Triethyloxonium tetrafluoroborate → {(S)-1-[6-Fluoro-1-(5-fluoropyridin-3-yl)-1H-benzoimidazol-2-yl]propyl}carbamic acid tert-butyl ester

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Reaction Steps

To a suspension of ((S)-1-carbamoylpropyl)carbamic acid tert-butyl ester (250 mg, 1.24 mmol) in DCM (5 mL) was added triethyloxonium tetrafluoroborate (228 mg, 1.20 mmol) and the reaction mixture stirred at RT for 1.5 h under argon. The reaction mixture was concentrated in vacuo and the residue dissolved in ethanol (3 mL). 4-Fluoro-N2-(5-fluoropyridin-3-yl)benzene-1,2-diamine (88 mg, 0.40 mmol) was added and the reaction mixture heated at 60° C. for 20 min. The reaction mixture was concentrated in vacuo, and the 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 0-50% EtOAc in cyclohexane) to afford the title compound as a white foam (128 mg, 82%). LCMS (Method J): RT=3.42 min, [M+H]+=389.

Provenance & Evidence