METHOD OF PRODUCING 5-(FLUOROSULPHONYL)PERFLUOROPENTYLVINYL ETHER Russian patent published in 2025 - IPC C07C303/02 C07C309/82 

FIELD: organic chemistry.

SUBSTANCE: invention relates to organic chemistry, specifically to a process for preparation of 5-(fluorosulphonyl)perfluoropentylvinyl ether of formula FSO₂CF₂-(CF₂)₄-O-CF=CF₂, copolymers of which with tetrafluoroethylene are used to produce polymer electrolytes for fuel cells, as well as for making membranes. Method is characterized by that intermediate 5-(fluorosulphonyl)perfluoropentanoyl fluoride is obtained in several steps. For this, by successive bonding of perfluoroallyl iodide to C₂F₄, oxidation of obtained 5-iodoperfluoropentene with NaClO in aqueous acetonitrile and isomerisation of obtained 5-iodoperfluoropentene oxide under action of triethylamine 5-iodoperfluoropentanoyl fluoride is obtained. Further, by action on it of dimethyl sulphate in diglyme in presence of KF, 5-(methoxy)perfluoropentanoyl iodide is obtained, which is converted to (5-methoxyperfluoropentyl)trimethylsilane by reaction with trimethylsilyl methanesulphonate and a Zn-Cu pair in DMF. Successive action of SO₂, Cl₂ and KF on (5-methoxyperfluoropentyl)trimethylsilane leads to formation of 5-(methoxy)perfluoropentylsulphonyl fluoride, and heating latter with SbCl₅ to obtain 5-(fluorosulphonyl)perfluoropentanoyl fluoride. Method then includes condensation of synthesized FSO₂(CF₂)₄C(O)F with HFP oxide in diglyme in presence of KF, distilling the condensation product from the reaction mixture, treating said product with Na₂CO₃ to form a salt, pyrolysis of which enables to obtain the desired ether.

EFFECT: providing a method for synthesis of an end compound from perfluoroallyl iodide which does not require use of hazardous, difficult to obtain reagents and special equipment and enables to avoid an electrochemical fluorination step.

1 cl, 4 ex