Preparation method of aminomethylbenzoic acid

Abstract

The invention discloses a preparation method of aminomethylbenzoic acid. Specifically, p-cyanobenzyl chloride (particularly 4-cyanobenzyl chloride) is taken as a raw material, and then 4-cyanobenzyl chloride is subjected to ammonolysis reaction under the catalysis of urotropine, so that the intermediate 4-cyanobenzylamine is obtained, and acid hydrolysis is carried out to obtain the end product aminomethylbenzoic acid. According to the preparation method of aminomethylbenzoic acid, provided by the invention, the synthetic procedures are short, the raw materials are easy to get, the yield is high, the cost is low, the quality is good, the pollution is less, the operation is simple and convenient and large-scale industrial production is facilitated.

Description

technical field [0001] The invention belongs to the technical field of medicine synthesis, and in particular relates to a preparation method of aminomethylbenzoic acid. Background technique [0002] The relevant information of aminomethylbenzoic acid is as follows: [0003] Chinese name: aminomethylbenzoic acid; [0004] English name: Aminomethylbenzoic Acid; [0005] Chemical name: 4-aminomethylbenzoic acid; [0006] CAS: 56-91-7; [0007] Structural formula: ; [0008] Molecular formula: C 8 h 9 NO 2 ; [0009] Molecular weight: 151.16; [0010] Properties: White scaly crystal or crystalline powder, slightly soluble in cold water, soluble in hot water, almost insoluble in ethanol and chloroform; [0011] Melting point: around 345°C. [0012] Aminomethylbenzoic acid is a commonly used powerful hemostatic drug, which has the hemostatic effect of anti-fibrinolysis. Its mechanism of action is the same as that of aminocaproic acid, but it is 4 to 5 times stronger t...

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Problems solved by technology

[0014] The first method (see pages 506-509 of "National Compendium of Raw Materials Processes") uses p-nitrobenzoic acid as a raw material, which is reduced by iron powder and hydrochloric acid to obtain p-aminobenzoic acid, and then uses sodium nitrite for diazotization reaction, and then React with sodium cyanide to generate p-cyanobenzoic acid, and finally obtain the product aminotoluic acid through hydrogen reduction under the catalysis of Raney nickel. However, the synthesis route has long steps, great pollution, and uses highly toxic sodium cyanide. There are major safety hazards in the

[0015] The second method uses p-xylene as a raw material, and the product is obtained through three steps of catalytic oxidation, chlorination and ammoniation, but the chlorination reaction has many restrictions, many by-products, and the yield is low

[0016] The third method is similar to the second method, but the raw material p-cumyl toluene is not easy to get, and the price of bromine is relatively high now, resulting in an increase in production costs

[0017] The fourth method (see CN102718673A) uses p-cyanobenzyl chloride as a raw material to obtain the product through acid hydrolysis and ammoniation. Although this method has a short route, it produces a hydrolysis by-product—benzyl chloride during hydrolysis, and the crystal structure of the product is different.

[0018] The fifth method is an existing process currently used in industry. It uses p-chloromethylbenzoic acid as a raw material, through ammoniation, acidification, removal of impurities, and neutralization with ammonia to obtain the product. However, there are many by-products in this process, and the yield lower

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