Abstract: During the research on the tandem Michael addition-elimination reaction of 5-alkoxy-3,4-dihalo-2(5H)-furanone with 2-substituted benzimidazoles, the reaction that the solvent N,N-dimethylformamide (DMF) participated in was witnessed as an unexpected result. Based on the discussions of the synthetic conditions, such as reaction time, catalyst dosage, and reaction temperature, four compounds (4a-4d), including two novel compounds, were obtained by the reaction of 5-alkoxyl-3,4-dihalo-2(5H)-furanone with DMF in the presence of the catalyst ethanol sodium. The structure of 4a-4d was characterized by UV, IR, 1H NMR, 13C NMR, MS and elemental analysis. A possible reaction mechanism was proposed and confirmed by GC-MS.