Trifluoroacetic acid → HCID 22598374, compound

Participants

Reaction Steps

A solution of heptanal (0.59 g, 5.16 mmol) and trifluoroacetic acid (100 mg) in anhydrous dichloromethane (50 mL) was added dropwise to a solution of 3-aminothiophene (0.93 g, 9.38 mmol) in anhydrous dichloromethane (50 mL) at −5° C. The reaction mixture was stirred at room temperature for 1.5 h. Trifluoroacetic acid (1.07 g, 9.38 mmol) was added and the reaction mixture was then heated at reflux for 6 h. The solution was cooled and diethyl ether (150 mL) and water (30 mL) were added. The aqueous layer was basified with 0.5 N aqueous sodium hydroxide solution. The organic layer was separated. The aqueous layer was again extracted into diethyl ether (150 mL). The combined organic extracts were dried over sodium sulfate and concentrated in vacuo. Purification by flash chromatography (eluent: 90% petroleum ether 80-100/10% dichloromethane to 100% dichloromethane) afforded 4-hexyldithieno[3,2-b:2′3′-e]pyridine (0.58 g, 45%) as a red oil: δH(CDCl3, 250 MHz) 7.75 (2H, d, 3JHH=6 Hz), 7.59 (2H, d, 3JHH=6 Hz), 3.16 (2H, t, 3JHH=8 Hz), 1.90 (2H, m), 1.27-1.49 (6H, m), 0.89 (3H, t, 3JHH=7 Hz); δC(CDCl3, 63 MHz) 156.2, 140.4, 130.7, 129.7, 34.8, 31.9, 29.8, 28.3, 22.9, 14.4.

Provenance & Evidence