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A kind of preparation method of tetramethylbiphenyl

A technology of tetramethylbiphenyl and halogenated o-xylene, which is applied in the field of preparation of tetramethylbiphenyl, and can solve problems such as harsh reaction conditions, harsh preparation process conditions, and complicated processes

Inactive Publication Date: 2015-10-07
CHANGCHUN INST OF APPLIED CHEMISTRY - CHINESE ACAD OF SCI
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Although this process can carry out large-scale industrial production, due to the use of a large amount of zinc powder, a large amount of waste residue containing zinc and zinc salts will be produced after the reaction, and the product tetramethylbiphenyl must be obtained after complicated post-treatment; The preparation process conditions of the nickel triaryl phosphorus ligand catalyst used are harsh, and the reaction steps are increased
Therefore, this method requires a self-made catalyst in advance, the process is more complicated, and the reaction conditions are harsh.

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  • A kind of preparation method of tetramethylbiphenyl
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  • A kind of preparation method of tetramethylbiphenyl

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[0026] The invention provides a kind of preparation method of tetramethylbiphenyl, comprising the following steps:

[0027] a) mixing halogenated o-xylene, magnesium, iodine and an organic solvent to react to obtain a Grignard reagent;

[0028] b) performing a coupling reaction on the Grignard reagent obtained in step a) under the action of a catalyst to obtain tetramethylbiphenyl;

[0029] The catalyst is manganese simple substance and / or manganese-containing compound.

[0030] The present invention uses halogenated o-xylene as a raw material, reacts it with magnesium and iodine in an organic solvent to form a Grignard reagent; then performs a coupling reaction on the Grignard reagent under the action of a manganese simple substance and / or a manganese-containing compound catalyst, Tetramethylbiphenyl is obtained. The manganese simple substance and / or manganese compound catalyst adopted in the present invention does not require complex preparation methods and harsh experimen...

Embodiment 1

[0055] Under an atmosphere protected by argon, add 0.37g (15.4mmol) of magnesium strips, 5.0mL of 3-chloro-o-xylene, 5.0mL of 4-chloro-o-xylene, and 2.46mL of anhydrous tetrahydrofuran into the branched reaction tube. (30.4mmol) and the iodine of catalytic amount, stir at 110 ℃ until magnesium disappears, obtain red-brown reaction solution, comprise Grignard reagent in the described reaction solution; The Grignard reagent that will obtain is cooled to 60 ℃, to Add 96.0mg (0.76mmol) of manganese dichloride and 1.46mL (18.3mmol) of 1,2-dichloroethane in sequence, stir under the protection of argon, carry out the coupling reaction for 13h, and then quench the reaction with dilute hydrochloric acid. The resulting reaction solution was extracted with ethyl acetate to obtain a reaction product.

[0056] The present invention carries out nuclear magnetic resonance spectrum detection to the obtained reaction product, and the result is as follows: figure 1 as shown, figure 1 The prot...

Embodiment 2

[0059] Under an atmosphere protected by argon, 0.37 g (15.4 mmol) of magnesium bars, 10.0 mL of 4-chloro-o-xylene, 2.46 mL (30.4 mmol) of anhydrous tetrahydrofuran and a catalytic amount of iodine were sequentially added to the branched reaction tube. Stir at 110°C until magnesium disappears to obtain a reddish-brown reaction solution, which includes a Grignard reagent; the obtained Grignard reagent is cooled to 60°C, and manganese dichloride 96.0mg (0.76 mmol) and 1.46mL (18.3mmol) of 1,2-dichloroethane, stirred under the protection of argon, carried out the coupling reaction for 13h, then quenched the reaction with dilute hydrochloric acid, and extracted the resulting reaction solution with ethyl acetate, A reaction product was obtained, and the obtained reaction product was crystallized in methanol.

[0060] The present invention carries out nuclear magnetic resonance spectrum detection to the obtained reaction product, and the result is as follows: figure 2 as shown, f...

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Abstract

The invention provides a preparation method of tetramethyl biphenyl. The preparation method comprises the following steps: a) mixing o-xylene halide, magnesium, iodine and an organic solvent for a reaction so as to obtain a Grignard reagent; and b) carrying out a coupled reaction on the Grignard reagent obtained from the step a) under the action of a catalyst so as to obtain tetramethyl biphenyl, wherein the catalyst is elemental manganese and / or a manganese-containing compound. According to the invention, o-xylene halide is used as a raw material to react with magnesium and iodine in the organic solvent so as to prepare the Grignard reagent; and then, the obtained Grignard reagent is subjected to a coupled reaction under the catalytic action of elemental manganese and / or the manganese-containing compound so as to obtain tetramethyl biphenyl. The elemental manganese and / or manganese-containing compound are used as a catalyst for the coupled reaction. The catalyst requires no complex preparation method or harsh experiment condition. The operation process is simple. Under the catalytic action of the elemental manganese and / or manganese-containing compound, the coupled reaction of the Grignard reagent also can be carried out under a mild condition.

Description

technical field [0001] The invention belongs to the technical field of organic synthesis, in particular to a preparation method of tetramethylbiphenyl. Background technique [0002] As a high-performance polymer, polyimide has excellent heat resistance, solvent resistance, radiation resistance, and good mechanical and dielectric properties. Among them, the thermal decomposition temperature of biphenyl polyimide can reach 600 ℃, is one of the varieties with the highest thermal stability among polymer materials, and has broad application prospects in the fields of mechanical electronics, aerospace, and heat-resistant filter materials. In the prior art, biphenyl polyimide is often obtained by polymerization of biphenyl tetracarboxylic dianhydride and p-phenylenediamine. As one of the key monomers of biphenyl polyimide, biphenyltetracarboxylic dianhydride is often prepared by chlorinated phthalic anhydride through esterification, coupling, hydrolysis, and anhydride formation; o...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07C15/14C07C1/26
Inventor 吴强康传清丁金英金日哲姚海波邱雪鹏高连勋
Owner CHANGCHUN INST OF APPLIED CHEMISTRY - CHINESE ACAD OF SCI