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

Participants

Reaction Steps

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%).

Provenance & Evidence