On the chemistry of 5-aryl-2-hydrazino-benzo[6,7]cyclohepta[1 2-b]pyrido[2,3-e]pyrimidin-4-one

Several pyrido[2,3-e]pyrimidine fused with other rings have been prepared by intramolecular cyclization of 5-(4-chlorophenyl)-2-hydrazino-benzo [6,7]cyclohepta-[1,2-b]pyrido[2,3-e]pyrimidine-4-one (1) with acids, carbon disulfide to form triazole derivatives (2,4), halo-ketones to give triazine derivative (5), beta-ketoesters, beta-cyanoesters, and beta-diketones to yield 2-(1-pyrazolyl) derivatives (7,9,10), and aldehydes to form arylhydrazone derivatives (11a,b) which cyclized to form triazoles (12a,b). Also, acyclic N-nucleosides are prepared by heating under reflux 2-hydrazino-benzo[6,7]cyclohepta[1,2-b]pyrido[2,3-e] pyrimidin-4-one (1) with xylose and glucose to give the corresponding acyclic N-nucleosides (13a,b) which are cyclized to afford the corresponding protected tetra and penta-O-acetate C-nucleosides (14a,b). Deacetylating of the latter nucleosides afforded the free acyclic C-nucleosides (15a,b). (c) 2007 Wiley Periodicals, Inc.