Dimethylformamide → 5-Formylimidazo[5,1-b]thiazole

HRID 382601Notes

Reaction equation

HRID 382601 reaction equation
CN([CH:4]=[O:5])C.P(Cl)(Cl)(Cl)=O.[S:11]1[CH:15]=[CH:14][N:13]2[CH:16]=[N:17][CH:18]=[C:12]12.[OH-].[Na+]>ClCCl.ClC>[CH:4]([C:16]1[N:13]2[C:12]([S:11][CH:15]=[CH:14]2)=[CH:18][N:17]=1)=[O:5]

Participants

7

Reactant 4

HCID 6228DimethylformamideHCID 14798Sodium HydroxideHCID 24813Phosphorus oxychlorideHCID 21262404Imidazo[5,1-b]thiazole

Product 1

HCID 183599385-Formylimidazo[5,1-b]thiazole

Reagents, catalysts & solvents 2

HCID 6327Methyl ChlorideSolventHCID 6344DichloromethaneSolvent2×

Procedure

To the mixture of 15.48 ml of DMF and 80 ml of dichloromethane was added dropwise a solution of 18.32 ml of phosphorus oxychloride in 80 ml of dichloromethane under ice-cooling. The mixture was reacted at room temperature for 30 minutes, and a solution of imidazo[5,1-b]thiazole in 40 ml of chloromethane was added dropwise. After heating under reflux for 2.5 hours, the reaction mixture was poured onto ice, adjusted to pH 9.8 with a 5 N aqueous sodium hydroxide solution, extracted five times with 200 ml of dichloromethane, dried over anhydrous magnesium sulfate, and the solvent was removed under reduced pressure. The residue thus obtained was purified by column chromatography on silica gel (dichloromethane:ethyl acetate=5:1-ethyl acetate alone—dichloromethane:methanol=10:1). As a low polar component, 5-formylimidazo[5,1-b]thiazole was obtained in a yield of 495 mg.

Workup

  1. temperaturecooling
  2. customThe mixture was reacted at room temperature for 30 minutes
  3. temperatureAfter heating
  4. temperatureunder reflux for 2.5 hours
  5. additionthe reaction mixture was poured onto ice
  6. extractionextracted five times with 200 ml of dichloromethane
  7. dry with materialdried over anhydrous magnesium sulfate
  8. customthe solvent was removed under reduced pressure
  9. customThe residue thus obtained
  10. customwas purified by column chromatography on silica gel (dichloromethane

Sources & evidence

ORD record
ord-0254871c41884083b22baefc03156ecf
Source dataset
uspto-grants-2001_10
Patent number
US06310056B1

Reaction notes

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