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

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).

1. temperaturethe resulting mixture was heated
2. temperatureat reflux for 18 h
3. temperatureThe reaction mixture was cooled
4. concentrationconcentrated
5. customthe residue was partitioned between half-saturated aqueous NaCl solution (50 mL) and EtOAc (50 mL)
6. dry with materialThe organic layer was dried over sodium sulfate
7. concentrationconcentrated
8. customThe residue was purified by flash column chromatography (dichloromethane

ORD record

ord-c521e8e398144ed192da3d912f6b3a94

Source dataset

uspto-grants-2006_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07125888B2