Preparation method of medical intermediate 1, 5-benzodiazepine derivative containing fused ring

The invention relates to the field of medicine and chemical engineering, and particularly discloses a preparation method of a fused ring-containing medical intermediate 1, 5-benzodiazepine derivative. A magnetic nano sulfonic acid material which can be recycled, is easy to separate from a product, and is relatively high in catalytic efficiency and selectivity is used as a catalyst, so that the fused ring-containing medical intermediate 1, 5-benzodiazepine derivative is prepared. Meanwhile, the ethanol aqueous solution is used as a reaction solvent, so that the catalytic efficiency of the catalyst can be effectively improved, and the reaction time is shortened. Besides, a catalytic system composed of the catalyst and the reaction solvent can be repeatedly used, so that the pollution to the environment in the treatment process of the catalyst and the reaction solvent is reduced, and meanwhile, the utilization efficiency of the reaction raw materials is also improved. And finally, the ethanol aqueous solution al