Abstract In the present study, a molecular simplification approach was employed to design novel bicyclic pyrazolo [3, 4-d] pyrimidine (PP) derivatives from tricyclic pyrazolo [4, 3-e]-1, 2, 4-triazolo-[1, 5-c] pyrimidines (PTP) as promising human A 3 adenosine receptor (hA 3 AR) antagonists. All the target compounds were synthesized using novel and efficient synthetic schemes and the structure–activity relationship studies of these PPs were explored ...