Background and Objective: Synthesis of new compound with appropriate therapeutic importance is a major challenge in medicinal chemistry. Recently fused rings compounds of pyridine and pyrimidine have significant importance in the pharmaceutical industry due to their various interesting biological activities displayed over a broad range of therapeutic classes, therefore development of some novel fused heterocycles is the main goal of the present study. Materials and Methods: Thus, a simple and cost effective procedure, novel fused heterocycles compounds of 3-substituted heterocyclic compounds containing bridge head nitrogen were synthesized through multi step reactions to give new compound of 2-biphenyl-3-oxypyrimidine imidazo (1,2-a) pyrimidine. In addition, all prepared compounds were characterized via Fourier Transform Infrared (FT-IR) spectroscopy, some of them were characterized by Hydrogen-1-Nuclear MagneticResonance ( 1 H-NMR) spectroscopy. These new 3-substituted derivatives of imidazo/pyrimidine rings were tested in vivo by determining these activities on liver function enzymes Glutamic Oxaloacetic Transaminase (GOT), Glutamic Pyruvic Transaminase (GPT) and Alanine Aminotransferase (ALT) in addition to evaluating the hepatoprotective activity on liver tissue after treatments with these compounds alone or after interaction with the toxic compound carbon tetrachloride CCl 4 . Results: These compounds showed promising antitumor activity by reducing the level of liver function enzyme to or near the normal level when given alone or after interactions with CCl 4 for GOT, GPT and ALP, respectively. Also, all synthesized compounds had the ability to return liver tissue to normal state after damaged by CCl 4 .a] pyrimidine -3-yl]-4-nitro pyrimidine -2 (1H)-one expressed hepatoprotective activity against damaged caused by CCl 4 at enzyme level or liver tissue.