(R)-4-((2-(1'-(3-chlorobenzyl)-1-(2-fluoro-6-(trifluoromethyl)benzyl)-2,4-dioxo-1H-spiro[furo[3,4-d]pyrimidine-5,4'-piperidin]-3 (2H,4H,7H)-yl)-1-phenylethyl)amino)butanoic acid   、                                                                                      
3-(2-amino-2-(6-methylpyridin-2-yl)ethyl)-1-(2-fluoro-6-(trifluoromethyl)benzyl)-1'-((5-(trifluoromethyl)furan-2-yl)methyl)-1H-spiro[furo[3,4-d]pyrimidine-5,4'-piperidine]-2,4(3H,7H)-dione                                                                                                                                                                                                                                                                                                          以to obtain the title compound as white foam (46.0 mg, yield: 62%)的产率得到4-((2-(1-(2-fluoro-6-(trifluoromethyl)benzyl)-2,4-dioxo-1'-((5-(trifluoromethyl)furan-2-yl)methyl)-1H-spiro[furo[3,4-d]pyrimidine-5,4'-piperidine]-3(2H,4H,7H)-yl)-1-(6-methylpyridin-2-yl)ethyl)amino)butanoic acid