Triethyl orthoacetate → 5-bromo-2-methyl-3H-imidazo[4,5-b]pyridine

HRID 2181029Notes

Reaction equation

HRID 2181029 reaction equation
[NH2:1][C:2]1[C:7]([NH2:8])=[CH:6][CH:5]=[C:4]([Br:9])[N:3]=1.[C:10](OCC)(OCC)(OCC)[CH3:11]>C(O)(=O)C.ClCCl.C(=O)([O-])[O-].[K+].[K+].C>[Br:9][C:4]1[N:3]=[C:2]2[N:1]=[C:10]([CH3:11])[NH:8][C:7]2=[CH:6][CH:5]=1

Participants

7

Reactant 2

HCID 66221Triethyl orthoacetateHCID 223883866-Bromopyridine-2,3-diamine

Product 1

HCID 223879615-bromo-2-methyl-3H-imidazo[4,5-b]pyridine

Reagents, catalysts & solvents 4

HCID 176Acetic AcidSolventHCID 297MethaneSolventHCID 6344DichloromethaneSolventHCID 11430Potassium CarbonateSolvent

Procedure

2,3-Diamino-6-bromopyridine (8.16 g) and triethyl orthoacetate (12.0 ml) were mixed in acetic acid (41 ml), and the mixture was refluxed under heating for 29 hr. After allowing to cool, the solvent was evaporated under reduced pressure to give a crude product (10 g). This was dissolved in a sufficient amount of dichloromethane and anhydrous potassium carbonate and active charcoal were added. The mixture was stirred at room temperature. The insoluble matter was removed by filtration and the solvent was evaporated to give 5-bromo-2-methyl-1H-imidazo[4,5-b]pyridine (7.59 g) as a pale-yellow powder.

Workup

  1. temperaturethe mixture was refluxed
  2. temperatureunder heating for 29 hr
  3. temperatureto cool
  4. customthe solvent was evaporated under reduced pressure
  5. customto give a crude product (10 g)
  6. additionwere added
  7. customThe insoluble matter was removed by filtration
  8. customthe solvent was evaporated

Sources & evidence

ORD record
ord-89ea27320a9e40cbbde7b54e6d1fca6d
Source dataset
uspto-grants-2005_05
Patent number
US06890934B2

Reaction notes

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