反应详情

Next, to a solution of EDCl (51.2 mg, 0.267 mmol), 1-hydroxy-7-azabenzotriazole (36.4 mg, 0.267 mmol) and 6:1 mixture of 1-(2-(benzyloxy)-2-oxoethyl)cyclopentanecarboxylic acid and 2-(1-(benzyloxycarbonyl)cyclopentyl)acetic acid (65.6 mg, 0.214 mmol) in DMF (1 ml), which is stirred for 1.5 hours in advance, the crude 3-amino-4-biphenyl-4-yl-butyric acid tert-butyl ester hydrochloride and DIPEA (0.093 ml, 0.535 mmol) are added. After stirring for 2.5 hours, the reaction mixture is diluted with H2O, and the products are extracted with EtOAc. The organic layer is washed with brine, dried over Na2SO4, filtered, and concentrated. The obtained residue is purified by silica gel flash column chromatography (heptane/EtOAc=100:0 to 0:100) to give crude tert-butyl 3-(1-(2-(benzyloxy)-2-oxoethyl)cyclopentanecarboxamido)-4-(biphenyl-4-yl)butanoate (38 mg).

1. stirringAfter stirring for 2.5 hours
2. extractionthe products are extracted with EtOAc
3. washThe organic layer is washed with brine
4. dry with materialdried over Na2SO4
5. filtrationfiltered
6. concentrationconcentrated
7. customThe obtained residue is purified by silica gel flash column chromatography (heptane/EtOAc=100:0 to 0:100)