Abstract: | Reaction of 3‐amino‐3‐methylthio‐2‐cyanoacrylonitrile (1) with excess dimethyl acetylenedi‐carboxylate(DMAD) in the presence of potassium carbonate in dimethyl sulfoxide gave a novel tricyclic heterocycle, hexamethyl lH‐1,4,7‐triazaphenalene‐2,3,5,6,8,9‐hexacarboxylate ( 5a ). When one equivalent of DMAD was used in this reaction, dimethyl 4‐amino‐3‐cyano‐2‐methylthiopyridine‐5,6‐dicarboxylate ( 3a ), a key intermediate of 5a , was obtained. |