Chloroacetaldehyde → Imidazo(1,2-a)pyrazine

HRID 923185Notes

Reaction equation

HRID 923185 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-917d3c20d7624f2ab31de26a40ebc29e
Source dataset
uspto-grants-2016_03
Patent number
US09278971B2

Reaction notes

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