(2S)-cyclopentyl{4-[(5-oxo-2-phenyl-5,6-dihydro-4H-1,3,4-oxadiazin-4-yl)methyl]-phenyl}acetic Acid 、
tert-butyl 6-amino-2,2-dimethylhexanoate 在
吡啶 、 N-[(dimethylamino)-3-oxo-1H-1,2,3-triazolo[4,5-b]pyridin-1-yl-methylene]-N-methylmethanaminium hexafluorophosphate 作用下,
以
N,N-二甲基甲酰胺 为溶剂,
以36%的产率得到tert-butyl 6-{[(2S)-2-cyclopentyl-2-{4-[(5-oxo-2-phenyl-5,6-dihydro-4H-1,3,4-oxadiazin-4-yl)methyl]phenyl}acetyl]amino}-2,2-dimethylhexanoate