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Communication | Special issue | Vol 42, No. 1, 1996, pp.53-56
Published online, 1st January, 1970
DOI: 10.3987/COM-95-S13
Synthesis of Polycyclic Nitrogen-containing Heterocycles: One Pot Formation of 1,6-Naphthyridine Ring System by Reaction of Amino-cycano-methylyhio-heterocycles with Dialkyl Acetylenedicarboxylates

Yoshinori Tominaga and Noriko Yoshioka

*Faculty of Pharmaceutical Sciences, Nagasaki University, 1-14, Bunkyo-machi, Nagasaki 852-8521, Japan


The reaction of 5-amino-6-cyano-1,3-dimethyl-7-methylthiopyrido[2,3-d]pyrimidine-2,4(1H,3H)-dione (1c) with dimethyl acetylenedicarboxylate (DMAD) in the presence of potassium carbonate in dimethyl sulfoxide gave tetramethyl 8,9,10,11-tetrahydro-8,10-dimethyl-9,10-dioxo-4H-pyrimido[4’,5’:5,6]pyrido[2,3,4-cb] [1,6]naphthyridine-2,3,5,6-tetracarboxylate (2c). The reaction of other heterocycles bearing amino, cyano, and methylthio groups with DMAD or DEAD under the same reaction conditions gave the corresponding tetracyclic heterocycles containing the fundamental 1,6-naphthyridine ring system.