Reaction Steps
Methyl 6-(2-(3-(4′-formylbiphenyl-4-yl)propanoyl)oxazol-5-yl)pyridine-2-carboxylate (19 mg, 0.043 mmol) and 1-methyl piperazine (0.007 mL, 0.07 mmol) were dissolved in dichloroethane (2 mL) and NaBH(OAc)3 (18 mg, 0.086 mmol) was added. The reaction solution was stirred under an atmosphere of Ar at ambient temperature for 3.5 h and then quenched with saturated aqueous NaHCO3. The crude product was extracted with EtOAc and the solvent was removed in vacuo. The crude product was purified by flash chromatography (SiO2, 2.5% Et3N/EtOAc) to furnish methyl 6-(2-(3-(4′-((4-methylpiperazin-1-yl)methyl)biphenyl-4-yl)propanoyl)oxazol-5-yl)pyridine-2-carboxylate as a clear tan oil (13 mg, 58%): 1H NMR (CDCl3, 600 MHz) δ 8.11 (d, 1H, J=7.7 Hz), 8.02 (d, 2H, J=9.0 Hz), 7.96 (t, 1H, J=7.8 Hz), 7.51 (dd, 4H, J=8.2, 2.2 Hz), 7.36 (d, 2H, J=8.0 Hz), 7.33 (d, 2H, J=8.0 Hz), 4.03 (s, 3H), 3.54 (s, 2H), 3.51 (t, 2H, J=7.6 Hz), 3.15 (t, 2H, J=7.6 Hz), 2.50 (bs, 8H), 2.30 (s, 3H); 13C NMR (CDCl3, 150 MHz) δ 187.3, 165.1, 157.4, 152.4, 148.5, 146.5, 139.7, 139.3, 139.0, 138.3, 137.1, 129.6, 128.9, 128.0, 127.1, 126.8, 125.2, 123.3, 62.6, 55.1, 53.1, 53.0, 45.9, 40.6, 29.3; HR ESI-TOF m/z 525.2493 (M+H+, C31H32N4O4, requires 525.2496).
