1-Hydroxybenzotriazole → 5-Chloro-N-[(1S)-2-[[2-[4-(4-chlorophenyl)-1-piperazinyl]-2-oxoethyl]amino]-2-oxo-1-(2-pyridylmethyl)ethyl]-1-benzofuran-2-carboxamide

Participants

Reaction Steps

To a suspension of (2S)-2-amino-N-[2-[4-(4-chlorophenyl)-1-piperazinyl]-2-oxoethyl]-3-(2-pyridyl)propanamide (18 g) and 5-chloro-1-benzofuran-2-carboxylic acid (8.8 g) in N,N-dimethyl-formamide (180 ml) were added 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide hydrochloride (9.44 g) and N-hydroxybenzotriazole (6.66 g) at 0° C. The mixture was stirred at room temperature for 14 hours. The reaction mixture was poured into ice-cold saturated aqueous sodium hydrogencarbonate solution and the resulting solid was collected by filtration. The solid was washed successively with saturated aqueous sodium hydrogencarbonate solution and water. The solid was crystallized from water:ethanol (1:9 (v/v)) to give the title compound (23 g) as crystals.

Provenance & Evidence