Trifluoroacetic acid → (6R)-2-chlorophenyl 6-(5-chloro-2-methoxybenzyl)-3,7-dioxo-1,4-diazepane-1-carboxylate

Participants

Reaction Steps

To the compound S141C described in WO 06-059801A, that is, (6R)-2-chlorophenyl 6-(5-chloro-2-methoxybenzyl)-3,7-dioxo-4-(2,4,6-trimethoxybenzyl)-1,4-diazepan-1-carboxylate (996 mg), anisole (1.75 ml) and trifluoroacetic acid (10 ml) were added, and the mixture was stirred at room temperature for 4.5 hours. The reaction solution was diluted with toluene and concentrated in vacuo. This operation was repeated two times and excessive anisole was distilled off under reduced pressure of a vacuum pump. To the residue, ethyl acetate was added. The precipitated solid was collected by filtration to obtain the title compound (396 mg). Furthermore, the filtrate was concentrated, and the residue was purified by flash column chromatography (silica gel, hexane/ethyl acetate=2/1 to 1/3) to obtain the title compound (198 mg).

Provenance & Evidence