A series of diazipine, pyrimidine, fused triazolopyrimidine and imide derivatives were newly synthesized using 4-phenyl-but-3-en-2-one 1 as a starting material and compounds 2 and 9 are intermediates. Initially the acute toxicity of the compounds was assayed via the determination of their LD(50). All the compounds were interestingly less toxic than the reference drug. The pharmacological screening showed that many of these obtained compounds have good analgesic, anticonvulsant and anti-inflammatory activities comparable to Valdecoxib, Carbamazepine and Predensilone as reference drugs. Regarding the protection against Carrageenan induced edema, five compounds were found more potent than Prednisolone. On the other hand, in searching for COX-2 inhibitor, the inhibition of plasma PGE2 for the compounds were determined and four compounds were found more potent than Prednisolone. The detailed synthesis, spectroscopic data, pharmacological screening and acute toxicity LD(50) for the synthesized compounds were reported.