反应详情

Phosphorus pentoxide (22 g, 155.24 mmol) was added to a mixture of N-[2-(4-methoxyphenyl)-ethyl]-acetamide (50 g, 258.73 mmol) prepared in Step 1 and phosphorus oxychloride (48 ml, 517.46 mmol). The reaction mixture was refluxed for 3 hours. The reaction mixture was cooled to room temperature, added to ice water, basified with 2N potassium hydroxide solution, and then extracted with ethyl acetate. The organic layer washed with a saturated sodium chloride solution, dried on anhydrous magnesium sulfate, filtered, and then concentrated under reduced pressure. The resulting residue was purified with silica gel column chromatography to give 14.72 g of the titled compound as brown oil. (Yield: 32%) The product was used in the subsequent step without further purification.

1. temperatureThe reaction mixture was refluxed for 3 hours
2. extractionextracted with ethyl acetate
3. washThe organic layer washed with a saturated sodium chloride solution
4. dry with materialdried on anhydrous magnesium sulfate
5. filtrationfiltered
6. concentrationconcentrated under reduced pressure
7. customThe resulting residue was purified with silica gel column chromatography