142346-13-2Relevant academic research and scientific papers
4-Acylhydrazinomethylene-2-phenyloxazol-5(4H)-ones as acylating agents: Synthesis of salicylanilides and 1,2,4-triazolo[4,3-b] pyridazines
Po?gan, Franc,Polanc, Slovenko,Ko?evar, Marijan
, p. 1011 - 1019 (2007/10/03)
A simple and general method for the acylation of an amino or hydrazino group by the application of hydrazides has been developed. It starts from hydrazides (2), which are converted with 4-ethoxymethylene-2-phenyl-oxazol-5(4H)-one (1) to the corresponding 4-acylhydrazinomethylene-2-phenyloxazol-5(4H)-ones (3). The latter react with nitrogen-containing nucleophiles in 1,4-dioxane in the presence of triethylamine or zirconium(IV) chloride to give the corresponding amides (7) or mixtures of hydrazides (12) and 1,2,4-triazolo[4,3-b]pyridazines (11). Upon prolonged heating, compounds (11) are the main products.
