Diisopropylethylamine → ((1R)-2-(Benzo[b]thiophen-3-yl)-1-(methyl-((1R)-1-methylcarbamoyl-2-phenyl-ethyl)carbamoyl)ethyl)-methylcarbamic acid tert-butylester

Participants

Reaction Steps

(2R)-3-(Benzo[b]thiophen-3-yl)-2-(tert-butoxycarbonyl-methylamino)propionic acid (2.00 g ; 5.96 mmol) was dissolved in methylene chloride (10 mL). 1-Hydroxy-7-azabenzotriazole (0.81 g; 5.96 mmol) and N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride (1.26 g ; 6.56 mmol) were added. The reaction mixture was stirred for 15 min at room temperature. (2R)-N-Methyl-2-methylamino-3-phenylpropionamide (1.15 g; 5.96 mmol) was dissolved in methylene chloride (10 mL) and added. Diisopropylethylamine (1.02 mL; 5.96 mmol) were added. The reaction mixture was stirred for 48 hours. Methylene chloride (10 mL) was added. The reaction was washed with water (30 mL), an aqueous solution of sodium hydrogen sulfate 10%; 30 mL), an aqueous solution of sodium hydrogen carbonate (saturated; 30 mL) and dried (magnesium sulfate). The solvent was removed in vacuo and the residue was chromatographed on silica (3×30 cm) using ethyl acetate/methylene chloride (1:1) as eluent to afford 0.89 g of ((1R)-2-(benzo[b]thiophen-3-yl)-1-(methyl-((1R)-1-methylcarbamoyl-2-phenylethyl)carbamoyl)ethyl)methyl carbamic acid tert-butylester.

Provenance & Evidence