Synthetic method of p-bromobenzaldehyde

Abstract

According to the invention, p-bromobenzaldehyde is synthesized by taking p-bromotoluene as a raw material. P-bromotoluene is subjected to a bromination reaction under the catalysis of bromine, and the mass ratio of p-bromotoluene to bromine is 1: 1-1: 2; and the method further comprises the following steps: heating to 120-150 DEG C in an oil bath, adding bromine, carrying out a heat preservation reaction for about 1-3 hours, stopping heating to obtain bromide, adding 200-600 mL of water into the bromide to carry out a hydrolysis reaction, heating to 100-110 DEG C, and carrying out a reflux heat preservation reaction for 10-15 hours; cooling to temperature below 10 DEG C, carrying out suction filtration to neutral, and drying; dissolving the dried material, carrying out suction filtration, and carrying out evaporative crystallization to obtain p-bromobenzaldehyde; and obtaining 76.29 g of p-bromobenzaldehyde of which the yield is 82.5%, the bromine content is 42.48%, the melting point is 54.6-56.7 DEG C, and the purity is 98.87%. The p-bromobenzaldehyde is synthesized by adopting the method, the raw material cost is low, operation is simple and feasible, and the tail gas absorption device is arranged, so that emission of harmful gas is reduced, and industrialization is easy to realize.

Description

technical field [0001] The invention relates to a synthesis method of p-bromobenzaldehyde, which belongs to the field of fine chemicals. Background technique [0002] 4-Bromobenzaldehyde is an important fine chemical. It is used as an intermediate in chemical synthesis to synthesize many benzene-containing compounds. It is widely used in pharmaceutical, pesticide and dye industries. At present, there is no large-scale industrial production of p-bromobenzaldehyde in China, and it needs to be imported in large quantities from abroad every year. The traditional method for synthesizing p-bromobenzaldehyde is to utilize the hydrolysis of isocarbon dihalocarbons. This production method has simple process and high yield, but the discharge of toxic gas and waste liquid will cause serious pollution to the surrounding environment. At present, the electro-oxidation method is mostly used for the preparation of p-bromobenzaldehyde, but the treatment of the circulating water phase and hi...

AI Technical Summary

Problems solved by technology

The traditional method for synthesizing p-bromobenzaldehyde is to utilize the hydrolysis of isocarbon dihalocarbons. This production method has simple process and high yield, but the discharge of toxic gas and waste liquid will cause serious pollution to the surrounding environment.

At present, the electro-oxidation method is mostly used for the preparation of p-bromobenzaldehyde, but the treatment of the circulating water phase and high energy consumption make the electro-oxidation method difficult to achieve large-scale production

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