反应详情

To a solution of 3-(4-chloro-phenyl)-5-([E]-styryl)-isoxazole-4-carboxylic acid (6.0 g, 18.4 mmol) and triethylamine (2.58 mL, 18.4 mmol) in THF (150 mL) was added at room temperature a solution of ethyl chloroformate (1.8 mL, 18.4 mmol) in THF (17.4 mL). After 1 h triethylamine hydrochloride salt was filtered off, and washed with a small amount of THF. The solution was then added to a solution of sodium borohydride (1.82 g, 46.1 mmol) in water (18 mL). After stirring overnight at room temperature sodium hydroxide solution (1 N) was added. Extraction with tert-butylmethylether and purification by chromatography (silica, dichloromethane) afforded the title compound (4.52 g, 79%) as a white solid. MS: m/e=369.9 [M+CH3COO]−.

1. filtrationAfter 1 h triethylamine hydrochloride salt was filtered off
2. washwashed with a small amount of THF
3. additionwas added
4. extractionExtraction
5. customwith tert-butylmethylether and purification by chromatography (silica, dichloromethane)