ABSTRACT A simple, environmentally benign protocol for synthesis of hydrazones from carbonyl compounds and hydrazides has been developed in the presence of meglumine in aqueous-ethanol media at room temperature. The salient features of the present protocol are mild reaction conditions, short reaction time, high yields, operational simplicity, metal-free, applicability toward large-scale synthesis, and biodegradable
Rearrangement of 3,3-Disubstituted 1-Aryl-4,5-dihydro-5-oxo-3<i>H</i>-1,2,4-triazolium Tetrafluoroborates; Part 2. A Convenient Synthesis of 1,5-Annulated 1,2-Dihydro-2-phenyl-3<i>H</i>-1,2,4-triazol-3-ones
作者:Hubert Gstach、Patrick Seil
DOI:10.1055/s-1990-27022
日期:——
1-Isocyanato-1-(phenylazo)cycloalkanes 3 react with tetrafluoroboric acid to yield 3-spiro substituted 4,5-dihydro-5-oxo-1-phenyl-3H-1,2,4-triazolium tetrafluoroborates 4. Compounds 4 rearrange with ring expansion in good yield to give, after basic workup, 1,5-annulated 1,2-dihydro-2-phenyl-3H-1,2, 4-triazol-3-ones 5.