A practical and transition-metal-freeoxidative cyclization of acylhydrazones into 1,3,4-oxadiazoles has been developed by employing stoichiometric molecular iodine in the presence of potassium carbonate. The conditions of this cyclization reaction also work well with crude acylhydrazone substrates obtained from the condensation of aldehydes and hydrazides. A series of symmetrical and asymmetrical
Facile Synthesis of Symmetric and Unsymmetric 1,3,4-Oxadiazoles Using 2-Acyl(or aroyl)pyridazin-3-ones
作者:Yong-Jin Yoon、Yong-Dae Park、Jeum-Jong Kim、Hyun-A Chung、Deok-Heon Kweon、Su-Dong Cho、Sang-Gyeong Lee
DOI:10.1055/s-2003-37647
日期:——
Symmetric and unsymmetric 1,3,4-oxadiazoles were synthesized in situ from hydrazine hydrate and the corresponding 2-acyl-4,5-dichloropyridazin-3-ones as acylating agents in polyphosphoric acid or BF 3 OEt 2 in excellent yields.