Hydrochloric Acid → 4-Methyl-1-[(4-methylphenyl)sulfonyl]-5-phenyl-1H-pyrrole-3-carbaldehyde

Temperatur

-78 °C

A solution of (10 mL) ethyl 4-methyl-1-[(4-methylphenyl)sulfonyl]-5-phenyl-1H-pyrrole-3-carboxylate (420 mg) in tetrahydrofuran was cooled to −78° C., a 1.5 mol/l solution (2.1 mL) of diisobutylaluminum hydride in toluene was added dropwise, and the mixture was further stirred at −78° C. for 30 min. 1 mol/l Hydrochloric acid (10 mL) was added to the reaction mixture, and the mixture was stirred at room temperature and extracted with ethyl acetate. The extract was washed with saturated brine, dried over anhydrous sodium sulfate, and concentrated under reduced pressure. A solution (15 mL) of the residue in acetonitrile was cooled to −78° C., tetra-n-propylammonium perruthenate (37 mg), N-methylmorpholine N-oxide (185 mg) and molecular sieves 4A powder (1.0 g) were added, and the mixture was stirred at room temperature for 1 hr. The reaction mixture was concentrated under reduced pressure, and the residue was suspended in ethyl acetate and filtered through celite. The filtrate was concentrated under reduced pressure, and the residue was purified by silica gel column chromatography (eluent: hexane-ethyl acetate=9:1→1:1) to give the title compound as a brown oil (yield 320 mg, 90%).

1. stirringthe mixture was stirred at room temperature
2. extractionextracted with ethyl acetate
3. washThe extract was washed with saturated brine
4. dry with materialdried over anhydrous sodium sulfate
5. concentrationconcentrated under reduced pressure
6. temperatureA solution (15 mL) of the residue in acetonitrile was cooled to −78° C.
7. additiontetra-n-propylammonium perruthenate (37 mg), N-methylmorpholine N-oxide (185 mg) and molecular sieves 4A powder (1.0 g) were added
8. stirringthe mixture was stirred at room temperature for 1 hr
9. concentrationThe reaction mixture was concentrated under reduced pressure
10. filtrationfiltered through celite
11. concentrationThe filtrate was concentrated under reduced pressure
12. customthe residue was purified by silica gel column chromatography (eluent: hexane-ethyl acetate=9:1→1:1)

ORD-Eintrag

ord-cbe0da5050634cf482b4f265cb6fe7e7

Quelldatensatz

uspto-grants-2011_11

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US08048909B2