Cesium carbonate → HCID 66749350, compound

Participants

Reaction Steps

A solution of Cesium carbonate was treated with a solution of 1-(2,2-dimethylpropyl)-4-fluoro-3-methyl-2-oxo-2,3-dihydro-1H-benzimidazol-5-yl trifluoromethanesulfonate (7-7, 80 mg, 0.21 mmol) and Phenylboronic acid (50.8 mg, 0.42 mmol, 2.0 eq) in anhydrous THF (5 ml). The mixture was deoxygenated, and 1,1′-Bis(diphenylphosphino)ferrocene-palladium(II)dichloride dichloromethane complex was introduced (8.5 mg, 10.4 μmol, 0.05 eq) and the mixture was irradiated in a microwave at 140 deg C. for 15 min. The reaction was not complete, so more Phenylboronic acid (26 mg, 0.24 mmol, 1.0 eq) and catalyst (8.5 mg, 10.4 μmol, 0.05 eq) was added and the reaction was irradiated again at 170 deg C. for 25 min. LC/MS showed complete conversion, so the crude maroon oil was partitioned between EtOAc (2×45 ml) and aqueous saturated NaHCO3 (55 ml), the combined organic layers were dried over Na2SO4 and concentrated, then purified via reverse-phase HPLC (Acetonitrile/Water gradient with 0.1% TFA present). The title compound, 1-(2,2-dimethylpropyl)-4-fluoro-3-methyl-5-phenyl-1,3-dihydro-2H-benzimidazol-2-one (7-8), was obtained as a brown oil with >95% purity. 1H NMR (500 MHz, CDCl3) δ 7.54-7.52 (m, 2H), 7.45 (t, 2H, J=5.86 Hz), 7.38-7.35 (m, 1H), 7.09 (t, 1H, J=5.38 Hz), 6.89 (d, 1H, J=6.35 Hz), 3.69 (s, 2H), 3.66 (s, 3H), 1.06 (s, 9H). LRMS m/z: Calc'd for C19H21FN2O (M+H) 313.4, found 313.1.

Provenance & Evidence