3-Bromobenzyl bromide → 1-Bromo-3-(but-3-en-1-yl)benzene

HRID 573920Notes

Reaction equation

HRID 573920 reaction equation
[Br:1][C:2]1[CH:7]=[CH:6][CH:5]=[C:4]([CH2:8]Br)[CH:3]=1.[CH2:10]([Mg]Br)[CH:11]=[CH2:12]>O1CCCC1>[Br:1][C:2]1[CH:7]=[CH:6][CH:5]=[C:4]([CH2:8][CH2:12][CH:11]=[CH2:10])[CH:3]=1

Participants

4

Procedure

To a solution of 1-bromo-3-(bromomethyl)benzene (10.0 g, 40.0 mmol) in tetrahydrofuran (50 mL), under an inert atmosphere was added allylmagnesium bromide (1.0 M in diethyl ether, 40.0 mL, 40.0 mmol). The reaction was allowed to reflux overnight. The reaction was quenched with sulfuric acid (2 M, 45 mL). The resulting biphasic solution was solution was partitioned. The aqueous layer was extracted with diethyl ether (2×50 mL). The combined organic layers were dried over magnesium sulfate, filtered, and concentrated. The resulting residue was purified by flash column chromatography using 100% hexanes as eluent providing the title compound as a clear liquid (7.51 g, 71%, ˜80% pure): 1H NMR (400 MHz, DMSO-d6) δ 7.42 (ddd, J=2.1, 1.4, 0.7 Hz, 1H), 7.37 (dt, J=7.1, 2.1 Hz, 1H), 7.28-7.18 (m, 2H), 5.81 (ddt, J=16.9, 10.2, 6.5 Hz, 1H), 5.09-4.90 (m, 2H), 2.67 (dd, J=8.6, 6.8 Hz, 2H), 2.32 (tdt, J=7.7, 6.5, 1.5 Hz, 2H); 13C NMR (101 MHz, DMSO-d6) δ 144.35, 137.61, 131.05, 130.28, 128.62, 127.44, 121.53, 115.37, 34.59, 33.91; EIMS m/z 210 ([M]+).

Workup

  1. temperatureto reflux overnight
  2. customThe reaction was quenched with sulfuric acid (2 M, 45 mL)
  3. customwas partitioned
  4. extractionThe aqueous layer was extracted with diethyl ether (2×50 mL)
  5. dry with materialThe combined organic layers were dried over magnesium sulfate
  6. filtrationfiltered
  7. concentrationconcentrated
  8. customThe resulting residue was purified by flash column chromatography

Sources & evidence

ORD record
ord-5a4fe2b988d540fa9927f406110a20fd
Source dataset
uspto-grants-2015_05
Patent number
US09029560B2

Reaction notes

Loading…