Synthetic method of benzimidazole compounds

Abstract

The invention discloses a synthetic method of benzimidazole compounds. The synthetic route of the synthetic method is shown in the description. The method comprises the following steps: 1) substitutedo-phenylenediamine (I), aromatic aldehyde (II) and L-carnitine are added to a solvent for a heating reaction, and a crude product is obtained; 2) the crude product obtained in step 1) is filtered, solid substances are collected and dried, and the benzimidazole compounds (III) are obtained, wherein Ar of aromatic aldehyde is a benzene ring with substituents in ortho-position, meta-position and / orpara-position, and the substituents comprise halogen, methoxy and nitro; R of substituted o-phenylenediamine comprises hydrogen and nitro. According to the synthetic method, starting materials are cheap and easily available, reaction conditions are relatively mild, the catalyst L-carnitine is high in catalysis efficiency, postprocessing is simple, the compounds are low-toxic and safe, and industrialization is easy to realize.

Description

technical field [0001] The invention belongs to the field of synthesis of organic heterocyclic compounds, and in particular relates to a synthesis method of benzimidazole compounds. Background technique [0002] Benzimidazole compounds are a very important class of organic heterocyclic compounds, which have a variety of biological and pharmacological activities, such as: blood coagulation, anticancer, antispasmodic, antiallergic, etc. At the same time, benzimidazole derivatives are also many natural An important constituent unit of the product. Therefore, in recent years, people's research on benzimidazole derivatives has become more and more in-depth, and has become a hot spot in the field of organic synthetic chemistry research. [0003] In the prior art, the common method for synthesizing benzimidazole derivatives is to prepare them by dehydration and ring closure of o-phenylenediamine and aromatic aldehyde. Usually strong acid conditions are required, sometimes very hi...

AI Technical Summary

Problems solved by technology

These oxidants catalyze the synthesis of benzimidazoles usually at high temperature, and the conditions are harsh, the operation is complicated, and the post-treatment of the product is cumbersome.

In addition, metal indium compounds, rare earth metal ytterbium compounds, tannic acid, etc. are used as catalysts to synthesize benzimidazole compounds. Although they can effectively catalyze the reaction of o-phenylenediamine and aromatic aldehydes to generate benzimidazole compounds, there are more or less Some problems, such as expensive catalysts, difficult catalyst preparation, harsh reaction conditions, cumbersome post-treatment operations, inability to recycle and reuse catalysts, and hazards of catalyst residues, etc.

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