双氢青蒿素合成工艺探讨

摘要

The dihydroartemisinin were formed from artemisinin using sodium borohydride as reductant,and the content of each component were analysised by high performance liquid chromatography (HPLC);The factors on the influence of synthetic reaction were investigated,such as reaction solvent,dosage of reducing agent,additives,reaction temperature and so on. The results showed that the solvent affects the solubility of artemisinin and the stability of sodium borohydride,and it is also not the decisive factor of the reaction rate and the yield of dihydroartemisinin;Methanol is the most suitable solvents in the process,and the reduction of artemisinin to dihydroartemisinin promoted by BH3 (OCH3 )-,which producted from the reaction sodium borohydride with methanol;The calcium chloride helps to improve the reaction rate;The side effect were significantly when temperature rising and time prolonged. As a result,in methanol solution,when n (CaCl2 ) (DHA)= 0. 3,n (NaBH4 ) (ART)= 2. 5,the reacton temperature is 0 ℃ and reactin time is 1. 5 h,the conversion of artemisinin above 98%,the yield of dihydroartemisinin is higher than 96%.%用硼氢化钠还原青蒿素合成双氢青蒿素,用高效液相色谱法分析组分含量;考察了反应溶剂、还原剂用量、添加剂种类和用量、反应温度等因素对合成反应的影响.结果表明,溶剂性质影响青蒿素的溶解度和硼氢化钠的稳定性,但不是影响反应速率及双氢青蒿素产率的决定性因素;甲醇是最适宜的反应溶剂,反应过程中,硼氢化钠与甲醇反应生成甲氧基硼氢负离子(BH3(OCH3)-),然后将青蒿素还原为双氢青蒿素;添加氯化钙有助于提高反应速率;反应温度过高以及反应时间过长会导致副反应增多.在甲醇溶液中,当n(CaCl2)(DHA)=0.3,n(NaBH4)(ART)=2.5,0℃反应1.5 h.青蒿素转化率高于98%,双氢青蒿素产率高于96%.