Carbon Dioxide → 2,6-Difluoropyridine-3-carboxylic acid

Participants

Reaction Steps

In a round bottom flask, to 2,6-difluoro-pyridine (39, 7.10 g, 61.7 mmol) in 150.0 mL of tetrahydrofuran under an atmosphere of nitrogen at −78° C., n-butyllithium (26.0 mL, 2.50 M in hexane, 65.0 mmol) is slowly added. After 30 minutes, 3.0 g of dry ice is added and an hour later the reaction is allowed to warm to room temperature. The reaction is poured into water, extracted with ethyl acetate and the aqueous layer is adjusted to pH 4-5 with 1 N hydrochloric acid. This is extracted with ethyl acetate and the organic layer is dried over sodium sulfate, filtered and the filtrate concentrated under vacuum to provide the desired compound (51, 5.6 g).

Provenance & Evidence