tert-Butyl bromoacetate → 2-{4-[(E)-3-(3,4-Dichloro-phenyl)-acryloyl]-7-oxo-[1,4]diazepan-1-yl}-succinic acid 4-tert-butyl ester 1-methyl ester

Participants

Reaction Conditions

Reaction Steps

A solution of 0.50 g (1.30 mmol) of {4-[(E)-3-(3,4-dichloro-phenyl)-acryloyl]-7-oxo-[1,4]diazepan-1-yl}-acetic acid methyl ester in 25 ml of THF was treated slowly at −78° C. with 1.48 ml (1.48 mmol) of lithium hexamethyldisilylazide 1M in THF. After 30 min at −78° C., a solution of 0.67 ml (4.54 mmol) of tert-butyl bromoacetate in 2.5 ml of THF was added dropwise. The solution was stirred at −78° C. for 5 h, poured on cooled aqueous 10% KHSO4 solution and extracted with Et2O (3×). The organic phases were washed with aqueous 10% NaCl, dried (Na2SO4) and evaporated. The residue was purified on a SiO2-column (n-heptane/EtOAc 1:1 to 2:3) to afford the titled compound in 18% yield as light yellow foam. MS: 499.1 (MH+, 2Cl).

Provenance & Evidence