Download full text in PDF Opens in a new window. Article suggestions will be shown in a dialog on return to ScienceDirect. ... Please enable JavaScript to use all the features on this page. ... The treatment of ketal hydrazones of arylglyoxals (2) with 75% sulfuric acid leads to 3-aroyl-4-phenyl-1-methylpyrazoles (6) as well as 4-phenyl-1-methylpyrazole (7) and the corresponding benzoic acids. Possible mechanisms are discussed. ... K. Kano, JC Warner, D. Scarpetti, ...