Method for preparing chlorobenzaldehyde through catalytic oxidation of chlorotoluene

Abstract

The invention discloses a method for preparing chlorobenzaldehyde through catalytic oxidation of chlorotoluene. According to the method, a high-pressure reaction kettle is adopted as a reactor, M / Al-MCM-41 (M=Co, Mn) loaded metal oxide is adopted as a catalyst, an Al-MCM-41 molecular sieve is adopted as a carrier, Co and Mn are adopted as active components, oxygen is adopted as an oxidizing agent,KBr is adopted as a cocatalyst, and acetic acid is adopted as a solvent. The optimal reaction conditions are as follows: the reaction temperature is 120 DEG C, the reaction time is 10 hours, the catalyst dosage is 2.5%, the active component loading capacity is 13%, the Co / Mn ratio is 1 / 2, the cocatalyst dosage is 0.5%, the oxygen introduction control reaction pressure is not more than 0.2 MPa, the solvent dosage is 30%, the highest o-chlorotoluene conversion rate can reach 90%, and the highest chlorobenzaldehyde selectivity is 92%. The catalyst provided by the invention has the characteristics of good stability, low catalyst cost, environmental friendliness, simple reaction process and the like, and has a good industrial application prospect.

Description

technical field [0001] The invention belongs to the technical field of chlorobenzaldehyde preparation, and in particular relates to a method for preparing chlorobenzaldehyde by catalytic oxidation of chlorotoluene. Background technique [0002] O-chlorobenzaldehyde has a density of 1.243g / cm3 and a boiling point of 211.9°C (normal pressure), and p-chlorobenzaldehyde has a density of 1.196g / cm3 and a boiling point of 214°C. They are important intermediates for synthetic dyes, pesticides and medicines body. [0003] At present, chlorobenzaldehyde can be synthesized by the following methods, including chlorination hydrolysis, electrochemical oxidation, hydrogen peroxide oxidation, air or oxygen direct oxidation, etc. The traditional industrial production of chlorobenzaldehyde is mainly through the chlorination and hydrolysis of chlorinated toluene, which has the disadvantages of complex process, difficulty in controlling the degree of chlorination, high production cost, and se...

AI Technical Summary

Problems solved by technology

The traditional industrial production of chlorobenzaldehyde is mainly through the chlorination hydrolysis of chlorinated toluene. This method has the disadvantages of complex process, difficult control of chlorination degree, high production cost, and serious environmental pollution.

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