[1-(2-Phenylaminophenylcarbamoyl)ethyl]carbamic acid tertbutyl ester → 1-(1-Phenyl-1H-benzoimidazol-2-yl)ethylamine

関与物質

反応条件

反応手順

[1-(2-Phenylaminophenylcarbamoyl)ethyl]carbamic acid tertbutyl ester (400 mg, 1.59 mmol) was suspended in AcOH (4 mL) and the resulting mixture was heated at 80° C. for 12 h whereupon the mixture clarified. The cooled solution was diluted with toluene and volatiles removed under reduced pressure. The resulting residue was stirred with TFA (4 mL) for 2 h and the resulting solution was loaded onto an SCX-2 cartridge which was initially washed with MeOH. The product was eluted with 2M NH3/MeOH and further purified by column chromatography (Si—PCC, gradient 0-6% MeOH in DCM) affording 1-(1-phenyl-1H-benzo[d]imidazol-2-yl)ethanamine as a white crystalline solid (211 mg, 80%). LCMS: RT 0.27 min [M−NH2]+ 221.1. The enantiomers, (S)-1-(1-phenyl-1H-benzo[d]imidazol-2-yl)ethanamine and (R)-1-(1-phenyl-1H-benzo[d]imidazol-2-yl)ethanamine can be resolved and separated. Alternatively, (S)-1-(1-phenyl-1H-benzo[d]imidazol-2-yl)ethanamine can be prepared from enantiopure (S)-2-tertbutoxycarbonylaminopropionic acid.

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