4-(cyclopropanecarbonyl-amino)-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,
                                                                                                                                                    反应 18.0h,
                                                                                                                以26%的产率得到L-2-(4'-{[4-(cyclopropanecarbonyl-amino)-3-methylbenzofuran-2-carbonyl]amino}biphenyl-4-sulfonylamino)-3-methylbutyric acid methyl ester