3-Methyl-1H-imidazo[4,5-b]pyridin-2(3H)-one → 2-Chloro-3-methyl-3H-imidazo[4,5-b]pyridine

HRID 82585Notes

Reaction equation

HRID 82585 reaction equation
[CH3:1][N:2]1[C:6]2=[N:7][CH:8]=[CH:9][CH:10]=[C:5]2[NH:4][C:3]1=O.[Cl-:12].[Cl-].[Ca+2]>P(Cl)(Cl)(Cl)=O>[Cl:12][C:3]1[N:2]([CH3:1])[C:6]2=[N:7][CH:8]=[CH:9][CH:10]=[C:5]2[N:4]=1

Participants

4

Reactant 2

HCID 9112333-Methyl-1H-imidazo[4,5-b]pyridin-2(3H)-oneHCID 5284359Calcium Chloride

Product 1

HCID 108209862-Chloro-3-methyl-3H-imidazo[4,5-b]pyridine

Reagents, catalysts & solvents 1

HCID 24813Phosphorus oxychlorideSolvent

Procedure

The mixture of 3-methyl-1,3-dihydro-2H-imidazo[4,5-b]pyridin-2-one (1.0 g) in phosphorus oxychloride (10 g) was stirred at 100° C. under a dry atmosphere (CaCl2 tube) for 5 h. The mixture was neutralized with sat.NaHCO3 at 0° C. and extracted with EtOAc. The organic layer was separated, washed with water and brine, dried over MgSO4 and concentrated in vacuo. The residue was purified by column chromatography (NH silica gel, eluted with 0%-50% EtOAc in hexane) to give 2-chloro-3-methyl-3H-imidazo[4,5-b]pyridine (230 mg) as a white solid.

Workup

  1. extractionNaHCO3 at 0° C. and extracted with EtOAc
  2. customThe organic layer was separated
  3. washwashed with water and brine
  4. dry with materialdried over MgSO4
  5. concentrationconcentrated in vacuo
  6. customThe residue was purified by column chromatography (NH silica gel, eluted with 0%-50% EtOAc in hexane)

Sources & evidence

ORD record
ord-b682f322c9984c8495f7c6e778bdfabd
Source dataset
uspto-grants-2014_09
Patent number
US08846713B2

Reaction notes

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