Acetic Acid → 3-[2-(Benzofuran-2-ylmethoxycarbonylamino)-2-(1-phenyl-ethylcarbamoyl)-propyl]-indole-1-carboxylic acid 4-{[(2-dimethylamino-ethyl)-methyl-amino]-methyl}-benzoyloxymethyl ester dihydrochloride salt

Participants

Reaction Steps

NaHB(OAc)3 (0.21 g, 1.0 mmol, 1.4 eq.) was added in three equal portions in 10 minutes to a cloudy solution of compound 19 (0.5 g, 0.713 mmol), N,N,N′-trimethylethylenediamine (0.316 mL, 1.07 mmol, 1.5 eq.) and acetic acid (0.061 mL, 1.07 mmol, 1.5 eq.) in dry chloroform (20 mL) under N2 in an ice bath. The reaction was stirred in ice bath for 30 minutes and room temperature for 20 hours to give a white suspension. Saturated sodium bicarbonate (20 mL) was added to the reaction mixture and stirred for 30 minutes. The organic layer was washed with saturated sodium bicarbonate (30 mL), saturated sodium chloride and dried over anhydrous sodium sulfate. The product was further purified by silica gel chromatography (2.5×6 cm) eluting with CHCl3/MeOH (10:0.5) to give compound 20f as a white foam (0.47 g, 84%).

Provenance & Evidence