Phosphorus oxychloride → Imidazo(1,5-a)pyridine

HRID 442019Notes

Reaction equation

HRID 442019 reaction equation
[CH:1]([NH:3][CH2:4][C:5]1[CH:10]=[CH:9][CH:8]=[CH:7][N:6]=1)=O.P(Cl)(Cl)(Cl)=O>>[CH:4]1[N:3]=[CH:1][N:6]2[CH:7]=[CH:8][CH:9]=[CH:10][C:5]=12

Participants

3

Reactant 2

HCID 24813Phosphorus oxychlorideHCID 12228441N-Pyridin-2-ylmethyl-formamide

Product 1

HCID 274090Imidazo(1,5-a)pyridine

Procedure

To 13.6 g. of 2-formamidomethylpyridine in a round-bottom flask is added 25 ml. of phosphorous oxychloride. Following the exothermic reaction, the reaction mixture is cooled to room temperature, and quenched on crushed ice. The aqueou mixture is treated with sufficient 20% aqueous sodium hydroxide solution to provide a pH of 9-10, and the liberated product extracted into chloroform (3 × 300 ml.). The extracts are combined, dried over sodium sulfate and concentrated to give imidazo[1,5-a]pyridine as a light brown oil, 14.0 g. b. The procedure of Preparation AII-a is repeated starting with the appropriate reagents to provide the following intermediates:

Workup

  1. customthe exothermic reaction
  2. customquenched
  3. customon crushed ice
  4. additionThe aqueou mixture is treated with sufficient 20% aqueous sodium hydroxide solution
  5. customto provide a pH of 9-10
  6. extractionthe liberated product extracted into chloroform (3 × 300 ml.)
  7. dry with materialdried over sodium sulfate
  8. concentrationconcentrated

Sources & evidence

ORD record
ord-26d897762dcd4b03a40547ce20e614b4
Source dataset
uspto-grants-1977_08
Patent number
US04044015

Reaction notes

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