(2R)-2-hydroxy-2-[(2R)-3-oxo-4-[4-(trifluoromethoxy)phenyl]morpholin-2-yl]acetic acid 、
3-(4-氨基苯基)-1,2,4-恶二唑-5(2H)-酮 、
6-amino-1-(di-tert-butoxycarbonylamino)isoquinoline 以
N,N-二甲基甲酰胺 为溶剂,
以to obtain compound 56-1 (26 mg) as a colorless amorphous solid的产率得到(2R)-2-hydroxy-N-[4-(5-oxo-4H-1,2,4-oxadiazol-3-yl)phenyl]-2-[(2R)-3-oxo-4-[4-(trifluoromethoxy)phenyl]morpholin-2-yl]acetamide