Water → 7-Methoxy-2,5-dimethylpyrazolo[1,5-a]pyrimidine-6-carboxylic acid

HRID 1393652Notes

Reaction equation

HRID 1393652 reaction equation
[OH:1][C:2]1[N:7]2[N:8]=[C:9]([CH3:11])[CH:10]=[C:6]2[N:5]=[C:4]([CH3:12])[C:3]=1[C:13]([O:15]CC)=[O:14].[C:18](=O)([O-])[O-].[K+].[K+].CI.O>CC(C)=O>[CH3:18][O:1][C:2]1[N:7]2[N:8]=[C:9]([CH3:11])[CH:10]=[C:6]2[N:5]=[C:4]([CH3:12])[C:3]=1[C:13]([OH:15])=[O:14]

Participants

6

Reactant 4

HCID 962WaterHCID 6328Methyl iodideHCID 11430Potassium CarbonateHCID 178469184HCID 178469184, compound

Product 1

HCID 497615147-Methoxy-2,5-dimethylpyrazolo[1,5-a]pyrimidine-6-carboxylic acidYield 73.3%

Reagents, catalysts & solvents 1

HCID 180AcetoneSolvent

Procedure

The ethyl 7-hydroxy-2,5-dimethylpyrazolo[1,5-a]pyrimidine-6-carboxylate (235 mg) obtained above was suspended in acetone (5 ml), and potassium carbonate (138 mg) was added thereto and stirred for 30 minutes at room temperature. Methyl iodide (1.0 ml) was added to the mixture which was then refluxed for 2 hours. The reaction mixture was cooled to room temperature, then water was added to the reaction mixture which was extracted with chloroform, and the organic phase was washed with a saturated saline solution and dried over sodium sulfate anhydrous. The resulting product was concentrated under reduced pressure, and the resulting crystals were dissolved in ethanol (5 ml). 5 N Sodium hydroxide solution (1 ml) was added thereto and stirred for 1 hour at 50° C. The reaction mixture was cooled to room temperature, and water was added to the mixture which was then washed with ethyl acetate. 2 N Hydrochloric acid was added to the aqueous phase until it became acidic, and precipitated crystals were collected by filtration and washed with water and n-hexane. The crystals were dried under reduced pressure to give the title compound (162 mg, Y.:73%) as white crystals.

Workup

  1. temperaturewas then refluxed for 2 hours
  2. temperatureThe reaction mixture was cooled to room temperature
  3. extractionwas extracted with chloroform
  4. washthe organic phase was washed with a saturated saline solution
  5. dry with materialdried over sodium sulfate anhydrous
  6. concentrationThe resulting product was concentrated under reduced pressure
  7. dissolutionthe resulting crystals were dissolved in ethanol (5 ml)
  8. addition5 N Sodium hydroxide solution (1 ml) was added
  9. stirringstirred for 1 hour at 50° C
  10. temperatureThe reaction mixture was cooled to room temperature
  11. additionwater was added to the mixture which
  12. washwas then washed with ethyl acetate
  13. addition2 N Hydrochloric acid was added to the aqueous phase until it
  14. customprecipitated crystals
  15. filtrationwere collected by filtration
  16. washwashed with water and n-hexane
  17. customThe crystals were dried under reduced pressure

Sources & evidence

ORD record
ord-ecd0287d029d44cabdacf54dd0cc75e3
Source dataset
uspto-grants-2008_03
Patent number
US07345180B2

Reaction notes

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