An unusual bicyclic oxidation product of dithizone

Publisher Website
Google Scholar
Abstract
The oxidation of dithizone [3-mercapto-1,5-diphenylformazan, C13H12N4S, (I); R = SH] under alkaline conditions to a sydnone, C13H10N4S (II), is reversible; however under acid conditions elimination of a proton from the ortho-position of one of the phenyl residues leads to a purple isomer with a new bicyclic ring system (IV), the structure of which has been established by X-ray structure analysis.