N,N-diethylthiophene-3-carboxamide → (Benzo(1,2-b:4,5-b)dithiophene-4,8-dione)

Participants

Reaction Steps

N,N-diethylthiophene-3-carboxamide (18.3 g, 0.1 mol) was dissolved in THF (100 mL) in a flame dried flask kept under an inert atmosphere. The reaction flak was placed in an ice bath followed by the dropwise addition of n-BuLi (40.0 mL, 2.5 M BuLi in hexane) over a period of 30 minutes. The reaction mixture was then allowed to warm to room temperature and stirred over a period of 2 hours. The reaction mixture was subsequently slowly poured into ice water (250 mL) and stirred for several hours. The resulting reaction mixture was filtered and the yellow precipitate washed successively with water, methanol (50 mL) and hexanes (50 mL). The title compound was obtained as a yellow powder (yield: 75%): GC-Ms: 220; 1H NMR (400 MHz, CDCl3,ppm) δ: 7.69-7.68(d, 2H), 7.65-7.64(d, 2H); 1H NMR (400 MHz, DMSO-d6, ppm) δ: 8.12-8.11(d, 2H), 7.60-7.59(d, 2H); 13C NMR (100 MHz, CDCl3, ppm) δ: 174.7, 145.1, 143.1, 133.8, 126.8.

Provenance & Evidence