Chloroacetaldehyde → Imidazo(1,2-a)pyrazine

HRID 572957Notes

Reaction equation

HRID 572957 reaction equation
[NH2:1][C:2]1[CH:7]=[N:6][CH:5]=[CH:4][N:3]=1.Cl[CH2:9][CH:10]=O>CCO>[N:1]1[CH:9]=[CH:10][N:3]2[CH:4]=[CH:5][N:6]=[CH:7][C:2]=12

Participants

4

Reactant 2

HCID 33ChloroacetaldehydeHCID 78747Aminopyrazine

Product 1

HCID 2771670Imidazo(1,2-a)pyrazineYield 64%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

A solution of aminopyrazine (1 g, 10.5 mmol) and chloroacetaldehyde (50% wt in H2O; 1.98 g, 12.6 mmol) in 1.6 mL of EtOH was heated at 90° C. in a sealed tube for 5 h. Upon cooling to ambient temperature, the reaction mixture was concentrated and diluted with dichloromethane (DCM). The organic layer washed with saturated aqueous NaHCO3 then dried over MgSO4 and concentrated. The crude product was purified by silica gel flash chromatography (eluted with 10% MeOH/DCM) to provide 0.8 g of product.

Workup

  1. concentrationthe reaction mixture was concentrated
  2. additiondiluted with dichloromethane (DCM)
  3. washThe organic layer washed with saturated aqueous NaHCO3
  4. dry with materialthen dried over MgSO4
  5. concentrationconcentrated
  6. customThe crude product was purified by silica gel flash chromatography (eluted with 10% MeOH/DCM)

Sources & evidence

ORD record
ord-a519d605d2b04776bb33472559c68021
Source dataset
uspto-grants-2015_05
Patent number
US09029533B2

Reaction notes

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