L-Tryptophan, N-[(4-methylphenyl)sulfonyl]- → methyl (2S)-6-[[(2S)-3-(1H-indol-3-yl)-2-(p-tolylsulfonylamino)propanoyl]amino]-2-[isobutyl(p-tolylsulfonyl)amino]hexanoate

Participants

Reaction Steps

To a stirred solution of Nα-isobutyl-Nα-(4-methylbenzenesulfonyl)-L-lysine methyl ester (369 mg, 1 mmol, example 65, step C) in THF/K2CO3 (1M) (3 mL/3 mL) was added Nα-(4-methylbenzenesulfonyl)-L-tryptophan N-hydroxysuccininide ester (547 mg, 1.2 mmol). The reaction mixture was stirred overnight, then diluted with 1N HCl and extracted with EtOAc. The organic layer was dried (MgSO4) and concentrated. The crude was purified by flash chromatography using hexane/EtOAc as eluent to afford the desired product (71% yield).

Provenance & Evidence