Pyridine → Tert-butyl 2,6-dichloro-5-fluoronicotinate

Participants

Reaction Steps

P-toluenesulfonyl chloride (53.5 g) was added to a pyridine (100 ml)/tert-butanol (300 ml) solution of 2,6-dichloro-5-fluoronicotinic acid (24.5 g), and stirred overnight at room temperature. The reaction liquid was poured into aqueous 10% sodium hydrogencarbonate solution, stirred at room temperature for 2 hours, and then extracted with ethyl acetate. The extract was washed with saturated saline water, dried with anhydrous magnesium sulfate, the solvent was evaporated off, the obtained residue was purified by silica gel column chromatography (hexane/ethyl acetate=9/1) to obtain the entitled compound (29.5 g).

Provenance & Evidence