Diethyl Ether → 8-Bromo-2-chloro-10-methylene-10h-chromeno[3,2-b]pyridine

Participants

Reaction Conditions

Reaction Steps

To a suspension of 8-bromo-2-chloro-10H-chromeno[3,2-b]pyridin-10-one (20 g, 64.4 mmol) in 500 mL of THF at −78° C. was added dropwise methylmagnesium bromide 3.0 M in diethyl ether (13.82 mL, 116 mmol). The reaction was allowed to slowly warmed up to 0° C. in about 2 h. The reaction was quenched with NH4Cl solution, extracted with EtOAc, dried over Na2SO4, filtered and evaporated to give the corresponding crude tertiary alcohol. This solid residue was re-dissolved in 100 mL of THF and treated with mL of chloroform and the resulting solution was evaporated on a 75° C. water bath for 10 min to give crude 8-bromo-2-chloro-10-methylene-10H-chromeno[3,2-b]pyridine as a brownish solid.

Provenance & Evidence