Ammonium Chloride → (5-Bromo-2-methoxyphenyl)(2,6-difluoropyridin-3-yl)methanol

Participants

Reaction Steps

DIPA (8.0 mL, 56.6 mmol) was dissolved in dry THF (40 mL) under nitrogen and cooled in a dry ice bath to −78°. n-Butyllithium solution, 2.5 m in hexanes (23.0 mL, 57.5 mmol) was added and the solution stirred for a few minutes prior to dropwise addition of 2,6-difluoropyridine (5.0 mL, 55.1 mmol) in dry THF (10 mL) via an addition funnel over 10 minutes. The pale yellow solution was stirred for 30 minutes then additional dry THF (70 mL) was added dropwise via an addition funnel. Solid 5-bromo-2-methoxybenzaldehyde (11.85 g, 55.1 mmol) was added in one portion and the reaction stirred for 5 minutes. Additional dry THF (100 mL) was added dropwise to keep the mixture stirring freely. After 15 minutes saturated ammonium chloride (20 mL) was added to quench followed by ethyl acetate (200 mL) and water (200 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 DCM gradient) gave (5-bromo-2-methoxyphenyl)(2,6-difluoropyridin-3-yl)methanol.

Provenance & Evidence