Synthesis of 2H,2H-perfluoroalkyl and 2H-perfluoroalkenyl carboxylic acids and amides
摘要:
An efficient and convenient procedure for the synthesis of 2-perfluoroalkyl ethanoic acids by direct oxidation of 2-perfluoroalkyl ethanols with Jones' reagent (CrO3/H2SO4) is described. Treatment of the acids with aqueous sodium hydroxide gave 3-perfluoroalkyl, 3-fluoro-2,3-propenyl carboxylic acids which may be used for the preparation of the corresponding chlorides and amides.
The reaction of alcoholates with esters of perfluoroalkylethanoic acid (I) and 3-perfluoroalkyl-3-fluoro-propenoic acid (II) has been studied. Formation of ethers of the enol ester III or the acetal IV depends on the stoichiometric conditions used. The formation of the products proceeds via a Michael-type addition and elimination of fluoride ions from the enolate formed as an intermediate.
An efficient and convenient procedure for the synthesis of 2-perfluoroalkyl ethanoic acids by direct oxidation of 2-perfluoroalkyl ethanols with Jones' reagent (CrO3/H2SO4) is described. Treatment of the acids with aqueous sodium hydroxide gave 3-perfluoroalkyl, 3-fluoro-2,3-propenyl carboxylic acids which may be used for the preparation of the corresponding chlorides and amides.