K2S2O8-promoted C3-thiocyanation of pyrazole [1,5-a] pyrimidine-7-amines

K2S2O8-promoted direct C3-thiocyanation of pyrazolo[1,5-a]pyrimidin-7-amine with KSCN is described. A series of C3-thiocyanated products bearing multiple functional groups are obtained with moderate to excellent yields. The present approach exhibits unique features including mild reaction conditions, a wide range of substrates, and gram-scale production. This strategy provides an alternative way for the synthesis of novel pyrazolo[1,5-a]pyrimidine-7-amine derivatives.