Preparation method of photoacid generator (4, 7-dihydroxy-1-naphthyl) dimethyl sulfonium trifluoromethanesulfonate

Abstract

The invention provides a preparation method of a light-induced acid generator (4, 7-dihydroxy-1-naphthyl) dimethyl sulfonium trifluoromethanesulfonate. The preparation method comprises the following steps: adding a catalyst into a reaction kettle; compared with the prior art, the intermediate in the preparation method provided by the invention does not need to be purified and is directly used for the second-step reaction, and after the second-step reaction is finished, impurities can be directly separated and removed by utilizing the solubility difference of the intermediate in a corresponding solvent (ethyl acetate), so that the operation process is greatly simplified, and the production cost is reduced. The method provided by the invention improves the treatment efficiency, is beneficial to industrial large-scale production, and at the same time, the purity of the final product reaches 99.99%, and the yield reaches 69.16%.

Description

Technical Field

[0001] The invention belongs to the technical field of photolithography materials, and in particular relates to a method for preparing a photoacid generator (4,7-dihydroxy-1-naphthyl) dimethylsulfonium trifluoromethanesulfonate. Background Art

[0002] Photoacid generator is the core component of chemically amplified photoresist system. When it is exposed to light of a specific wavelength, it can decompose to produce protons (H+) or other strong acidic substances. When a light source of a specific wavelength is used to irradiate a wafer coated with photoresist, the photoacid generator decomposes under the excitation of light to generate strong acid. The generated acid can catalyze subsequent chemical reactions. Specifically, after the acid catalysis of the photoresist in the exposed area, the cross-linking or solubility performance of the photoresist is promoted, so that the specific area can be dissolved by the developer during the development process, thereby realizing the transfer of the pattern.

[0003] The photoacid generator (4,7-dihydroxy-1-naphthyl) dimethylsulfonium trifluoromethanesulfonate commonly used in chemically amplified photoresist systems has a current preparation method that uses perchloric acid and phosphorus oxychloride. The process has dangerous materials and complicated operations, and cannot be industrially scaled up; the process uses N-chlorosuccinimide and dimethyl sulfide. The dimethyl sulfide in this process has a strong odor and is not environmentally friendly. In addition, N-chlorosuccinimide and dimethyl sulfide need to be reacted into an intermediate state before subsequent reactions can be carried out, and the operation is complicated; there is also a method that uses Lewis acids such as aluminum trichloride and hydrogen chloride, but the selectivity of Lewis acids is not good. The substituents on the product structure will cause the newly attached groups to be positioned on different atoms, ultimately resulting in an increase in isomers in the product that affects purity. At the same time, the reaction of Lewis acids requires harsh conditions, generally requiring low temperature and anhydrous conditions. The reaction is difficult to control and the cost is high, which is not conducive to industrial production. Summary of the invention

[0004] In order to solve the problems in the prior art, the present invention provides a method for preparing a photoacid generator (4,7-dihydroxy-1-naphthyl) dimethylsulfonium trifluoromethanesulfonate.

[0005] The specific technical solutions of the present invention are as follows:

[0006] The present invention provides a method for preparing a photoacid generator (4,7-dihydroxy-1-naphthyl) dimethylsulfonium trifluoromethanesulfonate, characterized in that the route of the preparation method is:

[0007] first step,

[0008] Step 2:

[0009] Specifically, in the first step, 1,6-dihydroxynaphthalene, dimethyl sulfoxide and methanol are added to a reaction container, stirred to dissolve and clarify, the reaction system is cooled to -5±5°C under nitrogen protection, and HCl gas is introduced therein. After the reaction is completed, (4,7-dihydroxy-1-naphthyl)dimethylsulfonium chloride is obtained.

[0010] Specifically, in the second step, (4,7-dihydroxy-1-naphthyl)dimethylsulfonium chloride, sodium trifluoromethanesulfonate and acetone are added to another reaction container, and mechanical stirring is performed to obtain (4,7-dihydroxy-1-naphthyl)dimethylsulfonium trifluoromethanesulfonate after the reaction is complete.

[0011] The present invention also provides a compound used in the above preparation method, characterized in that the molecular structure of the compound is:

[0012] The present invention also provides a method for preparing the above compound, characterized in that the route of the preparation method is: Functions and Effects of the Invention

[0013] Compared with the prior art, the preparation method of the photoacid generator (4,7-dihydroxy-1-naphthyl) dimethylsulfonium trifluoromethanesulfonate provided by the present invention has the following technical advantages:

[0014] The intermediate can be directly used in the second step reaction without purification. After the second step reaction, the impurities can be directly separated and removed by utilizing the difference in solubility in the corresponding solvent (ethyl acetate), which greatly simplifies the operation process, improves the processing efficiency, and is conducive to large-scale industrial production. At the same time, the purity of the final product reaches 99.99% and the yield reaches 69.16%. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is the HNMR spectrum of the compound (4,7-dihydroxy-1-naphthyl)dimethylsulfonium chloride prepared in the embodiment of the present invention.

[0016] Figure 2 It is the HNMR spectrum of the compound (4,7-dihydroxy-1-naphthyl) dimethylsulfonium trifluoromethanesulfonate prepared in the embodiment of the present invention. DETAILED DESCRIPTION

[0017] The terms used in the present invention generally have the meanings commonly understood by those of ordinary skill in the art unless otherwise specified.

[0018] In the following examples, various processes and methods not described in detail are conventional methods well known in the art.

[0019] The reagents used in the following examples were purchased from common commercial sources, and the experimental operations and experimental conditions not specified were referred to the conventional operations and conventional conditions in the art.

[0020] The specific implementation of the present invention is described below in conjunction with embodiments and drawings.

[0021] <Example>

[0022] This embodiment provides a method for preparing a photoacid generator (4,7-dihydroxy-1-naphthyl) dimethylsulfonium trifluoromethanesulfonate. The route of the preparation method is:

[0023] first step,

[0024] The specific process is:

[0025] Add 5kg of 1,6-dihydroxynaphthalene, 2.56kg of dimethyl sulfoxide, and 20kg of methanol to a 50L reactor, stir to dissolve and clarify, cool the reaction system to -5±5°C under nitrogen protection, and then slowly introduce HCl gas into it. Control the temperature at -5±5°C and react until a large amount of solid precipitates. Monitor the reaction progress by TLC until the reaction of the raw materials is complete.

[0026] 19 kg of methyl tert-butyl ether was added to the system, and the mixture was stirred for 30 min and filtered. The filter cake was washed with 5 L of methyl tert-butyl ether, and the filter cake was collected and dried to obtain 8 kg of off-white solid (compound (4,7-dihydroxy-1-naphthyl) dimethylsulfonium chloride), with a yield of 99.8%. The obtained off-white solid was used directly for the next step without purification.

[0027] The obtained (4,7-dihydroxy-1-naphthyl) dimethylsulfonium chloride was characterized by HNMR, LC-MS, and HPLC tests, and the results are as follows:

[0028] Figure 1 It is the HNMR spectrum of the compound (4,7-dihydroxy-1-naphthyl)dimethylsulfonium chloride prepared in the embodiment of the present invention.

[0029] HNMR spectrum analysis of compound (4,7-dihydroxy-1-naphthyl)dimethylsulfonium chloride: 1H NMR (400MHz, DMSO-d6) δ11.60 (s, 1H), 10.59 (s, 1H), 8.22 (d, J = 8.5 Hz, 1H), 8.15 (d, J = 9.1 Hz, 1H), 7.46 (d, J = 2.2 Hz, 1H), 7.22 (dd, J = 4.5, 2.4 Hz, 1H), 7.01 (d, J = 8.4 Hz, 1H), 3.30 (s, 6H).

[0030] The molecular structure of the compound (4,7-dihydroxy-1-naphthyl) dimethylsulfonium chloride is:

[0031] LC-MS (ES-): M-220.8. HPLC purity: 85.8%.

[0032] Step 2:

[0033] The specific process is:

[0034] Add 4 kg (4,7-dihydroxy-1-naphthyl) dimethylsulfonium chloride, 3.5 kg sodium trifluoromethanesulfonate and 32 kg acetone into a 50L four-necked bottle. Stir mechanically at room temperature (25±5°C) for 48 hours and spot on TLC plate until no (4,7-dihydroxy-1-naphthyl) dimethylsulfonium chloride remains.

[0035] The solid sodium chloride was removed by filtration, and the filtrate was concentrated until a large amount of solid precipitated, and the dissolution was stopped. The filter cake was collected by filtration, and the filter cake was rinsed twice with ethyl acetate until a white solid was obtained. The mother liquor was further concentrated until solid precipitated, and the filtration was continued, and the filter cake was rinsed with ethyl acetate. The solids collected twice were combined and dried to obtain 4 kg of the product (compound (4,7-dihydroxy-1-naphthyl) dimethylsulfonium trifluoromethanesulfonate), with a yield of 69.3%.

[0036] The obtained (4,7-dihydroxy-1-naphthyl) dimethylsulfonium trifluoromethanesulfonate was characterized by HNMR, LC-MS, and HPLC tests, and the results are as follows:

[0037] Figure 2 It is the HNMR spectrum of the compound (4,7-dihydroxy-1-naphthyl) dimethylsulfonium trifluoromethanesulfonate prepared in the embodiment of the present invention.

[0038] HNMR spectrum analysis of compound (4,7-dihydroxy-1-naphthyl) dimethylsulfonium trifluoromethanesulfonate: 1H NMR (400MHz, DMSO-d6) δ11.43 (s, 1H), 10.46 (s, 1H), 8.18 (t, J = 8.4 Hz, 2H), 7.41 (d, J = 2.2 Hz, 1H), 7.20 (dd, J = 9.2, 2.3 Hz, 1H), 6.93 (d, J = 8.5 Hz, 1H), 3.27 (s, 6H).

[0039] The molecular structure of the compound (4,7-dihydroxy-1-naphthyl) dimethylsulfonium trifluoromethanesulfonate is:

[0040] LC-MS (ES-): M-220.6, LC-MS (ES+): M+148.8. HPLC purity: 99.99%.

[0041] The above is a detailed description of the embodiments, which is convenient for those skilled in the art to correctly understand and use the present invention. Any improvements or modifications to the technical solutions obtained by those skilled in the art based on the present invention on the basis of the prior art, without innovative work, only through analysis, analogy or limited enumeration, etc., should be within the scope of protection determined by the claims.

Claims

1. A method for preparing a photoacid generator (4,7-dihydroxy-1-naphthyl) dimethylsulfonium trifluoromethanesulfonate, characterized in that: The route of the preparation method is: first step, Step 2:

2. A compound for use in the preparation method according to claim 1, characterized in that: The molecular structure of the compound is:

3. A method for preparing the compound as claimed in claim 2, characterized in that: The route of the preparation method is:

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