Antitumor pyrido[3,2-d][1]benzazepines: synthesis and in vitro activity of thiophene analogs.

The bioisosteric replacement of benzene elements in the antitumor lead structures 2 and 3 led to the thienyl substituted 5H-pyrido[3,2-d][1]benzazepin-6(7H)-ones 8a and 8b, the analogous thiolactams 4a and 4b, and the 4H-pyrido[2,3-d]-thieno[3,2-b]azepines 11 and 12 which represent a novel heterocyclic scaffold. The in vitro evaluation of 4a in a cell line based screening revealed a noteworthy antitumor activity and a remarkable selectivity for renal tumor cell lines. The cell line selectivity pattern of 4a differs distinctly from the pattern displayed by standard antitumor agents.