Benzyl Bromide → 1-Benzyl-3-bromo-5-chloro-2-pyridone

HRID 895892Notes

Reaction equation

HRID 895892 reaction equation
[Br:1][C:2]1[C:3](=[O:9])[NH:4][CH:5]=[C:6]([Cl:8])[CH:7]=1.C(=O)([O-])[O-].[K+].[K+].[CH2:16](Br)[C:17]1[CH:22]=[CH:21][CH:20]=[CH:19][CH:18]=1>[Cl-].C([N+](CCCC)(CCCC)CCCC)CCC.C(OCC)(=O)C>[CH2:16]([N:4]1[CH:5]=[C:6]([Cl:8])[CH:7]=[C:2]([Br:1])[C:3]1=[O:9])[C:17]1[CH:22]=[CH:21][CH:20]=[CH:19][CH:18]=1

Participants

6

Reactant 3

HCID 7498Benzyl BromideHCID 11430Potassium CarbonateHCID 27267913-Bromo-5-chloropyridin-2-ol

Product 1

HCID 223820541-Benzyl-3-bromo-5-chloro-2-pyridoneYield 31.1%

Reagents, catalysts & solvents 2

HCID 70681Tetrabutylammonium ChlorideCatalystHCID 8857Ethyl AcetateSolvent

Procedure

A mixture of 3-bromo-5-chloro-1H-2-pyridone (950 mg, 4.56 mmol), freshly ground potassium carbonate (1.26 g, 9.1 mmol) and tetrabutyl ammonium chloride (100 mg) in was stirred mechanically without solvent for 30 min and benzyl bromide (0.56 mL, 4.7 mmol) was added. The mixture was stirred at room temperature for 72 hr. The mixture was diluted with ethyl acetate and filtered, washing the solids with ethyl acetate. The filtrate was evaporated to dryness and the residue was triturated with several portions of hexane. The residue was chromatographed over 90 g of silica gel eluting with 3:1 hexane:ethyl acetate followed by 100% ethyl acetate to give 1-benzyl-3-bromo-5-chloro-2-pyridone (423 mg, 31%), mp 108-110° C. LR(+)LSIMS: m/z 595 (2M+H, 2 Cl, 2 Br), 298 (M+H, 1 Cl, 1 Br).

Workup

  1. stirringThe mixture was stirred at room temperature for 72 hr
  2. filtrationfiltered
  3. washwashing the solids with ethyl acetate
  4. customThe filtrate was evaporated to dryness
  5. customthe residue was triturated with several portions of hexane
  6. customThe residue was chromatographed over 90 g of silica gel eluting with 3:1 hexane

Sources & evidence

ORD record
ord-18ca42917f424cbcbece01bd7afc719b
Source dataset
uspto-grants-2005_07
Patent number
US06916933B2

Reaction notes

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