Cornforth reagent → 5-Bromo-2-chlorobenzaldehyde

HRID 1453241Notes

Reaction equation

HRID 1453241 reaction equation
[Cr](O[Cr]([O-])(=O)=O)([O-])(=O)=O.[NH+]1C=CC=CC=1.[NH+]1C=CC=CC=1.[Br:22][C:23]1[CH:24]=[CH:25][C:26]([Cl:31])=[C:27]([CH:30]=1)[CH2:28][OH:29]>C(Cl)Cl>[Br:22][C:23]1[CH:24]=[CH:25][C:26]([Cl:31])=[C:27]([CH:30]=1)[CH:28]=[O:29]

Participants

4

Reactant 2

HCID 2724130Cornforth reagentHCID 5074766(5-Bromo-2-chlorophenyl)methanol

Product 1

HCID 106089255-Bromo-2-chlorobenzaldehydeYield 86%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

Pyridinium dichromate (3.82 g, 10.2 mmol) was added to a solution of 5-bromo-2-chlorobenzylalcohol (1.5 g, 6.8 mmol) in CH2Cl2 (30 mL). The reaction was stirred for 5 hours and then celite was added. The mixture was stirred for 20 mins and then filtered through a pad of celite washing with ether. The filtrate was concentrated to a brown oil. The residue was purified by flash silica gel chromatography (0% to 10% EtOAc in hexanes) to give the title compound as a clear oil (1.28 g, 86%). 1H NMR (400 MHz, CDCl3): δ 7.35 (d, J=8.6 Hz, 1H), 7.65 (dd, J=8.3, 2.5 Hz, 1H), 8.04 (d, J=2.5 Hz, 1H), 10.41 (s, 1H).

Workup

  1. additioncelite was added
  2. stirringThe mixture was stirred for 20 mins
  3. filtrationfiltered through a pad of celite
  4. washwashing with ether
  5. concentrationThe filtrate was concentrated to a brown oil
  6. customThe residue was purified by flash silica gel chromatography (0% to 10% EtOAc in hexanes)

Sources & evidence

ORD record
ord-67f8e48be7e1483e98e091853df482e2
Source dataset
uspto-grants-2009_01
Patent number
US07473790B2

Reaction notes

Loading…