4-Methylmorpholine → {(1S)-1-[N'-(4-Bromo-benzyl)-hydrazinocarbonyl]-2,2-dimethyl-propyl}-carbamic acid methyl ester

Participants

Reaction Steps

N-(Methoxycarbonyl)-(L)-tert-leucine (J. Med. Chem., 41, 3387-3401, 1998) (1.74 g, 9.20 mmol) was dissolved in EtOAc (50 mL) and EDAC (1.94 g, 10.1 mmol), HOBT (1.37 g, 10.1 mmol), and NMM (1.11 mL, 10.1 mmol) were added. The reaction mixture was stirred at room temperature for 30 min and then 4-bromo-benzylhydrazine (prepared as described in Zh. Org. Khim., 28, 43-50, 1992) (2.31 g, 11.5 mmol) in EtOAc (20 mL) was added and the stirring was continued over night. The reaction mixture was washed with saturated NaHCO3 (aq.), H2O and brine and then the organic phase was dried (Na2SO4), filtered and evaporated. The crude product was purified by column chromatography (silica, CHCl3/MeOH, 100:0-96:4) yielding the title compound (1.85 g, 54%) as a white solid.

Provenance & Evidence