Synthesis of New Isolated and Fused Tri- and Tetracyclic Pyridine Derivatives

A number of functionalized pyridine derivatives in which the pyridine ring is linked to triazole, thiadiazole, thiazole, and tetrazole moieties were synthesized by cyclization with carbon disulfide, phenylisothiocyanate, and sodium azide. Benzylation of the synthesized tetrazolylmethylpyridone derivative afforded the N (1)-benzylated product; its crystal structure is reported. The substituted fused tetracyclic pyridofuropyrimidine was synthesized by sequential reactions starting from the 2-pyridone derivative.