DIPA (3.5 mL, 24.97 mmol) was dissolved in dry THF (10 mL) under nitrogen and cooled in a dry ice bath. Butyllithium solution (2.5 m in hexanes, 10.0 mL, 25.00 mmol) was added and after stirring for a few minutes 2-fluoro-3-(methoxymethoxy)pyridine (3.71 g, 23.64 mmol) in dry THF (25 mL) was added dropwise. The reaction was stirred for 1 h. A solution of 2-fluoro-5-(2-fluoropyridin-3-yl)benzaldehyde (4.71 g, 21.49 mmol) in dry THF (40 mL) was added dropwise over 10 min. The reaction was removed from the cold bath and stirred for an additional 15 min. Saturated sodium bicarbonate (20 mL) was added followed by EtOAc (300 mL) and water (400 mL). The phases were mixed and separated and the organic dried with magnesium sulfate before evaporating to dryness under reduced pressure. Purification using silica chromatography (hexane to EtOAc gradient) gave the desired (2-fluoro-3-(methoxymethoxy)pyridin-4-yl)(2-fluoro-5-(2-fluoropyridin-3-yl)phenyl)methanol (5.52 g, 14.67 mmol). MS m/z=377.1 [M+H]+. Calculated for C19H15F3N2O3: 376.10.
