Triethylamine → 2-Chloro-5-fluoropyridine-3-carbonitrile

Participants

Reaction Conditions

Reaction Steps

A suspension of crude compound 3a (65 g, 372.4 mmol) and Et3N (114 mL, 819.2 mmol) in DCM (700 mL) was cooled to 0° C. and TFAA (57 mL, 409.6 mmol) and was added dropwise. The resulting yellow solution was stirred for 90 minutes at 0° C., diluted with DCM, washed with sat. aq. NaHCO3 and brine, and dried (Na2SO4). The mixture was filtered and concentrated. Kugel Rohr distillation of the residue (˜70° C./1 mbar) gave 50 g (86%) of compound 4a as a beige solid. Compound 4a can also be purified by column chromatography (SiO2, 8:1 heptane: EtOAc). 1H NMR (CDCl3, 300 MHz): δ 7.78 (dd, 1H); 8.49 (d, 1H).

Provenance & Evidence