| Cyanic acid (Y = O) as well as Thiocyanic Acid (Y = S) can be generated in situ by dissolving potassium cyanate or potassium thiocyanate in acetic acid or formic acid. | Thus an equilibrium between two tautomeric forms of the according acid is established, providing cyanic or thiocyanic acid - the presumed active species in the CYCLOADDITION REACTION to hydrazones. |