Method for preparing adamantane ester by using microchannel reactor

Abstract

The invention provides a method for preparing adamantane ester by using a micro-channel reactor, which comprises the following steps: respectively dissolving adamantanecarboxylic acid and a hydroxyl sulfonic acid compound or a sodium sulfonate compound thereof in a solvent, and then carrying out esterification reaction under the action of an acidic material and an activating agent through the micro-channel reactor to obtain the adamantane ester. The reaction process is carried out at low temperature, the temperature is controllable, the product yield is high, and the production efficiency is high.

Description

Technical Field

[0001] The present invention belongs to the field of organic synthesis, and particularly relates to a method for preparing adamantane esters using a microchannel reactor. Background Art

[0002] Photoacid generators are an important component of photoresists. Photoacid generators generally consist of a sulfonium cation containing a phenyl group and an anion containing a sulfonic acid group. In particular, in high-end ArF and KrF photoresists, sulfonic acid anions containing adamantane ester groups are widely used because of their good compatibility with resins. Adamantane ester derivatives are an important component of the anions of photoacid generators (PAGs). Sulfonic acid anions containing adamantane ester groups are usually synthesized by the esterification reaction of adamantane acid with hydroxyl groups. Among these reactions, there are methods using acyl chlorides and methods using condensing agents for esterification. The method using acyl chlorides is rarely used industrially because of the instability of adamantane acyl chloride, and the method of esterification using a condensing agent easily produces some by-products of condensation, and generally the yield is not high, which limits its scale-up in industry. Summary of the Invention

[0003] Technical Problem to be Solved: The purpose of the present invention is to provide a method for preparing adamantane esters using a microchannel reactor, which can obtain adamantane esters with a high yield in a short time.

[0004] Technical Solution: A method for preparing adamantane esters using a microchannel reactor, comprising the following steps: S1. Dissolve adamantane formic acid, a hydroxyl sulfonic acid compound, its sodium sulfonate compound, and an acidic substance in a solvent to form a solution A with a mass fraction of 5 - 50 wt%; S2. Dissolve an activator in a solvent to form a solution B with a mass fraction of 5 - 50 wt%; S3. Mix solution A and solution B in a microchannel reactor and carry out a reaction to obtain an adamantane esterification product. Preferably, the adamantane carboxylic acid in S1 has a structure as shown in formula (1): Wherein, R 1 is H, -OH, and =O. Preferably, the hydroxyl sulfonic acid compound or its sodium sulfonate compound in S1 has a structure as shown in formula (2): Wherein, R 1 is H, F, methyl, ethyl, and trifluoromethyl, R 2 is H, F, methyl, ethyl, and trifluoromethyl, R 3H, Na and K, and n is 1 - 10. Preferably, the acidic substance in S1 is one or more of acetic acid, propionic acid or trifluoroacetic acid. Preferably, the activator in S2 is one or two of acetic anhydride or trifluoroacetic anhydride. Preferably, the reaction temperature in S3 is -20 - 0 °C, the residence time of the reaction is 1 - 30 min, and the reaction pressure is 0.5 - 3 Mpa. Preferably, the flow rate introduced in S3 is 0.8 - 45 mL / min, the diameter of the microchannel reactor is 0.2 - 10 mm, and the length of the microchannel reactor is 1 - 20 m. Preferably, the solvent is one or more of dichloromethane, dichloroethane, chloroform or trifluoroacetic acid. Preferably, the equivalent ratio of adamantane carboxylic acid to hydroxy sulfonic acid compounds is 1:1 - 1.5, the dosage of the acidic substance is 1 - 10 equivalents relative to adamantane acid, and the dosage of the activator is 0.2 - 3.0 equivalents of adamantane acid. Preferably, the volume ratio of solution A to solution B in S3 is 1:0.3 - 1.5. Preferably, the concentration of solution A in S1 is 5 - 20 wt%. Preferably, the concentration of solution B in S2 is 5 - 20 wt%. Preferably, solution A is introduced from flow path 1 and solution B is introduced from flow path 2. Preferably, the ratio of the introduction flow rates of solution A to solution B is 1:0.5 - 2. Beneficial effects: The present invention has the following advantages: 1. The present invention adopts a flow reaction. Compared with a batch reaction, due to the continuous flow of reactants and products, the reaction conditions are relatively uniform throughout the reaction process, and the desired compound can be obtained with high selectivity in a shorter time. 2. In the present invention, the reaction process is carried out at a low temperature and the temperature is controllable, with a high product yield and high production efficiency. 3. In the present invention, by applying a flow reaction system in the above reaction, when using an acid anhydride as an activator to catalyze the esterification reaction, the batch reaction system often has a situation where water absorption causes the activator to fail. The present invention can effectively suppress side reactions in a closed reaction system, and achieve obtaining the target sulfonic acid esterification compound with higher selectivity in a short time at low energy cost. Description of the Drawings Figure 1 It is a schematic structural diagram of a microchannel reactor: The reactor is composed of flow path 1, flow path 2, a converging part 3 and a reaction flow path 4; Figure 2It is the H-NMR test spectrum of adamantane ester; Figure 3 This is the LC-MS test spectrum of adamantane ester. DETAILED DESCRIPTION The present invention will be further described below in conjunction with embodiments, which are explanations of the present invention and are not limited to the following embodiments: Example 1 Reaction equation: A method for preparing adamantane ester using a microchannel reactor comprises the following steps: S1. Add adamantane carboxylic acid, sodium 2-hydroxyethanesulfonate and trifluoroacetic acid to a dichloromethane solution, wherein the equivalent ratio of adamantane carboxylic acid to sodium 2-hydroxyethanesulfonate is 1:1, and the amount of trifluoroacetic acid is relative to 1 equivalent of adamantane carboxylic acid to obtain 40 ml of a solution A with a concentration of 5 wt%; S2. Dissolve trifluoroacetic anhydride and acetic anhydride in a mass ratio of 2:3 in dichloromethane, wherein the trifluoroacetic anhydride and acetic anhydride are 0.2 equivalents of adamantane carboxylic acid in S1, to form 30 ml of a 5 wt % solution B; S3. Solution A and solution B are mixed in a microchannel reactor and reacted under a pressure of 0.5 MPa. The reactor has a diameter of 4 mm and a length of 3 m. Solution A is introduced through flow path 1 at a flow rate of 0.8 ml / min, and solution B is introduced through flow path 2 at a flow rate of 0.6 mL / min. The reaction temperature is -10°C and the reaction residence time is 10 min to obtain a diamond esterification product. Example 2 Reaction equation: A method for preparing adamantane ester using a microchannel reactor comprises the following steps: S1. Add adamantane carboxylic acid, sodium 2-hydroxyethanesulfonate and trifluoroacetic acid to a dichloromethane solution, wherein the equivalent ratio of adamantane carboxylic acid to sodium 2-hydroxyethanesulfonate is 1:1, and the amount of trifluoroacetic acid is relative to 1 equivalent of adamantane carboxylic acid to obtain 40 ml of a solution A with a concentration of 5 wt%; S2. Dissolve trifluoroacetic anhydride and acetic anhydride in a mass ratio of 2:3 in dichloromethane, wherein the trifluoroacetic anhydride and acetic anhydride are 3 equivalents of adamantane carboxylic acid in S1, to form 30 ml of a 5 wt % solution B; S3. Mix solution A and solution B in a microchannel reactor and carry out the reaction under a pressure of 0.5 MPa. The diameter of the reactor is 4 mm and the length is 3 m. Solution A is introduced through flow path 1 at a flow rate of 0.8 ml / min, and solution B is introduced through flow path 2 at a flow rate of 0.6 mL / min. The reaction temperature is -10 °C and the reaction residence time is 10 min to obtain the adamantane esterification product. Example 3 Reaction equation: A method for preparing adamantane esters using a microchannel reactor, comprising the following steps: S1. Add 1-adamantane carboxylic acid, 2-hydroxyethanesulfonic acid and acetic acid to dichloromethane solution. The equivalent ratio of adamantane carboxylic acid to 2-hydroxyethanesulfonic acid is 1:1.2, and the amount of acetic acid used is 5 equivalents relative to adamantane carboxylic acid to obtain 100 ml of solution A with a concentration of 15 wt%. S2. Dissolve trifluoroacetic anhydride in dichloromethane. Trifluoroacetic anhydride is 0.8 equivalent of adamantane carboxylic acid in S1 to form 20 ml of solution B with a mass fraction of 10 wt%. S3. Mix solution A and solution B in a microchannel reactor and carry out the reaction under a pressure of 1 MPa. The diameter of the reactor is 0.5 mm and the length is 2 m. Solution A is introduced through flow path 1 at a flow rate of 3.5 ml / min, and solution B is introduced through flow path 2 at a flow rate of 0.7 mL / min. The reaction temperature is -15 °C and the reaction residence time is 10 min to obtain the adamantane esterification product. Example 4 Reaction equation: A method for preparing adamantane esters using a microchannel reactor, comprising the following steps: S1. Add adamantane carboxylic acid, 1,1-difluoro-2-hydroxyethanesulfonate and trifluoroacetic acid to dichloromethane solution. The equivalent ratio of adamantane carboxylic acid to 2-hydroxyethanesulfonic acid is 1:1.1, and the amount of trifluoroacetic acid used is 4 equivalents relative to adamantane carboxylic acid to obtain 50 ml of solution A with a concentration of 18 wt%. S2. Dissolve trifluoroacetic anhydride in dichloromethane. Trifluoroacetic anhydride is 2 equivalents of adamantane carboxylic acid in S1 to form 50 ml of solution B with a mass fraction of 12 wt%. S3. Mix solution A and solution B in a microchannel reactor and carry out the reaction under a pressure of 1.2 MPa. The reactor has a diameter of 3 mm and a length of 2 m. Solution A is introduced through flow path 1 at a flow rate of 2.5 ml / min, and solution B is introduced through flow path 2 at a flow rate of 2.5 mL / min. The reaction temperature is -20 °C, and the reaction residence time is 20 min to obtain the adamantane esterification product. Example 5 Reaction equation: A method for preparing adamantane esters using a microchannel reactor, comprising the following steps: S1. Add adamantane formic acid, 1,1-difluoro-2-hydroxyethanesulfonate and trifluoroacetic acid to dichloromethane solution. The equivalent ratio of adamantane formic acid to 2-hydroxyethanesulfonic acid is 1:1.1, and the amount of trifluoroacetic acid used is 6 equivalents relative to adamantane formic acid to obtain 50 ml of solution A with a concentration of 18 wt%. S2. Dissolve trifluoroacetic anhydride in dichloromethane. The trifluoroacetic anhydride is 2 equivalents of the adamantane formic acid in S1 to form 50 ml of solution B with a mass fraction of 12 wt%. S3. Mix solution A and solution B in a microchannel reactor and carry out the reaction under a pressure of 1.2 MPa. The reactor has a diameter of 3 mm and a length of 2 m. Solution A is introduced through flow path 1 at a flow rate of 2.5 ml / min, and solution B is introduced through flow path 2 at a flow rate of 2.5 mL / min. The reaction temperature is -20 °C, and the reaction residence time is 20 min to obtain the adamantane esterification product. Example 6 Reaction equation: A method for preparing adamantane esters using a microchannel reactor, comprising the following steps: S1. Add adamantane formic acid, 1,1-difluoro-2-hydroxyethanesulfonate and trifluoroacetic acid to dichloromethane solution. The equivalent ratio of adamantane formic acid to 2-hydroxyethanesulfonic acid is 1:1.1, and the amount of trifluoroacetic acid used is 8 equivalents relative to adamantane formic acid to obtain 50 ml of solution A with a concentration of 18 wt%. S2. Dissolve trifluoroacetic anhydride in dichloromethane. The trifluoroacetic anhydride is 2 equivalents of the adamantane formic acid in S1 to form 50 ml of solution B with a mass fraction of 12 wt%. S3. Mix solution A and solution B in a microchannel reactor and carry out the reaction under a pressure of 1.2 MPa. The diameter of the reactor is 3 mm and the length is 2 m. Solution A is introduced through flow path 1 at a flow rate of 2.5 ml / min, and solution B is introduced through flow path 2 at a flow rate of 2.5 mL / min. The reaction temperature is -20 °C and the reaction residence time is 20 min to obtain the adamantane esterification product. Example 7 Reaction equation: A method for preparing adamantane esters using a microchannel reactor, comprising the following steps: S1. Add 4-oxo-adamantane carboxylic acid, 1,1-difluoro-2-trifluoromethyl-2-hydroxyethanesulfonate and trifluoroacetic acid to dichloromethane solution. The equivalent ratio of adamantane carboxylic acid to 1,1-difluoro-2-trifluoromethyl-2-hydroxyethanesulfonate is 1:1.5, and the amount of trifluoroacetic acid used is 7 equivalents relative to adamantane carboxylic acid to obtain 100 ml of solution A with a concentration of 8 wt%. S2. Dissolve trifluoroacetic anhydride in dichloromethane. The trifluoroacetic anhydride is 1 equivalent of the adamantane carboxylic acid in S1 to form 35 ml of solution B with a mass fraction of 5 wt%. S3. Mix solution A and solution B in a microchannel reactor and carry out the reaction under a pressure of 1.2 MPa. The diameter of the reactor is 1 mm and the length is 2 m. Solution A is introduced through flow path 1 at a flow rate of 25 ml / min, and solution B is introduced through flow path 2 at a flow rate of 25 mL / min. The reaction temperature is -5 °C and the reaction residence time is 30 min to obtain the adamantane esterification product. Example 8 Reaction equation: A method for preparing adamantane esters using a microchannel reactor, comprising the following steps: S1. Add 4-oxo-adamantane carboxylic acid, 1,1-difluoro-2-trifluoromethyl-2-hydroxyethanesulfonate and trifluoroacetic acid to dichloromethane solution. The equivalent ratio of adamantane carboxylic acid to 1,1-difluoro-2-trifluoromethyl-2-hydroxyethanesulfonate is 1:1.2, and the amount of trifluoroacetic acid used is 7 equivalents relative to adamantane carboxylic acid to obtain 100 ml of solution A with a concentration of 8 wt%. S2. Dissolve trifluoroacetic anhydride in dichloromethane. The trifluoroacetic anhydride is 1 equivalent of the adamantane carboxylic acid in S1 to form 35 ml of solution B with a mass fraction of 5 wt%. S3. Mix solution A and solution B in a microchannel reactor and carry out the reaction under a pressure of 1.2 MPa. The diameter of the reactor is 1 mm and the length is 2 m. Solution A is introduced through flow path 1 at a flow rate of 25 ml / min, and solution B is introduced through flow path 2 at a flow rate of 25 mL / min. The reaction temperature is -5 °C and the reaction residence time is 30 min to obtain the adamantane esterification product. Comparative Example 1 A method for preparing adamantane ester using a microchannel reactor, comprising the following steps: S1. Add 4-oxo-adamantane carboxylic acid, 1,1-difluoro-2-trifluoromethyl-2-hydroxyethanesulfonate and trifluoroacetic acid to dichloromethane solution. The equivalent ratio of adamantane carboxylic acid to 1,1-difluoro-2-trifluoromethyl-2-hydroxyethanesulfonate is 1:1.2, and the amount of trifluoroacetic acid used is 7 equivalents relative to adamantane formic acid to obtain 500 ml of solution A with a concentration of 8 wt%. S2. Dissolve trifluoroacetic anhydride in dichloromethane. The trifluoroacetic anhydride is 1 equivalent of the adamantane formic acid in S1 to form 165 ml of solution B with a mass fraction of 5 wt%. S3. Mix solution A and solution B in a microchannel reactor and carry out the reaction under a pressure of 1.2 MPa. The diameter of the reactor is 1 mm and the length is 2 m. Solution A is introduced through flow path 1 at a flow rate of 35 ml / min, and solution B is introduced through flow path 2 at a flow rate of 25 mL / min. The reaction temperature is 10 °C and the reaction residence time is 30 min to obtain the adamantane esterification product. Table 1 Influence of different reaction temperatures on product yield Name Reaction Temperature / °C Yield / % Example 8 0 83.5 Comparative Example 1 10 56.7 Comparative Example 2 A method for preparing adamantane ester using a microchannel reactor, comprising the following steps: S1. Add 1-hydroxyadamantane carboxylic acid, 2-hydroxyethanesulfonic acid and acetic acid to dichloromethane solution. The equivalent ratio of adamantane formic acid to 2-hydroxyethanesulfonic acid is 1:1.2, and the amount of acetic acid used is 5 equivalents relative to adamantane formic acid to obtain 100 ml of solution A with a concentration of 15 wt%. S2. Dissolve trifluoroacetic anhydride in dichloromethane. The trifluoroacetic anhydride is 0.8 equivalent of the adamantane formic acid in S1 to form 20 ml of solution B with a mass fraction of 10 wt%. S3. Mix solution A and solution B in a microchannel reactor and carry out the reaction under a pressure of 1 MPa. The diameter of the reactor is 0.5 mm and the length is 2 m. Solution A is introduced through flow path 1 at a flow rate of 3.5 ml / min, and solution B is introduced through flow path 2 at a flow rate of 0.7 mL / min. The reaction temperature is -15 °C and the reaction residence time is 38 min to obtain the adamantane esterification product. Table 2 Influence of Different Reaction Residence Times on Product Yield Name Reaction Residence Time / min Yield / % Example 3 10 90.5 Comparative Example 2 38 86.4 Comparative Example 3 A method for preparing adamantane ester using a microchannel reactor, comprising the following steps: S1. Add 4-oxo-adamantane carboxylic acid, 1,1-difluoro-2-trifluoromethyl-2-hydroxyethanesulfonate and trifluoroacetic acid into dichloromethane solution. The equivalent ratio of adamantane carboxylic acid to 1,1-difluoro-2-trifluoromethyl-2-hydroxyethanesulfonate is 1:1.8, and the dosage of trifluoroacetic acid is 7 equivalents relative to adamantane carboxylic acid, to obtain 100 ml of solution A with a concentration of 8 wt%. S2. Dissolve trifluoroacetic anhydride in dichloromethane. The amount of trifluoroacetic anhydride is 1 equivalent of the adamantane carboxylic acid in S1, to form 35 ml of solution B with a mass fraction of 5 wt%. S3. Mix solution A and solution B in the microchannel reactor and carry out the reaction under a pressure of 1.2 MPa. The diameter of the reactor is 1 mm and the length is 2 m. Solution A is introduced through flow path 1 at a flow rate of 25 ml / min, and solution B is introduced through flow path 2 at a flow rate of 25 mL / min. The reaction temperature is -5°C and the reaction residence time is 30 min, to obtain the adamantane esterification product. Table 3 Influence of Different Ratios of Adamantane Carboxylic Acid to 2-Hydroxyethanesulfonic Acid on Product Yield Name Ratio of Adamantanecarboxylic Acid to 2-Hydroxyethanesulfonic Acid Yield / % Example 7 1：1.5 90.4 Example 8 1：1.2 83.5 Comparative Example 3 1：1.8 75.6 Comparative Example 4 A method for preparing adamantane ester using a microchannel reactor, comprising the following steps: S1. Add adamantane carboxylic acid, 1,1-difluoro-2-hydroxyethanesulfonate and trifluoric acid into dichloromethane solution. The equivalent ratio of adamantane carboxylic acid to 2-hydroxyethanesulfonic acid is 1:1.1, and the dosage of trifluoroacetic acid is 12 equivalents relative to adamantane carboxylic acid, to obtain 50 ml of solution A with a concentration of 18 wt%. S2. Dissolve trifluoroacetic anhydride in dichloromethane. The amount of trifluoroacetic anhydride is 2 equivalents of the adamantane carboxylic acid in S1, to form 50 ml of solution B with a mass fraction of 12 wt%. S3. Mix solution A and solution B in the microchannel reactor and carry out the reaction under a pressure of 1.2 MPa. The diameter of the reactor is 3 mm and the length is 2 m. Solution A is introduced through flow path 1 at a flow rate of 2.5 ml / min, and solution B is introduced through flow path 2 at a flow rate of 2.5 mL / min. The reaction temperature is -20°C and the reaction residence time is 20 min, to obtain the adamantane esterification product. Table 4 Influence of the Equivalent Amount of Different Acidic Substances Relative to Adamantane Carboxylic Acid on Product Yield Name Equivalent of Acidic Substance Used Relative to Adamantanecarboxylic Acid Yield / % Example 4 4 85.4 Example 5 6 85.3 Example 6 8 90.3 Comparative Example 4 12 90.2 Comparative Example 5 A method for preparing adamantane ester using a microchannel reactor, comprising the following steps: S1. Add adamantane formic acid, 2-hydroxyethanesulfonic acid sodium salt and trifluoroacetic acid into dichloromethane solution. The equivalent ratio of adamantane formic acid to 2-hydroxyethanesulfonic acid sodium salt is 1:1, and the dosage of trifluoroacetic acid is 1 equivalent relative to adamantane formic acid, to obtain 40 ml of solution A with a concentration of 5 wt%. S2. Dissolve trifluoroacetic anhydride and acetic anhydride with a mass ratio of 2:3 in dichloromethane. The trifluoroacetic anhydride and acetic anhydride are 5 equivalents of adamantane formic acid in S1, to form 30 ml of solution B with a mass fraction of 5 wt%. S3. Mix solution A and solution B in a microchannel reactor and carry out the reaction under a pressure of 0.5 MPa. The diameter of the reactor is 4 mm and the length is 3 m. Solution A is introduced through flow path 1 at a flow rate of 0.8 ml / min, and solution B is introduced through flow path 2 at a flow rate of 0.6 mL / min. The reaction temperature is -10°C and the reaction residence time is 10 min to obtain the adamantane esterification product. Table 5 Influence of the dosage of activator relative to the equivalent of adamantane formic acid on the product yield Name Equivalent of Activator Used Relative to Adamantanecarboxylic Acid Yield / % Example 1 0.2 65.3 Example 2 3 89.6 Comparative Example 5 5 87.3 Comparative Example 6 In this comparative example, the adamantane ester is not prepared by a microchannel reactor, but by using the method of acyl chloride. The specific experimental steps are as follows: S11. Dissolve 15 g of 2-hydroxyethanesulfonic acid, 19 g of triethylamine and 1 g of DMAP in 150 ml of dichloromethane and cool to 0°C; S12. Dissolve 19 g of adamantane acyl chloride in 100 ml of dichloromethane, and then drop the adamantane acyl chloride / dichloromethane solution into the solution obtained in S11. Control the temperature at -5°C during the dropping process, and after the dropping is completed, naturally warm up to room temperature and react for 16 h; S13. Spin-dry the solution obtained in S12, add tert-butyl methyl ether for pulping, filter and dry to obtain the esterification product. Table 6 Influence of different synthesis methods on the product yield Name Synthesis Method Yield / % Example 2 Synthesis in a Microchannel Reactor 89.6 Comparative Example 6 Acyl Chloride Synthesis 56.4 Obviously, the above-mentioned embodiments are merely examples for clear illustration and not limitations on the implementation manners. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to enumerate all the implementation manners here. And the obvious changes or modifications derived therefrom are still within the protection scope of the present invention.

Claims

1. A method for preparing adamantane esters using a microchannel reactor, characterized in that: The method comprises the following steps: S1. dissolving adamantane carboxylic acid, a hydroxysulfonic acid compound or a sodium sulfonate compound thereof and an acidic substance in a solvent to form a solution A having a mass fraction of 5-50wt%; S2. The activator is dissolved in a solvent to form a solution B having a mass fraction of 5-50wt%; S3. Introduce solution A and solution B into a microchannel reactor, mix and react to obtain an adamantane esterification product.

2. The method for preparing adamantane esters using a microchannel reactor according to claim 1, characterized in that: The structure of adamantane carboxylic acid in S1 is shown in formula (1): Among them, R1 is H, -OH and =O.

3. The method for preparing adamantane esters using a microchannel reactor according to claim 1, characterized in that: The structure of the hydroxysulfonic acid compound or its sodium sulfonate compound in S1 is shown in formula (2): Among them, R1 is H, F, methyl, ethyl and trifluoromethyl, R2 is H, F, methyl, ethyl and trifluoromethyl, R3 is H, Na and K, and n is 1-10.

4. The method for preparing adamantane esters using a microchannel reactor according to claim 1, characterized in that: The acidic substance in S1 is one or more of acetic acid, propionic acid or trifluoroacetic acid.

5. The method for preparing adamantane esters using a microchannel reactor according to claim 1, characterized in that: The activating agent in S2 is one or both of acetic anhydride and trifluoroacetic anhydride.

6. The method for preparing adamantane esters using a microchannel reactor according to claim 1, characterized in that: The reaction temperature in S3 is -20-0°C, the reaction residence time is 1-30 min, and the reaction pressure is 0.5-5 MPa.

7. The method for preparing adamantane esters using a microchannel reactor according to claim 1, characterized in that: The flow rate introduced into S3 is 0.8-45 mL / min, the inner diameter of the microchannel reactor is 0.2-10 mm, and the length of the microchannel reactor is 1-20 m.

8. The method for preparing adamantane esters using a microchannel reactor according to claim 1, characterized in that: The solvent is one or more of dichloromethane, dichloroethane, chloroform or trifluoroacetic acid.

9. The method for preparing adamantane esters using a microchannel reactor according to claim 1, characterized in that: The equivalent ratio of the adamantane carboxylic acid to the hydroxysulfonic acid compound is 1:1-1.5, the amount of the acidic substance used is 1-10 equivalents of the adamantane carboxylic acid, and the amount of the activator used is 0.2-3.0 equivalents of the adamantane carboxylic acid.

10. The method for preparing adamantane esters using a microchannel reactor according to claim 1, characterized in that: The volume ratio of solution A to solution B in S3 is 1:0.3-1.5.

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