Method for preparing 4,5-diaryl-2H-1,2,3-triazole compound

Abstract

The invention relates to a method for preparing a 4,5-diaryl-2H-1,2,3-triazole compound. The method specifically comprises steps as shown in the description, wherein a compound of formula II as shownin the description is reacted with R2CN to generate a compound of formula I as shown in the description under the action of an alkali in an organic solvent; R1 and R2 are respectively and independently selected from C5-C10 aryl which are optionally substituted by halogen, alkoxy, alkyl and chloroalkyl; the alkali is selected from t-BuOK and NaHMDS; the mole ratio of the compound of formula II as shown in the description to R2CN to the alkali is 1:(1.0-1.2):(2.5-3.0); the organic solvent is optimally selected from methylbenzene, xylene, DMF (Dimethyl Formamide), dioxane, polyethyleneglycol dimethyl ether, methyl tertiary butyl ether and N-methyl pyrrolidone; a reaction temperature is optimally 60-100 DEG C, and further optimally 60-80 DEG C; the reaction time is optimally 3-4 hours.

Description

technical field [0001] The invention belongs to the field of organic synthesis, and in particular relates to a preparation method of a 4,5-diaryl-2H-1,2,3-triazole compound. Background technique [0002] 1,2,3-triazole is an important five-membered heterocyclic structure, which plays an important role in many medicines, pesticides, and material molecules. Many 1,2,3-triazole compounds or compounds containing triazole structures have special physiological activities, such as antibacterial, antitumor, antiallergic, anti-HIV virus and so on. At the same time, they have important applications in herbicides, fluorescent materials and so on. 4,5-diaryl-2H-1,2,3-triazole compound is a special triazole compound. NH-1,2,3-triazole is a class of triazoles with no substituents on the N atom. Experimental studies have shown that NH-1,2,3-triazole has in vitro antitumor activity against a variety of tumor cells, such as lobules Pulmonary hyperplasia, etc. In 2015, a series of 4,5-dia...

AI Technical Summary

Problems solved by technology

However, in this reaction, when the two aromatic aldehyde sulfonylhydrazones are different, the reaction will generate self-coupling products and cross-coupling products to varying degrees, and these self-coupling products are also 4,5-diaryl-2H- 1,2,3-triazole compound, which brings difficulties to the separation and purification in the later stage of the reaction

It is worth noting that the author also tried cesium carbonate to promote the reaction between p-chlorobenzaldehyde p-toluenesulfonylhydrazone and 2-chlorobenzonitrile and 3-chlorobenzonitrile, and also obtained the corresponding 4,5 -Diaryl-2H-1,2,3-triazole compound (yield less than 50%); however, the reaction excludes the expected 4,5-diaryl-2H-1,2,3-triazole compound In addition, a large amount of aromatic aldehyde sulfonylhydrazone self-coupling products have also been produced, and these self-coupling products and expected products all belong to 4,5-diaryl-2H-1,2,3-triazole compounds, thereby, self- The coupling product is used as an impurity, and the impurity is relatively close to the expected product in polarity and molecular size, which makes it difficult to separate and purify the expected product, which in turn affects the purity of the expected product

Simultaneously, this reaction yield is low, and these factors have all limited the application value of this reaction

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