Diisopropylethylamine → N-methyl-N-((1R)-1-(N-methyl-N-((1R)-2-phenyl-1-((2,2,2-trifluoroethyl) carbamoyl)ethyl)carbamoyl)-2-(2-naphthyl)ethyl)carbamic acid tert-butyl ester

Participants

Reaction Conditions

Reaction Steps

A solution of (2R)-2-(N-(tert-butoxycarbonyl)-N-methylamino)-3-(2-naphthyl)propionic acid (1.35 g, 4.1 mmol) and 1-hydroxy-7-azabenzotriazole (0.56 g, 4.1 mmol) in N,N-dimethylformamide (5 ml) and dichloromethane (5 ml) was cooled to 0° C. N-(3-Dimethylaminopropyl)-N′-ethylcarbodiimide hydrochloride (0.79 g, 4.1 mmol) was added. The reaction mixture was stirred for 15 min at 0° C. A solution of (2R)-2-methylamino-3-phenyl-N-(2,2,2-trifluoroethyl)propionamide (1.07 g, 4.1 mmol) in dichloromethane (5 ml) was added. Ethyldiisopropylamine (0.71 ml) was added. The reaction mixture was stirred for 16 h, while it was warming up to room temperature. It was diluted with ethyl acetate (100 ml) and washed with 10% aqueous sodium hydrogen sulfate solution (100 ml). The aqueous phase was extracted with with ethyl acetate (2×50 ml). The combined organic layers were washed with saturated sodium hydrogen carbonate solution (100 ml) and dried over magnesium sulfate. The solvent was removed in vacuo. The crude product was purified by flash chromatography on silica (170 g), using ethyl acetate/heptane 1:2 (300 ml), and then ethyl acetatelheptane/dichloromethane 1:1:1 as eluent to give 1.14 g of N-methyl-N-((1R)-1-(N-methyl-N-((1R)-2-phenyl-1-((2,2,2-trifluoroethyl)carbamoyl)ethyl)carbamoyl)-2-(2-naphthyl)ethyl)carbamic acid tert-butyl ester.

Provenance & Evidence