Water → 4-fluoro-5-phenyl-1-(pyridin-3-ylsulfonyl)-1H-pyrrole-3-carbaldehyde

Temperature

0 °C

Under a nitrogen atmosphere, a solution of methyl 4-fluoro-5-phenyl-1-(pyridin-3-ylsulfonyl)-1H-pyrrole-3-carboxylate (200 mg) in tetrahydrofuran (10 mL) was cooled to −78° C., and a 1.5 mol/L solution (1.85 mL) of diisobutylaluminum hydride in toluene was added with stirring. After stirring at the same temperature for 15 min, the mixture was raised to 0° C. over 1.5 hr. Water (20 mL) was added, and the mixture was stirred at the same temperature for 5 min. After stirring, ethyl acetate (20 mL) was added, and the mixture was stirred for 15 min, and then stirred at room temperature for 20 min. The reaction mixture was filtered through celite, and celite was washed with ethyl acetate. The filtrate was extracted with ethyl acetate. The extract was washed with saturated brine, dried over anhydrous magnesium sulfate, and concentrated under reduced pressure. The residue was dissolved in tetrahydrofuran (10 mL), manganese dioxide (75% chemically treated product, 1.0 g) was added, and the mixture was stirred at room temperature for 16 hr. The reaction mixture was filtered through celite, and celite was washed with ethyl acetate. The filtrate was concentrated under reduced pressure and the residue was purified by silica gel column chromatography (eluent: hexane-ethyl acetate=19:1→1:2) to give the title compound as a colorless solid (yield 123 mg, 67%).

1. stirringAfter stirring at the same temperature for 15 min
2. stirringthe mixture was stirred at the same temperature for 5 min
3. stirringAfter stirring
4. stirringthe mixture was stirred for 15 min
5. stirringstirred at room temperature for 20 min
6. filtrationThe reaction mixture was filtered through celite, and celite
7. washwas washed with ethyl acetate
8. extractionThe filtrate was extracted with ethyl acetate
9. washThe extract was washed with saturated brine
10. dry with materialdried over anhydrous magnesium sulfate
11. concentrationconcentrated under reduced pressure
12. dissolutionThe residue was dissolved in tetrahydrofuran (10 mL)
13. additionmanganese dioxide (75% chemically treated product, 1.0 g) was added
14. stirringthe mixture was stirred at room temperature for 16 hr
15. filtrationThe reaction mixture was filtered through celite, and celite
16. washwas washed with ethyl acetate
17. concentrationThe filtrate was concentrated under reduced pressure
18. customthe residue was purified by silica gel column chromatography (eluent: hexane-ethyl acetate=19:1→1:2)

ORD record

ord-45007b94ab8d42eabd48f68260c7a547

Source dataset

uspto-grants-2009_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07498337B2