Formic Acid → 6-Bromo-4H-imidazo[4,5-b]pyridine

HRID 241017Notes

Reaction equation

HRID 241017 reaction equation
[NH2:1][C:2]1[C:7]([NH2:8])=[CH:6][C:5]([Br:9])=[CH:4][N:3]=1.[CH:10](O)=O>>[Br:9][C:5]1[CH:6]=[C:7]2[NH:8][CH:10]=[N:1][C:2]2=[N:3][CH:4]=1

Participants

3

Reactant 2

HCID 284Formic AcidHCID 6911565-Bromopyridine-2,3-diamine

Product 1

HCID 9115786-Bromo-4H-imidazo[4,5-b]pyridineYield 95%

Procedure

A suspension of 2,3-diamino-5-bromopyridine (3.0 g, 16.00 mmol) in formic acid (30 mL) was heated to reflux for 3 hours. After cooling the reaction mixture to room temperature it was concentrated and the residue was taken into 50% ethyl acetate in toluene (100 mL) then concentrated and the process repeated once more to remove excess formic acid. The resulting solid was triturated with ethyl acetate and the solid residue collected by filtration to give 6-bromo-1H-imidazo[4,5-b]pyridine (3.7 g, 95%). GCMS (EI) for C6H4BrN3: 198 (M+).

Workup

  1. temperaturewas heated
  2. temperatureto reflux for 3 hours
  3. concentrationwas concentrated
  4. concentrationthen concentrated
  5. customto remove excess formic acid
  6. customThe resulting solid was triturated with ethyl acetate
  7. filtrationthe solid residue collected by filtration

Sources & evidence

ORD record
ord-7b5ae499fc8644f7b92cf2b1a9766e7a
Source dataset
uspto-grants-2014_02
Patent number
US08648066B2

Reaction notes

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