3-(4-Nitrobenzylidene)-5-phenylfuran-2(3H)-one 2 was prepared and converted into a variety of heterocyclic systems of synthetic and biological importance via reaction with nitrogen nucleophiles. Benzylamine reacted with the furanone 2; the product was found to depend on the reaction conditions. Thus, at room temperature the open-chain N-benzylamide 3 was obtained, whereas under refluxing conditions the 3-(4-Nitrobenzylidene)-5-phenyl-1-benzyl-2(3H)-pyrrolone 4 was obtained. Hydrazine hydrate affected ring opening of the furanone to give the corresponding acid hydrazide 5. The latter was used as key starting materials for the synthesis of aminotriazole 17 and 1,3,4-oxadiazole derivatives 15a-c. The structural elucidation of products is reported and also some of the products were screened for their antimicrobial activity.