Chloroacetaldehyde → Methyl imidazo(1,2-a)pyridine-7-carboxylate

HRID 341241Notes

Reaction equation

HRID 341241 reaction equation
[NH2:1][C:2]1[CH:7]=[C:6]([C:8]([O:10][CH3:11])=[O:9])[CH:5]=[CH:4][N:3]=1.C([O-])(O)=O.[Na+].Cl[CH2:18][CH:19]=O>CCO>[N:1]1[CH:18]=[CH:19][N:3]2[CH:4]=[CH:5][C:6]([C:8]([O:10][CH3:11])=[O:9])=[CH:7][C:2]=12

Participants

5

Reactant 3

HCID 33ChloroacetaldehydeHCID 236984Methyl 2-aminopyridine-4-carboxylateHCID 516892Sodium Bicarbonate

Product 1

HCID 15096964Methyl imidazo(1,2-a)pyridine-7-carboxylateYield 72.2%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

To a solution of Methyl 2-aminopyridine-4-carboxylate (10.0 g, 66 mmol, 1.0 equiv) in EtOH (150 ml) was added NaHCO3 (11.1 g, 132 mmol, 2.0 equiv) followed by chloroacetaldehyde (13.0 ml, 99 mmol, 1.5 equiv). The mixture was refluxed for 2 h. Solvents were removed under reduced pressure and the crude mixture was partitioned between water and EtOAc. The resulting precipitate was washed with Et2O and recrystallised from MeOH/Et2O to afford 8.4 g of product. 1H NMR (400 MHz, DMSO-d6): 8.66 (1H, d), 8.16 (2H, s), 7.80 (1H, s), 7.33 (1H, d), 3.90 (3H, s). MS: [M+H]+ 177.

Workup

  1. temperatureThe mixture was refluxed for 2 h
  2. customSolvents were removed under reduced pressure
  3. customthe crude mixture was partitioned between water and EtOAc
  4. washThe resulting precipitate was washed with Et2O
  5. customrecrystallised from MeOH/Et2O

Sources & evidence

ORD record
ord-bb050890774746689ad99ed63ecf81a4
Source dataset
uspto-grants-2014_11
Patent number
US08895745B2

Reaction notes

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