Triethyloxonium tetrafluoroborate → [(S)-1-(6-Fluoro-7-methyl-1-pyridin-2-yl-1H-benzoimidazol-2-yl)ethyl]carbamic acid tert-butyl ester

Participants

Reaction Steps

To a suspension of ((S)-1-carbamoylethyl)carbamic acid tert-butyl ester (1.52 g, 8.1 mmol) in DCM (15 mL) was added triethyloxonium tetrafluoroborate (1.63 g, 8.6 mmol) 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 (15 mL). 4-fluoro-3-methyl-N2-pyridin-2-yl-benzene-1,2-diamine (1.0 g, 5.1 mmol) was added and the reaction heated at 75° C. for 16 h. The reaction mixture was concentrated in vacuo, the residue dissolved in water and the product extracted with EtOAc (3×20 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 solid (1.29 g, 76%). LCMS (Method C): RT=3.22 min, [M+H]+=371.

Provenance & Evidence