Lithium diisopropylamide → 7-bromo-2-(diethylamino)-5H-chromeno[2,3-b]pyridin-5-one

Participants

Reaction Conditions

Reaction Steps

To a solution of 5-bromo-N,N-diethyl-2-(6-fluoropyridin-2-yloxy)benzamide (2.90 g, 7.90 mmol) in 50 mL of dry THF at −78° C. was added dropwise lithium diisopropylamide (2.0 M heptane/THF/ethylbenzene, 11.8 mL, 23.69 mmol) and the reaction was stirred at −78° C. for 2 hours. The reaction quenched at −78° C. with 30 mL of 1 N HCl in ether. After warming to rt, the reaction was further quenched with saturated NH4Cl (250 mL) extracted with ethyl acetate (3×250 mL). The combined organics were washed with brine, and evaporated to dryness. Purification by silica gel chromatography (hexane to hexane/CH2Cl2=1:1 to CH2Cl2 to CH2Cl2/EA=10:1) gave 7-bromo-2-fluoro-5H-chromeno[2,3-b]pyridin-5-one as a white solid and 7-bromo-2-(diethylamino)-5H-chromeno[2,3-b]pyridin-5-one as a white solid.

Provenance & Evidence