Researchers from Zelinsky Institute developed a cascade process for the synthesis of carbonyl-substituted pyrazoles

Currently, cascade reactions are widely used in organic synthesis for efficient and fast synthesis of molecules of complex structure. High selectivity of cascade transformations is provided by the sequential formation of several new chemical bonds during one process.

Researchers from Laboratory № 22 of the Institute of Organic Chemistry developed a new cascade process for the synthesis of carbonyl-substituted pyrazoles — important structural fragments of many natural compounds and drugs. Thus, the reaction of 1,3-dicarbonyl compounds with thiohydrazides of oxamic acids in the presence of iodine leads to the formation of 3,4-dicarbonyl pyrazoles. Due to the possibility of a wide variation of the structures of the starting reagents, researchers succeeded in the synthesis of previously difficult-to-obtain pyrazoles with carboxyl, ester, and amide groups. The possibility of using the obtained structures in the synthesis of functionalized annulated nitrogen-containing heterocycles was also shown. The simplicity of the developed approach permits to use it as a preparative one, and also makes it possible to apply it in pharmacological studies and the design of new materials for various purposes.

Source:

A. S. Komendantova, K. A. Lyssenko, I. V. Zavarzin, Yu. A. Volkova Iodine-promoted synthesis of pyrazoles from 1,3-dicarbonyl compounds and oxamic acid thiohydrazides Org. Chem. Front., 2020, 7, 1640-1646, DOI: 10.1039/D0QO00476F