3-Aminophenylboronic acid → 3-Imidazo[1,2-a]pyridin-3-yl-phenylamine

HRID 1093520Notes

Reaction equation

HRID 1093520 reaction equation
Br[C:2]1[N:6]2[CH:7]=[CH:8][CH:9]=[CH:10][C:5]2=[N:4][CH:3]=1.[NH2:11][C:12]1[CH:13]=[C:14](B(O)O)[CH:15]=[CH:16][CH:17]=1>CC#N.C([O-])([O-])=O.[Na+].[Na+]>[N:4]1[CH:3]=[C:2]([C:16]2[CH:17]=[C:12]([NH2:11])[CH:13]=[CH:14][CH:15]=2)[N:6]2[CH:7]=[CH:8][CH:9]=[CH:10][C:5]=12

Participants

5

Reactant 2

HCID 922693-Aminophenylboronic acidHCID 3279513-Bromoimidazo[1,2-a]pyridine

Product 1

HCID 665926673-Imidazo[1,2-a]pyridin-3-yl-phenylamineYield 66.3%

Reagents, catalysts & solvents 2

HCID 6342AcetonitrileSolventHCID 10340Sodium CarbonateSolvent

Conditions

Temperature
80 °C

Procedure

A mixture of 3-bromo-imidazo[1,2-a]pyridine (2.7 g, 13.7 mmol) and 3-aminobenzeneboronic acid (2.4 g, 17.5 mmol) in CH3CN (20 ml) and 2N aqueous Na2CO3 (20 ml) was deoxygenated by evacuation then refill with N2 (×3). PdCl2dppf (500 mg, 0.68 mmol) was added and the mixture was deoxygenated again (×3). The reaction was stirred and heated at 80° C. for 8 hours. After cooling to RT the mixture was partitioned between EtOAc/H2O and then filtered through Celite®. The Celite® was washed with CH2Cl2. The layers were separated and the aqueous layer was extracted with CH2Cl2 (×2). The combined extracts were dried (MgSO4), filtered and evaporated. The residue was purified by chromatography on silica (100% CH2Cl2→2% 2M NH3-MeOH/CH2Cl2) to give the title compound (1.9 g, solid). MS: [M+H]+ 210

Workup

  1. customwas deoxygenated by evacuation
  2. customthe mixture was deoxygenated again (×3)
  3. temperatureAfter cooling to RT the mixture
  4. customwas partitioned between EtOAc/H2O
  5. filtrationfiltered through Celite®
  6. washThe Celite® was washed with CH2Cl2
  7. customThe layers were separated
  8. extractionthe aqueous layer was extracted with CH2Cl2 (×2)
  9. dry with materialThe combined extracts were dried (MgSO4)
  10. filtrationfiltered
  11. customevaporated
  12. customThe residue was purified by chromatography on silica (100% CH2Cl2→2% 2M NH3-MeOH/CH2Cl2)

Sources & evidence

ORD record
ord-2e55f5653eab4c6b863e2f2361d3e384
Source dataset
uspto-grants-2012_03
Patent number
US08131527B1

Reaction notes

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