阅读说明：本技术 一种4-碘联苯的合成方法 (Synthetic method of 4-iodobiphenyl ) 是由 孟纪文 王可为 韩建国 于 2020-06-11 设计创作，主要内容包括：本发明公开了一种4-碘联苯的合成方法。该方法是基于Suzuki偶联反应,以1,4-二碘苯和苯硼酸为原料,水为溶剂,在Pd/C催化下,于50-100℃反应4-12h,反应产物后处理得到所述目标产物。本发明以水为反应溶剂,催化剂可以回收重复使用,收率高,无污染,符合绿色环保要求,过程简单,操作方便,利于工业化生产。(The invention discloses a method for synthesizing 4-iodobiphenyl. The method is based on Suzuki coupling reaction, 1, 4-diiodobenzene and phenylboronic acid are used as raw materials, water is used as a solvent, the reaction is carried out for 4-12h at 50-100 ℃ under the catalysis of Pd/C, and the target product is obtained by post-processing the reaction product. The method takes water as a reaction solvent, the catalyst can be recycled, the yield is high, no pollution is caused, the method meets the requirements of environmental protection, the process is simple, the operation is convenient, and the method is beneficial to industrial production.)

1. A synthetic method of 4-iodobiphenyl is characterized by comprising the following steps:

adding 1, 4-diiodobenzene, phenylboronic acid, alkali and a catalyst into a reaction solvent, stirring and heating to 50-100 ℃ for reaction for 4-12h, cooling a reaction liquid to room temperature after the reaction is finished, filtering and separating, washing a filter cake with water, recovering the catalyst for reuse, extracting a filtrate with ethyl acetate, and performing rotary evaporation on an organic layer to recover the ethyl acetate to obtain a target product.

2. The method for synthesizing 4-iodobiphenyl as claimed in claim 1, wherein the reaction solvent is water.

3. The method for synthesizing 4-iodobiphenyl according to claim 1, wherein the base is one or more of sodium hydroxide, potassium hydroxide, sodium carbonate, sodium bicarbonate, potassium carbonate, sodium phosphate, potassium phosphate, sodium acetate, potassium acetate, cesium carbonate, and triethylamine.

4. The method for synthesizing 4-iodobiphenyl as claimed in claim 1, wherein said catalyst is Pd/C.

5. The method for synthesizing 4-iodobiphenyl as claimed in claim 1, wherein the molar ratio of 1, 4-diiodobenzene, phenylboronic acid, alkali and catalyst is 1: 0.95-1.05: 1-3: 0.01-0.05.

Technical Field

The invention belongs to the technical field of fine chemical synthesis, and particularly relates to a synthesis method of 4-iodobiphenyl.

Background

Biphenyl type liquid crystal materials have the characteristics of good photostability and chemical stability, the synthesis of the liquid crystal materials attracts more and more attention, and 4-iodobiphenyl is an important intermediate for preparing photosensitive materials and liquid crystal materials; at present, a biphenyl direct iodination method is mainly adopted for preparing 4-iodobiphenyl, biphenyl and iodine are used as raw materials, ammonium persulfate or potassium persulfate is used as an oxidant, acetic acid is used as a reaction solvent, and a target product is generated in the presence of concentrated sulfuric acid and concentrated nitric acid; persulfate is a strong oxidant and is easy to decompose when meeting heat and humidity, and acetic acid, concentrated sulfuric acid and concentrated nitric acid all corrode equipment and cannot be recycled to generate a large amount of acidic waste liquid; chinese patent CN104725185A adopts Cu-La silicon dioxide mesoporous composite catalyst to replace persulfate, but still can not avoid using a large amount of concentrated sulfuric acid and concentrated nitric acid. The reaction formula of the traditional biphenyl direct iodination method is as follows:

suzuki coupling reaction, also called Suzuki coupling reaction, under the catalysis of zero-valent palladium, aryl boric acid and halogenated aromatic hydrocarbon are subjected to cross coupling, and the method is an important method for synthesizing biphenyl compounds; in order to overcome the defects of the existing technology for synthesizing 4-iodobiphenyl, the invention provides a method for synthesizing 4-iodobiphenyl by using Suzuki coupling reaction.

Disclosure of Invention

The invention aims to overcome the defects of the existing 4-iodobiphenyl synthesis method technology and provide an efficient and environment-friendly 4-iodobiphenyl synthesis method.

The technical scheme adopted by the invention is as follows:

in a water phase, Pd/C is used as a catalyst, 1, 4-diiodobenzene and phenylboronic acid are used as reaction raw materials in the presence of alkali, and 4-iodobiphenyl is generated through one-step reaction.

The reaction formula is as follows:

the synthesis method of the 4-iodobiphenyl comprises the following steps:

adding 1, 4-diiodobenzene, phenylboronic acid, alkali, a catalyst and water into a reaction bottle, stirring and heating to 50-100 ℃, preserving heat for reaction for 4-12h, cooling a reaction solution to room temperature after the reaction is finished, filtering and separating, washing a filter cake with water, recycling the catalyst, extracting a filtrate with ethyl acetate, and carrying out rotary evaporation on an organic layer to recycle the ethyl acetate to obtain a solid product.

The alkali is one or more of sodium hydroxide, potassium hydroxide, sodium carbonate, sodium bicarbonate, potassium carbonate, sodium phosphate, potassium phosphate, sodium acetate, potassium acetate, cesium carbonate and triethylamine.

The catalyst is Pd/C, and the Pd loading capacity is 5%.

The mol ratio of the 1, 4-diiodobenzene, the phenylboronic acid, the alkali and the catalyst is 1: 0.95-1.05: 1-3: 0.01-0.05.

The method of the invention has the following remarkable advantages: (1) the method takes water as a solvent, has no pollution, and avoids the generation of a large amount of acidic waste liquid in the traditional method; (2) the used Pd/C catalyst can be recycled, so that the cost is reduced; (3) high product yield, mild reaction conditions, simple process and convenient operation.

Detailed Description