Rearrangement of 3,3-Disubstituted 1-Aryl-4,5-dihydro-5-oxo-3<i>H</i>-1,2,4-triazolium Tetrafluoroborates; Part 1. A Versatile Synthesis of 1,5-Disubstituted 2-Aryl-1,2-dihydro-3<i>H</i>-1,2,4-triazol-3-one Tetrafluoroborates
作者:Hubert Gstach、Patrick Seil
DOI:10.1055/s-1990-27021
日期:——
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-triazo-lium tetrafluoroborates 4. These compounds rearrange under mild conditions and in good yields to the tetrafluoroborates of 1,5 disubstituted 2-aryl-1,2-dihydro-3H-1,2, 4-triazol-3-ones 5. Our results show that the nature of the substituents determines their migratory aptitude for the rearrangement.
α-(芳基氮)烷基异氰酸酯 3 与四氟硼酸反应生成 3, 3-取代的 1-芳基-4,5-二氢-5-氧-3H-1,2,4-三氮鎓四氟硼酸盐 4。这些化合物在温和条件下以良好的收率重排生成 1,5-双取代的 2-芳基-1,2-二氢-3H-1,2,4-三氮烯-3-酮的四氟硼酸盐 5。我们的结果表明,取代基的性质决定了它们在重排中的迁移适应性。