Phosphorus oxychloride → 2-chloro-1-methyl-1H-imidazo[4,5-b]pyridine

HRID 82580Notes

Reaction equation

HRID 82580 reaction equation
[CH3:1][N:2]1[C:10]2[C:5](=[N:6][CH:7]=[CH:8][CH:9]=2)[NH:4][C:3]1=O.P(Cl)(Cl)([Cl:14])=O.[Cl-].[Cl-].[Ca+2]>>[Cl:14][C:3]1[N:2]([CH3:1])[C:10]2[C:5]([N:4]=1)=[N:6][CH:7]=[CH:8][CH:9]=2

Participants

4

Reactant 3

HCID 24813Phosphorus oxychlorideHCID 8542361-Methyl-1h-imidazo[4,5-b]pyridin-2(3h)-oneHCID 5284359Calcium Chloride

Product 1

HCID 585772702-chloro-1-methyl-1H-imidazo[4,5-b]pyridine

Procedure

The mixture of 1-methyl-1,3-dihydro-2H-imidazo[4,5-b]pyridin-2-one (1.1 g) and phosphorus oxychloride (6.87 mL) 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-1-methyl-1H-imidazo[4,5-b]pyridine (600 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-6607e43563d64a358ef3c5c77e199b27
Source dataset
uspto-grants-2014_09
Patent number
US08846713B2

Reaction notes

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