Hydrogen Bromide → 6,8-Dimethylimidazo[1,2-b]pyridazine

HRID 1904531Notes

Reaction equation

HRID 1904531 reaction equation
CO[CH:3](OC)[CH2:4]Br.Br.C(=O)(O)[O-].[Na+].[NH2:14][C:15]1[N:16]=[N:17][C:18]([CH3:22])=[CH:19][C:20]=1[CH3:21]>O.C(O)C>[CH3:22][C:18]1[CH:19]=[C:20]([CH3:21])[C:15]2[N:16]([CH:3]=[CH:4][N:14]=2)[N:17]=1

Participants

7

Reactant 4

HCID 260Hydrogen BromideHCID 816722-Bromo-1,1-dimethoxyethaneHCID 205057Pyridazine, 3-amino-4,6-dimethyl-HCID 516892Sodium Bicarbonate

Product 1

HCID 147503576,8-Dimethylimidazo[1,2-b]pyridazineYield 44.6%

Reagents, catalysts & solvents 2

HCID 702EthanolSolventHCID 962WaterSolvent2×

Procedure

A mixture of 25 g (148 mmol) of bromoacetaldehyde dimethyl acetal, 5 mL of water and 5 mL of 48% HBr was refluxed 2 h. After cooling, it was poured into 50 mL of ethanol. Solid sodium bicarbonate was added until bubbling ceased. The mixture was filtered and to the filtrate was added 7.5 g (61 mmol) of 3-amino-4,6-dimethylpyridazine. After stirring 16 h, the ethanol was removed with a rotary evaporator. The residue was triturated with ethanol to give a brown solid which was dissolved in water and washed with dichloromethane. The aqueous layer was brought to pH 9 with sodium bicarbonate and extracted with dichloromethane. Drying (Na2SO4) and solvent removal with a rotary evaporator gave 4 g of the title compound as a brown solid, m.p. 70°-74° C.

Workup

  1. temperaturewas refluxed 2 h
  2. temperatureAfter cooling
  3. customuntil bubbling
  4. filtrationThe mixture was filtered and to the filtrate
  5. customthe ethanol was removed with a rotary evaporator
  6. customThe residue was triturated with ethanol
  7. customto give a brown solid which
  8. washwashed with dichloromethane
  9. extractionextracted with dichloromethane
  10. customDrying
  11. custom(Na2SO4) and solvent removal
  12. customwith a rotary evaporator

Sources & evidence

ORD record
ord-b0e5edde47d2464bb2effbcf5969a59b
Source dataset
uspto-grants-1989_06
Patent number
US04838925

Reaction notes

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