3-Methoxytyramine → (S)-2-(Ethylsulfonylamino)-3-methyl-butyric acid N-[2-(4-hydroxy-3-methoxyphenyl)-ethyl]-amide

Participants

Reaction Steps

A mixture of 2.1 g of (S)-2-(ethylsulfonylamino)-3-methyl-butyric acid, 1.7 g of 2-(4-hydroxy-3-methoxyphenyl)-ethylamine, 4.6 g of (benzotriazol-1-yloxy)-tris(dimethylamino)phosphonium hexafluorophosphate (BOP) and 4.5 ml of N,N-diisopropylethylamine is stirred in 40 ml of N,N-dimethylformamide at room temperature for 2 hours. The reaction mixture is introduced into 500 ml of water and extracted twice with 400 ml of ethyl acetate each time. The organic phases are washed once with 300 ml of water and once with 200 ml of saturated sodium chloride solution, dried over magnesium sulfate and concentrated. (S)-2-(Ethylsulfonylamino)-3-methyl-butyric acid N-[2-(4-hydroxy-3-methoxyphenyl)-ethyl]-amide is obtained in the form of an oil, which can be purified by flash-chromatography on silica gel using a mixture of ethyl acetate/n-hexane=3:1.

Provenance & Evidence