A novel benzo[1,5]oxazepin-4-one skeleton compound and its four derivatives were synthesized effectively from 1,5-difluoro- 2,4-dinitrobenzene(DFDNB)under mild conditions.In the process,four intermediates were synthesized by substitutions of the two fluorine atoms and reductions of the meta-dinitro groups in DFDNB respectively.The results showed that the key for synthesizing the intermediates was the substitution of one of the two fluorine atoms in DFDNB by 3-hydroxy butyric acid ethyl ester first,then the other fluorine atom by morpholine,and then the reduction of the meta-dinitro groups in the substitute by HCOONH_4 with Pd/C.The products were purified with silica gel column chromatography,and confirmed by HPLC,LC-MS and ~1H NMR.They should contribute to construct the molecular libraries for therapeutic applications. A novel benzo [1,5] oxazepin-4-one skeleton compound and its four derivatives were synthesized effectively from 1,5-difluoro- 2,4-dinitrobenzene (DFDNB) under mild conditions. substitutions of the two fluorine atoms and reductions of the meta-dinitro groups in DFDNB respectively. The results showed that the key for synthesizing the intermediates were the substitution of one of the two fluorine atoms in DFDNB by 3-hydroxy butyric acid ethyl ester first, then the other fluorine atom by morpholine, and then the reduction of the meta-dinitro groups in the substitute by HCOONH_4 with Pd / C. The products were purified with silica gel column chromatography, and confirmed by HPLC, LC-MS and ~ 1H NMR They should contribute to construct the molecular libraries for therapeutic applications.