Sodium Carbonate → 3,7-Diphenylimidazo[1,2-a]pyridine

Reaktionsgleichung

I[C:2]1[N:6]2[CH:7]=[CH:8][C:9]([C:11]3[CH:16]=[CH:15][CH:14]=[CH:13][CH:12]=3)=[CH:10][C:5]2=[N:4][CH:3]=1.[C:17]1(B(O)O)[CH:22]=[CH:21][CH:20]=[CH:19][CH:18]=1.C(=O)([O-])[O-].[Na+].[Na+]>O1CCOCC1>[C:17]1([C:2]2[N:6]3[CH:7]=[CH:8][C:9]([C:11]4[CH:16]=[CH:15][CH:14]=[CH:13][CH:12]=4)=[CH:10][C:5]3=[N:4][CH:3]=2)[CH:22]=[CH:21][CH:20]=[CH:19][CH:18]=1

Komponenten

Versuchsvorschrift

Tetrakis(triphenylphosphoine)palladium(0) (16 mg, 0.014 mmol, 0.050 equiv) was added to a deoxygenated mixture of 3-iodo-7-phenylimidazo[1,2-a]pyridine (1-5, 88 mg, 0.28 mmol, 1 equiv), phenyl boronic acid (50 mg, 0.41 mmol, 1.5 equiv), and aqueous saturated sodium carbonate solution (0.42 mL, 3.0 equiv) in dioxane (5 mL), and the resulting mixture was heated at reflux for 18 h. The reaction mixture was cooled, then concentrated, and the residue was partitioned between half-saturated aqueous NaCl solution (50 mL) and EtOAc (50 mL). The organic layer was dried over sodium sulfate and concentrated. The residue was purified by flash column chromatography (dichloromethane, initially, grading to 40% EtOAc in dichloromethane) to give 3,7-diphenylimidazo[1,2-a]pyridine (1-6) as a tan solid. 1H NMR (300 MHz, CDCl3) δ 8.41 (dd, 1H, J=7.2, 0.6 Hz), 7.90 (dd, 1H, J=1.8, 0.6 Hz), 7.74 (s, 1H), 7.69 (m, 2H), 7.62–7.39 (m, 8H), 7.12 (dd, 1H, J=7.0, 1.8 Hz).