Potassium Carbonate → 4-Ethynylbenzaldehyde

HRID 358238

Reaction equation

HRID 358238 reaction equation
C[Si]([C:5]#[C:6][C:7]1[CH:14]=[CH:13][C:10]([CH:11]=[O:12])=[CH:9][CH:8]=1)(C)C.C(=O)([O-])[O-].[K+].[K+].[K+].[Br-]>CO>[C:6]([C:7]1[CH:14]=[CH:13][C:10]([CH:11]=[O:12])=[CH:9][CH:8]=1)#[CH:5]

Participants

5

Reactant 3

HCID 11430Potassium CarbonateHCID 253877Potassium BromideHCID 27716434-(Trimethylsilylethynyl)benzaldehyde

Product 1

HCID 27716454-Ethynylbenzaldehyde

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Conditions

Temperature
25 °C

Procedure

A solution of 16.0 g (79.2 mmoles) of p-trimethylsilylethynylbenzaldehyde in 50 ml of methanol was treated with 1 gm of potassium carbonate and the mixture was stirred under argon at 25° C. for two hours. The solvent methanol was removed and 100 ml of methylene chloride was added. The mixture was washed with aqueous sodium bicarbonate solution. The organic phase was separated, dried over magnesium sulfate and concentrated to a solid mass. The crude yield of p-ethynylbenzaldehyde was 10.3 g (79.2 moles, 100%). Further purification was carried out by sublimation at 80°-90° C./0.025-0.25 mm Hg to give white crystals: mp 88°-90°; ir (KBr) 3240 (medium, sharp, C≡CO), 2860, 2740 (weak, sharp, O=CH), 2100 (weak, sharp, C≡C), 1690 (strong broad, C=O) and 1590 cm-1 (medium, sharp C=C); mass spectrum: m/e 130 (100%, M.+), 129 (90.7%, M.+ --H), 101 (59.0% M.+ --CHO); nmr (CDCl3): δ3.21 (s, 1H, C≡C--H), 7.62 (distorted q, 4H, aromatic) and 9.88 ppm (s, 1H, CHO).

Workup

  1. customThe solvent methanol was removed
  2. addition100 ml of methylene chloride was added
  3. washThe mixture was washed with aqueous sodium bicarbonate solution
  4. customThe organic phase was separated
  5. dry with materialdried over magnesium sulfate
  6. concentrationconcentrated to a solid mass
  7. customFurther purification
  8. customwas carried out by sublimation at 80°-90° C.
  9. customto give white crystals

Sources & evidence

ORD record
ord-326d10396d194c258ba6a7788184b8d9
Source dataset
uspto-grants-1984_08
Patent number
US04465833

Linked notes

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