Polyfunctional fused heterocyclic compounds via indene-1,3-diones

2-Dimethylaminomethylene- and 2-ethoxymethylene-1,3-indendione 1a,b react with 6-amino-2-thioxopyrimidin-4(3H)-one 2 in boiling acetic acid to give 2-thioxo-1,3-dihydroindeno[3,2d]pyrimidino[4,5-b]pyridine-4,9-dione (4). The latter compound reacts with hydrazonoyl chlorides 5a-c to afford products 12a-c. Formamidine 15 reacts with indene-1,3-dione in boiling ethanol to give acyclic compound 16, which cyclizes to 12a in boiling glacial acetic acid. Also, enaminone 1a reacts with heterocyclic amines 17a-e in boiling ethanol, affording the corresponding substitution products 18a-c, respectively The latter products 18a-c cyclize in glacial acetic acid to give 19a-c, respectively. The structures of the newly synthesized compounds are established on the basis of chemical and spectroscopic evidence. (C) 2003 Wiley Periodicals, Inc.