反应详情

To a solution of 2-amino-3-cyano-4-methyl-5-(2-fluorophenyl)pyrrole (Compound No. 1) obtained in Example 5 (0.21 g) in methylene chloride (5 ml) was added a small amount of magnesium sulfate and the mixture was stirred under ice-cooling. Then, a solution of benzaldehyde (0.11 g) in methylene chloride (5 ml) was added dropwise at the same temperature and the mixture was stirred at room temperature for 5 days. The magnesium sulfate was then filtered off and the filtrate was concentrated under reduced pressure. After the residue was dissolved in methanol (15 ml), sodium borohydride (76 mg) was added thereto under ice-cooling. This mixture was stirred at room temperature for 1 hour and the reaction mixture was concentrated under reduced pressure. To the residue was added ethyl acetate, and the ethyl acetate layer was washed with water, dried over MgSO4, and concentrated under reduced pressure. The residue was purified by silica gel column chromatography (Wakogel C-200, 50 g; eluent: chloroform/methanol=50/1) and the resulting crystals were recrystallized from benzene/n-hexane to provide the title compound as light-yellow powder (0.17 g). m.p. 151-152° C.

1. temperaturecooling
2. stirringthe mixture was stirred at room temperature for 5 days
3. filtrationThe magnesium sulfate was then filtered off
4. concentrationthe filtrate was concentrated under reduced pressure
5. dissolutionAfter the residue was dissolved in methanol (15 ml)
6. additionsodium borohydride (76 mg) was added
7. temperatureunder ice-cooling
8. stirringThis mixture was stirred at room temperature for 1 hour
9. concentrationthe reaction mixture was concentrated under reduced pressure
10. additionTo the residue was added ethyl acetate
11. washthe ethyl acetate layer was washed with water
12. dry with materialdried over MgSO4
13. concentrationconcentrated under reduced pressure
14. customThe residue was purified by silica gel column chromatography (Wakogel C-200, 50 g; eluent: chloroform/methanol=50/1)
15. customthe resulting crystals were recrystallized from benzene/n-hexane