反应详情

温度

0 °C

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.

1. customThe reaction was quenched with NH4Cl solution
2. extractionextracted with EtOAc
3. dry with materialdried over Na2SO4
4. filtrationfiltered
5. customevaporated
6. customto give the corresponding crude tertiary alcohol
7. customthe resulting solution was evaporated on a 75° C. water bath for 10 min