反应详情

温度

50 °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 (5 mL) were successively added 4-(dimethylamino)pyridine (21.0 mg, 172 μmol) and 6-methoxy-1-naphthoyl chloride (22) prepared above at room temperature, and the mixture was heated with stirring at 50° C. 18 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 successively purified twice by column chromatography (silica gel 50 g, dichloromethane/ethyl acetate=9/1, and silica gel 50 g, n-hexane/ethyl acetate=2/1) to give Compound 11z (775 mg, 1.17 mmol, <68.3%) as a brown foamy solid containing some impurities. Rf=0.21 (n-hexane/ethyl acetate=2/1); 1H NMR (400 MHz, DMSO-d6) δ 3.82 (s, 3H), 3.83 (s, 6H), 4.39 (s, 2H), 7.04-7.09 (AA′BB′, 2H), 7.15-7.23 (m, 6H), 7.26-7.31 (m, 1H), 7.34-7.41 (m, 4I), 7.63-7.69 (m, 2H), 7.75-7.80 (AA′BB′, 2H), 8.02-8.08 (m, 4H), 9.07 (s, 1H).

1. customprepared above at room temperature
2. temperaturethe mixture was heated
3. custom18 hours
4. temperatureAfter cooling to room temperature, to the mixture
5. extractionthe product was extracted with dichloromethane (×3)
6. extractionThe combined organic extract
7. dry with materialwas dried over anhydrous sodium sulfate
8. filtrationfiltered
9. concentrationconcentrated under reduced pressure
10. customThe residual pyridine was azeotropically removed with toluene (×3)
11. customThe residue was successively purified twice by column chromatography (silica gel 50 g, dichloromethane/ethyl acetate=9/1, and silica gel 50 g, n-hexane/ethyl acetate=2/1)