Hydrochloric Acid → (rac)-2-{4-[(E)-3-(3,4-Dichloro-phenyl)-acryloyl]-7-oxo-[1,4]diazepan-1-yl}-4-hydroxy-butyric acid methyl ester

Participants

Reaction Steps

A solution of 0.175 g (0.320 mmol) of (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 in 4.9 ml of methanol was treated at 0° C. with 0.8 ml (3.22 mmol, 4 M in dioxane) of HCl and kept 1.5 h at RT. Extraction with cold sat. aq. sodium hydrogencarbonate solution and diethyl ether (2×) followed by drying (Na2SO4) and evaporation gave 0.165 g (quantitative) of the titled compound together with 50% of the lactone (1-[(E)-3-(3,4-dichloro-phenyl)-acryloyl]-4-(2-oxo-tetrahydro-furan-3-yl)-[1,4]diazepan-5-one) as a white gum. MS: 429.3 (MH+, 2Cl).

Provenance & Evidence