(2S)-5-amino-2-({[5-(diphenylmethyl)thiophen-2-yl]carbonyl}amino)pentanoic acid trifluoroacetate   、                                                                                      
乙醇   、                                                                                      
ethyl isobutyrimidate hydrochloride                                                                                                                                                                                              以
                                                                                         
三乙胺                                                                                  为溶剂,
                                                                                                                                                    反应 16.0h,
                                                                                                                以to give (2S)-2-({[5-(diphenylmethyl)thiophen-2-yl]carbonyl}amino)-5-[(2-methylpropanimidoyl)amino]pentanoic acid•TFA (132, 85 mg) as an off-white solid的产率得到(2S)-2-({[5-(diphenylmethyl)thiophen-2-yl]carbonyl}amino)-5-[(2-methylpropanimidoyl)amino]pentanoic acid trifluoroacetate