Benzoyl chloride and paraphthaloyl chloride co-production method

Abstract

The invention discloses a benzoyl chloride and paraphthaloyl chloride co-production method. An acylating chlorination reaction is conducted under the action of a lewis acid catalyst with terephthalic acid and trichlorotoluene as raw materials, and paraphthaloyl chloride and benzoyl chloride are generated, wherein the catalyst is one or more of FeCl3, AlCl3, TiCl4 and tetrabutyl titanate, and the amount of the catalyst is 0.1-0.5% of the total mass of reactants; the molar ratio of the trichlorotoluene to the terephthalic acid is 2-3 to 1, the reaction temperature of the acylating chlorination reaction is 70-140 DEG C, and the reaction time is 2-6 hours. The benzoyl chloride is produced while the paraphthaloyl chloride is produced; the benzoyl chloride and paraphthaloyl chloride co-production method has the advantages that the raw materials are obtained easily, the reaction conditions are mild, safety is good, and the comprehensive production cost is low; the sulfur-containing raw material is not used in the new technology, micro sulphur does not exist in the paraphthaloyl chloride product, the inherent quality is high, and the para-aramid fiber production requirement can be met better.

Description

technical field [0001] The invention belongs to the technical field of organic chemical industry, and relates to a co-production method of benzoyl chloride and terephthaloyl dichloride, in particular to a method for preparing terephthaloyl dichloride co-production by using trichlorotoluene as a chlorination agent and terephthalic acid. Method for producing benzoyl chloride. Background technique [0002] With the demand of domestic and foreign aramid fiber industries, especially the rapid development of aramid fiber 1414, terephthaloyl chloride, one of the important raw materials for the synthesis of aramid fiber 1414, also develops rapidly thereupon. In addition, terephthaloyl chloride can be As a monomer of insulating materials, dyes, pigments, polyamides, polyesters, polyarylates, polyester amides, polyarylamides, liquid crystal polymers, etc., it can also be used as a modifier for high polymers, and as an agent for pesticides and pharmaceutical processes. Intermediates, ...

AI Technical Summary

Problems solved by technology

Phosphorus pentachloride is a good chlorinating agent, but because it is solid, it is more difficult to feed than phosphorus trichloride, and phosphorus pentachloride can easily absorb moisture in the air and decompose to release hydrogen chloride gas, which not only affects the operator health, and affect the ratio of feeding, inconvenient to operate, so the phosphorus pentachloride method is not suitable for industrial scale applications

However, when p-xylene chlorination is used to prepare p-dichlorobenzene, chlorination on the benzene ring is prone to occur, and the mixing of chlorinated products and p-dichlorobenzene will inevitably increase the difficulty of post-processing and affect the purity of the product.

In addition, compared with other raw materials, the preparation process of this two-step reaction is complicated, the process is long, the reaction requirements are high, and the yield is low. At the same time, it generally requires ultraviolet radiation to react, which consumes a lot of energy and has high cost. Ideal production method of terephthaloyl chloride