(2S)-2-({[1-(4-bromobenzyl)-2-oxo-1,2-dihydropyridin-3-yl]carbonyl}amino)-5-[(tert-butoxycarbonyl)amino]pentanoic acid   、                                                                                      
三氟乙酸                                                                                                                                                                                              以
                                                                                         
二氯甲烷                                                                                  为溶剂,
                                                                                                                                                    反应 2.0h,
                                                                                                                以to give (2S)-5-amino-2-({[1-(4-bromobenzyl)-2-oxo-1,2-dihydropyridin-3-yl]carbonyl}amino)pentanoic acid•TFA (0.56 g) as an off-white solid的产率得到(2S)-5-amino-2-({[1-(4-bromobenzyl)-2-oxo-1,2-dihydropyridin-3-yl]carbonyl}amino)pentanoic acid trifluoroacetate