Synthesis and heterocyclizations of 3-alkynyl-6,8-dimethylpyrimido-[4,5-c]pyridazine-5,7(6H,8H)-diones and their lumazine analogues

Abstract

Synthesis of some condensed pyrrolo‐, thieno‐, furo‐, pyrido‐ and pyranopteridines as well as isomeric pyrrolo‐ and thienopyrimido[4,5‐c]pyridazines from alkynyl derivatives of 6,8‐dimethylpyrimido[4,5‐c]pyridazine‐5,7(6H,8H)‐dione and 1,3‐dimethyllumazine is represented.