Diisopropylethylamine → N-((1R)-1-(N-((1R)-1-Benzyl-2-((methylsulfonyl)amino)ethyl)-N-methylcarbamoyl)-2-(2-naphthyl)ethyl)-N-methylcarbamic acid tert-butylester

Participants

Reaction Conditions

Reaction Steps

(2R)-2-(N-(tert-Butoxycarbonyl)-N-methylamino)-3-(2-naphthyl)propionic acid (1.05 g, 3.2 mmol) was dissolved in N,N-dimethylformamide (2 ml) and dichloromethane (2 ml). Hydroxy-7-azabenzotriazole (434 mg, 3.2 mmol) was added as a solid. The solution was cooled to 0° C. N-(3-dimethylaminopropyl)-N′-ethylcarbodiimide hydrochloride (612 mg, 3.2 mmol) was added. The solution was stirred for 5 min at 0° C. A solution of N-((2R)-2-methylamino-3-phenylpropyl)methansulfonamide (703 mg, 2.9 mmol) in dichloromethane (2 ml) was added. Ethyldiisopropylamine (0.50 ml, 2.90 mmol) was added. The solution was stirred for 27 h, while it was warming up to room temperature. It was diluted with ethyl acetate (200 ml) and extracted with 1N hydrochloric acid (100 ml). The aqueous phase was extracted with ethyl acetate (50 ml). The combined organic layers were washed with saturated sodium hydrogen carbonate solution and dried over magnesium sulfate. The solvent was removed in vacuo. The crude product was purified by flash chromatography on silica (45 g), using ethyl acetate/heptane (2:1) as eluent, to give 1.037 g of N-((1R)-1-(N-((1R)-1-Benzyl-2-((methylsulfonyl)amino)ethyl)-N-methylcarbamoyl)-2-(2-naphthyl)ethyl)-N-methylcarbamic acid tert-butylester.

Provenance & Evidence