Oxalyl chloride → Methyl 7-bromoimidazo[1,2-a]pyridine-3-carboxylate

HRID 706592Notes

Reaction equation

HRID 706592 reaction equation
[Br:1][C:2]1[CH:7]=[CH:6][N:5]2[C:8]([C:11]([OH:13])=[O:12])=[CH:9][N:10]=[C:4]2[CH:3]=1.[C:14](Cl)(=O)C(Cl)=O>ClCCl.CN(C=O)C>[Br:1][C:2]1[CH:7]=[CH:6][N:5]2[C:8]([C:11]([O:13][CH3:14])=[O:12])=[CH:9][N:10]=[C:4]2[CH:3]=1

Participants

5

Reactant 2

HCID 65578Oxalyl chlorideHCID 672614887-Bromoimidazo[1,2-a]pyridine-3-carboxylic acid

Product 1

HCID 67259752Methyl 7-bromoimidazo[1,2-a]pyridine-3-carboxylateYield 89%

Reagents, catalysts & solvents 2

HCID 6228DimethylformamideCatalystHCID 6344DichloromethaneSolvent

Procedure

7-bromoimidazo[1,2-a]pyridine-3-carboxylic acid (4.93 g, 20.5 mmol) was dissolved in 80 mL of dry dichloromethane. To this solution was added oxalyl chloride (20.5 mL, 40.9 mmol, 2M in dichloromethane) followed by a few drops of DMF. The mixture was stirred at ambient temperature for 16 hours, then concentrated under reduced pressure. The resulting material was taken up in 100 mL of methanol and stirred at ambient temperature for 6 hours, then concentrated under reduced pressure. The resulting material was suspended in saturated aqueous sodium bicarbonate, extracted with dichloromethane and EtOAc. The organics were combined, dried over sodium sulfate and concentrated under reduced pressure to give 4.63 g (89%) of the title compound.

Workup

  1. concentrationconcentrated under reduced pressure
  2. stirringstirred at ambient temperature for 6 hours
  3. concentrationconcentrated under reduced pressure
  4. extractionextracted with dichloromethane and EtOAc
  5. dry with materialdried over sodium sulfate
  6. concentrationconcentrated under reduced pressure

Sources & evidence

ORD record
ord-27e2f010cd3a4b9688a58513da1e1132
Source dataset
uspto-grants-2015_11
Patent number
US09174981B2

Reaction notes

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