Cesium carbonate → HCID 44124141, compound

HRID 1878480Notes

Reaction equation

HRID 1878480 reaction equation
C(=O)([O-])[O-].[Cs+].[Cs+].O1CCOCC1.I[C:14]1[CH:19]=[CH:18][CH:17]=[CH:16][N:15]=1.Br.CC1(C)C(C)(C)OB([C:29]2[CH:30]=[CH:31][C:32]3[N:33]([CH:35]=[C:36]([C:38]([O:40][CH2:41][CH3:42])=[O:39])[N:37]=3)[CH:34]=2)O1>C1C=CC(P(C2C=CC=CC=2)[C-]2C=CC=C2)=CC=1.C1C=CC(P(C2C=CC=CC=2)[C-]2C=CC=C2)=CC=1.Cl[Pd]Cl.[Fe+2].O>[N:15]1[CH:16]=[CH:17][CH:18]=[CH:19][C:14]=1[C:29]1[CH:30]=[CH:31][C:32]2[N:33]([CH:35]=[C:36]([C:38]([O:40][CH2:41][CH3:42])=[O:39])[N:37]=2)[CH:34]=1

Participants

7

Reactant 4

HCID 10796Cesium carbonateHCID 312751,4-DioxaneHCID 2211262-IodopyridineHCID 44125211HCID 44125211, compound

Product 1

HCID 44124141HCID 44124141, compoundYield 55.5%

Reagents, catalysts & solvents 2

HCID 178418228Bis(cyclopenta-1,4-dien-1-yl(diphenyl)phosphane);dichloropalladium;iron(2+)CatalystHCID 962WaterSolvent

Conditions

Temperature
110 °C

Procedure

A mixture of 3.18 g of caesium carbonate, 25 mL of dioxane, 9.3 mL of water, 500 mg of 2-iodopyridine, 89 mg of [1,1′-bis(diphenylphosphino)ferrocene]dichloropalladium and 848 mg of ethyl 6-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)imidazo[1,2-a]pyridine-2-carboxylate hydrobromide (1:1) is heated for 2 hours at 110° C., and then partially concentrated, diluted with dichloromethane and filtered. The organic phase is washed with water and dried over magnesium sulfate, filtered and concentrated to dryness under reduced pressure. The residue is chromatographed on a silica cartridge, eluting with a mixture of dichloromethane and cyclohexane (80/20). The fractions containing the expected product are combined and concentrated to dryness under reduced pressure to give 317 mg of ethyl 6-(pyrid-2-yl)imidazo[1,2-a]pyridine-2-carboxylate in the form of a brown oil.

Workup

  1. concentrationpartially concentrated
  2. additiondiluted with dichloromethane
  3. filtrationfiltered
  4. washThe organic phase is washed with water
  5. dry with materialdried over magnesium sulfate
  6. filtrationfiltered
  7. concentrationconcentrated to dryness under reduced pressure
  8. customThe residue is chromatographed on a silica cartridge
  9. washeluting with a mixture of dichloromethane and cyclohexane (80/20)
  10. additionThe fractions containing the expected product
  11. concentrationconcentrated to dryness under reduced pressure

Sources & evidence

ORD record
ord-33bc4da17cf7452b8f133a665502c697
Source dataset
uspto-grants-2012_11
Patent number
US08314109B2

Reaction notes

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