Acetic Acid → 3,3'-Dibromo-2,2'-bithiophene

3,3′,5,5′-Tetrabromo-2,2′-bithiophene, 10 (15 g, 31.1 mmol) was added in portion within 0.5 h to a refluxing dispersion of zinc powder (7.8 g, 0.12 mol) in 150 mL of ethanol containing 15 mL of water, 72 mL of glacial acetic acid, and 3.1 mL of 3 M HCl. After refluxing for an additional 2 h and then cooling to room temperature, the mixture was filtered and washed three times with ethanol, and the filtrate was collected. The solvent was then removed by evaporation, and 60 mL of H2O was added. The mixture was then extracted with dichloromethane (3×100 mL), and the combined extract was washed with water, dried over anhydrous MgSO4, and filtered. The solvent was removed by evaporation, and the crude product was crystallized from hexane to give colorless crystals of product 9.2 g, 92% yield. 1H NMR (400 MHz, CDCl3, δ) 7.43 (d, J=5.4 Hz, 2H), 7.09 (d, J=5.4 Hz, 2H). 13C NMR (100 MHz, CDCl3, δ) 130.8, 128.8, 127.5, 112.6. MS (FAB): m/z 324.0 (M+).

1. temperatureAfter refluxing for an additional 2 h
2. filtrationthe mixture was filtered
3. washwashed three times with ethanol
4. customthe filtrate was collected
5. customThe solvent was then removed by evaporation, and 60 mL of H2O
6. additionwas added
7. extractionThe mixture was then extracted with dichloromethane (3×100 mL)
8. extractionthe combined extract
9. washwas washed with water
10. dry with materialdried over anhydrous MgSO4
11. filtrationfiltered
12. customThe solvent was removed by evaporation
13. customthe crude product was crystallized from hexane

ORD-Eintrag

ord-c4fff5eb279d4f179297931f43f349f9

Quelldatensatz

uspto-grants-2015_03

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US08975419B2