Electrochemical thiocyanation of barbituric acids.

The electrochemical thiocyanation of barbituric acids with NH 4 SCN was disclosed in an undivided cell under constant current conditions. The electrosynthesis is the most efficient at a record high current density ( j anode ≈50-70 mA cm -2 ). NH 4 SCN has a dual role as the source of the SCN group and as the electrolyte. Electrochemical thiocyanation of barbituric acids starts with the generation of (SCN) 2 from the thiocyanate anion. The addition of thiocyanogen to the double bond of the enol tautomer of barbituric acid gives thiocyanated barbituric acid. A variety of thiocyanated barbituric acids bearing different functional groups were obtained in 18-95% yields and were shown to exhibit promising antifungal activity.