tert-butyl (2S)-2-({[1-(4-bromobenzyl)-2-oxo-1,2-dihydropyridin-3-yl]carbonyl}amino)-5-{[(2,2,5,7,8-pentamethyl-3,4-dihydro-2H-chromen-6-yl)sulfonyl]carbamimidamido}pentanoate 、
三氟乙酸 、
三乙基硅烷 以
水 为溶剂,
以to provide 67 mg (2S)-2-({[1-(4-bromobenzyl)-2-oxo-1,2-dihydropyridin-3-yl]carbonyl}amino)-5-carbamimidamidopentanoic acid•TFA的产率得到(2S)-2-({[1-(4-bromobenzyl)-2-oxo-1,2-dihydropyridin-3-yl]carbonyl}amino)-5-carbamimidamidopentanoic acid trifluoroacetate