Application of perfluoro(2-propoxypropyl vinyl ether) (PPVE-2) in the synthesis of perfluoro(propyl vinyl ether) (PPVE-1)

摘要

A novel preparative method for the conversion of n-C3F7OCF(CF3)CF2OCF = CF2 (PPVE-2) into n-C3F7OCF = CF2 (PPVE-1) is reported. It includes the catalytic oxidation of PPVE-2 with molecular oxygen to furnish a mixture of carbonyl fluorides which are subjected to alkaline hydrolysis resulting in a mixture of salts. Subsequent thermolysis of those salts give rise to an inseparable mixture of PPVE-1 and perfluoro-2-propoxypropanoyl fluoride. Treatment of this mixture with sodium carbonate allowed to obtain sodium perfluoro-2-propoxypropionate and to isolate PPVE-1. Thermolysis of this sodium salt produced an additional amount of PPVE-1, so that the total conversion of PPVE-2 into PPVE-1 is accomplished in good yields. The reaction conditions, the choice of reagent as well as the course of competitive reactions are discussed.