[Li]CCCC.CCCCCC.Br[C:13]1[CH:14]=[CH:15][C:16]([O:19][CH2:20][CH:21]([CH3:23])[CH3:22])=[N:17][CH:18]=1.B(OC)(OC)[O:25]C>C1COCC1.[OH-].[Na+].OO>[CH2:20]([O:19][C:16]1[N:17]=[CH:18][C:13]([OH:25])=[CH:14][CH:15]=1)[CH:21]([CH3:23])[CH3:22]A solution of nBuLi in hexane (2.5 M, 70 mL, 0.176 mol) was added to a solution of 5-bromo-2-isobutoxy-pyridine (Preparation 8, 27 g, 0.117 mol) in THF (300 mL) under a nitrogen atmosphere at −78° C. After stirring for 1 hour, trimethyl borate (18.3 g, 0.176 mol) was added. The mixture was stirred at 0° C. for 1 hour then diluted with 3N NaOH (15 mL) and hydrogen peroxide (30%, 175 mL). The resulting mixture was stirred at room temperature for 1 hour and extracted with EtOAc (3×500 mL). The combined organics were washed with saturated aqueous sodium sufite (3×500 mL), brine (300 mL) then dried over sodium sulfate and filtered. The filtrate was concentrated in vacuo to yield the crude product that was purified by silica gel chromatography (petroleum ether/EtOAc 100:1 to 10:1) to give the title compound as an off-white solid (6.0 g).
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