Diisopropylamine → 7-bromo-3-chloro-8-fluoro-5H-chromeno[2,3-c]pyridin-5-one

Participants

Reaction Conditions

Reaction Steps

n-Butyl lithium (3.14 mL, 7.84 mmol) was added to a solution of diisopropylamine (1.341 mL, 9.41 mmol) in THF (40 mL) at −78° C. The resulting solution was stirred at 0° C. for 15 minutes before being added dropwise via cannula to a solution of 5-bromo-2-(6-chloropyridin-3-yloxy)-N,N-diethyl-4-fluorobenzamide (2.1 g, 5.23 mmol) in THF (40.0 mL) cooled to −78° C. under positive pressure. The resulting solution was stirred 3 hours at −78° C. before being quenched with saturated ammonium chloride (100 mL). The reaction mixture was diluted with water (50 mL) and extracted with EtOAc (3×75 mL). The combined organic extracts were washed with saturated aqueous NH4Cl, water, saturated aqueous NaCl, and dried over sodium sulfate. The solution was filtered and concentrated in vacuo to give the crude material. The crude material was purified by dissolving in a minimal amount of CH2Cl2 and filtering through a pad of silica gel by eluting with 1:10 EtOAc in hexane, to provide 7-bromo-3-chloro-8-fluoro-5H-chromeno[2,3-c]pyridin-5-one as a off-white solid. MS m/z=330.0 [M+H].

Provenance & Evidence