4-Methylmorpholine → [(S)-1-(7-Chloro-1-phenyl-1H-benzoimidazol-2-yl)ethyl]carbamic acid tertbutyl ester

Participants

Reaction Steps

A mixture of 3-chloro-N2-phenylbenzene-1,2-diamine (495 mg, 2.26 mmol), (S)-2-tertbutoxycarbonylaminopropionic acid (470 mg, 2.48 mmol), HOAt (338 mg, 2.48 mmol), N-(3-dimethylaminopropyl)-N′-ethylcarbodiimide hydrochloride (477 mg, 2.48 mmol) and 4-methylmorpholine (0.550 mL, 4.97 mmol) in anhydrous DCM (15 mL) was stirred at RT for 19 h. The reaction mixture was diluted with DCM (100 mL) and washed with a saturated solution of NaHCO3. The organic layer was then dried and concentrated in vacuo. The resulting residue was dissolved in AcOH (20 mL) and heated at 70° C. for 22 h. After cooling to RT, volatiles were removed in vacuo and the residue was purified by column chromatography (Si—PCC, gradient 0-30% EtOAc in DCM) affording [(S)-1-(7-Chloro-1-phenyl-1H-benzoimidazol-2-yl)ethyl]carbamic acid tertbutyl ester as pale yellow oil (quantitative). LCMS: RT 3.83 min [M+H-tBu]+ 316.0.

Provenance & Evidence