阅读说明：本技术 一种2,6-二芳基吡啶类物质及其制备方法 (2, 6-diaryl pyridine substance and preparation method thereof ) 是由 陈久喜 姚鑫容 戚林军 邵银林 李仁豪 赵志伟 刘继超 曾鸽 熊文章 于 2019-10-11 设计创作，主要内容包括：本发明公开了一种2,6-二芳基吡啶类物质及其制备方法,以5-氧代-5-芳基戊腈和芳硼酸作为反应物进行反应制得；还加入了钯催化剂和酸性促进剂；钯催化剂为双(二亚苄基丙酮)钯或三(二亚苄基丙酮)二钯；酸性促进剂为三氟乙酸；反应温度为80-100℃,反应时间为12-24小时,整个反应在常压下进行,反应条件温和,容易达到,且安全。本发明方法可以直接合成目标产物,无需分离中间产物,反应过程简单产率最高可达到96％,大大简化了工艺工程,降低了能量消耗,具有高产率的优点；可以制备一系列的2,6-二芳基吡啶类物质,该方法具有较强的底物普适性,从而为开发有关吡啶衍生物提供了较好的保证。(The invention discloses a 2, 6-diaryl pyridine substance and a preparation method thereof, which are prepared by taking 5-oxo-5-aryl valeronitrile and aryl boric acid as reactants to react; a palladium catalyst and an acidic promoter are also added; the palladium catalyst is bis (dibenzylidene acetone) palladium or tris (dibenzylidene acetone) dipalladium; the acidic accelerant is trifluoroacetic acid; the reaction temperature is 80-100 ℃, the reaction time is 12-24 hours, the whole reaction is carried out under normal pressure, the reaction condition is mild, easy to achieve and safe. The method can directly synthesize the target product without separating intermediate products, has simple reaction process and high yield up to 96 percent, greatly simplifies process engineering, reduces energy consumption and has the advantage of high yield; a series of 2, 6-diaryl pyridine substances can be prepared, and the method has strong substrate universality, so that better guarantee is provided for developing related pyridine derivatives.)

1. A2, 6-diaryl pyridine substance is characterized in that:

the structural formula of the 2, 6-diaryl pyridine substance is shown as

wherein-R¹Is any one of hydrogen, methyl, tert-butyl, halogen and trifluoromethyl;

-R²is any one of hydrogen, methyl, methoxy, bromine, trifluoromethyl, naphthyl, nitro, trifluoromethyl and phenoxy.

2. A 2, 6-diarylpyridine species according to claim 1, characterized by: the 2, 6-diaryl pyridine substance is composed of

5-oxo-5-arylvaleronitrile and

arylboronic acid is reacted;

the structural formula of the 5-oxo-5-aryl valeronitrile is shown in the specification

The structural formula of the arylboronic acid is

Which is of the formula

Wherein 5-oxo-5-arylvaleronitrile and-R in 2, 6-diaryl pyridine substances¹The same, all are any one of hydrogen, methyl, tert-butyl, halogen and trifluoromethyl;

-R in the arylboronic acid and 2, 6-diarylpyridine²And the same is any one of hydrogen, methyl, methoxy, bromine, trifluoromethyl, naphthyl, nitro, trifluoromethyl and phenoxy.

3. A 2, 6-diarylpyridine species according to claim 2, characterized in that: the reaction of the 5-oxo-5-aryl valeronitrile with the arylboronic acid is carried out in a solvent, wherein the solvent is any one of toluene, xylene, methanol, tetrahydrofuran and N, N-dimethylformamide.

4. A 2, 6-diarylpyridine species according to claim 3, characterized in that: when the 5-oxo-5-aryl valeronitrile is reacted with the arylboronic acid in the solvent, a palladium catalyst and an acid promoter are also added into the solvent.

5. A2, 6-diarylpyridine species according to claim 4, characterized in that: the palladium catalyst is bis (dibenzylidene acetone) palladium or tris (dibenzylidene acetone) dipalladium.

6. A2, 6-diarylpyridine species according to claim 5, characterized in that: the acidic promoter is trifluoroacetic acid.

7. The method of claim 6, wherein the reaction is carried out in the presence of a 2, 6-diarylpyridine compound: under the air atmosphere, sequentially adding 5-oxo-5-aryl valeronitrile, arylboronic acid, a palladium catalyst, a solvent and an acidic promoter into a reaction container, and stirring and mixing; after being mixed evenly, the mixture reacts for 12 to 24 hours at the temperature of 80 to 100 ℃ to prepare the 2, 6-diaryl pyridine substance.

8. The method of claim 7, wherein the reaction is carried out in the presence of a 2, 6-diarylpyridine compound: adding 5-oxo-5-arylvaleronitrile and arylboronic acid in a mass ratio of 1: 1.5-2.5.

9. The method of claim 8, wherein the reaction is carried out in the presence of a 2, 6-diarylpyridine compound: the ratio of the amounts of the 5-oxo-5-arylvaleronitrile and the palladium catalyst material added to the reaction vessel was 1: 0.04-0.06.

Technical Field

The invention relates to the field of organic synthesis, in particular to a 2, 6-diaryl pyridine substance and a preparation method thereof.

Background

The pyridine derivatives are important organic compounds which are not only important solvents in metal organic catalytic reaction, but also denaturants and dyeing assistants commonly used in industrial production; meanwhile, the raw materials for synthesizing a series of products (including medicines, disinfectants, dyes and the like) are also used. Therefore, how to synthesize pyridine derivatives efficiently, rapidly and safely has been an important issue in organic synthetic chemistry.

2, 6-diaryl pyridine substances are one of common pyridine derivatives; in the prior art, 2, 6-diaryl pyridine substances are mainly prepared by the following method: 1. 2, 6-diaryl pyridine substances are prepared by the reaction between 2, 6-dichloropyridine, a chromite reagent and arylboronic acid (chem.Eur.J.2012,18, 446-450); 2.2, 6-diaryl pyridine substances (org.biomol.chem.,2014,12, 6944-one-dust 6952) are prepared by reacting 2, 6-dichloropyridine with arylboronic acid under the catalysis of Pd; however, the above preparation methods all have certain defects, for example, the raw materials of the method 1 are not easy to store, side reactions are more, various byproducts are easily generated, and the yield is influenced; the catalyst of the method 2 needs to be self-prepared and has certain limitation; due to the defects, the practicability and applicability of the methods are limited.

Disclosure of Invention

Aiming at the defects in the prior art, the invention aims to provide a 2, 6-diaryl pyridine substance and a preparation method thereof.

In order to achieve the purpose, the invention provides the following technical scheme: a2, 6-diaryl pyridine substance with a structural formula

wherein-R¹Is any one of hydrogen, methyl, tert-butyl, halogen and trifluoromethyl;

-R²is any one of hydrogen, methyl, methoxy, bromine, trifluoromethyl, naphthyl, nitro, trifluoromethyl and phenoxy.

As a further improvement of the invention, the 2, 6-diaryl pyridine substance is formed by the reaction of 5-oxo-5-aryl valeronitrile and aryl boric acid;

the structural formula of the 5-oxo-5-aryl valeronitrile is shown in the specification

The structural formula of the arylboronic acid is

Which is of the formula

Wherein 5-oxo-5-arylvaleronitrile and-R in 2, 6-diaryl pyridine substances¹The same, all are any one of hydrogen, methyl, tert-butyl, halogen and trifluoromethyl;

-R in the arylboronic acid and 2, 6-diarylpyridine²Are the same as hydrogen, methyl, methoxy,Any one of bromine, trifluoromethyl, naphthyl, nitro, trifluoromethyl and phenoxy.

As a further improvement of the invention, the reaction of the 5-oxo-5-arylvaleronitrile with the arylboronic acid is carried out in a solvent which is any one of toluene, xylene, methanol, tetrahydrofuran and N, N-dimethylformamide.

As a further improvement of the invention, when the 5-oxo-5-aryl valeronitrile is reacted with the arylboronic acid in the solvent, a palladium catalyst and an acidic promoter are also added into the solvent.

As a further development of the invention, the palladium catalyst is bis (dibenzylideneacetone) palladium or tris (dibenzylideneacetone) dipalladium.

As a further improvement of the invention, the acidic promoter is trifluoroacetic acid.

As a further improvement of the invention, under the air atmosphere, adding 5-oxo-5-aryl valeronitrile, arylboronic acid, palladium catalyst, solvent and acidic promoter in turn into a reaction container, stirring and mixing; after being mixed evenly, the mixture reacts for 12 to 24 hours at the temperature of 80 to 100 ℃ to prepare the 2, 6-diaryl pyridine substance.

As a further improvement of the present invention, the ratio of the amounts of the 5-oxo-5-arylvaleronitrile and arylboronic acid added to the reaction vessel is 1: 1.5-2.5.

As a further improvement of the invention, the 5-oxo-5-arylvaleronitrile and the palladium catalyst are added to the reaction vessel in a mass ratio of 1: 0.04-0.06.

The invention has the beneficial effects that: the raw materials are easy to obtain, the source is wide, the preparation by the raw materials is not needed, the cost is low, and meanwhile, the toxicity is low, so that the influence on the health of a human body is not easy to cause; the target product can be directly synthesized, the intermediate product does not need to be separated, the target product can be obtained only by reacting under normal pressure, the reaction process is simple, the yield can reach 96 percent at most, the process engineering is greatly simplified, the energy consumption is reduced, and the method has the advantage of high yield; in addition, the waste solution is less in the reaction process, and other polluted gases and liquid are not discharged, so that the method reduces the discharge of the waste solution, and has the advantages of protecting the environment and ensuring the health of operators; the toxicity of the substances used in the invention is low, thus ensuring the health of operators; in addition, a series of 2, 6-diaryl pyridine substances can be prepared, and the method has strong substrate universality, so that better guarantee is provided for developing related pyridine derivatives.

Drawings

FIG. 1 is a diagram of the reaction mechanism of the present invention;

Detailed Description