阅读说明：本技术 一种4-氟-2，3-二甲基苯基甲磺酸酯的合成方法 (Synthesis method of 4-fluoro-2, 3-dimethylphenylmethylsulfonate ) 是由 梁腾 吴阳 方勇 闫路 于 2019-11-27 设计创作，主要内容包括：本发明公开了一种4-氟-2,3-二甲基苯基甲磺酸酯的合成方法,该方法包括：一、3-氟二甲苯经卤代反应得到4-氟-2,3-二甲基卤代苯；二、4-氟-2,3-二甲基卤代苯经偶联反应得到4-氟-2,3-二甲基苯基醚；三、4-氟-2,3-二甲基苯基醚水解得到4-氟-2,3-二甲基苯酚；四、4-氟-2,3-二甲基苯酚与甲基磺酰氯经酯化反应得到4-氟-2,3-二甲基苯基甲磺酸酯。本发明以3-氟二甲苯为原料,依次经卤代、偶联、水解和酯化反应,通过对不同类型的反应进行组合设计,提高了4-氟-2,3-二甲基苯基甲磺酸酯的收率,同时避免使用昂贵的催化剂或原料,降低了制备成本,减少了废水排放,减轻了环保压力。(The invention discloses a method for synthesizing 4-fluoro-2, 3-dimethylphenylmethylsulfonate, which comprises the following steps: firstly, halogenating 3-fluoroxylene to obtain 4-fluoro-2, 3-dimethyl halogenated benzene; coupling reaction is carried out on the di-4-fluoro-2, 3-dimethyl halogenated benzene to obtain 4-fluoro-2, 3-dimethyl phenyl ether; hydrolyzing the 4-fluoro-2, 3-dimethylphenyl ether to obtain 4-fluoro-2, 3-dimethylphenol; esterification reaction is carried out on the tetra, 4-fluoro-2, 3-dimethylphenol and methylsulfonyl chloride to obtain 4-fluoro-2, 3-dimethylphenyl methanesulfonate. According to the invention, 3-fluoroxylene is taken as a raw material, and the raw material is subjected to halogenation, coupling, hydrolysis and esterification in sequence, and different types of reactions are combined, so that the yield of 4-fluoro-2, 3-dimethylphenylmethylsulfonate is improved, expensive catalysts or raw materials are avoided, the preparation cost is reduced, the wastewater discharge is reduced, and the environmental protection pressure is relieved.)

1. A method for synthesizing 4-fluoro-2, 3-dimethylphenylmethanesulfonate is characterized by comprising the following steps:

step one, performing halogenation reaction on 3-fluoroxylene to obtain 4-fluoro-2, 3-dimethyl halogenobenzene with a structural formula (I);

step two, performing coupling reaction on the 4-fluoro-2, 3-dimethyl halogenated benzene obtained in the step one to obtain 4-fluoro-2, 3-dimethyl phenyl ether with a structural formula (II);

step three, hydrolyzing the 4-fluoro-2, 3-dimethylphenyl ether obtained in the step two under an alkaline condition to obtain 4-fluoro-2, 3-dimethylphenol;

and step four, carrying out esterification reaction on the 4-fluoro-2, 3-dimethylphenol obtained in the step three and methylsulfonyl chloride in the presence of an acid-binding agent to obtain 4-fluoro-2, 3-dimethylphenylmethylsulfonate.

2. The method of claim 1The method for synthesizing 4-fluoro-2, 3-dimethylphenylmethylsulfonate is characterized in that a halogenating reagent adopted in the halogenating reaction in the step one is Br ₂、I ₂NBS or NCS.

3. The method of claim 2, wherein the halogenating agent is Br ₂。

4. The method for synthesizing 4-fluoro-2, 3-dimethylphenylmethanesulfonate according to claim 1, wherein X in the structural formula (I) in the first step represents Cl, Br or I.

5. The method for synthesizing 4-fluoro-2, 3-dimethylphenylmethanesulfonate according to claim 1, wherein the alcohol used in the coupling reaction in the second step is RnOH, wherein Rn represents C1-C4 alkyl.

6. The method for synthesizing 4-fluoro-2, 3-dimethylphenylmethanesulfonate according to claim 5, wherein Rn represents a C1-C4 linear alkyl group.

7. The method for synthesizing 4-fluoro-2, 3-dimethylphenylmethanesulfonate according to claim 1, wherein the base used in the alkaline condition in the third step is YOH, wherein Y represents Na or K.

8. The method for synthesizing 4-fluoro-2, 3-dimethylphenylmethanesulfonate according to claim 1, wherein the acid scavenger in the fourth step is triethylamine or pyridine.

Technical Field

The invention belongs to the technical field of organic matter synthesis, and particularly relates to a synthesis method of 4-fluoro-2, 3-dimethylphenyl methanesulfonate.

Background

The 4-fluoro-2, 3-dimethylphenyl methanesulfonate is a novel chemical, can be used as an intermediate of pesticide, medicine, liquid crystal and organic electroluminescent material, and has large potential market demand. Patent publication No. CN108602765 discloses a preparation method of 4-fluoro-2, 3-dimethylphenylmethanesulfonic acid ester: firstly, 4-nitro-2, 3-dimethylphenol reacts with methylsulfonyl chloride under the condition of triethylamine to generate 4-nitro-2, 3-dimethyl sulfonate, then the nitro group is reduced by palladium-carbon hydrogenation to obtain 4-amino-2, 3-dimethyl phenyl methyl sulfonate, and then sodium nitrite is used for diazotization in pyridine hydrogen fluoride solution to obtain a target product. The method takes 4-nitro-2, 3-dimethylphenol as an initial raw material to directly react with methylsulfonate, has a simple and clear process route, but has the defects that the used palladium-carbon noble metal catalyst is expensive, the preparation cost is increased, and the diazotization reaction in the last step generates a large amount of wastewater, so that the environmental protection pressure is high.

Disclosure of Invention

The technical problem to be solved by the present invention is to provide a method for synthesizing 4-fluoro-2, 3-dimethylphenylmethylsulfonate, which is aimed at overcoming the disadvantages of the prior art. According to the method, 3-fluoroxylene is used as a raw material, ether is formed through halogenation and coupling reactions in sequence, then hydrolysis and esterification are carried out under an alkaline condition, and different types of reactions are combined to design to obtain the target product 4-fluoro-2, 3-dimethylphenyl methyl sulfonate, so that the yield of 4-fluoro-2, 3-dimethylphenyl methyl sulfonate is improved, expensive catalysts or raw materials are avoided, the preparation cost is reduced, the wastewater discharge is reduced, and the environmental protection pressure is relieved.

In order to solve the technical problems, the invention adopts the technical scheme that: a method for synthesizing 4-fluoro-2, 3-dimethylphenylmethanesulfonate is characterized by comprising the following steps:

step one, performing halogenation reaction on 3-fluoroxylene to obtain 4-fluoro-2, 3-dimethyl halogenobenzene with a structural formula (I);

step two, performing coupling reaction on the 4-fluoro-2, 3-dimethyl halogenated benzene obtained in the step one to obtain 4-fluoro-2, 3-dimethyl phenyl ether with a structural formula (II);

step three, hydrolyzing the 4-fluoro-2, 3-dimethylphenyl ether obtained in the step two under an alkaline condition to obtain 4-fluoro-2, 3-dimethylphenol;

and step four, carrying out esterification reaction on the 4-fluoro-2, 3-dimethylphenol obtained in the step three and methylsulfonyl chloride in the presence of an acid-binding agent to obtain 4-fluoro-2, 3-dimethylphenylmethylsulfonate.

The synthetic route of the invention is as follows:

the method takes 3-fluoroxylene as an initial raw material, and sequentially carries out halogenation reaction and coupling reaction to form ether, and then carries out hydrolysis and esterification reaction under the alkaline condition to obtain the target product 4-fluoro-2, 3-dimethylphenyl methyl sulfonate.

The synthesis method of the 4-fluoro-2, 3-dimethylphenylmethylsulfonate is characterized in that a halogenating reagent adopted in the halogenating reaction in the step one is Br ₂、I ₂NBS or NCS.

The method as described above, wherein the halogenating agent is Br ₂。

The synthesis method of the 4-fluoro-2, 3-dimethylphenylmethanesulfonate is characterized in that in the step one, X in the structural formula (I) represents Cl, Br or I.

The method for synthesizing 4-fluoro-2, 3-dimethylphenylmethylsulfonate is characterized in that the alcohol used in the coupling reaction in the second step is RnOH, wherein Rn represents C1-C4 alkyl.

The synthesis method of the 4-fluoro-2, 3-dimethylphenylmethanesulfonate is characterized in that Rn represents C1-C4 straight-chain alkyl.

The synthesis method of 4-fluoro-2, 3-dimethylphenylmethylsulfonate is characterized in that the alkali adopted in the alkaline condition in the step three is YOH, wherein Y represents Na or K.

The synthesis method of the 4-fluoro-2, 3-dimethylphenylmethylsulfonate is characterized in that the acid-binding agent in the fourth step is triethylamine or pyridine.

Compared with the prior art, the invention has the following advantages:

1. according to the invention, 3-fluoroxylene is taken as a raw material, the raw material is subjected to halogenation reaction and coupling reaction in sequence to form ether, then the ether is subjected to hydrolysis and esterification reaction under an alkaline condition, and different types of reactions are combined to design to obtain the target product 4-fluoro-2, 3-dimethylphenyl methyl sulfonate, so that the yield of the 4-fluoro-2, 3-dimethylphenyl methyl sulfonate is improved, expensive catalysts or raw materials are avoided, the preparation cost is reduced, the wastewater discharge is reduced, and the environmental protection pressure is relieved.

2. The synthetic starting material 3-fluoroxylene of the invention has simple molecular structure, low price and easy obtaining, and other raw materials adopted in the synthetic process are all easy to obtain, thereby further reducing the preparation cost and the synthetic difficulty.

3. The whole reaction process of the invention avoids using noble metal catalyst, avoids conventional diazotization reaction, generates less sewage in the whole process and meets increasingly severe environmental protection requirements.

The technical solution of the present invention is further described in detail by the accompanying drawings and examples.

Drawings

FIG. 1 is a GC spectrum of 4-fluoro-2, 3-dimethylphenylmethanesulfonate synthesized in example 1 of the present invention.

Detailed Description