Some reactions of perfluoromethacrylic acid derivatives

Conclusions

• 1. The dialkylamide of perfluoromethacrylic acid, in contrast to its ester, forms substitution products of the vinyl fluorine atom when treated with alcohols.

• 2. The dimethylamides ofα-trifluoromethyl-β-alkoxy-β-fluoroacrylic acids undergo rearrangement when heated, probably via a six-membered cyclic transition state, to the fluorides ofβ-trifluoromethyl-β-alkoxy-β-dimethylaminoacrylic acids.β,β-Diethoxyvinyltrifluoromethyl ketone rearranges in a similar manner to the ethyl ester ofβ-ethoxy-γ,γ,γ-trifluorocrotonic acid.

• 3. A fluorotropic allylic rearrangement is caused by the action of a catalytic amount of BF₃ on the dimethylamide ofα-trifluoromethyl-β-diethylamino-β-fluoroacrylic acid, which leads to the dimethylamide ofα-diethylaminodifluoromethyl-β,β-difluoroacrylic acid.