Abstract
Some novel pyridothienoxazine (5); pyridothienopyrimidines (6), (8), (9), (14); pyridothienoimidazole (16); isothiazolopyridine (17), and pyridoisothiazolopyrimidines (18–20) were synthesized. The structural assignment of the prepared compounds were based on microanalytical and spectroscopic evidences. Some prepared compounds were tested in vitro for their antitumor and radioprotective activities. Compounds (7), (12), (17) and (19) showed significant activities against EAC cells, at a concentration of 250μg/ml; while the isothiazolopyridine (17) exhibited radioprotective activity.