Diisopropylethylamine → Ethyl (2-ethyl-6,8-dimethylimidazo[1,2-b]pyridazin-3-yl)carboxylate

HRID 257259Notes

Reaction equation

HRID 257259 reaction equation
[NH2:1][C:2]1[N:3]=[N:4][C:5]([CH3:9])=[CH:6][C:7]=1[CH3:8].C(N(C(C)C)CC)(C)C.Cl[CH:20]([CH3:29])[C:21]([CH2:23][C:24]([O:26][CH2:27][CH3:28])=[O:25])=O>C(Cl)Cl>[CH2:20]([C:21]1[N:1]=[C:2]2[C:7]([CH3:8])=[CH:6][C:5]([CH3:9])=[N:4][N:3]2[C:23]=1[C:24]([O:26][CH2:27][CH3:28])=[O:25])[CH3:29]

Participants

5

Reactant 3

HCID 81531DiisopropylethylamineHCID 205057Pyridazine, 3-amino-4,6-dimethyl-HCID 13030833Ethyl 4-chloro-3-oxopentanoate

Product 1

HCID 53827167Ethyl (2-ethyl-6,8-dimethylimidazo[1,2-b]pyridazin-3-yl)carboxylateYield 73%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Conditions

Temperature
75 °C

Procedure

To a suspension of 0.598 g (4.86 mmol) of 3-amino-4,6-dimethylpyridazine in 10 mL of CH2Cl2 in a high pressure vessel was added 0.941 g (1.27 mL; 7.28 mmol) of diisopropylethylamine and 1.301 g (7.28 mmol) of ethyl a-chloropropionylacetate. The reaction mixture was equipped with a magnetic stir bar, tightly sealed, then heated and stirred in an oil bath at 75° C. for 16 hours. The flask was then cooled to room temperature, opened and the reaction mixture was evaporated in vacuo. The residue was partitioned between EtOAc and water, and the organic layer was separated. The organic layer was washed with brine, dried (MgSO4), filtered and evaporated. The residual brown solid was purified on a silica gel flash chromatography column eluted with 50% EtOAc-hexane. Combination of the purified fractions and evaporation in vacuo afforded 0.874 g (73%) of the title compound.

Workup

  1. customThe reaction mixture was equipped with a magnetic stir bar
  2. customtightly sealed
  3. temperatureheated
  4. temperatureThe flask was then cooled to room temperature
  5. customthe reaction mixture was evaporated in vacuo
  6. customThe residue was partitioned between EtOAc and water
  7. customthe organic layer was separated
  8. washThe organic layer was washed with brine
  9. dry with materialdried (MgSO4)
  10. filtrationfiltered
  11. customevaporated
  12. customThe residual brown solid was purified on a silica gel flash chromatography column
  13. washeluted with 50% EtOAc-hexane
  14. customCombination of the purified fractions and evaporation in vacuo

Sources & evidence

ORD record
ord-319d6efa352f420093a48509793e1a80
Source dataset
uspto-grants-1993_11
Patent number
US05260285

Reaction notes

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