tert-butyl (2S)-2-[({1-[(3'-isopropylbiphenyl-2-yl)methyl]-2-oxo-1,2-dihydropyridin-3-yl}carbonyl)amino]-5-{[(2,2,5,7,8-pentamethyl-3,4-dihydro-2H-chromen-6-yl)sulfonyl]carbamimidamido}pentanoate   、                                                                                      
三氟乙酸   、                                                                                      
三乙基硅烷                                                                                                                                                                                              以
                                                                                         
水                                                                                  为溶剂,
                                                                                                                                                                                        以to provide 30 mg (2S)-5-carbamimidamido-2-[({1-[(3′-isopropylbiphenyl-2-yl)methyl]-2-oxo-1,2-dihydropyridin-3-yl}carbonyl)amino]pentanoic acid•TFA的产率得到(2S)-5-carbamimidamido-2-[({1-[(3'-isopropylbiphenyl-2-yl)methyl]-2-oxo-1,2-dihydropyridin-3-yl}carbonyl)amino]pentanoic acid trifluoroacetate