Synthetic uses of polyphosphoric acid. Part III. A ready synthesis of aromatic aldazines and ketazines
Abstract
Azines are prepared conveniently by heating aromatic aldehydes or ketones with various carbonyl reagents (hydrazine and its salts, semicarbazide and toluene-p-sulphonohydrazide) in polyphosphoric acid at 100° for a few minutes. Various dialkylaminophenylazines have been made by this route.