Fluorination of 1,4-dioxan with sulfur tetrafluoride in hydrogen fluoride

Abstract

Reaction of sulfur tetrafluoride with 1,4-dioxan in anhydrous hydrogen fluoride in the presence of small additions of sulfur chlorides or chlorine results in the replacement of several hydrogen atoms in dioxan ring by fluorine atoms. Depending on various conditions, 2,3,3-trifluoro-1,4-dioxan, 2,3,3,5,6-pentafluoro-1,4-dioxans as well as 1,2,2,2,2-pentafluoroethyl ether can be obtained as major products in a good yield. The reaction appeared to proceed via initial chlorination followed by the replacement of chlorine atoms by fluorine atoms.