Amifostine is a broad-spectrum cytoprotective agent, once used as a military anti-radiation agent, and now used as a protective drug for radiotherapy and chemotherapy. It has significantly effective in reducing the side effects of anticancer drugs such as cyclophosphamide, ciplatin, doxorubicin, and anti-HIV drugs such as 3-azido-3-deoxythymidine, without affecting the efficacy of anticancer or anti-HIV drugs curative effect. At present, the commercially available amifostine products include freeze-dried powder injection（ETHYOL ）produced by American Life Sciences Co., Ltd. It is only available as a lyophilized powder for injection, but is thermally unstable.
1). In the 50L stainless steel reactor, add 13.6kg of pure water, 19.2mol (7.6kg) of sodium thiophosphate dodecahydrate, add N-(2-bromoethyl)-1,3-propanediamine bisulfite under stirring Hydrobromide salt 19.8mol (6.8kg, 3% excess), 11.0kg DMSO was added slowly while maintaining the reaction temperature not to exceed 25°C. After the dropwise addition of DMSO, the reaction solution was monitored with silver nitrate solution until no black precipitate was precipitated, and the reaction was completed. Centrifugal filtration to obtain 6.1 kg of crude amifostine trihydrate.2). In the 50L stainless steel crystallization kettle, add 22.0kg of pure water, add 6.1kg of the crude 3-aminopropylamine ethyl thiophosphoric acid prepared in the previous step, dissolve at room temperature, add 95.0g of activated carbon, and stir at room temperature for 15 minutes , filter, add methanol 8.7kg to the mother liquor, cool down to 0 ℃ through cooling water, maintain 18 hours, centrifugal filter, obtain 4.8kg of 3-aminopropylamine ethyl thiophosphoric acid without crystal water once recrystallization.3). Add 20.0kg of pure water to the 50L stainless steel crystallization kettle, add 4.8kg of 3-aminopropylamine ethyl thiophosphoric acid without crystal water obtained by the first recrystallization, stir and dissolve at room temperature, add 75.0g of activated carbon , stirred at room temperature for 15 minutes, filtered, added 3.2kg of ethanol to the mother liquor, cooled to 0°C through cooling water, maintained for 18 hours, centrifugally filtered, and vacuum dried at 30°C to obtain 3.6kg of amifostine trihydrate.
