Triethyloxonium tetrafluoroborate → [(S)-1-(6-Fluoro-1-pyridin-2-yl-1H-benzoimidazol-2-yl)ethyl]carbamic acid tert-butyl ester

Participants

Reaction Steps

(Prep 2) To a suspension of (S)-Boc-alaninamide (79.4 g, 0.42 mol) in DCM (750 mL) was added triethyloxonium tetrafluoroborate (69.5 g, 0.37 mol) and the reaction mixture stirred at RT for 2 h, during which the solids dissolved. The reaction mixture was concentrated in vacuo and the residue dissolved in ethanol (750 mL). (5-Fluoro-2-nitrophenyl)pyridin-2-yl-amine (57.1 g, 0.28 mol) was added and the reaction heated at 70° C. for 1 h. The reaction mixture was concentrated in vacuo, the residue dissolved in water and the product extracted with EtOAc (3×150 mL). The combined organic extracts were washed with brine, dried (MgSO4) and concentrated in vacuo. The resultant residue was subjected to flash chromatography (SiO2, eluting with 0-100% EtOAc in cyclohexane) to yield the title compound as a white foam (60.3 mg, 60%).

Provenance & Evidence