Boron tribromide → HCID 66783355, compound

Participants

Reaction Steps

A solution of 2.05 g (4.40 mmol) of (S)-4-benzyloxy-2-[4-(3,4-dichloro-phenyl)-7-oxo-[1,4]diazepan-1-yl]-butyric acid methyl ester (evaporated with toluene) in 20 ml CH2Cl2 was cooled (−20° C.) and treated with 4.62 ml (4.62 mmol, 1M in CH2Cl2) of boron tribromide. The solution was warmed in 1 h to 0° C. and kept for 1.5 h at this temperature, additional 0.22 ml (0.22 mmol, 1M in CH2Cl2) of boron tribromide was added and stirring was continued for 30 min. The mixture was extracted with cold sat. aq. NaHCO3 solution and EtOAc (3×). The organic phases were washed with sat. aq. NaHCO3 solution, aq. 10% NaCl solution, dried over Na2SO4 evaporated to give 1.98 g (76%) of the title compound as light yellow foam. MS: 375.2 (MH+, 2Cl).

Provenance & Evidence