An ANRORC approach to the synthesis of perfluoroalkylated 1,2,4-triazole-carboxamides

A series of perfluoroalkyl-1,2,4-triazole-carboxamides has been obtained through an ANRORClike rearrangement (Addition of Nucleophile, Ring-Opening and Ring-Closure) of 5- perfluoroalkyl-1,2,4-oxadiazole-3-carboxamides with methylhydrazine or hydrazine. The initial addition of the bidentate nucleophile to the electrophilic C(5) of the 1,2,4-oxadiazole ring, followed by ring opening and ring closure, leads to the formation of triazoles in good yield under mild experimental conditions. In some cases, a competitive ANRORC-enlargement reaction to form 1,2,4-triazin-6-ones was also observed. Obtained carboxamidotriazoles have also been explored as precursors for the synthesis of 3(5)-perfluoroalkyl-1,2,4-triazoles