Water → 5-[(5-Methyl-3-phenyl-isoxazol-4-ylmethyl)-amino]-pyrazine-2-carboxylic acid isopropylamide

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Reaction Steps

To a solution of isopropylamine (0.69 mL, 8 mmol) in dioxane (5 mL) was added dropwise trimethylaluminum solution (2M solution in hexane, 4 mL, 8 mmol). After stirring for 1 h at room temperature a suspension of 5-[(5-methyl-3-phenyl-isoxazol-4-ylmethyl)-amino]-pyrazine-2-carboxylic acid methyl ester (650 mg, 2 mmol) in dioxane (5 mL) was added. The reaction mixture was stirred at 90° C. for 90 min, cooled to room temperature and poured into water. Extraction (ethyl acetate/saturated aqueous Seignette salt solution) followed by drying of the organic phase over sodium sulfate and evaporation afforded an oil. Purification by chromatography (SiO2, heptane:ethyl acetate=100:0 to 20:80) afforded the title compound (600 mg, 85%) as a white solid MS: m/e=352.3 [M+H]+.

Provenance & Evidence