Triethylamine → 5-Cyclopropyl-3-phenyl-isoxazole-4-carboxylic acid ethyl ester

Beteiligte Stoffe

Reaktionsschritte

To a solution of N-hydroxybenzenecarboximidoyl chloride (Tetrahedron Letters, 2006, 47, 1457, 2006; 500 mg, 3.21 mmol) and cyclopropyl-propynoic acid ethyl ester (Organic Syntheses, 1988, 66, 173; 515 mg, 3.21 mmol) in diethyl ether (5 mL) was added dropwise over a period of 2 min at ambient temperature triethylamine (0.54 ml, 3.86 mmol) and the reaction mixture was stirred for 3 d at this temperature. The resulting suspension was diluted with tert-butylmethylether (5 mL) and water (10 mL). The aqueous layer was extracted with tert-butylmethylether (10 mL) and the organic layers were washed with water (10 mL) and brine (10 mL). Drying over sodium sulfate and purification by chromatography (SiO2, heptane:ethyl acetate=98:2 to 80:20) afforded the title compound (414 mg, 50%) as a colorless liquid. MS: m/e=258.1[M+H]+.

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