Diisopropylethylamine → (3E)-1,1-dimethyl-4-(N-methyl-N-((1R)-1-(N-methyl-N-(2-(2-thienyl)ethyl)carbamoyl)-2-(2-naphthyl)ethyl)carbamoyl)but-3-enylcarbamic acid tert-butyl ester

Participants

Reaction Conditions

Reaction Steps

(2E)-5-tert-Butoxycarbonylamino-5-methylhex-2-enoic acid (380 mg, 1.56 mmol) was dissolved in N,N-dimethylformamide (2 ml) and dichloromethane (2 ml). 1-Hydroxy-7-azabenzotriazole (299 mg, 1.56 mmol) was added as a solid. The solution was cooled to 0° C. N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride (380 mg, 1.56 mmol) was added. The solution was stirred for 15 min. at 0° C. A solution of (2R)-N-methyl-2-(methylamino)-3-(2-naphthyl)-N-(2-(2-thienyl)ethyl)propionamide (500 mg, 1.42 mmol) in dichloromethane (2 ml) was added. Ethyldiisopropylamine (0.25 ml, 1.42 mmol) was added. The solution was stirred for 16 h, while it was warming up to room temperature. It was diluted with ethyl acetate (70 ml) and washed with 1 N hydrochloric acid (100 ml). The organic layer was 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 (150 g), using ethyl acetate/heptane (1:1) as eluent, to give 679 mg of (3E)-1,1-dimethyl-4-(N-methyl-N-((1R)-1-(N-methyl-N-(2-(2-thienyl)ethyl)carbamoyl)-2-(2-naphthyl)ethyl)carbamoyl)but-3-enylcarbamic acid tert-butyl ester.

Provenance & Evidence