Water → 1,4-Dibromo-2-(4-bromobutoxy)benzene

Temperature

90 °C

To a solution of 12.63 g (39 mmol) of 4-(2,5-dibromophenoxy)butan-1-ol in 83 mL of toluene was added 1.65 mL (17.6 mmol, 0.45 equiv) of phosphorous tribromide. The solution was stirred under nitrogen at 90° C. for 2.5 hours. Additional phosphorous tribromide (0.37 mL, 3.9 mmol, 0.10 equiv) and 0.21 ml (11.5 mmol, 0.3 equiv) of water were added, and the mixture was stirred under nitrogen at 90° C. for 8 hours. The mixture was allowed to cool to ambient temperature, 69 mL of 1N NaOH was added dropwise over 30 minutes, and the layers were separated. The aqueous layer was extracted with 25 mL of toluene. The combined organic layer was washed with 25 mL each of water and brine, dried over sodium sulfate, filtered, and concentrated under reduced pressure to give the product as a cloudy yellow oil suitable for the next step. MS (m+1)=386.1, 385.1, 381.0; 1H NMR (400 MHz, CDCl3) 7.38 (d, 1H, J 8 Hz), 6.98 (m, 2H), 4.05 (t, 2H, J 6 Hz), 3.53 (t, 2H, J 6 Hz), 2.12 (m, 2H), 2.03 (m, 2H).

1. stirringthe mixture was stirred under nitrogen at 90° C. for 8 hours
2. temperatureto cool to ambient temperature
3. customthe layers were separated
4. extractionThe aqueous layer was extracted with 25 mL of toluene
5. washThe combined organic layer was washed with 25 mL each of water and brine
6. dry with materialdried over sodium sulfate
7. filtrationfiltered
8. concentrationconcentrated under reduced pressure
9. customto give the product as a cloudy yellow oil suitable for the next step

ORD record

ord-111db5db5a7c4d22802dadbce2ff8817

Source dataset

uspto-grants-2010_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07855201B2