Cesium carbonate → 7-(Furan-3-yl)-3-[3-(pyridin-3-yl)phenyl]imidazo[1,2-alpha]pyridine

HRID 985525Notes

Reaction equation

HRID 985525 reaction equation
Cl[C:2]1[CH:7]=[CH:6][N:5]2[C:8]([C:11]3[CH:16]=[CH:15][CH:14]=[C:13]([C:17]4[CH:18]=[N:19][CH:20]=[CH:21][CH:22]=4)[CH:12]=3)=[CH:9][N:10]=[C:4]2[CH:3]=1.[O:23]1[CH:27]=[CH:26][C:25](B(O)O)=[CH:24]1.C(=O)([O-])[O-].[Cs+].[Cs+]>O1CCOCC1.C1C=CC(/C=C/C(/C=C/C2C=CC=CC=2)=O)=CC=1.C1C=CC(/C=C/C(/C=C/C2C=CC=CC=2)=O)=CC=1.C1C=CC(/C=C/C(/C=C/C2C=CC=CC=2)=O)=CC=1.[Pd].[Pd].C(P(C(C)(C)C)C(C)(C)C)(C)(C)C>[NH3:5].[O:23]1[CH:27]=[CH:26][C:25]([C:2]2[CH:7]=[CH:6][N:5]3[C:8]([C:11]4[CH:16]=[CH:15][CH:14]=[C:13]([C:17]5[CH:18]=[N:19][CH:20]=[CH:21][CH:22]=5)[CH:12]=4)=[CH:9][N:10]=[C:4]3[CH:3]=2)=[CH:24]1

Participants

8

Reactant 3

HCID 10796Cesium carbonateHCID 2734358Furan-3-boronic acidHCID 99011257-Chloro-3-[3-(pyridin-3-yl)phenyl]imidazo[1,2-alpha]pyridine

Product 2

HCID 222AmmoniaHCID 99457517-(Furan-3-yl)-3-[3-(pyridin-3-yl)phenyl]imidazo[1,2-alpha]pyridineYield 37%

Reagents, catalysts & solvents 3

HCID 83681Tris(1,1-dimethylethyl)phosphineCatalystHCID 9811564Bis(dibenzylideneacetone)palladiumCatalystHCID 312751,4-DioxaneSolvent

Conditions

Temperature
90 °C

Procedure

7-Chloro-3-[3-(pyridin-3-yl)phenyl]imidazo[1,2-α]pyridine (0.27 g, 0.88 mmol), 3-furanboronic acid (0.15 g, 1.33 mmol and caesium carbonate (0.58 g, 1.77 mmol) were suspended in 1,4-dioxane (5 ml) under an atmosphere of nitrogen. Tris(dibenzylideneacetone)dipalladium(0) (12 mg, 0.015 mmol) and tri-tert-butylphosphine (6.5 mg, 0.032 mmol) were then added and the mixture heated at 90° C. for 24 h. The mixture was cooled and partitioned between dichloromethane and water. The organic layer was washed with brine, dried over sodium sulphate and concentrated in vacuo to give a brown oil. Purification by flash column chromatography eluting with dichloromethane/methanol/conc. ammonia (98:2:0.2) gave the title compound (110 mg, 37%) as a pale yellow crystalline solid, m.p. 158-160° C. 1H NMR (360 MHz, CDCl3) δH 6.79 (1H, s), 6.96-7.02 (1H, m), 7.39-7.43 (1H, m), 7.52-7.56 (1H, m), 7.59-7.69 (2H, m), 7.75-7.91 (8H, m), 8.32-8.37 (1H, m), 8.63-8.68 (1H, m), 8.92 (1H, s); m/z (ES+) 338 (M++H).

Workup

  1. temperatureThe mixture was cooled
  2. custompartitioned between dichloromethane and water
  3. washThe organic layer was washed with brine
  4. dry with materialdried over sodium sulphate
  5. concentrationconcentrated in vacuo
  6. customto give a brown oil
  7. customPurification by flash column chromatography
  8. washeluting with dichloromethane/methanol/conc

Sources & evidence

ORD record
ord-82960f99ce404a778c936a6091bfffc9
Source dataset
uspto-grants-2005_03
Patent number
US06872731B2

Reaction notes

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