Water → 2-Ethyl-5-[4-(trifluoromethyl)phenyl]thiophene-3-carbaldehyde

To a solution (100 mL) of ethyl 2-ethyl-5-[4-(trifluoromethyl)phenyl]thiophene-3-carboxylate (5.18 g) synthesized above in tetrahydrofuran was added lithium aluminum hydride (721 mg) at 0° C., and the mixture was stirred for 1 hr. Water (720 μL) was added to quench the reaction, 1N aqueous sodium hydroxide solution (3.60 mL) was added, and the mixture was stirred at room temperature for 1 hr. The resulting insoluble material was filtered off, and the filtrate was concentrated under reduced pressure to give a pale-yellow oil. To a solution of the obtained oil in tetrahydrofuran (100 mL) was added activated manganese dioxide (24.6 g), and the mixture was stirred at room temperature overnight. Manganese dioxide was filtered off, and the filtrate was concentrated under reduced pressure. The residue was purified by silica gel column chromatography (ethyl acetate:hexane=1:4, volume ratio) to give the title compound (4.38 g, 98%) as a brown oil.

1. customto quench
2. customthe reaction, 1N aqueous sodium hydroxide solution (3.60 mL)
3. additionwas added
4. stirringthe mixture was stirred at room temperature for 1 hr
5. filtrationThe resulting insoluble material was filtered off
6. concentrationthe filtrate was concentrated under reduced pressure
7. customto give a pale-yellow oil
8. stirringthe mixture was stirred at room temperature overnight
9. filtrationManganese dioxide was filtered off
10. concentrationthe filtrate was concentrated under reduced pressure
11. customThe residue was purified by silica gel column chromatography (ethyl acetate:hexane=1:4, volume ratio)

ORD record

ord-763ae60e72cb45969ebf218244b9b7c0

Source dataset

uspto-grants-2012_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08309580B2