4,9-Dimethoxynaphtho[1,2-b:5,6-b′]dithiophene (0.90 g, 3.0 mmol) was solubilized in anhydrous dichloromethane (20 mL). Dodecanoyl chloride (0.765 g, 3.5 mmol) was then added and stirring was continued for 10 minutes at this temperature. Aluminum trichloride (0.465 g, 3.5 mmol) was then added in 3 portions. The mixture was stirred overnight at room temperature. The mixture was cooled in ice water and extracted with chloroform (200 mL) and washed with water (100 mL) and brine (50 mL). After the solvent was removed, the residual was purified using a silica column with dichloromethane:hexane (1/3) to give compound 1-(4,9-dimethoxynaphtho[1,2-b:5,6-b′]dithiophen-2-yl)dodecan-1-one as a pale yellow solid (0.78 g, ˜54% yield). 1H NMR (500 MHz, CDCl3): δ 8.72 (s, 1H), 7.69 (d, J=5.5 Hz, 1H), 7.50 (m, 2H), 7.42 (s, 1H), 4.24 (s, 3H), 4.22 (s, 3H) 3.07. (t, J=7.0 Hz, 2H), 1.83 (m, 2H), 1.39 (m, 18H); 0.88 (m, J=6.0 Hz, 3H).
