Thiocyanation of Pyrazoles Using KSCN/K2S2O8 Combination

Abstract

A convenient and practical thiocyanation of pyrazoles is reported employing a combination of KSCN and K 2 S 2 O 8 in dimethyl sulfoxide (DMSO). The salient features of the present reaction include environmentally benign reagents and solvents, and simple operation. The reaction shows wide functional group tolerance and gives moderate to excellent yields.

Hydrogen Peroxide-Mediated Rapid Room Temperature Metal-Free C(sp2)-H Thiocyanation of Amino Pyrazoles, Amino Uracils, and Enamines

“…Aminopyrazole and aminouracils are found in diverse drugs and bioactive molecules, and they act as valuable starting materials for the construction of fused N -heterocycles . Although a plethora of methods are known in the literature for thiocyanation of arenes, indoles, carbazoles, pyrroles, and imidazopyridines, however, till now, only limited methods are known for the thiocyanation of the pyrazole moiety . Hydrogen peroxide is a popular and benign oxidizing agent used in various organic transformations .…”

Regioselective C(sp2)3−H thiocyanation of substituted 4H‐pyrido[1,2‐a]pyrimidin‐4‐ones and its derivatizations

“…In addition to that, several other procedures are widely documented in the literature for direct thiocyanation of heterocycles, especially imidazo[1,2‐ a ]pyridine, indoles, aminoquinoline, uracil, indazoles and pyrrolo[1,2‐ a ]quinoxalineand many of them are catalyzed by either Cu or Fe catalysts [11] . However, selective thiocyanation of other N ‐fused heterocycles is still at a nascent stage and remains an attractive area of research [11i–k] …”

Peroxodisulfate-assisted synthesis of 2-thiocyanato glycals and their transformation to C-2-thio acrylo/aryl nitrile-substituted glycals

“…Based on the aforementioned experimental findings and existing literature, [13][14][15][16][17][18][19] a plausible reaction pathway for the K 2 S 2 O 8 -mediated thiocyanation of glycals is proposed, as illustrated in Fig. 2…”