Nalpha-isobutyl-Nalpha-(4-methylbenzenesulfonyl)-L-lysine methyl ester → methyl (2S)-2-[isobutyl(p-tolylsulfonyl)amino]-6-[[(2S)-3-phenyl-2-(p-tolylsulfonylamino)propanoyl]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-phenylalanine N-hydroxysuccinimide ester (500 mg, 1.2 mmol). The reaction mixture was stirred overnight, then diluted with 1 N 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 (77% yield).

Provenance & Evidence