Ethanolamine → 2-[(E)-2-(3-Butyl-5-methyl-isoxazol-4-yl)-vinyl]-4-methyl-thiazole-5-carboxylic acid (2-hydroxy-ethyl)-amide

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Reaction Steps

To a stirred solution of 2-[(E)-2-(3-butyl-5-methyl-isoxazol-4-yl)-vinyl]-4-methyl-thiazole-5-carboxylic acid methyl ester (Example 93c, 1.0 g, 3.12 mmol) in toluene (7 mL) was added ethanolamine (229 mg, 3.75 mmol) and TBD (261 mg, 1.88 mmol). After 22 h the reaction mixture was diluted with Seignette's salt and extracted with ethyl acetate. The combined extracts were dried, filtered and concentrated in vacuo, then purified by chromatography (silica, 0 to 10% methanol in dichloromethane) then on a 5×50 cm Chiralpak AD column at room temperature using an isopropanol:heptane (2:8) mobile phase with UV detection at 220 nM to give the less polar component 2-[(E)-2-(3-butyl-5-methyl-isoxazol-4-yl)-vinyl]-4-methyl-thiazole-5-carboxylic acid (2-hydroxy-ethyl)-amide (884 mg, 81%) as a pale yellow solid then the most polar component 2-[(Z)-2-(3-butyl-5-methyl-isoxazol-4-yl)-vinyl]-4-methyl-thiazole-5-carboxylic acid (2-hydroxy-ethyl)-amide (80 mg, 7%) as a pale yellow solid. MS: m/e=350.4 [M+H]+.

Provenance & Evidence