Esterification of (4'-biphenyl)acetic acid (I) with ethanol and p-toluenesulfonic acid provides the corresponding ethyl ester (II). Subsequent carbethoxylation of (II) with diethyl carbonate (III) under Claisen's condensation conditions furnishes the biphenylmalonate (IV). Cyclization of malonate (IV) with urea (V) in the presence of NaOEt leads to 5-(4'-biphenyl)barbituric acid (VI), which is further brominated to (VII) employing Br2 in aqueous HBr. The title compound is finally obtained by displacement of the 5-bromo barbituric acid (VII) with N-(4-nitrophenyl)piperazine (VIII) in refluxing MeOH.