Reaction of 1,1,2-trifluoro-2-hexafluoro-2′-(heptafluoropropoxy)-propoxyethylene with amines or alcohols

Abstract

Reaction between 1,1,2-trifluoro-2-hexafluoro-2′-(heptafluoropropoxy)-propoxyethylene and secondary amines (dimethylamine, diethylamine, dibutylamine, pyrrolidine, piperidine, morpholine) leads either to perfluoro-2-propoxy-3(1H′)-ethoxy-2″-alkoxypropanes — the addition products to the double bond — or to an N, N-dialkylamide of α-substituted fluoroacetic acid depending on the solvent used and the following work-up of the crude product. With primary amines (propylamine, butylamine, monoethanolamine), fluorine-containing imines or N-alkylamides of the α-substituted fluoroacetic acid (as a mixture of diastereomers) were obtained. The use of diethanolamine produces 2-{fluoro-2[hexafluoro-2′-(heptafluoropropoxy)-propoxy]-methyl}-4,5,7,8-tetrahydro-[1.6.3]dioxasozine. Reaction of 1,1,2-trifluoro-2′-hexafluoro-2′-(heptafluoropropoxy)-propoxyethylene with alcohols (methanol, ethanol, β,β,β-trifluoroethanol, 2-methoxyethanol, 2-ethoxyethanol, iso-propanol, butanol and pentafluorophenol) in the presence of KOH in tetrahydrofuran (sulfolane, DMSO, acetonitrile) or sodium alkoxide in an alcoholic medium yields only the corresponding ethers as a mixture of diastereomers. Treatment of ethyleneglycol, glycerine, pentaerythritol, triethanolamine, 2-(2-hydroxyethylsulphanyl) ethanol, 4-(2-hydroxyethyl) phenol with 1,1,2-trifluoro-2′-(heptafluoropropoxy)-2-hexafluoropropoxyethylene provides the addition products to all OH groups if the reaction is carried out in DMSO, sulfolane or acetonitrile. However, the use of THF as the solvent leads to the formation of α-substituted tetrahydrofuran together with the formation of ethers. The initial perfluoro(propoxypropoxy) olefin can be hydrolyzed in the alkaline media to give fluoro-[hexafluoro-2-(heptafluoropropoxy)propoxy]acetic acid.