Hydrochloric Acid → Imidazo(1,2-a)pyridine

HRID 572144Notes

Reaction equation

HRID 572144 reaction equation
Br[C:2]1[N:3]=[C:4]2[CH:9]=[CH:8][CH:7]=[CH:6][N:5]2[CH:10]=1.Cl>CN(C=O)C.[C-]#N.[Zn+2].[C-]#N.C1C=CC([P]([Pd]([P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)([P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)[P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)=CC=1>[N:3]1[CH:2]=[CH:10][N:5]2[CH:6]=[CH:7][CH:8]=[CH:9][C:4]=12

Participants

6

Reactant 2

HCID 313Hydrochloric AcidHCID 124289572-Bromoimidazo[1,2-a]pyridine

Product 1

HCID 78960Imidazo(1,2-a)pyridine

Reagents, catalysts & solvents 3

HCID 11186Zinc cyanide (Zn(CN)2)CatalystHCID 178418397HCID 178418397, compoundCatalystHCID 6228DimethylformamideSolvent

Conditions

Temperature
130 °C

Procedure

To a solution of bromo-imidazo[1,2-a]pyridine derivatives (1.0 equiv.) in DMF, Zinc cyanide (1.1 equiv.) and Pd(PPh3)4 (5%) were added under inert atmosphere. The resulting mixture was heated through microwave irradiation for 10 min at 130° C. (Power max tolerated was 70 W). The yellow cloudy reaction mixture was hydrolyzed with HCl 1N solution then extracted with Et2O. Aqueous layer was cooled by an ice bath, and NaOH solid was added until a pH was greater than 10. The resulting aqueous basic layer was extracted with EtOAC. Organic layer was washed with brine, dried over MgSO4 and concentrated under reduced pressure.

Workup

  1. customThe yellow cloudy reaction mixture
  2. extractionthen extracted with Et2O
  3. temperatureAqueous layer was cooled by an ice bath
  4. additionNaOH solid was added until a pH was greater than 10
  5. extractionThe resulting aqueous basic layer was extracted with EtOAC
  6. washOrganic layer was washed with brine
  7. dry with materialdried over MgSO4
  8. concentrationconcentrated under reduced pressure

Sources & evidence

ORD record
ord-bfe2417c3c094405b9c796085c4e141b
Source dataset
uspto-grants-2015_05
Patent number
US09029393B2

Reaction notes

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