One-Pot Synthesis of 4-Thiocyanato-1H-pyrazoles through Electrochemical Multicomponent Thiocyanation under Metal- and Oxidant-Free Conditions

An electrochemical oxidative three-component tandem reaction of arylhydrazines, 1,3-diketones and ammonium thiocyanate has been established to construct 4-thiocyanato-1H-pyrazoles under metal-, oxidant-free and mild conditions in an undivided cell. Various 4-thiocyanato-1H-pyrazole derivatives could be obtained with broad substrate scope, and excellent functional group tolerance from available raw materials in moderate to excellent yields. This thiocyanation protocol with practicability and scalability features economical and eco-friendly.

Automated summary

An electrochemical three-component reaction was developed for the synthesis of 4-thiocyanato-1H-pyrazoles from arylhydrazines, 1,3-diketones and ammonium thiocyanate. The reaction proceeded under mild conditions without the need for any metal catalyst or oxidant in an undivided cell. The protocol demonstrated broad substrate scope, excellent functional group tolerance, and was economically and eco-friendly.