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

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.

1. customdried flask
2. customThe reaction flak was placed in an ice bath
3. additionfollowed by the dropwise addition of n-BuLi (40.0 mL, 2.5 M BuLi in hexane) over a period of 30 minutes
4. additionThe reaction mixture was subsequently slowly poured into ice water (250 mL)
5. stirringstirred for several hours
6. customThe resulting reaction mixture
7. filtrationwas filtered
8. washthe yellow precipitate washed successively with water, methanol (50 mL) and hexanes (50 mL)

ORD record

ord-b9f613f3feaf4bbea178e1743e064318

Source dataset

uspto-grants-2014_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08816035B2