The Study On β-hydroxy-pent-4-enoate And Synthesis Of Inhalation Anesthetics Sevoflurane

This paper focused on the study of β-hydroxy-pent-4-enoate and inhalation anesthetics sevoflurane.In the first part, Radical reaction of3with fluorinated iodides initiated by Na2S2O4and transformation of the adducts. Cyclization of the adducts in different bases were investigated in52.1～74.3%yields. The further reaction studied the feasibility of the synthesis of five-membered ring and reaction of hydrofluoromethylisoxazoles with aldehydes. Studies have shown that the reactions produce two different locations to replace the product, so to find out the best conditions of the reaction that the hydrogen fluoromethylisoxazoles with the aldehydes and apply to the hydrofluoromethyl-pyrazoles. In the end of this part, it studied on the coupling reaction of hydrofluoromethypyrazoles with β-hydroxy-pent-4-enoate3to achieve31.4%-45.6%of the yield to be a series of compounds21、23.Shows reaction mechanism was discussed.In the second part, the synthesis and purification methods of inhalation anesthetics sevoflurane were studied. Through the Chloromethylation and fluorination reaction from Hexafiuoroisopropanol, sevoflurane was produced. Purified by distillation, the pure sevoflurane product was finally obtained, with GC purity>99.9%. This process avoids the problems of slow reaction rate, high cost and toxic reagents. It is a simple and environment friendly process for the synthesis of sevoflurane. The process can be used for industrial production.