Ethyl chloroformate → Ethyl 3,5-dichloropyridine-4-carboxylate

Participants

Reaction Conditions

Reaction Steps

To a stirred solution of lithium diisopropylamide (45 mL, 1.5 M in THF, 67.6 mmol) in 150 mL THF at −78° C. is treated with 3,5-dichloropyridine (10 g, 67.6 mmol) in 40 mL THF over 1.5 hours, stirred for 1 hour at −78° C., treated with ethyl chloroformate (9.5 mL, 100 mmol), stirred for 2 hours, transferred into saturated sodium bicarbonate (200 ml) at 0° C., treated with diethyl ether (200 ml), and extracted with ethyl ether (2×100 mL). The extract is washed sequentially with saturated sodium bicarbonate solution (2×100 mL), brine (2×100 mL), dried (MgSO4), and concentrated. The residue is purified by flash chromatography on silica gel with hexane/ethyl acetate to provide the title compound.

Provenance & Evidence