Oxone-mediated facile access to substituted pyrazoles

An Oxone-mediated transition-metal-free oxidative C-N bond formation has been achieved for the regioselective synthesis of substituted pyrazoles. The reactions accompany the chelation-controlled ortho-oxidation of N-substituted aromatic ring to provide phenol derivatives in some cases. This method displays a facile access to diverse range of substituted pyrazoles from readily accessible hydrazones.