Hydrochloric Acid → [2,2'-Bithiophene]-5-carboxaldehyde

HRID 1663266Notes

Reaction equation

HRID 1663266 reaction equation
P(Cl)(Cl)(Cl)=O.[S:6]1[CH:10]=[CH:9][CH:8]=[C:7]1[C:11]1[S:12][CH:13]=[CH:14][CH:15]=1.Cl.CN([CH:20]=[O:21])C>>[CH:20]([C:10]1[S:6][C:7]([C:11]2[S:12][CH:13]=[CH:14][CH:15]=2)=[CH:8][CH:9]=1)=[O:21]

Participants

5

Reactant 4

HCID 313Hydrochloric AcidHCID 6228DimethylformamideHCID 24813Phosphorus oxychlorideHCID 681202,2'-Bithiophene

Product 1

HCID 364428[2,2'-Bithiophene]-5-carboxaldehydeYield 81%

Procedure

In a round bottom flask, phosphorus oxychloride (1.83 g) was added at 0° C. to 15 mL of DMF. After 30 minutes, 2,2′-bithiophene (500 mg) was further added and the solution stirred at room temperature for 30 minutes before heating to 50° C. until completion. Diluted hydrochloric acid was added at 0° C., the solution warmed to room temperature and the crude product extracted with ethyl acetate. Purification by flash chromatography (SiO2) yielded the title product as a light brown powder (81%). 1H-NMR (300 MHz, [D] acetone): δ=9.89 (s, 1H), 7.70 (d, 1H, 3J=3.9 Hz), 7.39 (d, 2H, 3J=4.3 Hz), 7.28 (d, 1H, 3J=3.9 Hz), 7.11 (t, 1H, 3J=4.4 Hz). 13C-NMR (50 MHz, [D] acetone): δ=183.0, 147.6, 142.1, 137.8, 136.5, 128.8, 127.5, 126.6, 124.7. EI-MS: m/z ([M]+, 100%).

Workup

  1. temperaturebefore heating to 50° C. until completion
  2. temperaturethe solution warmed to room temperature
  3. extractionthe crude product extracted with ethyl acetate
  4. customPurification by flash chromatography (SiO2)

Sources & evidence

ORD record
ord-a4522f0f1ff54259a4f5713f4b5d0a63
Source dataset
uspto-grants-2011_10
Patent number
US08034895B2

Reaction notes

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