Dimethylformamide → 4-(Isopropyldimethylsilyl)benzaldehyde

HRID 2101272Notes

Reaction equation

HRID 2101272 reaction equation
Br[C:2]1[CH:7]=[CH:6][C:5](Br)=[CH:4][CH:3]=1.C([Li])CCC.CCCCCC.[CH3:20][Si:21](Cl)([CH3:25])[CH:22]([CH3:24])[CH3:23].CN([CH:30]=[O:31])C>C1COCC1.O>[CH:22]([Si:21]([CH3:25])([CH3:20])[C:2]1[CH:7]=[CH:6][C:5]([CH:30]=[O:31])=[CH:4][CH:3]=1)([CH3:24])[CH3:23]

Participants

8

Reactant 5

HCID 6228DimethylformamideHCID 78041,4-DibromobenzeneHCID 8058Hexane2×HCID 5102883Chloro-isopropyl-dimethylsilaneHCID 178418339Butyllithium2×

Product 1

HCID 574385094-(Isopropyldimethylsilyl)benzaldehydeYield 87.2%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 8028TetrahydrofuranSolvent

Conditions

Temperature
-78 °C

Procedure

1,4-Dibromo-benzene (1.18 g, 5 mmol) was dissolved in THF (15 ml) and cooled to −78° C. Under argon a 1.6 M solution of n-butyl lithium in hexane (3.13 ml, 5 mmol) was added slowly under stirring keeping the temperature below −70° C. After complete addition the reaction was stirred at −78° C. for 30 min and dimethyl-isopropyl-silylchloride (683 mg, 5 mmol) was added carefully keeping the temperature again below −70° C. The reaction was stirred at −78° C. for 30 min and a 1.6 M solution of n-butyl lithium in hexane (3.13 ml, 5 mmol) was added at this temperature keeping the temperature below −70° C. After stirring for 30 min at −78° C. DMF (1.1 g, 15 mmol) was added in one portion and the reaction was allowed to warm to rt. Water was added and the solvent was evaporated. The reaction was extracted twice with diethylether. The combined organic layers were dried over sodium sulfate, filtered and the solvent was evaporated, to yield 4-(isopropyl-dimethyl-silanyl)-benzaldehyde (900 mg, 87%) as a colorless oil. The product was pure enough to be used directly in the next step. MS (ISP): 207.1 (M+H)+. 1HNMR (CDCl3, 300 MHz): δ 10.0 (s, 1H), 7.84 (d, J=8.1 Hz, 2H), 7.67 (d, J=8.1 Hz, 2H), 0.93-0.99 (m, 7H), 0.28 (s, 6H).

Workup

  1. customthe temperature below −70° C
  2. additionAfter complete addition the reaction
  3. stirringwas stirred at −78° C. for 30 min
  4. customthe temperature again below −70° C
  5. stirringThe reaction was stirred at −78° C. for 30 min
  6. customthe temperature below −70° C
  7. stirringAfter stirring for 30 min at −78° C
  8. temperatureto warm to rt
  9. customthe solvent was evaporated
  10. extractionThe reaction was extracted twice with diethylether
  11. dry with materialThe combined organic layers were dried over sodium sulfate
  12. filtrationfiltered
  13. customthe solvent was evaporated

Sources & evidence

ORD record
ord-71d307d075574237bedebb71eb79a670
Source dataset
uspto-grants-2009_08
Patent number
US07572823B2

Reaction notes

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