Synthesis method of fused-ring pyrazole compounds

Abstract

The invention provides a synthesis method of fused-ring pyrazole compounds. The method includes the steps of: with a p-tosylhydrazone compound connected by an alkynyl group as a raw material, performing a one-step reaction in an organic solvent at certain temperature without catalysis by a catalyst to generate a coarse product of the fused-ring pyrazole compound; and washing the coarse product in dichloromethane to obtain pure products of the fused-ring pyrazole compounds in different structures. The method is free of any catalyst, employs easy-to-synthesized raw materials, has high reaction yield, is free of column chromatography and has simple and safe operations. The fused-ring pyrazole compounds are important chemical and medicinal intermediates, and among of the compound, some having special structures further have excellent bioactivity and can be widely applied in the field of the chemical and medicinal industries.

Description

technical field [0001] The invention belongs to the technical field of synthesis, in particular to a method for synthesizing fused ring pyrazole compounds. Background technique [0002] Pyrazole compounds are a kind of basic framework for constructing biologically active compounds, and there are many substances containing such structural units in nature. In the past few years, the effective methods for the synthesis of pyrazoles mainly include Knorr cycloaddition and cycloaddition of diazo or diazo precursors to hydrazones and alkynes. In these reports, the regioselectivity of the Knorr cycloaddition is not very good due to the use of electrically similar biscarbonyl compounds. However, after the cycloaddition of diazonium and alkyne, further aromatization is required to generate pyrrole, which inevitably has the problem of selectivity during group migration. Moreover, the above two types of methods are less involved in the direct synthesis of fused ring pyrazole compounds...

AI Technical Summary

Problems solved by technology

In these reports, the regioselectivity of the Knorr cycloaddition is not very good due to the use of electrically similar biscarbonyl compounds.

However, after the cycloaddition of diazo and alkyne, further aromatization is required to generate pyrrole, and there will inevitably be a problem of selectivity during group migration.

And above-mentioned two kinds of methods are less involved in the direct synthesis of fused ring pyrazole compounds with biological activity.

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