HOAt → Diisopropylethylamine

Participants

Reaction Steps

To a solution of (2E)-5-(tert-butyloxycarbonylamino)-5-methylhex-2-enoic acid (0.35 g, 1.42 mmol) in methylene chloride (5 ml) was added a mixture of 1-hydroxy-7-azabenzotriazole (0.193 g, 1.42 mmol) and 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide hydrochloride (0.272 g, 1.42 mmol) and stirred for 30 min. Then a mixture of the obtained crude (2R)-N-[(1R)-1-(N',N'-dimethylhydrazinocarbonyl)-2-phenylethyl]-N-methyl-2-(methylamino)-3-(2-naphthyl)propionamide and diisopropylethylamine (0.61 ml, 3.55 mmol) was added and the mixture was stirred overnight. The mixture was concentrated in vacuo and chromatographed on silica (40 g) with ethyl acetate (95):methanol/10% ammonia (5) to give 0.37 g of ((3E)4-[N-((1R)-1-(N-[(1R)-1-(N',N'-dimethylhydrazinocarbonyl)-2-phenylethyl]-N-methylcarbamoyl)-2-(2-naphthyl)ethyl)-N-methylcarbamoyl]-1,1-dimethylbut-3-enyl)carbamic acid tert-butyl ester as an oil.

Provenance & Evidence