1,4-Dibromobutane → 3-(4-Bromobutyl)thiophene

Temperature

-45 °C

3-bromothiophene (9 ml, 96 mmol) was dissolved in 120 ml dry hexanes. The solution was cooled down to −45° C., and 60 ml n-BuLi (60 ml 1.6M, 96 mmol) were added dropwise. The solution was stirred at −45° C. for 10 min, after which 6 ml dry THF were added and the lithium salt precipitated. After stirring at −45° C. for 1 h, the solution was warmed up to −10° C., and an excess of 1,4-dibromobutane (44 ml, 368 mmol) was added. After stirring at room temperature for 2 h, the solution was extracted with ether, washed with water, brine, dried over magnesium sulfate, and the solvent was removed. Excess 1,4-dibromobutane was removed under vacuum. Posterior filtration of the residue through a silica plug (hexanes), and solvent removal afforded the title compound (10.7 g, 51% yield) as a colorless oil. 1H-NMR (ppm, CDCl3): 1.75-1.81 (2H, m), 1.86-1.91 (2H, m), 2.67 (2H, t, J=7.32 Hz), 3.44 (2H, t, J=7.32 Hz), 6.92-6.94 (2H, m), 7.25-7.26 (1H, m); 13C-NMR (ppm, CDCl3): 29.2, 29.5, 32.4, 33.8, 120.4, 125.6, 128.3, 142.3; ESI-MS (m/z) found: 218.9843 [M+H], calculated: 218.9838.

1. customthe lithium salt precipitated
2. stirringAfter stirring at −45° C. for 1 h
3. temperaturethe solution was warmed up to −10° C.
4. stirringAfter stirring at room temperature for 2 h
5. extractionthe solution was extracted with ether
6. washwashed with water, brine
7. dry with materialdried over magnesium sulfate
8. customthe solvent was removed
9. customExcess 1,4-dibromobutane was removed under vacuum
10. filtrationPosterior filtration of the residue
11. customthrough a silica plug (hexanes), and solvent removal

ORD record

ord-28b9539dbf2249469ce3a38b5b9ab349

Source dataset

uspto-grants-2014_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08847068B2