3-Bromo-5-methoxypyridine → 5-Bromo-2-ethoxy-3-methoxypyridine

Participants

Reaction Steps

As shown in step 3(b)-i of Scheme 3(b), 5-bromo-2-chloro-3-methoxypyridine (1.0 g, 4.5 mmol, prepared in the same manner as Compound 2003 in Example 2 starting with 3-bromo-5-methoxypyridine) was treated with a sodium ethoxide/ethanol solution (5.05 mL, 21% w/v, 13.5 mmol) and the reaction mixture microwave irradiated at 100° C. for 20 minutes. Water was added and the ethanol evaporated under reduced pressure. The resulting aqueous solution was extracted with DCM and ether, followed by drying the combined extracts over MgSO4. After filtration, removal of the volatiles under reduced pressure provided 5-bromo-2-ethoxy-3-methoxypyridine (Compound 2011), 0.72 g, 69% yield): ESMS (M+H) 232.32/234.23. As shown in step 3(b)-ii of Scheme 3(b), Compound 2012 (ESMS (M+H) 218.32/220.23) was prepared in the same manner as Compound 2011, using sodium methoxide in methanol instead of sodium ethoxide in ethanol.

Provenance & Evidence