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

HRID 226097Notes

Reaction equation

HRID 226097 reaction equation
[CH3:1][C:2]1[N:7]=[N:6][C:5]([NH2:8])=[CH:4][CH:3]=1.Cl[CH2:10][C:11](=O)[CH3:12].C([O-])(O)=O.[Na+]>C(O)C>[CH3:12][C:11]1[N:8]=[C:5]2[CH:4]=[CH:3][C:2]([CH3:1])=[N:7][N:6]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 58.5%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Conditions

Temperature
70 °C

Procedure

A 3 neck 1 L round bottom flask is charged with 6-methyl-pyridazin-3-ylamine (20 g, 0.18 moles), ethanol 2B (200 mL), and chloroacetone (23.7 g, 20.4 mL, 0.256 moles, 1.4 equiv). The reaction mixture is heated at 70° C. overnight. NaHCO3 (23.2 g, 0.276 moles, 1.5 equiv) is added portion wise. After most of bubbling subsides, the reaction is heated at 100° C. overnight. The solvents are removed in vacuo and the residue is taken up in dichloromethane and filtered through a filter paper. The solvent is again removed in vacuo. The residue is purified using silica gel chromatography with a hexanes:ethyl acetate gradient to obtain the title compound (15.5 g, 57%). 1H-NMR (DMSO-d6), δ 2.34 (s, 3H), 2.47 (s, 3H), 7.03, (d, J=10 Hz, 1H), 7.85 (d, J=10 Hz, 1H), 7.91 (s, 1H) ppm. MS (APCI): 148 (M+1).

Workup

  1. temperatureAfter most of bubbling subsides, the reaction is heated at 100° C. overnight
  2. customThe solvents are removed in vacuo
  3. filtrationfiltered through a filter paper
  4. customThe solvent is again removed in vacuo
  5. customThe residue is purified

Sources & evidence

ORD record
ord-227417ba871540b3a85f1194ddee3efe
Source dataset
uspto-grants-2009_07
Patent number
US07557103B2

Reaction notes

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