阅读说明：本技术 一种对乙酰氧基苯乙烯的合成方法 (Synthesis method of p-acetoxystyrene ) 是由 刘显伟 马青松 吴国印 刘娇 王晓莹 马心旺 于 2020-11-20 设计创作，主要内容包括：本发明公开了一种对乙酰氧基苯乙烯的合成方法,包括：对溴苯酚经乙酰化反应生成4-乙酰氧基溴苯,然后4-乙酰氧基溴苯与乙烯基硼酸类化合物得到对乙酰氧基苯乙烯。该方法反应条件温和,收率高,环境友好,适合工业化生产。(The invention discloses a method for synthesizing p-acetoxystyrene, which comprises the following steps: and (3) carrying out acetylation reaction on the p-bromophenol to generate 4-acetoxybromobenzene, and then obtaining the p-acetoxystyrene by using the 4-acetoxybromobenzene and a vinyl boric acid compound. The method has the advantages of mild reaction conditions, high yield, environmental friendliness and suitability for industrial production.)

1. A method for synthesizing p-acetoxystyrene comprises the following steps: 4-acetoxybromobenzene and a compound of formula (I) are subjected to catalytic coupling reaction to obtain 4-acetoxystyrene, wherein the structural formula of the compound of formula (I) is shown in the specification

The structural formula of R is as follows:

。

2. the method as claimed in claim 1, wherein the coupling reaction of 4-acetoxybromobenzene with the compound of formula (I) is carried out in the presence of organic solvent and alkali under the action of catalyst to obtain p-acetoxystyrene.

3. The process of claim 2, wherein the catalyst is a combination of one or more of tetrakis triphenylphosphine palladium, [1,1' -bis (diphenylphosphino) ferrocene ] dichloropalladium, palladium acetate, and tris (dibenzylideneacetone) dipalladium.

4. The process according to claim 2, characterized in that the base is an organic or inorganic base or a mixture thereof, selected from tertiary amines, alkali metal alkoxides, alkali metal carbonates, alkali metal fluorides, alkali metal phosphates, alkali metal hydrogen phosphates and alkali metal hydroxides.

5. The method according to claim 2, wherein the organic solvent is one or a combination of methanol, ethanol, acetonitrile, dichloromethane, dichloroethane, dimethylformamide, dimethylacetamide, dimethylsulfoxide, tetrahydrofuran, toluene, and xylene.

6. The method according to claim 1 or 2, wherein the molar ratio of the 4-acetoxybromobenzene to the compound of formula (I) is 1: 1-3, preferably 1: 1-1.5; the molar ratio of the 4-acetoxybromobenzene to the catalyst is 1: 0.0005-0.01, preferably 1: 0.005-0.01; the molar ratio of the 4-acetoxybromobenzene to the alkali is 1: 1-5, preferably 1: 1.5-3; the reaction temperature is 20-150 ℃, and preferably 50-100 ℃.

7. The method according to any one of claims 1 to 6, further comprising subjecting the bromophenol to acetylation to produce 4-acetoxybromobenzene.

8. The process according to claim 7, characterized in that p-bromophenol is reacted with an acetylating agent, which is acetyl chloride or acetic anhydride or a mixture thereof, to produce 4-acetoxybromobenzene.

9. The method according to claim 7 or 8, characterized in that a solvent is optionally added to the reaction system; the solvent is selected from one or the combination of esters, carbonates, ketones, ethers, halogenated alkanes and acids.

10. The method according to any one of claims 1 to 9, comprising subjecting bromophenol to acetylation reaction to produce 4-acetoxybromobenzene; then 4-acetoxybromobenzene and a compound of formula (I) are subjected to palladium catalytic coupling reaction to obtain 4-acetoxystyrene, wherein the structural formula of the compound of formula (I)R is as defined in claim 1.

Technical Field

The invention belongs to the field of chemical synthesis, and particularly relates to a synthesis method of p-acetoxystyrene.

Background

The photoresist is a mixed liquid which is composed of three main components of photosensitive resin, sensitizer (visible spectrum sensitizing dye) and solvent and is sensitive to light. After the photosensitive resin is irradiated by light, the photocuring reaction can be quickly carried out in an exposure area, so that the physical properties of the material, particularly the solubility, the affinity and the like are obviously changed. The soluble fraction is dissolved away by treatment with a suitable solvent to give the desired image. 248nm deep ultraviolet photoresist is the mainstream photoresist product in the world at present and is one of the key materials for manufacturing photoetching integrated circuits and chips. The main component of the photoresist is poly-p-hydroxystyrene, which can be used for preparing various materials such as chemical adhesives, coatings and the like besides the application in the field of microelectronics. The p-acetoxystyrene is an important intermediate for synthesizing the poly-p-hydroxystyrene, so that the research on the synthetic method of the p-acetoxystyrene and the optimization of the synthetic process conditions are of great significance.

The synthesis method of p-acetoxystyrene reported at present mainly uses p-hydroxyacetophenone as a raw material and is prepared by multi-step reaction.

Xiaoping et al (fine chemical engineering, 2011,28(9):920-923) use 4-hydroxyacetophenone as raw material, and obtain the compound p-acetoxystyrene through acetylation, catalytic hydrogenation and dehydration reaction. The yield of the method is too low, and the total yield is only 68.5 percent.

CN110655462 discloses that p-acetoxystyrene is obtained by acetylation, hydrogenation reduction and alkaline dehydration reaction of p-hydroxyacetophenone serving as a raw material. The method needs strong alkali to obtain high yield in the dehydration reaction, and if weak alkali is used, the yield is obviously reduced. However, the dehydration reaction is carried out by using strong alkali, a large amount of three wastes are generated, and environmental pollution is caused.

CN111087303 discloses that p-acetoxy phenylethanol is used as raw material, solid acid is used as catalyst, and p-acetoxy styrene is prepared by one-pot boiling method in the presence of polymerization inhibitor. Although the method has simple steps, the reaction raw material p-acetoxy phenethyl alcohol is not easy to obtain, and the yield is not high and is lower than 78 percent.

Disclosure of Invention

Aiming at the problems in the prior art, the invention provides a novel method for synthesizing p-acetoxystyrene by adopting 4-acetoxybromobenzene and vinyl boric acid compounds, which has high yield and is environment-friendly and more suitable for industrial production.

A method for synthesizing p-acetoxystyrene comprises the following steps: 4-acetoxybromobenzene reaction with formula (I)The compound is subjected to coupling reaction to obtain 4-acetoxystyrene, wherein the structural formula of the compound in the formula (I) is shown in the specificationThe reaction formula is as follows:

the structural formula of R is as follows:

further, in the presence of an organic solvent and alkali, 4-acetoxybromobenzene and a compound of a formula (I) are subjected to Heck reaction under the action of a catalyst to obtain p-acetoxystyrene,

the catalyst is one or a combination of more of tetratriphenylphosphine palladium, [1,1' -bis (diphenylphosphino) ferrocene ] palladium dichloride, palladium acetate and tris (dibenzylideneacetone) dipalladium.

The base is an organic base or an inorganic base or a mixture thereof. Such organic bases include, but are not limited to, tertiary amines such as triethylamine, tripropylamine, pyridine, N-methylpyrrolidine, N-ethylpyrrolidine, N-methylpiperidine, and the like; alkali metal alkoxides such as sodium methoxide, sodium ethoxide, sodium tert-butoxide, potassium tert-butoxide, and the like. The inorganic base includes, but is not limited to, alkali metal carbonates such as sodium carbonate, potassium carbonate, and the like; alkali metal fluorides such as potassium fluoride, sodium fluoride and the like; alkali metal phosphates such as sodium phosphate, potassium phosphate and the like; alkali metal hydrogen phosphates such as disodium hydrogen phosphate, dipotassium hydrogen phosphate and the like; alkali metal hydroxides such as sodium hydroxide, potassium hydroxide and the like.

The organic solvent is selected from one or the combination of methanol, ethanol, acetonitrile, dichloromethane, dichloroethane, dimethylformamide, dimethylacetamide, dimethylsulfoxide, tetrahydrofuran, toluene and xylene.

The molar ratio of the 4-acetoxybromobenzene to the compound of the formula (I) is 1: 1-3, and preferably 1: 1-1.5.

The molar ratio of the 4-acetoxybromobenzene to the catalyst is 1: 0.0005-0.01, and preferably 1: 0.005-0.01.

The molar ratio of the 4-acetoxybromobenzene to the alkali is 1: 1-5, and preferably 1: 1.5-3.

The reaction temperature is 20-150 ℃, and preferably 50-100 ℃.

Further, the synthesis method of the p-acetoxystyrene also comprises the steps of distillation and the like.

The coupling reaction time is adjusted by a person skilled in the art according to conventional experimental methods (e.g. thin layer chromatography, liquid chromatography), and preferably the reaction time is 4-30 hours.

In some embodiments, the method for synthesizing p-acetoxystyrene further comprises acetylating p-bromophenol to produce 4-acetoxybromobenzene. The reaction formula is as follows:

preferably, the method for synthesizing the p-acetoxyphenylacetyl further comprises reacting the p-bromophenol with an acetylation reagent to generate the 4-acetoxybromobenzene.

The acetylation reagent is acetyl chloride or acetic anhydride or a mixture thereof.

The molar ratio of the p-bromophenol to the acetylation reagent is 1: 1-10, preferably 1: 1-3.

In a preferred embodiment, p-bromophenol is reacted with acetyl chloride in the presence of an acid scavenger and an organic solvent to give 4-acetoxybromobenzene.

The acid-binding agent is an organic base and/or an inorganic base, and the organic base is preferably tert-butylamine, such as triethylamine, tripropylamine, tributylamine, dimethylisopropylamine, diisopropylethylamine, 4-methylmorpholine, 4-ethylmorpholine, N-methylpyrrolidine, N-ethylpyrrolidine, N-methylpiperidine, N-ethylpiperidine, and the like. The inorganic base is an alkali metal carbonate such as sodium carbonate, potassium carbonate, or the like.

The solvent is selected from esters, such as ethyl acetate, propyl acetate, and the like; carbonates such as methyl carbonate, ethyl carbonate, etc.; ketones such as butanone, hexanone, and the like; ethers such as tetrahydrofuran; haloalkanes such as dichloromethane, chloroform, and the like; acids such as acetic acid and the like; or a combination thereof.

The molar ratio of the p-bromophenol to the acid-binding agent is 1: 1-5, preferably 1: 1-2.5.

In another preferred embodiment, p-bromophenol is reacted with acetic anhydride to give 4-acetoxybromobenzene. The reaction system may or may not contain a solvent.

In the acetylation reaction, the reaction temperature is 0-180 ℃, and when the acetylation reagent is acetyl chloride, the reaction temperature is 0-50 ℃; when the acetylation reagent is acetic anhydride, the reaction temperature is 100-180 ℃.

The acetylation time is adjusted by the skilled person according to conventional experimental methods (such as thin layer chromatography and liquid chromatography), and preferably the reaction time is 1-10 h.

In a particularly preferred embodiment, the synthesis of p-acetoxystyrene comprises acetylating p-bromophenol to produce 4-acetoxybromobenzene; then 4-acetoxybromobenzene and a compound of a formula (I) are subjected to coupling reaction to obtain p-acetoxystyrene, wherein the structural formula of the compound of the formula (I) isR is as defined above. The reaction formula is as follows:

compared with the prior art, the method creatively adopts the 4-acetoxybromobenzene to perform coupling reaction with the ethylene boric acid to obtain the p-acetoxystyrene, and has the advantages of mild reaction conditions, high yield and little environmental pollution.

Detailed Description

Example 1

In a 1L reaction flask, 450g of ethyl acetate, p-bromophenol (86.5g, 0.5mol), and sodium carbonate (63.6g, 0.6mol) were sequentially added. Stirring was turned on and acetyl chloride (58.8g, 0.75mol) was added dropwise while maintaining the temperature at 0 ℃. After the dropwise addition, the mixture is kept at the temperature and stirred for 8 hours, then the mixture is washed for 3 times by water, kept stand and layered, and the organic layer is distilled to recover the solvent, so that 98g of light brown liquid, namely the 4-acetoxybromobenzene, is obtained, the yield is 91 percent, and the purity is 96.0 percent.

4-Acetooxybromine (107.5g, 0.5mol), vinylboronic acid (39.5g, 0.55mol) and tetratriphenylphosphine palladium (2.9g, 2.5mmol), sodium phosphate (163.9g, 1.0mol), ethanol (500mL) were added to the reaction flask and mixed with stirring. Then, the reaction was carried out at 100 ℃ for 12 hours. After the reaction, the mixture is cooled to room temperature, washed and kept stand for layering, the organic phase is dried over anhydrous magnesium sulfate overnight, and the organic phase is distilled after filtration to obtain 72.9g of colorless liquid, namely the p-acetoxystyrene, wherein the yield is 91 percent, and the purity is 94.9 percent.

¹H NMR(CDCl3)δ＝7.51(m,2H),7.11(m,2H),6.74(dd,1H),5.81(dd,1H),5.26(dd,1H),2.26(s,3H).

Example 2

In a 2L reaction flask, 600g of methylene chloride, p-bromophenol (86.5g, 0.5mol), and triethylamine (65.7g, 0.65mol) were sequentially added. Stirring was turned on and acetyl chloride (51g, 0.65mol) was added dropwise while maintaining the temperature at 10 ℃. After the dropwise addition, stirring at room temperature for 6 hours, washing with 10% sodium bicarbonate water solution for 3 times, standing for layering, separating out an organic phase, drying over night through anhydrous magnesium sulfate, filtering, and distilling the organic layer to recover the solvent to obtain 101g of light brown liquid, namely the 4-acetoxybromobenzene, wherein the yield is 94% and the purity is 96.5%.

To a reaction flask were added 4-acetoxybromobenzene (107.5g, 0.5mol), vinyl borate (101.4g, 0.6mol) and palladium acetate (0.9g, 4mmol), potassium carbonate (82.9g, 0.6mol), dichloroethane (500 mL). The mixture was stirred and then reacted at 80 ℃ for 24 hours. After the reaction, the reaction product is cooled to room temperature, washed with water, kept stand for layering, and the organic phase is distilled to obtain 73.4g of colorless liquid, namely the p-acetoxystyrene, wherein the yield is 90 percent, and the purity is 94.0 percent.

Example 3

Para-bromophenol (86.5g, 0.5mol) and acetic anhydride (61.2g, 0.6mol) were sequentially added to a 500mL reaction flask, and the reaction was stirred for 2 hours while maintaining the temperature at 180 ℃. After the reaction is finished, reduced pressure distillation is carried out to obtain 102g of red brown oil-filled liquid, namely the 4-acetoxybromobenzene, the yield is 95%, and the purity is 95.8%.

4-acetoxybromobenzene (107.5g, 0.5mol), potassium vinyltrifluoroborate (87.1g, 0.65mol) and [1,1' -bis (diphenylphosphino) ferrocene ] dichloropalladium (3.9g, 5mmol), sodium carbonate (127.2g, 1.2mol), dimethylformamide (500mL) were charged into a reaction flask, mixed and stirred, and then reacted at 100 ℃ for 8 hours. After the reaction, the mixture is cooled to room temperature, washed and kept stand for layering, and the organic phase is dried by anhydrous magnesium sulfate and distilled to obtain 74.2g of colorless liquid, namely the p-acetoxystyrene, wherein the yield is 91 percent, and the purity is 93.8 percent.

The foregoing description of specific embodiments of the present invention has been presented. It is to be understood that the invention is not limited to the embodiments described above, which are described in the specification only to illustrate the principles of the invention. The invention also includes various insubstantial changes and modifications within the spirit of the invention, as claimed by those skilled in the art.