1,3-Dibromopropane → 7,8-Dihydro-1-methyl-6H-pyrazolo[3',4':4,5]pyrimido[2,1-b]-[1,3]thiazin-4(1H)-one

HRID 260522Notes

Reaction equation

HRID 260522 reaction equation
[SH:1][C:2]1[NH:3][C:4](=[O:12])[C:5]2[CH:10]=[N:9][N:8]([CH3:11])[C:6]=2[N:7]=1.C(=O)([O-])[O-].[K+].[K+].Br[CH2:20][CH2:21][CH2:22]Br>CN(C)C=O>[CH3:11][N:8]1[C:6]2[N:7]=[C:2]3[N:3]([C:4](=[O:12])[C:5]=2[CH:10]=[N:9]1)[CH2:22][CH2:21][CH2:20][S:1]3

Participants

5

Reactant 3

HCID 80011,3-DibromopropaneHCID 11430Potassium CarbonateHCID 178481768HCID 178481768, compound

Product 1

HCID 224016717,8-Dihydro-1-methyl-6H-pyrazolo[3',4':4,5]pyrimido[2,1-b]-[1,3]thiazin-4(1H)-oneYield 38.2%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Conditions

Temperature
80 °C

Procedure

In 80 ml of dimethylformamide was dissolved 4.0 g (22.0 mmol) of 4,5-dihydro-6-mercapto-1-methylpyrazolo[3,4-d]pyrimidin-4(1H)-one [Helv. Chim. Acta, 42, 349 (1959)], and 9.1 g (66 mmol) of potassium carbonate and 3.34 ml (32.9 mmol) of 1,3-dibromopropane were added to the solution, followed by stirring at 80° C. for 8 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-methanol (100:1) to give 1.87 g (38%) of Compound 44. The compound was recrystallized from ethanol for purification.

Workup

  1. additionwere added to the solution
  2. customAfter evaporation of the solvent
  3. customto partition between chloroform and water
  4. concentrationthe chloroform layer was concentrated to dryness under reduced pressure
  5. washeluted with chloroform-methanol (100:1)

Sources & evidence

ORD record
ord-c99c7185df5a4a24ad81fd0aff434707
Source dataset
uspto-grants-1996_06
Patent number
US05527908

Reaction notes

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