Diisopropylethylamine → (R)-N-(2-(tert-Butyldiphenylsilyloxy)ethyl)-N-ethyl-4-(phenylthio)-3-(4-sulfamoyl-2-(trifluorom ethylsulfonyl)phenylamino)butanamide

Participants

Reaction Steps

2-(tert-Butyldiphenylsilyloxy)-N-ethylethanamine (INTERMEDIATE 23, 0.263 g, 0.80 mmol) in THF (2.5 ml), diethyl 4-oxobenzo[d][1,2,3]triazin-3(4H)-yl phosphate (0.480 g, 1.60 mmol) and DIPEA (0.280 ml, 1.60 mmol) were added sequentially to a solution of (R)-4-(phenylthio)-3-(4-sulfamoyl-2-(trifluoromethylsulfonyl)phenylamino)butanoic acid (INTERMEDIATE 8, 0.4 g, 0.80 mmol) in THF (5.0 ml) and the mixture was stirred at room temperature for 3 hrs. The reaction mixture was then concentrated under reduced pressure, diluted with EtOAc and the organic layer was washed with 1N aq. NaHSO4 and saturated aq. NaHCO3. The organic layer was dried (Na2SO4), concentrated under reduced pressure to give a residue, which was purified by column chromatography (ISCO, 40 g silica gel column, eluting with 0→100% EtOAc/hexanes) to provide the title product (590 mg, yield: 91%).

Provenance & Evidence