A new method for the synthesis of 3‐Thiocyanatopyrazolo[1,5‐a]pyrimidines

Abstract

In this article, we demonstrate how an original effective “metal‐free” and “chromatography‐free” route for the synthesis of 3‐thiocyanatopyrazolo[1,5‐a]pyrimidines has been developed. It is based on electrooxidative (anodic) C–H thiocyanation of 5‐aminopyrazoles by thiocyanate ion leading to 4‐thiocyanato‐5‐aminopyrazoles (stage 1, yields up to 87%) following by their chemical condensation with 1,3‐dicarbonyl compounds or their derivatives (stage 2, yields up to 96%). This method is equally effective for the synthesis of 3‐thiocyanatopyrazolo[1,5‐a]pyrimidines, both without substituents and with various donor (acceptor) substituents in the pyrimidine ring.