a 30% sodium methoxide methanol solution is not acceptable.

[0032] The synthesis of oxaloyl chloride monomethyl ester employs reaction inhibitors to slow the reaction rate and facilitate control of reaction selectivity. The inhibitors are sodium sulfate, sodium chloride, sodium acetate, sodium formate, sodium nitrate, sodium carbonate, and sodium bicarbonate, with sodium sulfate being the preferred option.

[0033] The synthesis of oxaloyl chloride monomethyl ester involved the use of a reaction inhibitor in an amount of 0.05-0.2 equivalents, preferably 0.08-0.15 equivalents, and more preferably 0.09-0.1 equivalents.

[0034]

[0035] 2. Preparation of substituted aromatic formylformate methyl ester

[0036] Methyl substituted aromatic formylformate is prepared by a Friedel-Crafts reaction under specific catalytic conditions using oxaloyl chloride monomethyl ester and a substituted aromatic compound as raw materials. The selected catalyst includes one or a mixture of two of aluminum trichloride, ferric chloride, and zinc chloride, or aluminum trichloride, ferric chloride, and zinc chloride supported on a small amount of p-toluenesulfonic acid, with aluminum trichloride supported on p-toluenesulfonic acid being preferred.

[0037] The reaction temperature is -20-100℃, preferably -10-80℃, and more preferably 0-50℃. The reaction time is 0.5-25h, preferably 1-20h, and more preferably 2-15h. The selected solvents include 1,2-dichloroethane, dichloromethane, chloroform, carbon tetrachloride, toluene, cyclohexane, n-heptane, etc., with 1,2-dichloroethane being preferred.

[0038]

[0039] An exemplary synthesis is the preparation of the representative compound methyl benzoylformate (MBF). Starting with oxalic acid, oxalyl chloride is prepared, followed by esterification and Friedel-Crafts yielding MBF. This route is safe, has a high yield, and is environmentally friendly, providing a mild and efficient way to obtain the target product, thus possessing significant economic and environmental competitive advantages.

[0040]

[0041] Exemplary, and not limiting, compounds of substituted aromatic methylformate that can be prepared via the techniques disclosed in this application include, for example, the following structures:

[0042]

[0043] The technical solution of this invention involves preparing oxalyl chloride from oxalic acid, followed by reaction with a measured amount of sodium methoxide under specific solvent and inhibitor conditions. This process stably and efficiently yields the intermediate oxalyl chloride monomethyl ester. The oxalyl chloride monomethyl ester is then reacted with substituted aryl compounds under specific catalytic conditions to obtain a series of photoinitiator-substituted aromatic formylformate methyl esters. This series of products can be used in UV-curable coatings and inks. Detailed Implementation

[0044] The essence of the invention is further illustrated below with reference to specific embodiments:

[0045] Example 1

[0046]

[0047] Under nitrogen protection, 63.5 g (0.5 mol) of oxalyl chloride was dissolved in 32 mL of diethyl ether and added to a 250 mL reaction flask. 7 g of sodium sulfate was added, and the mixture was cooled to -5 to 0 °C. A mixture of 25.4 g (0.47 mol) of solid sodium methoxide and 40 mL of diethyl ether was slowly added in batches, controlling the reaction temperature to not exceed 0 °C. After the addition was complete, the reaction was maintained at 0 °C for 2 h. The generated salt was filtered off, the solvent was recovered by distillation, and further distillation yielded 50.8 g of oxalyl chloride monomethyl ester with a purity of 97.8% and a yield of 88.5%.

[0048] Example 2

[0049]

[0050] Under nitrogen protection, 63.5 g (0.5 mol) of oxalyl chloride was dissolved in 32 mL of tetrahydrofuran and added to a 250 mL reaction flask. 7 g of sodium sulfate was added, and the mixture was cooled to -5 to 0 °C. A mixture of 25.4 g (0.47 mol) of solid sodium methoxide and 40 mL of tetrahydrofuran was slowly added in batches, with the reaction temperature controlled to not exceed 0 °C. After the addition was complete, the reaction was maintained at 0 °C for 2 h. The generated salt was filtered off, the solvent was recovered by distillation, and further distillation yielded 45.1 g of oxalyl chloride monomethyl ester with a purity of 98.2% and a yield of 78.5%.

[0051] Example 3

[0052]

[0053] Under nitrogen protection, 63.5 g (0.5 mol) of oxalyl chloride was dissolved in 32 mL of dichloromethane and added to a 250 mL reaction flask. 7 g of sodium sulfate was added, and the mixture was cooled to -5 to 0 °C. A mixture of 25.4 g (0.47 mol) of solid sodium methoxide and 40 mL of dichloromethane was slowly added in batches, with the reaction temperature controlled to not exceed 0 °C. After the addition was complete, the reaction was maintained at 0 °C for 2 h. The generated salt was filtered off, the solvent was recovered by distillation, and further distillation yielded 53.4 g of oxalyl chloride monomethyl ester with a purity of 98.8% and a yield of 93%.

[0054] Example 4

[0055]

[0056] Under nitrogen protection, 63.5 g (0.5 mol) of oxalyl chloride was dissolved in 32 mL of dichloromethane and added to a 250 mL reaction flask. The mixture was cooled to -5 to 0 °C, and a mixture of 25.4 g (0.47 mol) of solid sodium methoxide and 40 mL of dichloromethane was slowly added in batches, controlling the reaction temperature to not exceed 0 °C. After the addition was complete, the reaction was maintained at 0 °C for 2 h. The generated salt was filtered off, the solvent was recovered by distillation, and further distillation yielded 47.7 g of oxalyl chloride monomethyl ester with a purity of 95.8% and a yield of 83%.

[0057] Example 5

[0058]

[0059] Under nitrogen protection, 63.5 g (0.5 mol) of oxalyl chloride was dissolved in 32 mL of dichloromethane and added to a 250 mL reaction flask. 2.9 g of sodium chloride was added, and the mixture was cooled to -5 to 0 °C. A mixture of 25.4 g (0.47 mol) of solid sodium methoxide and 40 mL of dichloromethane was slowly added in batches, with the reaction temperature controlled to not exceed 0 °C. After the addition was complete, the reaction was maintained at 0 °C for 2 h. The generated salt was filtered off, the solvent was recovered by distillation, and further distillation yielded 50.5 g of oxalyl chloride monomethyl ester with a purity of 96.8% and a yield of 87.9%.

[0060] Example 6

[0061]

[0062] Under nitrogen protection, 300 g of 1,2-dichloroethane was added to a 500 mL reaction flask, the temperature was lowered to 0-5 °C, and stirring was started. 63 g (0.47 mol) of aluminum trichloride and 30 g (0.38 mol) of benzene were added, and the mixture was stirred for 30 min after the addition was complete. 50 g of 0.41 mol of monomethyl oxalate chloride was slowly added dropwise to the mixture. After the addition was complete, the temperature was slowly raised to 20-25 °C and the reaction was carried out for 8 h. Samples were taken to check the reaction until the reactants were completely reacted. The mixture was then poured into 300 g of ice water and stirred to quench the reaction, keeping the temperature below 35 °C. The phases were separated, and the aqueous phase was extracted with solvent. The organic phases were combined, washed once with water, and separated again. The solvent was recovered from the organic phase under vacuum, and the product was collected by high-vacuum distillation, yielding 53.4 g of product with a purity of 99.1% and a yield of 84.8%.

[0063] Example 7

[0064]

[0065] Under nitrogen protection, 300 g of 1,2-dichloroethane was added to a 500 mL reaction flask, the temperature was lowered to 0-5 °C, and stirring was started. 63 g of aluminum trichloride loaded with p-toluenesulfonic acid (the p-toluenesulfonic acid loading in the aluminum trichloride was 2.5 wt%) and 30 g (0.38 mol) of pure benzene were added, and the mixture was stirred for 30 min after the addition was complete. 50 g of oxaloyl chloride monomethyl ester (0.41 mol) was slowly added dropwise to the mixture. After the addition was complete, the temperature was slowly raised to 20-25 °C and the reaction was carried out for 2 h. Samples were taken to check the reaction until the reactants were completely reacted. The mixture was then poured into 300 g of ice water and stirred to quench the reaction, controlling the temperature not to exceed 35 °C. The phases were separated, and the aqueous phase was extracted with solvent. The organic phases were combined, washed once with water, and separated again. The solvent was recovered from the organic phase under vacuum, and the product was collected by high-vacuum distillation, yielding 59.1 g of product with a purity of 99.1% and a yield of 93.9%.

[0066] Example 8

[0067]

[0068] Under nitrogen protection, 300 g of 1,2-dichloroethane was added to a 500 mL reaction flask, the temperature was lowered to 0-5 °C, and stirring was started. 63 g of aluminum trichloride loaded with p-toluenesulfonic acid (the p-toluenesulfonic acid loading in the aluminum trichloride was 2.5 wt%) and 75 g (0.38 mol) of N-ethylcarbazole were added, and the mixture was stirred for 30 min after the addition was complete. 50 g of oxaloyl chloride monomethyl ester (0.41 mol) was slowly added dropwise to the mixture. After the addition was complete, the mixture was kept at 10-15 °C for 3 h. Samples were taken to check the reaction until the reactants were completely reacted. The mixture was then poured into 300 g of ice water and stirred to quench the reaction, keeping the temperature below 35 °C. The phases were separated, and the aqueous phase was extracted with solvent. The organic phases were combined, washed once with water, and separated again. The solvent was recovered from the organic phase under vacuum, and the organic phase was desolventized under high vacuum. 300 g of ethanol was added for purification, yielding 101.8 g of product with a purity of 99.4% and a yield of 94.2%.

[0069] Example 9

[0070]

[0071] Under nitrogen protection, 300 g of 1,2-dichloroethane was added to a 500 mL reaction flask, the temperature was lowered to -5 to 0 °C, and stirring was started. 63 g of aluminum trichloride loaded with p-toluenesulfonic acid (the p-toluenesulfonic acid loading in the aluminum trichloride was 2.5 wt%) and 60 g (0.39 mol) of biphenyl were added, and the mixture was stirred for 30 min after the addition was complete. 50 g of 0.41 mol of monomethyl oxaloyl chloride was slowly added dropwise to the mixture, and the reaction was maintained at 30-45 °C for 4 h. Samples were taken to check the reaction until the reactants were completely reacted. The mixture was then poured into 300 g of ice water and stirred to quench the reaction, controlling the temperature not to exceed 35 °C. The phases were separated, the aqueous phase was extracted with solvent, the organic phases were combined, washed once with water, and separated again. The solvent was recovered from the organic phase under vacuum, and the organic phase was purified by adding 300 g of ethanol to obtain 89.8 g of product with a purity of 99.2% and a yield of 98.2%.

[0072] Example 10

[0073]

[0074] Under nitrogen protection, 300 g of 1,2-dichloroethane was added to a 500 mL reaction flask, the temperature was lowered to 0-5 °C, and stirring was started. 63 g of aluminum trichloride loaded with p-toluenesulfonic acid (the p-toluenesulfonic acid loading in the aluminum trichloride was 2.5 wt%) and 47 g (0.38 mol) of nitrobenzene were added, and the mixture was stirred for 30 min after the addition was complete. 50 g of oxaloyl chloride monomethyl ester (0.41 mol) was slowly added dropwise to the mixture. After the addition was complete, the mixture was kept at 0-5 °C for 2 h. A sample was taken to check for any change, and the mixture was quenched by stirring in 300 g of ice water, with the temperature controlled not to exceed 35 °C. The phases were separated, and the aqueous phase was extracted again with solvent. The organic phases were combined, washed once with water, and separated again. The solvent was recovered from the organic phase under vacuum, and the product was purified by adding 300 g of ethanol to obtain 36.2 g of product with a purity of 96.8% and a yield of 45.3%.

[0075] Example 11

[0076]

[0077] Under nitrogen protection, 300 g of 1,2-dichloroethane was added to a 500 mL reaction flask, the temperature was lowered to 0-5 °C, and stirring was started. 63 g of aluminum trichloride loaded with p-toluenesulfonic acid (the p-toluenesulfonic acid loading in the aluminum trichloride was 2.5 wt%) and 32 g (0.38 mol) of thiophene were added, and the mixture was stirred for 30 min after the addition was complete. 50 g of oxaloyl chloride monomethyl ester (0.41 mol) was slowly added dropwise to the mixture. After the addition was complete, the mixture was kept at 30-40 °C for 5 h. A sample was taken and tested until no change was observed. The mixture was then poured into 300 g of ice water and stirred to quench the reaction, with the temperature controlled not to exceed 35 °C. The phases were separated, and the aqueous phase was extracted again with solvent. The organic phases were combined, washed once with water, and separated again. The solvent was recovered from the organic phase under vacuum, and the product was collected by high-vacuum distillation, yielding 42.3 g of product with a purity of 95.3% and a yield of 65.4%.

[0078] Example 12

[0079]

[0080] Under nitrogen protection, 300 g of 1,2-dichloroethane was added to a 500 mL reaction flask, the temperature was lowered to 0-5 °C, and stirring was started. 63 g of aluminum trichloride loaded with p-toluenesulfonic acid (the p-toluenesulfonic acid loading in the aluminum trichloride was 2.5 wt%) and 46 g (0.38 mol) of thiophene were added, and the mixture was stirred for 30 min after the addition was complete. 50 g of oxaloyl chloride monomethyl ester (0.41 mol) was slowly added dropwise to the mixture. After the addition was complete, the mixture was kept at 40-50 °C for 6 h. A sample was taken for testing until no change was observed. The mixture was then poured into 300 g of ice water and stirred to quench the reaction, controlling the temperature not to exceed 35 °C. The phases were separated, and the aqueous phase was extracted again with solvent. The organic phases were combined, washed once with water, and separated again. The solvent was recovered from the organic phase under vacuum, and the organic phase was desolventized under high vacuum. 300 g of ethanol was added for purification, yielding 33.1 g of product with a purity of 95.8% and a yield of 42%.

[0081] It should be emphasized that the above embodiments are merely exemplary and not limiting. Based on the disclosure of this application, any adjustments or changes to the reaction conditions or parameters that a person skilled in the art might normally adopt will not deviate from the spirit of the invention. The scope of protection of this patent should be determined by the relevant claims.

Claims

1. A synthetic process for the preparation of substituted methyl aromatic formyl carboxylate by Friedel-Crafts reaction, characterized by, Includes the following steps: Oxalic acid and phosphorus pentachloride are reacted under appropriate conditions to prepare oxalyl chloride; The generated oxalyl chloride is then reacted with sodium methoxide in a solvent to prepare oxalyl chloride monomethyl ester. The synthesis of oxalyl chloride monomethyl ester uses a reaction inhibitor, namely sodium sulfate. The solvent selected for the synthesis of oxaloyl chloride monomethyl ester includes any one of the following nonprotic solvents: 1,2-dichloroethane, dichloromethane, chloroform, carbon tetrachloride, toluene, diethyl ether, acetone, cyclohexane, n-heptane, or acetonitrile. The water content of the solvent selected for the synthesis of oxaloyl chloride monomethyl ester is <0.2%. Oxaloyl chloride monomethyl ester reacts with an aromatic compound in the presence of a catalyst via a Friedel-Crafts reaction to yield substituted aromatic formylformate methyl ester, as shown in the following reaction formula: The reaction temperature of synthesizing oxalyl chloride monomethyl ester is -5-5°C. The amount of sodium methoxide used in the synthesis of oxaloyl chloride monomethyl ester is 0.5-2 equivalents; The sodium methoxide selected for the synthesis of oxaloyl chloride monomethyl ester was solid sodium methoxide. The amount of reaction inhibitor used in the synthesis of oxaloyl chloride monomethyl ester is 0.05-0.2 equivalents; The catalyst selected for the preparation of substituted aromatic formylformate was aluminum trichloride supported on p-toluenesulfonic acid, with the p-toluenesulfonic acid loading being 0.5-3 wt%. The substituted aromatic methyl formanoate compound is prepared by any one of the following formulas: 。 2. The synthetic method for preparing substituted aromatic formylformate by Friedel-Crafts reaction according to claim 1, characterized in that, The reaction time for synthesizing oxalyl chloride monomethyl ester is 0.5-8 h.

3. The method for preparing substituted aromatic formylformate methyl ester by Friedel-Crafts reaction according to claim 2, characterized in that, The reaction time for synthesizing oxaloyl chloride monomethyl ester is 1-5 h.

4. The method for preparing substituted aromatic formylformate methyl ester by Friedel-Crafts reaction according to claim 2, characterized in that, The reaction time for synthesizing oxaloyl chloride monomethyl ester is 2-3 hours.

5. The method for synthesizing substituted aromatic formylformate by Friedel-Crafts reaction according to claim 1, characterized in that, The amount of sodium methoxide used in the synthesis of oxaloyl chloride monomethyl ester is 0.7-1.3 equivalents.

6. The synthetic method for preparing substituted aromatic formylformate by Friedel-Crafts reaction according to claim 1, characterized in that, The amount of sodium methoxide used in the synthesis of oxaloyl chloride monomethyl ester is 0.8-1.0 equivalents.

7. The synthetic method for preparing substituted aromatic formylformate methyl ester by Friedel-Crafts reaction according to claim 1, characterized in that, The solvent selected for the synthesis of oxaloyl chloride monomethyl ester is dichloromethane, and the water content of the solvent selected for the synthesis of oxaloyl chloride monomethyl ester is <0.1%.

8. The method for preparing substituted aromatic formylformate methyl ester by Friedel-Crafts reaction according to claim 7, characterized in that, The solvent selected for the synthesis of oxaloyl chloride monomethyl ester is dichloromethane, and the water content of the solvent selected for the synthesis of oxaloyl chloride monomethyl ester is <0.05%.

9. The synthetic method for preparing substituted aromatic formylformate by Friedel-Crafts reaction according to claim 1, characterized in that, The amount of reaction inhibitor used in the synthesis of oxaloyl chloride monomethyl ester is 0.08-0.15 equivalents.

10. The method for preparing substituted aromatic formylformate methyl ester by Friedel-Crafts reaction according to claim 9, characterized in that, The amount of reaction inhibitor used in the synthesis of oxaloyl chloride monomethyl ester is 0.09-0.1 equivalents.

11. The method for preparing substituted aromatic formylformate methyl ester by Friedel-Crafts reaction according to claim 1, characterized in that, The reaction temperature for preparing substituted aromatic methylformylformate is -20~100℃; the reaction time is 0.5-25h.

12. The method for preparing substituted aromatic formylformate methyl ester by Friedel-Crafts reaction according to claim 11, characterized in that, The reaction temperature for preparing substituted aromatic methylformylformate is -10~80℃; the reaction time is 1-20h.

13. The method for preparing substituted aromatic formylformate methyl ester by Friedel-Crafts reaction according to claim 12, characterized in that, The reaction temperature for preparing substituted aromatic methylformylformate is 0~50℃; the reaction time is 2-15h.

14. The synthetic method for preparing substituted aromatic formylformate by Friedel-Crafts reaction according to claim 1, characterized in that, The solvents selected for preparing substituted aromatic methyl formanoates include any one of 1,2-dichloroethane, dichloromethane, chloroform, carbon tetrachloride, toluene, cyclohexane, or n-heptane.

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