3-Amino-4-(phenyl or p-methoxyphenyl)-6-pyridin-3-ylthieno[2,3-b]-pyridine-2-carboxamide and 3-amino-4- (phenyl or p-methoxyphenyl)-6-pyridin-3-ylthieno[2,3-b]pyridine-2-carbonitrile were used as the starting materials aiming to obtain the newly synthesized pyridothieno-pyrimidines, pyridothienotriazines and pyridothienoxazines via their reactions with several reagents e.g. CS2, HCOOH, CH(OEt)3, Ac2O and HNO2. These newly synthesized heterocyclic compounds were tested as anti-Alzheimer and anti COX-2 agents and their structures were elucidated by considering the data of IR, 1H NMR, mass spectra and elemental analyses.