4-Nitrophenol → (2S)-N-[(5S)-5-[(4-aminophenyl)sulfonyl-isobutyl-amino]-6-hydrazino-6-oxo-hexyl]-3-phenyl-2-(2-thienylsulfonylamino)propanamide

Participants

Reaction Steps

A solution of Nα-(4-aminobenzenesulfonyl)-Nα-isobutyl-Nε-[N′α-(2-thiophenesulfonyl)-L-phenylalanyl]-L-lysine (650 mg, 1.0 mmol, example 46) dissolved in EtOAc (20 mL) was treated with p-nitrophenol (139 mg, 1.0 mmol) and DCC (206 mg, 1.0 mmol) and was left in a refrigerator overnight. Afterwards, the precipitate was filtered off through celite and the solvent evaporated. The crude residue was used without further purification. A portion of the residue (55 mg, 0.072 mmol) was added to a solution of hydrazine hydrate in ethanol (1M, 10 mL). The resulting solution was stirred for 3 h before evaporation of the solvent. The residue was purified by preparative HPLC to yield 25 mg, 30% of the desired material.

Provenance & Evidence