Chloroacetaldehyde → Imidazo[1,2-a]pyridin-8-amine

HRID 1909074Notes

Reaction equation

HRID 1909074 reaction equation
Cl[CH2:2][CH:3]=O.C(=O)(O)[O-].[Na+].[NH2:10][C:11]1[C:16]([NH2:17])=[CH:15][CH:14]=[CH:13][N:12]=1>[Na+].[Cl-]>[N:10]1[CH:14]=[CH:13][N:12]2[CH:3]=[CH:2][CH:15]=[C:16]([NH2:17])[C:11]=12

Participants

5

Reactant 3

HCID 33ChloroacetaldehydeHCID 99562,3-DiaminopyridineHCID 516892Sodium Bicarbonate

Product 1

HCID 15413215Imidazo[1,2-a]pyridin-8-amineYield 51%

Reagents, catalysts & solvents 1

HCID 5234Sodium ChlorideSolvent

Procedure

To a solution of 50% aqueous chloroacetaldehyde (4.14 mL, 32.6 mmol) were added sodium bicarbonate (3.19 g, 40.0 mmol) and 2,3-diaminopyridine (3.56 g, 32.6 mmol). The reaction mixture was stirred at rt overnight, then diluted with saturated aqueous NaCl (100 mL) and extracted with n-butanol (3×200 mL). The organic layers were combined, dried (MgSO4), and concentrated. The crude residue was purified (FCC, 2 N NH3 in MeOH/DCM) to give imidazo[1,2-a]pyridin-8-ylamine (2.18 g, 51%). MS (ESI+): calcd for C7H7N3 m/z 133.06, found 134.1 (M+H)+. 1H NMR (d6-DMSO): 7.79-7.75 (m, 2H), 7.40 (d, J=1.1, 1H), 6.60 (s, 1H), 6.21 (dd, J=7.3, 1.1, 1H), 5.53 (br s, 2H).

Workup

  1. extractionextracted with n-butanol (3×200 mL)
  2. dry with materialdried (MgSO4)
  3. concentrationconcentrated
  4. customThe crude residue was purified (FCC, 2 N NH3 in MeOH/DCM)

Sources & evidence

ORD record
ord-ea39d7c447f544108c8759ceee901da3
Source dataset
uspto-grants-2013_12
Patent number
US08598356B2

Reaction notes

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