Hydrochloric Acid → (S)-2-(N,N-dimethylsulfamoyl)-amino-3-methyl-butyric acid N-[2-(3,4-dimethoxyphenyl)-ethyl]-amide

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Reaction Steps

7.2 g of (S)-2-amino-3-methyl-butyric acid N-[2-(3,4-dimethoxyphenyl)-ethyl]-amide and 4 ml of triethylamine are initially introduced in 120 ml of 1,4-dioxane at room temperature, while stirring. 2.8 ml of N,N-dimethylsulfamoyl chloride are added dropwise in the course of 5 minutes. The reaction mixture is then stirred at room temperature for 20 hours and subsequently introduced into 80 ml of 2N hydrochloric acid. The mixture is extracted twice with 200 ml of ethyl acetate each time. The organic phases are washed once with 80 ml of 2N hydrochloric acid, once with 80 ml of saturated sodium chloride solution, once with 80 ml of 5% sodium bicarbonate solution and once with 80 ml of saturated sodium chloride solution, combined, dried over sodium sulfate and concentrated. (S)-2-(N,N-dimethylsulfamoyl)-amino-3-methyl-butyric acid N-[2-(3,4-dimethoxyphenyl)-ethyl]-amide, which can be purified by recrystallization from ethyl acetate/hexane, is obtained, melting point 97°-99° C.

Provenance & Evidence