反应详情

温度

55 °C

Under an argon atmosphere, to a solution of 3-benzyl-5-(4-methoxyphenyl)pyrazin-2-amine (12) (synthesized by the process of M. Adamczyk, et al., Org. Prep. Proced. Int., 33, 477-485 (2001)) (500 mg, 1.72 mmol) in pyridine (8 mL) were successively added 4-(dimethylamino)pyridine (21.0 mg, 172 μmol) and 2-(4-methoxyphenyl)propanoyl chloride (16) prepared above at room temperature, and the mixture was heated with stirring at 55° C. for 14 hours. After cooling to room temperature, to the mixture was added water and the product was extracted with dichloromethane (×3). The combined organic extract was dried over anhydrous sodium sulfate, filtered and concentrated under reduced pressure. The residual pyridine was azeotropically removed with toluene (×3). The residue was purified twice by column chromatography (silica gel 50 g, dichloromethane/ethyl acetate=9/1, and silica gel 50 g, n-hexane/ethyl acetate=9/1→6/1) to give Compound 11w (942 mg, <quant.) as a colorless foamy solid containing some impurities.

1. customprepared above at room temperature
2. temperaturethe mixture was heated
3. temperatureAfter cooling to room temperature, to the mixture
4. extractionthe product was extracted with dichloromethane (×3)
5. extractionThe combined organic extract
6. dry with materialwas dried over anhydrous sodium sulfate
7. filtrationfiltered
8. concentrationconcentrated under reduced pressure
9. customThe residual pyridine was azeotropically removed with toluene (×3)
10. customThe residue was purified twice by column chromatography (silica gel 50 g, dichloromethane/ethyl acetate=9/1, and silica gel 50 g, n-hexane/ethyl acetate=9/1→6/1)