Cesium carbonate → HCID 56651050, compound

Participants

Reaction Steps

An aqueous solution of Cesium carbonate (54.8 mg, 0.17 mmol, 5.0 eq) in water (2 mL) was charged with a solution of 5-bromo-1-(2,2-dimethylpropyl)-3-methyl-1,3-dihydro-2H-benzimidazol-2-one (1-5, 10 mg, 0.034 mmol) and phenylboronic acid (8.21 mg, 0.067 mmol, 2.0 eq), then deoxygenated. The 1,1′-Bis(diphenylphosphino)ferrocene-palladium(II)dichloride dichloromethane complex (1.37 mg, 1.68 μmol, 0.05 eq) was introduced and the mixture was irradiated in a microwave at 125 deg C. for 15 min. LC/MS showed complete conversion, so the reaction was partitioned between EtOAc (2×85 ml) and saturated aqueous NaHCO3 (95 ml). The combined organic layers were dried over Na2SO4 and concentrated. The crude oil was purified via reverse-phase HPLC (Acetonitrile/Water gradient with 0.1% TFA present), affording the desired compound, 1-(2,2-dimethylpropyl)-3-methyl-5-phenyl-1,3-dihydro-2H-benzimidazol-2-one (1-6), with >95% purity. 1H NMR (300 MHz, CDCl3) δ 7.59 (d, 2H, J=7.3 Hz), 7.45 (t, 2H, J=7.3 Hz), 7.30-7.36 (m, 2H), 7.19 (s, 1H), 7.10 (d, 1H, J=8.2 Hz), 3.70 (8, 2H), 3.49 (s, 3H), 1.07 (s, 9H). LRMS m/z: Calc'd for C19H22N2O (M+H) 295.4, found 295.1.

Provenance & Evidence