Malignant tumors are common diseases that seriously threaten human life. Among them, about 70%~80% of tumor patients need radiation therapy. Radiosensitizers have received a lot of attention from radiotherapy because they can improve the sensitivity of tumor cells to radiation. 2-Nitroimidazole is an important intermediate of a variety of tumor radiation therapy sensitizers, such as misoninitro Chemicalbook (Misonidazole), pimonidazole (pimonidazole), etanidazole (etanidazole) and so on. 2-Nitroimidazole cannot be prepared by the direct nitrification reaction of imidazole, and direct nitrification of imidazole will give 4(5)-nitroimidazole, but not 2-nitroimidazole.