Dimethylformamide → 7-Bromoimidazo[1,5-a]pyridine-1-carbaldehyde

HRID 252349Notes

Reaction equation

HRID 252349 reaction equation
[Br:1][C:2]1[CH:7]=[CH:6][N:5]2[CH:8]=[N:9][CH:10]=[C:4]2[CH:3]=1.P(Cl)(Cl)(Cl)=O.[OH-].[NH4+].CN(C)[CH:20]=[O:21]>>[Br:1][C:2]1[CH:7]=[CH:6][N:5]2[CH:8]=[N:9][C:10]([CH:20]=[O:21])=[C:4]2[CH:3]=1

Participants

5

Reactant 4

HCID 6228DimethylformamideHCID 14923Ammonium HydroxideHCID 24813Phosphorus oxychlorideHCID 668886407-Bromoimidazo(1,5-a)pyridine

Product 1

HCID 838395707-Bromoimidazo[1,5-a]pyridine-1-carbaldehyde

Conditions

Temperature
100 °C

Procedure

A solution of 4.93 g of 7-bromoimidazo[1,5-a]pyridine in 2.2 ml of dry N,N-dimethylformamide is cooled in an ice bath to 0-5° C. Phosphorus oxychloride (5.37 g) is added dropwise at 0-5° C. and the reaction mixture is subsequently stirred at 100° C. over 1 hour. The reaction mixture is cooled and poured onto ice-water. The quenched solution is basified with 25% ammonium hydroxide solution and extracted with dichloromethane (3×200 ml). The combined organic phases are dried over sodium sulphate and concentrated by evaporation. The title compound is identified on the basis of the Rf value from the residue by means of flash chromatography (SiO2 60F).

Workup

  1. temperatureThe reaction mixture is cooled
  2. additionpoured onto ice-water
  3. extractionextracted with dichloromethane (3×200 ml)
  4. dry with materialThe combined organic phases are dried over sodium sulphate
  5. concentrationconcentrated by evaporation

Sources & evidence

ORD record
ord-d973209466d746c6b6f635806f733881
Source dataset
uspto-grants-2011_01
Patent number
US07868036B2

Reaction notes

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