Sulfuric Acid → 2-Methyl-2-(4-trifluoromethylphenyl)propanaldehyde

Temperature

-50 °C

A stirred solution of 119.8 grams (0.56 mole) of 2-methyl-2-(4-trifluoromethylphenyl)propanenitrile in 100 mL of toluene was cooled to -50° C., and 487 mL (0.73 mole) of diisobutylaluminium hydride (1.5M in toluene) was added dropwise during a 45 minute period while keeping the reaction mixture temperature between -45° and -50° C. Upon completion of addition, the reaction mixture was stirred at -50° C. for 30 minutes. The reaction mixture was then warmed to about 0° C., where it stirred for an additional 30 minutes. After this time, the reaction mixture was carefully poured into 1000 mL of ice-cold aqueous 1.5M sulfuric acid. The resultant mixture was stirred for about three hours, then it was allowed to stand for about 18 hours. The aqueous layer was separated and extracted with 200 mL of diethyl ether. The organic layer and the diethyl ether extract were combined and dried with magnesium sulfate. The mixture was filtered, and the filtrate was concentrated under reduced pressure, yielding 102.3 grams of 2-methyl-2-(4-trifluoromethylphenyl)propanaldehyde. The NMR spectrum was consistent with the proposed structure.

1. customthe reaction mixture temperature between -45° and -50° C
2. additionUpon completion of addition
3. temperatureThe reaction mixture was then warmed to about 0° C.
4. stirringwhere it stirred for an additional 30 minutes
5. waitto stand for about 18 hours
6. customThe aqueous layer was separated
7. extractionextracted with 200 mL of diethyl ether
8. extractionThe organic layer and the diethyl ether extract
9. dry with materialdried with magnesium sulfate
10. filtrationThe mixture was filtered
11. concentrationthe filtrate was concentrated under reduced pressure

ORD record

ord-0a455149a9a844dc85f2ac116939e1c1

Source dataset

uspto-grants-1997_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05622954