反应详情

A mixture of isoxazol-5-ylacetonitrile from Example 48A (3.00 g, 27.8 mmol), tert-butyl 4-oxopiperidine-1-carboxylate (5.53 g, 27.8 mmol) and ammonium acetate (4.28 g, 55.5 mmol) in toluene (50 mL) was heated for 8 h to reflux. Subsequently, the mixture was extracted with water, dried over sodium sulfate, and the solvent was removed in vacuo. The crude product was purified by column chromatography on silica gel (eluent: cyclohexane/ethyl acetate 2:1) to yield an oil, which precipitated upon treatment with petroleum ether/tert-butyl methyl ether to yield 4.38 g (54.6%) of the title compound as yellowish crystals.

1. temperaturewas heated for 8 h
2. temperatureto reflux
3. extractionSubsequently, the mixture was extracted with water
4. dry with materialdried over sodium sulfate
5. customthe solvent was removed in vacuo
6. customThe crude product was purified by column chromatography on silica gel (eluent: cyclohexane/ethyl acetate 2:1)
7. customto yield an oil, which
8. customprecipitated upon treatment with petroleum ether/tert-butyl methyl ether