Trimethylsilylacetylene → 3-(Trimethylsilyl)ethynylbenzaldehyde

HRID 915732Notes

Reaction equation

HRID 915732 reaction equation
Br[C:2]1[CH:3]=[C:4]([CH:7]=[CH:8][CH:9]=1)[CH:5]=[O:6].[C:10]([Si:12]([CH3:15])([CH3:14])[CH3:13])#[CH:11]>C(N(CC)CC)C.C([O-])(=O)C.[Pd+2].C([O-])(=O)C.C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1>[CH3:13][Si:12]([C:10]#[C:11][C:2]1[CH:3]=[C:4]([CH:7]=[CH:8][CH:9]=1)[CH:5]=[O:6])([CH3:15])[CH3:14]

Participants

6

Reactant 2

HCID 66111TrimethylsilylacetyleneHCID 765833-Bromobenzaldehyde

Product 1

HCID 27716423-(Trimethylsilyl)ethynylbenzaldehydeYield 78%

Reagents, catalysts & solvents 3

HCID 11776TriphenylphosphineCatalystHCID 167845palladium(II) acetateCatalystHCID 8471TriethylamineSolvent

Procedure

To a solution of 3-bromobenzaldehyde (10.00 g, 54.08 mmol) and triphenylphosphine (0.500 g, 1.91 mmol) in anhydrous triethylamine (100 mL) under argon were added ethynyltrimethylsilane (6.00 g, 61.09 mmol) and palladium (II) acetate (0.100 g, 0.445 mmol). The final mixture was heated to reflux for 2 hours, and was then cooled to room temperature and filtered. The filtrate was concentrated under vacuum to a thick oil, which was purified by column chromatography (dichloromethane/petroleum ether 1:4) to give 8.52 g (78.0% yield) of 3-(trimethylsilylethynyl)benzaldehyde [1H-NMR (CDCl3) δ ppm: 0.26 (s, 9H, SiMe3), 7.47 (t, 1H, ArH, J=7.5 Hz), 7.70 (d, 1H, ArH, J=7.5 Hz), 7.82 (d, 1H, ArH, J=7.5 Hz), 7.96 (s, 1H ArH), 9.98 (s, 1H, CHO)]. This compound (5.00 g, 24.74 mmol) was treated with K2CO3 (0.500 g) in methanol (50 mL) at 25° C. for 2 hours under argon. The solvent was removed under vacuum, and the residue was dissolved in dichloromethane (100 mL). This solution was washed once with a saturated aqueous NaHCO3 solution, and once with water, before being dried over anhydrous Na2SO4 and the solvent evaporated under vacuum. The yellow residue was purified by column chromatography using dichloromethane/petroleum ether 1:4 for elution, and recrystallized from cyclohexane to give 2.80 g (87.1% yield) of the title compound; MS (EI) m/e 130.0; (M+). 1H-NMR (CDCl3) δ ppm: 3.20 (s, 1H, CH), 7.51 (t, 1H, ArH, J=7.8 Hz), 7.74 (d, 1H, ArH, J=7.8 Hz), 7.87 (d, 1H, ArH, J=7.8 Hz), 7.99 (s, 1H, ArH), 10.02 (s, 1H, CHO).

Workup

  1. temperatureto reflux for 2 hours
  2. filtrationfiltered
  3. concentrationThe filtrate was concentrated under vacuum to a thick oil, which
  4. customwas purified by column chromatography (dichloromethane/petroleum ether 1:4)

Sources & evidence

ORD record
ord-d35c5059cee74087ab5468f766a6376d
Source dataset
uspto-grants-2007_09
Patent number
US07267990B2

Reaction notes

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