Triethyloxonium tetrafluoroborate → (S)-tert-butyl 1-(6-fluoro-1-phenyl-1H-benzo[d]imidazol-2-yl)propylcarbamate

Participants

Reaction Steps

To a suspension of ((S)-1-carbamoylpropyl)carbamic acid tert-butyl ester (300 mg, 1.48 mmol) in DCM (5 mL) was added triethyloxonium tetrafluoroborate (273 mg, 1.43 mmol) and the reaction mixture stirred at RT for 1.5 h under argon. The reaction mixture was concentrated in vacuo and the resulting residue dissolved in ethanol (3 mL). 4-Fluoro-N2-phenylbenzene-1,2-diamine (97 mg, 0.48 mmol) was added and the reaction heated at 70° C. for 1 h. The reaction mixture was concentrated in vacuo, and the resulting residue partitioned between DCM and sat. NaHCO3. The organic fraction was washed with brine, dried (Na2SO4) and concentrated in vacuo. The resultant residue was subjected to flash chromatography (Si—PPC, gradient 0-20% EtOAc in cyclohexane) to afford the title compound as a pink foam (96 mg, 54%). LCMS (Method J): RT=3.70 min, [M+H]+=370.

Provenance & Evidence