Carbon tetrabromide → 1-(Bromomethyl)-2,4-dimethylbenzene

HRID 2379767Notes

Reaction equation

HRID 2379767 reaction equation
[CH3:1][C:2]1[CH:9]=[C:8]([CH3:10])[CH:7]=[CH:6][C:3]=1[CH2:4]O.C(Br)(Br)(Br)[Br:12].C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1>C(Cl)Cl>[CH3:1][C:2]1[CH:9]=[C:8]([CH3:10])[CH:7]=[CH:6][C:3]=1[CH2:4][Br:12]

Participants

5

Reactant 3

HCID 11205Carbon tetrabromideHCID 11776TriphenylphosphineHCID 278092,4-Dimethylbenzyl alcohol

Product 1

HCID 27346041-(Bromomethyl)-2,4-dimethylbenzeneYield 99%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent2×

Procedure

A solution of benzyl alcohol 9 (18.4 g; 135 mmol) and carbon tetrabromide (55.96 g; 169 mmol) in methylene chloride (220 ml) was cooled to 0° C. and treated in dropwise fashion with triphenylphosphine (44.33 g; 169 mmol) in 100 ml of methylene chloride. After the addition was complete the mixture was stirred overnight at room temperature. It was poured into ice-water and partitioned between methylene chloride and water. The organic phase was dried (MgSO4) and concentrated in vacuo. Chromatography of the residue, eluting with 10% ethyl acetate in hexane, gave 26 g (99%) of the product as a yellow liquid. 1HNMR (CDCl3): δ2.31, 2.38 (s, 3H each); 4.51 (s, 2H); 6.99 (m, 2H); 7.18 (d, 1H). IR (neat): 3013, 2972, 2921, 1617, 1507, 1450, 1262, 823 cm-1.

Workup

  1. additionAfter the addition
  2. custompartitioned between methylene chloride and water
  3. dry with materialThe organic phase was dried (MgSO4)
  4. concentrationconcentrated in vacuo
  5. washChromatography of the residue, eluting with 10% ethyl acetate in hexane

Sources & evidence

ORD record
ord-95b5ea5a7c92445d9aeecc138b096c6d
Source dataset
uspto-grants-1994_11
Patent number
US05364876

Reaction notes

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