Methylhydrazine → Pyrazolo(3,4-d)thiazolo(3,2-a)pyrimidin-4(1H)-one, 1-methyl-

HRID 260524Notes

Reaction equation

HRID 260524 reaction equation
[O:1]=[C:2]1[N:7]2[CH:8]=[CH:9][S:10][C:6]2=[N:5][CH:4]=[CH:3]1.C[N:12]([CH3:15])C=O.[CH2:16]([N:18](CC)CC)C.CNN>P(Cl)(Cl)(Cl)=O.C(O)C>[CH3:16][N:18]1[C:4]2[N:5]=[C:6]3[S:10][CH:9]=[CH:8][N:7]3[C:2](=[O:1])[C:3]=2[CH:15]=[N:12]1

Participants

7

Reactant 4

HCID 6061MethylhydrazineHCID 6228DimethylformamideHCID 8471TriethylamineHCID 3547845H-Thiazolo[3,2-a]pyrimidin-5-one

Product 1

HCID 609734Pyrazolo(3,4-d)thiazolo(3,2-a)pyrimidin-4(1H)-one, 1-methyl-Yield 71%

Reagents, catalysts & solvents 2

HCID 702EthanolSolventHCID 24813Phosphorus oxychlorideSolvent

Procedure

In 8 ml of phosphorus oxychloride was dissolved 2.00 g (11.9 mmol) of 5-oxo-5H-thiazolo[3,2-a]pyrimidine [Zh. Org. Khim., 11, 2200 (1975)], and 1.13 ml of dimethylformamide was added dropwise to the solution with stirring under ice-cooling. Then, the reaction mixture was heated under reflux for 30 minutes. After concentration of the reaction mixture to dryness under reduced pressure, the oily residue was dissolved in 60 ml of ethanol under ice-cooling. To the solution were added 10 ml of triethylamine and 2.52 ml (47.6 mmol) of methylhydrazine, followed by heating under reflux for 3 hours. After evaporation of the solvent, the residue was subjected to partition between chloroform and water, and the chloroform layer was concentrated to dryness under reduced pressure. The residue was subjected to silica gel column chromatography and eluted with chloroform to give 1.74 g (71%) of Compound 51. The compound was recrystallized from dimethylformamide/water for purification.

Workup

  1. additionwas added dropwise to the solution
  2. temperaturecooling
  3. temperatureThen, the reaction mixture was heated
  4. temperatureunder reflux for 30 minutes
  5. temperaturecooling
  6. temperatureby heating
  7. temperatureunder reflux for 3 hours
  8. customAfter evaporation of the solvent
  9. customto partition between chloroform and water
  10. concentrationthe chloroform layer was concentrated to dryness under reduced pressure
  11. washeluted with chloroform

Sources & evidence

ORD record
ord-a31185b1a8eb49b9a97cca884b8d3aea
Source dataset
uspto-grants-1996_06
Patent number
US05527908

Reaction notes

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