4-Aminopyrimidine-5-carbaldehyde 1 underwent facile condensation with various aromatic ketone derivatives in the presence of K2CO3 and small catalytic amount of KI in acetone was afforded corresponding 7-Substituted pyrido[2,3-d]pyrimidine derivatives 3a-j. Their chemical structures were characterized using IR, H1 NMR and Mass spectral studies. All the above compounds were screened for anti-microbial activity, anti-oxidant activity and their bioassay showed them to possess significant antimicrobial activity and anti-oxidant activity.