Thiocyanation of N,N-Dialkylhydrazonoyl Bromides: An Entry to Sulfur-Containing 1,2,4-Triazole Derivatives

A simple and practical one-pot protocol involving sequential C-H bromination and thiocyanation of readily available aldehyde-derived N,N-dialkylhydrazones has been established for the synthesis of 5-thioxo-1,2,4-triazolium inner salts. Application of the method toward the synthesis of value-added 3-sulfanyl-1,2,4-triazoles through NS alkyl group transfer has also been demonstrated.