C5-Alkyl-1,3,4-Oxadiazol-2-ones Undergo Dealkylation upon Nitrogen Insertion to Form 2 H-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-2 H-1,2,4-triazol-3(4 H)-ones as major product. Subsequent reactions of 2-aryl-2 H-1,2,4-triazol-3(4 H)-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. [ABSTRACT FROM AUTHOR]