Mononuclear heterocyclic rearrangements. Part 10. Rearrangements in the 1,2,5-oxadiazole series

Abstract

By studying the chemical behaviour of N-(4-methyl-1,2,5-oxadiazol-3-yl)-N′-phenylurea and of N-(4-methyl- or phenyl-1,2,5-oxadiazol-3-yl)-N′-arylformamidines in mononuclear heterocyclic rearrangements and comparing these results with those already obtained in the 1,2,4-oxadiazole and isoxazole series, relative tendencies towards mononuclear heterocyclic rearrangement have been estimated; viz. 1,2,4-oxadiazole > isoxazole > 1,2,5-oxadiazole.