Synthesis
Sodium hydride (60% mineral oil dispersion, 0.72 g, 18.0 mmol) was added to a dry reaction flask, followed by the addition of N,N-dimethylformamide (30 mL) to form a suspension, and the mixture was cooled to 5 °C. Under stirring, benzyl alcohol (1.04 mL, 10.0 mmol) was slowly added dropwise. After dropwise addition, stirring was continued for 15 minutes. Subsequently, 4-chloropyridine hydrochloride (1.00 g, 6.67 mmol) was added in batches, with each addition approximately 5 minutes apart. After the addition was completed, the reaction mixture was stirred at 5°C for 10 minutes, then gradually warmed to 60°C and stirred at this temperature for 1.5 hours. After completion of the reaction, the mixture was cooled to room temperature (23°C), the reaction was quenched by the addition of water and extracted with ethyl acetate. The organic phases were combined, dried with anhydrous magnesium sulfate, filtered and concentrated under reduced pressure. The crude product was purified by silica gel column chromatography with gradient elution of hexane solution with 5% to 50% ethyl acetate as eluent to give the target product 4-benzyloxypyridine (1.10 g, 89% yield).
References
[1] Journal of Organic Chemistry, 2017, vol. 82, # 24, p. 13756 - 13767
[2] Patent: US2011/275627, 2011, A1. Location in patent: Page/Page column 60
[3] Patent: EP2331541, 2011, A1. Location in patent: Paragraph 0070; 0071
[4] Patent: EP2331541, 2015, B1. Location in patent: Paragraph 0070; 0071
