Electrochemical Oxidation Involving Sulfonyl Hydrazine for the Synthesis of 2-Sulfonyl Quinolines/Pyridines

A mild electrochemical method was developed for the direct C2 sulfonylation of heteroaromatic N-oxides with sulfonyl hydrazides to obtain a serial of 2-sulfonyl quinoline/pyridine derivatives. The method has simple conditions, using potassium carbonate as base, CH3CN/H2O (9 : 1) as solvent, and reacting for 3 h under 15 mA current to prepare expected products.