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

HRID 1848128Notes

Reaction equation

HRID 1848128 reaction equation
[Br:1][C:2]1[CH:3]=[C:4]([NH2:9])[C:5]([NH2:8])=[N:6][CH:7]=1.[CH:10](O)=O>C(OC(OCC)OCC)C>[Br:1][C:2]1[CH:3]=[C:4]2[N:9]=[CH:10][NH:8][C:5]2=[N:6][CH:7]=1

Participants

4

Reactant 2

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

Product 1

HCID 9115786-Bromo-4H-imidazo[4,5-b]pyridineYield 86.7%

Reagents, catalysts & solvents 1

HCID 31214Ethyl orthoformateSolvent

Procedure

A solution of 5-bromo-pyridine-2,3-diamine (3.0 g, 15.96 mmol) and HCOOH (1.1 mL) in triethoxymethane (48 mL) was stirred at 90° C. for 3 h. The reaction mixture was concentrated under reduced pressure. The residue was purified by silica gel chromatography eluting with 40:1 DCM/MeOH to give 6-bromo-3H-imidazo[4,5-b]pyridine as a light brown solid (2.74 g, 86.7%). 1H NMR (300 MHz, DMSO-d6) δ 8.49 (s, 1H), 8.44 (s, 1H), 8.30 (br s, 1H). LCMS (ESI) m/z 198 (M+H)+.

Workup

  1. concentrationThe reaction mixture was concentrated under reduced pressure
  2. customThe residue was purified by silica gel chromatography
  3. washeluting with 40:1 DCM/MeOH

Sources & evidence

ORD record
ord-b3088262a26948b397eec6efa2a3ef7c
Source dataset
uspto-grants-2015_02
Patent number
US08952058B2

Reaction notes

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