Trifluoroacetyl fluoride → Methyl 4,4,4-trifluoro-3-oxo-2-(piperidin-1-ylmethylidene)butyrate

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

Methyl 3-piperidin-1-ylacrylate (97%, 25 g, 0.14 mol) and KF (12.5 g, 76.3 mmol) were initially charged in 250 ml of toluene and cooled to −30° C. At this temperature, trifluoroacetyl fluoride (99.5%, 18.3 g, 0.16 mol) was then introduced. The reaction mixture was stirred at −30° C. for 3 h and then, over a period of one hour, warmed to room temperature. The reaction mixture was washed with deionized water (100 ml). After phase separation, the aqueous phase was extracted once with toluene (100 ml). The toluene phases were combined, washed with an aqueous sat. NaCl solution (100 ml) and then freed from the solvent under reduced pressure. Methyl 4,4,4-trifluoro-3-oxo-2-(piperidin-1-ylmethylidene)butyrate was obtained as an orange solid (amount: 38.0 g; purity according to GC: 98%; yield: 98%). 1H-NMR (CDCl3): δ=1.75 (m, 6H), 3.3 (m, 2H), 3.6 (m, 2H), 3.75 (s, 3H), 7.65 ppm (s, 1H).

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