C5‐Alkyl‐1,3,4‐Oxadiazol‐2‐ones Undergo Dealkylation upon Nitrogen Insertion to Form 2H‐1,2,4‐Triazol‐3‐ones: Synthesis of 1,2,4‐Triazol‐3‐one Hybrids with Triazolothiadiazoles and Triazolothiadiazines

The present study emphasizes on the dealklylation of 3‐aryl‐5‐alkyl‐2‐oxo‐Δ4‐1,3,4‐oxadiazoles when reacted with formamide resulting in the formation of 2‐aryl‐2H‐1,2,4‐triazol‐3(4H)‐ones as major product. Subsequent reactions of 2‐aryl‐2H‐1,2,4‐triazol‐3(4H)‐one gave triazolo[3,4‐b][1,3,4]thiadiazoles and triazolo[3,4‐b][1,3,4]thiadiazines derivatives incorporated with 1,2,4‐triazol‐3‐one.