Synthesis
GENERAL STEPS: To a 1L four-necked flask equipped with a magnetic stirrer, thermometer, reflux condenser and bubbler was added 55.91 g (0.26 mol) of N-(4-bromo-pyridin-2-yl)acetamide and 66.02 g (0.26 mol) of bis(boronic acid) pinacol ester, followed by 76.44 g (0.78 mol) of potassium acetate and 450 mL of dioxane, and mixed by stirring. Under nitrogen protection, 3.81 g (0.0051 mol) of palladium dichlorodichalcogenide was added and the reaction was warmed to 100 °C for 18 to 24 h. The progress of the reaction was monitored by thin layer chromatography (TLC). Upon completion of the reaction, it was cooled to room temperature, precipitated as a solid, pulped and filtered. The filtrate was dissolved in 500 mL of methanol, filtered again, and the filtrate evaporated to dryness. Finally, heptane was added for pulping to obtain 62.08 g of the target product 2-acetylaminopyridine-4-boronic acid pinacol ester in 91.1% yield.
References
[1] Patent: CN103601745, 2017, B. Location in patent: Paragraph 0025; 0026
[2] Angewandte Chemie - International Edition, 2016, vol. 55, # 36, p. 10890 - 10894
[3] Angew. Chem., 2016, vol. 128, p. 11050 - 11054,5
[4] Journal of Medicinal Chemistry, 2017, vol. 60, # 13, p. 5613 - 5637
[5] Patent: US2013/165464, 2013, A1. Location in patent: Paragraph 0835
