6-(马来酰亚胺基)己酸琥珀酰亚胺酯   、                                                                                      
(4R)-4-[[2-[(1R,3R)-3-[2-[4-[[(2S)-2-[[(2S)-2-amino-3-methylbutanoyl]amino]-5-(carbamoylamino)pentanoyl]amino]phenyl]ethyl-[(2S,3S)-3-methyl-2-[[(2R)-1-methylpiperidine-2-carbonyl]amino]pentanoyl]amino]-4-methyl-1-(methylcarbamoyloxy)pentyl]-1,3-thiazole-4-carbonyl]amino]-2-methyl-5-phenylpentanoic acid                                                                                                                                                              在
                                                                                                                                                                                 
N,N-二异丙基乙胺                                                                                                                                  作用下,
                                                                                                                以
                                                                                         
N,N-二甲基甲酰胺                                                                                  为溶剂,
                                                                                                                                                                                        以16%的产率得到(2S,4R)-4-[[2-[(1R,3R)-3-[2-[4-[[(2S)-5-(carbamoylamino)-2-[[(2S)-2-[6-(2,5-dioxopyrrol-1-yl)hexanoylamino]-3-methylbutanoyl]amino]pentanoyl]amino]phenyl]ethyl-[(2S,3S)-3-methyl-2-[[(2R)-1-methylpiperidine-2-carbonyl]amino]pentanoyl]amino]-4-methyl-1-(methylcarbamoyloxy)pentyl]-1,3-thiazole-4-carbonyl]amino]-2-methyl-5-phenylpentanoic acid