Crystal structures of the "two" 4-aminofurazan-3-carboxylic acids
The crystal structures of the two compounds reported to be 4-aminofurazan-3-carboxylic acid have been determined. The compound reported by Sheremetev et al. (J Heterocycl Chem 2005, 42, 519) is the actual 4-aminofurazan-3-carboxylic acid. The compound reported by Meyer (Org Prep Proced Int 2004, 36, 361) is the interesting complex formed from a molecule of the acid and a molecule of the potassium salt of the acid. J. Heterocyclic Chem., (2012).