Method for synthesizing biaryl

Abstract

The invention provides a method for synthesizing biaryl and belongs to the field of organic catalytic synthesis. Poly p-anisidine loaded nano-palladium serves as a catalyst, diisopropylethylamine serves as an alkali, in a N-methyl pyrrolidinone solvent, and the reduction of halohyrocarbons with hydrazine hydrate is catalyzed to prepare biaryl. According to the method, the reaction condition is mild, products are easy to separate, the reaction is easy to operate, and good safety is achieved. Secondly, the catalyst used in the method is easy to prepare, the use amount is small, and after the reaction is completed, the catalyst can be recycled for many times. In addition, in the method, the green alkali and the green reduction agent are used, solid waste is little, corrosivity is low, and the method is green and environmentally friendly, and protects the environment.

Description

technical field

[0001] The invention belongs to the field of organic catalytic synthesis. Background technique

[0002] Biaryls are an important class of organic compounds, which widely exist in natural products, medicines, dyes, functional polymers, organic conductors and semiconductors. In 1901, German chemist Ullmann discovered that aryl halides could be used to prepare symmetrical biaryls under the catalysis of active copper powder. However, the reaction conditions were very harsh and required high temperatures (generally greater than 200 o C), and use excessive copper catalysis, although it has been improved by people in various experiments, it also faces many problems, such as large amount of catalyst, difficult to recycle, complex reducing agent, etc., which makes the reaction cost high And pollute the environment, not suitable for large-scale production. Contents of the invention

[0003] The purpose of the present invention is to provide a method for synthesizin...

Examples

Embodiment 1

[0012] 1. Prepare the catalyst:

[0013] Weigh 1231.6 mg (10 mol) of p-methoxyaniline and dissolve it in 100 ml of aqueous hydrochloric acid with a concentration of 1 mol / L to obtain solution a.

[0014] Weigh 44.3 mg of palladium dichloride and dissolve in 100 ml of aqueous hydrochloric acid with a concentration of 1 mol / L to obtain solution b.

[0015] Add solution b to solution a, stir for 2 minutes after mixing, and let stand for 24 hours. Adjust the pH value to 7.0 with 1mol / L sodium hydroxide aqueous solution to obtain a flocculent precipitate, which is centrifuged, washed three times with deionized water, and dried at 100°C for 6 hours to obtain a blue-yellow solid, that is, poly-p-methoxyaniline-loaded nanoparticles palladium.

[0016] 2. Synthesis of biaryls:

[0017] In a 50 ml reaction tube, add 6 mg poly-p-methoxyaniline supported nano-palladium catalyst, 2.04 g (10 mmol) iodobenzene, 589 mg (10 mmol) hydrazine hydrate (85%), 1.29 g (10 mmol) di Isopropylethyla...

Embodiment 2

[0019] Other conditions are the same as in Example 1, and the influence of the reaction temperature on the reaction is checked, and the experimental results are as shown in Table 1.

[0020] Table 1 Effect of reaction temperature

[0021] Reaction temperature (°C) 80 130 140 150 Product yield (%) 7.3 52.3 70.3 53.3

[0022] It can be seen from the above table that the effect is the best and the yield is the highest when the reaction temperature is 140°C.

Embodiment 3

[0024] Other conditions are the same as in Example 1, and the influence of the consumption of the reducing agent hydrazine hydrate on the reaction is checked, and the experimental results are shown in Table 2.

[0025] Table 2 The effect of reducing agent hydrazine hydrate dosage

[0026] Hydrazine hydrate / mmol 0 0.5 1.0 2.0 Product yield (%) 41.0 39.8 70.3 14.0

[0027] It can be seen from the above table that the yield is the highest when the molar ratio of reducing agent hydrazine hydrate to iodobenzene is 1:1.

technical field

[0001] The invention belongs to the field of organic catalytic synthesis. Background technique

[0002] Biaryls are an important class of organic compounds, which widely exist in natural products, medicines, dyes, functional polymers, organic conductors and semiconductors. In 1901, German chemist Ullmann discovered that aryl halides could be used to prepare symmetrical biaryls under the catalysis of active copper powder. However, the reaction conditions were very harsh and required high temperatures (generally greater than 200 o C), and use excessive copper catalysis, although it has been improved by people in various experiments, it also faces many problems, such as large amount of catalyst, difficult to recycle, complex reducing agent, etc., which makes the reaction cost high And pollute the environment, not suitable for large-scale production. Contents of the invention

[0003] The purpose of the present invention is to provide a method for synthesizin...

Examples

Embodiment 1

[0012] 1. Prepare the catalyst:

[0013] Weigh 1231.6 mg (10 mol) of p-methoxyaniline and dissolve it in 100 ml of aqueous hydrochloric acid with a concentration of 1 mol / L to obtain solution a.

[0014] Weigh 44.3 mg of palladium dichloride and dissolve in 100 ml of aqueous hydrochloric acid with a concentration of 1 mol / L to obtain solution b.

[0015] Add solution b to solution a, stir for 2 minutes after mixing, and let stand for 24 hours. Adjust the pH value to 7.0 with 1mol / L sodium hydroxide aqueous solution to obtain a flocculent precipitate, which is centrifuged, washed three times with deionized water, and dried at 100°C for 6 hours to obtain a blue-yellow solid, that is, poly-p-methoxyaniline-loaded nanoparticles palladium.

[0016] 2. Synthesis of biaryls:

[0017] In a 50 ml reaction tube, add 6 mg poly-p-methoxyaniline supported nano-palladium catalyst, 2.04 g (10 mmol) iodobenzene, 589 mg (10 mmol) hydrazine hydrate (85%), 1.29 g (10 mmol) di Isopropylethyla...

Embodiment 2

[0019] Other conditions are the same as in Example 1, and the influence of the reaction temperature on the reaction is checked, and the experimental results are as shown in Table 1.

[0020] Table 1 Effect of reaction temperature

[0021] Reaction temperature (°C) 80 130 140 150 Product yield (%) 7.3 52.3 70.3 53.3

[0022] It can be seen from the above table that the effect is the best and the yield is the highest when the reaction temperature is 140°C.

Embodiment 3

[0024] Other conditions are the same as in Example 1, and the influence of the consumption of the reducing agent hydrazine hydrate on the reaction is checked, and the experimental results are shown in Table 2.

[0025] Table 2 The effect of reducing agent hydrazine hydrate dosage

[0026] Hydrazine hydrate / mmol 0 0.5 1.0 2.0 Product yield (%) 41.0 39.8 70.3 14.0

[0027] It can be seen from the above table that the yield is the highest when the molar ratio of reducing agent hydrazine hydrate to iodobenzene is 1:1.

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