Taylor, Edward C.; Jacobi, Peter A. published an article in 1973, the title of the article was Pteridines. XXX. Facile synthesis of xanthopterin.Reference of 2-Aminomalononitrile 4-methylbenzenesulfonate And the article contains the following content:
Pterin 8-oxide (I) rearranges quant. to xanthopterin (II) upon dissolution in a mixture of CF3CO2H/(CF3CO)2O at 50°. The experimental process involved the reaction of 2-Aminomalononitrile 4-methylbenzenesulfonate(cas: 5098-14-6).Reference of 2-Aminomalononitrile 4-methylbenzenesulfonate
The Article related to pterin oxide rearrangement xanthopterin, Heterocyclic Compounds (More Than One Hetero Atom): Purines and Pteridines and other aspects.Reference of 2-Aminomalononitrile 4-methylbenzenesulfonate
Referemce:
Nitrile – Wikipedia,
Nitriles – Chemistry LibreTexts