Diisopropylethylamine → 2-((2R)-2-(N-((2R)-2-(N-((2E)-5-(tert-butoxycarbonylamino)-5-methylhex-2-enoyl)-N-methylamino)-3-(2-naphthyl)propionyl)-N-methylamino)-3-phenylpropionylamino)-1,1-dimethylethyl acetate

Participants

Reaction Conditions

Reaction Steps

(2E)-5-(tert-Butoxycarbonylamino)-5-methylhex-2-enoic acid (81 mg, 0.33 mmol) was dissolved in N,N-dimethylformamide (2 ml) and dichloromethane (2 ml). 1-Hydroxy-7-azabenzotriazole (45 mg, 0.33 mmol) was added. The solution was cooled to 0° C. N-(3-Dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride (69 mg, 0.36 mmol) was added. A solution of 1,1-dimethyl-2-((2R)-2-(N-methyl-N-((2R)-2-methylamino-3-(2-naphthyl)propionyl)amino)-3-phenylpropionylamino)ethyl acetate (152 mg, 0.30 mmol) in dichloromethane (2 ml) and ethyldiisopropylamine (0.05 ml, 0.30 mmol) were added successively. The solution was stirred for 16 h, while warming up to room temperature. It was diluted with ethyl acetate (150 ml), washed with 1 N hydrochloric acid (100 ml) and 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 (40 g), using ethyl acetate/heptane (first 1:1 (250 ml), then 2:1) to give 221 mg of 2-((2R)-2-(N-((2R)-2-(N-((2E)-5-(tert-butoxycarbonylamino)-5-methylhex-2-enoyl)-N-methylamino)-3-(2-naphthyl)propionyl)-N-methylamino)-3-phenylpropionylamino)-1,1-dimethylethyl acetate.

Provenance & Evidence