Chemistry of furazano[3,4-b]pyrazines: 3. Method for the synthesis of 5,6-disubstituted furazano[3,4-b]pyrazines

A method was developed for the synthesis of 5,6-dichlorofurazano[3,4-b]pyrazine (a compound with easily removed leaving groups). The optimum conditions for their substitution by various nucleophiles were determined.