7-氨基-4-甲基香豆素 、
(2S,8S)-21-azido-2-(4-((tert-butoxycarbonyl)amino)butyl)-4,7,10-trioxo-8-(3-(3-((2,2,4,6,7-pentamethyl-2,3-dihydrobenzofuran-5-yl)sulfonyl)guanidino)propyl)-13,16,19-trioxa-3,6,9-triazahenicosan-1-oic acid 在
N,N-二异丙基乙胺 、 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46%的产率得到tert-butyl ((14S,20S)-1-azido-20-((4-methyl-2-oxo-2H-chromen-7-yl)carbamoyl)-12,15,18-trioxo-14-(3-(3-((2,2,4,6,7-pentamethyl-2,3-dihydrobenzofuran-5-yl)sulfonyl)guanidino)propyl)-3,6,9-trioxa-13,16,19-triazatetracosan-24-yl)carbamate