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

HRID 924274Notes

Reaction equation

HRID 924274 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-c18bc197246340bcae10b5aa071561d1
Source dataset
uspto-grants-2016_03
Patent number
US09278964B2

Reaction notes

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