The benzannalated cycl [3. 2. 2] azine, benzo [g] cycl [3. 2. 2] azine (2), was synthesized from 2-methylthiopyrrolo [2, 1-a] isoquinoline (5) and dimethyl acetylenedicarboxylate. The key intermediate (5) for the synthesis of 2 was prepared using the reaction of isoquinolinium ketene dithioacetal (8) with nitromethane in good yields. Compound 8 was obtained using the reaction of 2-ethoxycarbonylmethylisoquinolinium bromide (6) with carbon disulfide and dimethyl sulfate in the presence of sodium hydroxide followed by methylation with methyl iodide.