The synthesis of pyrazino[2,3‐<i>d</i>]pyridazine and some of its derivatives

Abstract

Abstract Pyrazino[2,3‐ d ]pyridazine (I) was synthesized by two different routes. 5, 8‐Dihydroxy‐pyrazino[2, 3‐ d ]pyridazine (IV) was converted to 5, 8‐dichloropyrazino[2, 3‐ d ]pyridazine (V) and 5, 8‐dibromopyrazino[2, 3‐ d ]pyridazine (Va). When V was treated with various benzyl mercaptans and alkoxides the corresponding disubstituted derivatives were obtained. Compound V when allowed to react with aromatic amines gave 5, 8‐bisamino‐pyrazino[2,3‐ d ]pyridazines, however, with aliphatic amines only mono substituted products were obtained substituted in the 8‐position. The reaction of pyrazine‐2, 3‐dinitrile with hydrazine gave 5, 8‐diaminopyrazino[2, 3‐ d ]pyridazine (X).