CONDENSATION-REACTIONS OF 3-AMINO-4-IMINO-4H-THIENO-[3,4-C][1]BENZOPYRAN

The title compound 1 reacts with trifluoroacetic anhydride to give the doubly trifluoracetylated derivative 2 and in addition the coumarin d erivative 3. In refluxing DME two moles of 1 react with loss of one mo lecule of ammonia to afford 4, which undergoes subsequent N-acylation by beta-dicarbonyl compounds 9a-f to yield N-acyl derivatives 10a-f. W ith dimethyl malonate (9a) besides compound 10a, the cycloacylated com pound 11 was also obtained in good yield. Compound 11 is readily hydro lysed and decarboxylated with both acid and alkali to the previously d escribed fused derivative 12. The latter may be converted into the new thienopyrimidinone derivative by action of aqueous alkali.