Chloroacetone → 2,6-Dimethylimidazo[1,2-b]pyridazine

HRID 226023Notes

Reaction equation

HRID 226023 reaction equation
[NH2:1][C:2]1[N:3]=[N:4][C:5]([CH3:8])=[CH:6][CH:7]=1.Cl[CH2:10][C:11](=O)[CH3:12].C([O-])(O)=O.[Na+]>CCO>[CH3:12][C:11]1[N:1]=[C:2]2[CH:7]=[CH:6][C:5]([CH3:8])=[N:4][N:3]2[CH:10]=1

Participants

5

Reactant 3

HCID 6571ChloroacetoneHCID 877126-Methylpyridazin-3-amineHCID 516892Sodium Bicarbonate

Product 1

HCID 218176672,6-Dimethylimidazo[1,2-b]pyridazineYield 51%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

A solution of 3-amino-6-methyl-pyridazine (4.53 g, 41.58 mmol) in EtOH (60 mL) is treated with chloroacetone (3.5 mL, 43.66 mmol). The reaction is refluxed overnight. While it is hot, NaHCO3 (8.7 g, 103.9 mmol) is added in portions. The resulting mixture is refluxed for 2 h. It is cooled to rt and filtered through silical gel, washed with EtOAc, and concentrated. Purification of the crude material by chromatography gives the title compound (3.1 g, 21.11 mmol, 51%). 1H NMR (CDCl3): δ 2.49 (s, 3H), 2.55 (s, 3H), 6.84 (d, J=9.3 Hz, 1H), 7.64 (s, 1H), 7.70 (d, J=9.3 Hz, 1H) ppm. ES-MS (m/z): calcd for C8H9N3 (M+H)+: 148.2. found: 148.1.

Workup

  1. temperatureThe reaction is refluxed overnight
  2. temperatureThe resulting mixture is refluxed for 2 h
  3. filtrationfiltered through silical gel
  4. washwashed with EtOAc
  5. concentrationconcentrated
  6. customPurification of the crude material by chromatography

Sources & evidence

ORD record
ord-d8c34bddadeb48b6a48b90880cda2565
Source dataset
uspto-grants-2009_07
Patent number
US07557103B2

Reaction notes

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