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 with ethyl acetate and washing with saturated aqueous Seignette salt solution was followed by drying of the organic phase over sodium sulfate and evaporation which 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