Synthesis method for 4,4'-biphenyldicarboxylic acid

Abstract

The invention relates to the field of chemical synthesis, and in particular to a synthesis method for 4,4'-biphenyldicarboxylic acid. The synthesis method for 4,4'-biphenyldicarboxylic acid is characterized by comprising the following reaction steps of: step 1, reacting 4-diphenic acid, oxalyl chloride and aluminium trichloride in a molar ratio of 1: (1.1-1.8): (1.2-2.0) to obtain 4,4'-dicarboxylbibenzil, wherein the weight ratio of 4-diphenic acid to a solvent is 1: (3 to 10); and step 2, reacting 4,4'-dicarboxylbibenzil, an oxidant and potassium hydroxide in a molar ratio of 1: (1.2-2.0):(1.4-2.2), and then carrying out recrystallization by absolute methanol to obtain 4,4'-biphenyldicarboxylic acid, wherein the weight ratio of 4,4'-dicarboxylbibenzil to an organic solvent is 1: (3-10). Compared with the prior, the synthesis method for 4,4'-biphenyldicarboxylic acid disclosed by the invention has the beneficial effects of being reasonable and practicable in process flow, high in yield which is up to move than 93%, moderate in process reaction conditions, low in requirements on equipment, and suitable for industrialized production.

Description

technical field [0001] The invention relates to the field of chemical synthesis, in particular to a synthesis method of 4,4'-biphenyl dicarboxylic acid. Background technique [0002] 4,4'-biphenyldicarboxylic acid is the main organic synthesis intermediate, widely used in the synthesis of organic polymer materials, pharmaceuticals, coordination polymer supramolecular materials and liquid crystal products. At present, the synthesis of 4,4′-biphenyldicarboxylic acid mainly has the following routes: (1) 4,4′-dialkylbiphenyl is used as raw material and prepared by oxidation under high temperature and pressure. This method not only The raw materials are expensive, and the reaction conditions are harsh, there are many by-products, separation and purification are difficult, and the yield is low (generally lower than 56%); (2) biphenyl is used as a raw material, and 4,4-ˊdi(chloro Methyl) biphenyl, and then undergo nucleophilic substitution reaction with hexamethylenetetramine to h...

AI Technical Summary

Problems solved by technology

At present, the synthesis of 4,4′-biphenyldicarboxylic acid mainly has the following routes: (1) 4,4′-dialkylbiphenyl is used as raw material and prepared by oxidation under high temperature and pressure. This method not only The raw materials are expensive, and the reaction conditions are harsh, there are many by-products, separation and purification are difficult, and the yield is low (generally lower than 56%); (2) biphenyl is used as a raw material, and 4,4-ˊdi(chloro Methyl) biphenyl, and then undergo nucleophilic substitution reaction with hexamethylenetetramine to hydrolyze to 4,4′-biphenyldicarbaldehyde, and then oxidize with hydrogen peroxide to obtain 4,4′-biphenyldicarboxylic acid, which is synthesized by this method There are many steps, and the yield is only 38.2%; (3) Suzuki cross-coupling reaction is carried out using p-hydroxyphenylboronic acid and p-bromobenzoic acid as raw materials, but the reaction conditions are high, and the raw materials must be esterified, and there are many reaction steps. It is uneconomical and not suitable for industrialized production; (4) using p-iodobenzoic acid as raw material, through the coupling synthesis of zinc and triethylamine formate, the price of raw materials used is high and uneconomical; (5) using p-aminobenzoic acid As a raw material, it is prepared by diazotization and then catalytic coupling of monovalent copper ions. The yield can reach 82%, but the diazotization conditions are high and not suitable for large-scale production.

At present, the market price of 4,4'-biphenyl dicarboxylic acid is high, and it is necessary to develop a simple, economical and efficient new synthetic method to prepare 4,4'-biphenyl dicarboxylic acid, from the aspects of raw materials, synthesis steps, reaction system, etc. Reduce the production cost of 4,4′-biphenyldicarboxylic acid and meet market requirements