Hydrochloric Acid → 5-Decyl-2,2'-bithiophene

Magnesium (8.90 g, 0.365 mmol) and THF (100 ml) were placed in a 300-ml flask equipped with a reflux tube. A solution of 2-bromothiophene (54.0 g, 0.332 mmol) in THF (100 ml) was slowly added drowpwise thereto, and the mixture was heated under reflux for about 2 hr to prepare a Grignard reagent. This Grignard reagent was added dropwise to a mixed solution composed of [1,1′-bis(diphenylphosphino)ferrocene]palladium(II) dichloride dichloromethane complex (1:1) (1.80 g, 2.21 mmol), 2-bromo-5-decylthiophene (67.0 g, 221 mmol) prepared above, and THF (100 ml) at about 0° C. After the completion of the dropwise addition, the mixture was stirred at room temperature overnight. After the completion of the reaction, 1 N HCl (200 ml) was added to the reaction solution, and the organic layer was extracted with chloroform, was dried over sodium sulfate, and was applied to column chromatography (n-hexane) to give an objective compound 5-decyl-2,2′-bithiophene as a light yellow solid (67.1 g, yield 99.1%). An NMR spectrum of the compound thus obtained was measured at room temperature with an NMR spectrometer (model JNM-LA400W, manufactured by Japan Electric Optical Laboratory). 1H-NMR (CDCl3, TMS/ppm): 0.88 (t, 3H, J=6.83 Hz), 1.31 (m, 14H), 1.67 (m, 2H), 2.78 (t, 2H, J=7.32 Hz), 6.67 (d, 1H, J=3.90 Hz), 6.98 (m, 2H), 7.09 (d, 1H, J=3.90 Hz), 7.15 (d, 1H, J=4.88 Hz)