Triethylamine → Trifluoroacetic acid

Participants

Reaction Steps

4-Methoxy phenylhydrazine (1 g, 7.24 mmol) and ethyl 2-(ethoxymethylene)-4,4,4-trifluoro-3-oxobutyrate (1.408 ml, 7.24 mmol) were stirred in acetonitrile (40 mL) at room temperature. To this mixture was added triethylamine (1.0 mL, 7.24 mmol). LCMS trace of aliquot taken immediately after the addition indicated completion of reaction. The crude mixture was further aged for 1 hr. Volatiles were removed under reduce pressure. The resulting crude mixture was purified by flash chromatography (SiO2, Isolute Flash Si; 100 g). The column was eluted by an EtOAc/hexanes mixture (0% to 20%). Related fractions were pooled and evaporated to afford a yellow oil of 1.4015 g. This oil was further purified by preparative HPLC (reverse phase, Kromasil® 100-5C18, 100×21.1 mm) eluting with acetonitrile/water+0.1% TFA (30% to 100% organic in 10 min, then to 100% for 2 min, 20 mL/min). Related fractions were pooled and evaporated under reduced pressure to afford an oil as a TFA salt of the titled compound.

Provenance & Evidence