1-Ethyl-3-(3'-dimethylaminopropyl)carbodiimide → [(S)-1-(2-Benzylamino-4-fluorophenylcarbamoyl)ethyl]carbamic acid tert-butyl ester

Participants

Reaction Conditions

Reaction Steps

N2-Benzyl-4-fluoro-benzene-1,2-diamine (1.2 g, 5.55 mmol) was dissolved in DCM (20 mL) and (S)-2-tert-butoxycarbonylaminopropionic acid (1.14 g, 6.0 mmol) and HOAt (0.82 g, 6.0 mmol) added. The reaction mixture was cooled to 0° C. and N-(3-dimethylaminopropyl)-N′ ethylcarbodiimide (1.15 g, 6.0 mmol) added. The resultant dark brown mixture was stirred at 0° C. for 1 h. The mixture was allowed to reach RT and was diluted with DCM (20 mL) and washed with 10% aqueous citric acid. The organic fraction was washed with brine (20 mL), dried (MgSO4), filtered and concentrated in vacuo. The residue was purified by column chromatography (silica gel, gradient 0-50% EtOAc in cyclohexane) to afford the title compound as a dark yellow gum, which solidified on standing (1.7 g, 79%). LCMS (Method B): RT 3.67 min [M+H]+ 388.1

Provenance & Evidence