Synthesis
Step A: Synthesis of 5-phenylpyridin-3-amine
5-Bromopyridin-3-amine (248 mg, 1.43 mmol), tetrakis(triphenylphosphine)palladium (Pd(PPh3)4, 50.4 mg, 0.04 mmol), toluene (3 mL), sodium carbonate (2 M, 3 mL, 6 mmol, dissolved in ethanol), and phenylboronic acid (195 mg, 1.60 mmol) were mixed and heated in an oil bath at 90 °C for 4 hour. Upon completion of the reaction, it was cooled to room temperature and allowed to stand for 16 hours. The reaction mixture was transferred to a partition funnel and extracted with ethyl acetate and water by partition. The aqueous phase was washed again with ethyl acetate and the combined organic phases were washed with brine, dried over magnesium sulfate, filtered and concentrated in vacuum. The residue was purified by column chromatography (80% ethyl acetate/hexane) to afford 5-phenylpyridin-3-amine (31.9 mg, 0.19 mmol, 13% yield) as a white solid.
1H NMR (500 MHz, CDCl3) δ ppm: 8.17-8.42 (m, 1H), 8.02-8.20 (m, 1H), 7.32-7.62 (m, 4H), 7.25 (s, 1H), 7.06-7.20 (m, 1H).
MS (LC/MS) retention time (R.T.) = 0.91 min; [M + H]+ = 171.09.
References
[1] Journal of Medicinal Chemistry, 2017, vol. 60, # 2, p. 695 - 709
[2] Patent: US2009/270405, 2009, A1. Location in patent: Page/Page column 84
[3] Patent: WO2011/53292, 2011, A1. Location in patent: Page/Page column 136
[4] Patent: JP5714745, 2015, B2. Location in patent: Paragraph 0271; 0272
[5] New Journal of Chemistry, 2017, vol. 41, # 24, p. 15420 - 15432
