1,6-Dibromohexane → 6-Bromohexylbut-3-ynyl ether

Temperature

50 °C

A mixture of 50% w/v aqueous sodium hydroxide (2500 ml), 1,6-dibromohexane (2610 g) and tetra-butylammonium bromide (25 g) was warmed to 50° C., with stirring. But-3-yn-1-ol (500 g) was then added to the reaction mixture at such a rate as to ensure the content's temperature did not exceed 65° C. The reaction was left at 50° C. overnight before being cooled to room temperature. Tert-butyl methyl ether (2500 ml) and brine (2000 ml) was added to the cooled mixture and the layers allowed to separate. The ethereal layer was washed with water (2×2000 ml), brine (1×2000 ml), and then dried over anhydrous MgSO4. The solution was filtered and concentrated under reduced pressure to give crude product as a liquid. This was further purified by fractional distillation using a 60 cm vacuum jacketed Vigreux column at ca. 0.5 mbar. The product was obtained in the fraction which boiled at 92-98° C., to give the title compound (518 g), LC RT=6.16, δ (CDCl3) 3.55 (2H, t, J 6.9 Hz), 3.46 (2H, t, J 6.9 Hz), 3.41 (2H, t, J 6.9 Hz), 2.46 (2H, dt, J 2.5, 6.9 Hz), 1.98 (1H, t, J 2.5 Hz), 1.86 (2H, m), 1.59 (2H, m), 1.46 (2H, m), 1.38 (2H, m).

1. additionA mixture of 50%
2. customdid not exceed 65° C
3. temperaturebefore being cooled to room temperature
4. customto separate
5. washThe ethereal layer was washed with water (2×2000 ml), brine (1×2000 ml)
6. dry with materialdried over anhydrous MgSO4
7. filtrationThe solution was filtered
8. concentrationconcentrated under reduced pressure
9. customto give crude product as a liquid
10. distillationThis was further purified by fractional distillation
11. customThe product was obtained in the fraction which boiled at 92-98° C.

ORD record

ord-b37305421e214accbd64d8289fc6ce7f

Source dataset

uspto-grants-2008_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07442836B2