Azobisisobutyronitrile → Methyl 3,5-dibromo-4-(bromomethyl)benzoate

HRID 271190Notes

Reaction equation

HRID 271190 reaction equation
[Br:1][C:2]1[CH:3]=[C:4]([CH:9]=[C:10]([Br:13])[C:11]=1[CH3:12])[C:5]([O:7][CH3:8])=[O:6].[Br:14]NC(=O)CCC(N)=O.N(C(C)(C)C#N)=NC(C)(C)C#N>C(Cl)(Cl)(Cl)Cl>[CH3:8][O:7][C:5](=[O:6])[C:4]1[CH:3]=[C:2]([Br:1])[C:11]([CH2:12][Br:14])=[C:10]([Br:13])[CH:9]=1

Participants

5

Reactant 3

HCID 6547AzobisisobutyronitrileHCID 624016Methyl 3,5-dibromo-4-methylbenzoateHCID 9834204N-Bromosuccinamide

Product 1

HCID 22647948Methyl 3,5-dibromo-4-(bromomethyl)benzoateYield 99%

Reagents, catalysts & solvents 1

HCID 5943Carbon TetrachlorideSolvent

Procedure

A solution of methyl 3,5-dibromo-4-methylbenzoate (5 g, 16.24 mmol) in carbon tetrachloride (50 mL) was treated with N-bromosuccinamide (3.6 g, 20.23 mmol) and 2,2′-azobisisobutyronitrile (0.56 g, 3.410 mmol). The reaction mixture was heated to reflux for 24 h. The reaction was cooled to room temperature and concentrated under vacuum. The resulting mixture was absorbed onto silica and was purified by flash chromatography using silica gel eluted with 3:1 hexanes:ethyl acetate. The desired fractions were collected and concentrated under vacuum to afford a solid which was dried under high vacuum to afford 3,5-dibromo-4-bromomethyl-benzoic acid methyl ester (57) (6.22 g, 99%) as a yellow solid; LRMS for C9H7Br3O2 (M+Na) m/z=407. MW=386.8669, Exact Mass=383.7996

Workup

  1. temperatureThe reaction mixture was heated
  2. temperatureto reflux for 24 h
  3. concentrationconcentrated under vacuum
  4. customThe resulting mixture was absorbed onto silica
  5. customwas purified by flash chromatography
  6. washeluted with 3:1 hexanes
  7. customThe desired fractions were collected
  8. concentrationconcentrated under vacuum
  9. customto afford a solid which
  10. customwas dried under high vacuum

Sources & evidence

ORD record
ord-5e367a68f5eb4d44a62786d37dc6e33b
Source dataset
uspto-grants-2008_11
Patent number
US07452882B2

Reaction notes

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