Thiophene → 2-Dodecylthiophene

Participants

Reaction Conditions

Reaction Steps

Thiophene (51.2 g, 623 mmol, 1.2 eq) was first placed in a three-necked flask equipped with a dropping funnel and a reflux tube. The atmosphere in the flask was replaced by Ar (argon), 200 ml of dehydrated tetrahydrofran (hereinafter referred to as “THF”) was then added thereto, and the mixture was stirred. The reaction solution was cooled to −78° C., 2.6 M n-BuLi (200 ml, 520 mmol, 1.0 eq) was added dropwise to the cooled solution, and the mixture was stirred for 30 min. The reaction solution was brought to 0° C. and was stirred for 2 hr. Thereafter, the reaction solution was brought to room temperature and was stirred for 15 min, followed by cooling to 0° C. 1-Bromo-n-dodecane (130 g, 520 mmol, 1.0 eq) was added dropwise thereto, and the mixture was stirred at 0° C. for 2 hr. The reaction solution was brought to room temperature, was stirred for 6 hr, and was then refluxed for one hr. The reaction solution was allowed to cool to room temperature and was extracted with diethyl ether, followed by washing with water until pH=7. The extract was dehydrated over Na2SO4, and the solvent was then removed by evaporation. The residue was purified by chromatography on silica gel to give an objective substance 2-dodecylthiophene as a light yellow liquid (about 125 g yield about 95%). 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), 1.26 (m, 18H), 1.67 (m, 2H), 2.81 (t, 2H, J=7.32 Hz), 6.77 (d, 1H, J=3.42 Hz), 6.90 (dd, 1H, J=3.42 Hz, J=5.37 Hz), 7.09 (d, 1H, J=0.98 Hz, J=4.88 Hz).

Provenance & Evidence