Rearrangement of 3,3-Disubstituted 1-Aryl-4,5-dihydro-5-oxo-3H-1,2,4-triazolium Tetrafluoroborates; Part 1. A Versatile Synthesis of 1,5-Disubstituted 2-Aryl-1,2-dihydro-3H-1,2,4-triazol-3-one Tetrafluoroborates

Article abstract of DOI:10.1055/s-1990-27021

α-(Arylazo)alkyl isocyanates 3 react with tetrafluoroboric acid to yield 3,3-disubstituted 1-aryl-4,5-dihydro-5-oxo-3H-1,2,4-triazolium tetrafluoroborates 4.These compounds rearrange under mild conditions and in good yields to the tetrafluoroborates of 1,