A practical synthesis of trifluoromethyl alkyl ketones

Abstract

A practical approach to TFMKs under mild conditions by “trifluoroacetic ester/ketone metathesis” was described. The i -Pr and t -Bu alkyl ketones were used to produce TFMKs with high boiling points by distillation or recrystallization. The solvent-free strategy was effective used to collect volatile TFMKs. • A trifluoroacetic ester/ketone metathesis was applied on alkyl alkyl ketones. • TFMKs with high boiling points were prepared from i -Pr/ t -Bu alkyl ketones. • The solvent-free condition is suitable for trifluoroacetic ester/ketone metathesis. • TFMKs with low boiling points can be easily gained with the solvent-free condition. Trifluoromethyl ketones (TFMKs) significantly contribute to biologically active compounds and special materials. TFMKs can be prepared by “trifluoroacetic ester/ketone metathesis” along with the accompanying products, aromatic acid esters. As an important extension of our previous studies on the use of aryl alkyl ketones, wherein the separation of the resulting TFMKs and aromatic acid esters proved problematic, i -Pr and t -Bu alkyl ketones were shown in this work to be competent reaction partners for easy TFMK separation from the product mixtures, thereby providing a practical synthesis route to TFMKs. With the removal of accompanying products, i -Pr and t -Bu carboxylic esters, TFMKs with high boiling points were efficiently obtained by distillation or recrystallization. Furthermore, a solvent-free condition was also effective for this reaction, which allowed TFMKs with low boiling points to be separated from the reaction mixture by distillation in good yield.