Potassium bisulfate → (rac)-4-(tert-Butyl-dimethyl-silanyloxy)-2-{4-[(E)-3-(3,4-dichloro-phenyl)-acryloyl]-7-oxo-[1,4]diazepan-1-yl}-butyric acid methyl ester

Participants

Reaction Conditions

Reaction Steps

A suspension of 0.313 g (0.100 mmol) of 1-[(E)-3-(3,4-dichloro-phenyl)-acryloyl]-[1,4]diazepan-5-one (intermediate 5A) in 10 ml of THF was treated at 0° C. with 0.135 g (0.120 mmol) of potassium tert-butylate. After 10 min, 0.394 g (0.110 mmol) of (rac)-4-(tert-butyl-dimethyl-silanyloxy)-2-iodo-butyric acid methyl ester (intermediate 1) was added. The reaction was stirred 1 h at 0° C., 15 h at RT and then neutralized with cold 10% aq. potassium hydrogensulfate solution and extracted with diethyl ether (3×). The organic phases were washed with sat. aq. sodium hydrogencarbonate solution, 10% aq. sodium chloride solution, dried over Na2SO4 evaporated and purified by flash silica gel column (n-heptane/ethyl acetate 1:1 to 2:3) to yield 0.19 g (35%) of the titled compound as light yellow viscous oil. MS: 543.3 (MH+, 2Cl).

Provenance & Evidence