4-isopropoxy-3-methyl-benzofuran-2-carboxylic acid 、
(S)-2-(4'-aminobiphenyl-4-sulfonylamino)-3-methylbutyric acid methyl ester 在
(benzotriazo-1-yloxy)tris(dimethylamino)phosphonium hexafluorophosphate 、
N,N-二异丙基乙胺 作用下,
以
DMF (N,N-dimethyl-formamide) 为溶剂,
以69%的产率得到(S)-2-{4'-[(4-isopropoxy-3-methyl-benzofuran-2-carbonyl)-amino]-biphenyl-4-sulfonylamino}-3-methyl-butyric acid methyl ester