1,3-Dibromopropane → 4H,5H,6H,7H-pyrazolo(1,5-a)pyrimidine

HRID 2380290Notes

Reaction equation

HRID 2380290 reaction equation
[NH2:1][C:2]1[NH:6][N:5]=[CH:4][CH:3]=1.Br[CH2:8][CH2:9][CH2:10]Br.O1CCOCC1>C(N(CC)CC)C>[N:5]1[N:6]2[CH2:8][CH2:9][CH2:10][NH:1][C:2]2=[CH:3][CH:4]=1

Participants

5

Reactant 3

HCID 80011,3-DibromopropaneHCID 312751,4-DioxaneHCID 74561Pyrazol-3-ylamine

Product 1

HCID 1356276294H,5H,6H,7H-pyrazolo(1,5-a)pyrimidine

Reagents, catalysts & solvents 1

HCID 8471TriethylamineSolvent

Procedure

5-Aminopyrazole (10 g) and 1,3-dibromopropane (13.4 ml) were added to 1,4-dioxane (20 ml) under stirring at ambient temperature. Triethylamine (40.1 ml) was added thereto. The mixture was refluxed under stirring for 4 hours. The reaction mixture was cooled to 0°-5° C. in an ice-bath and stirred for 30 minutes. An insoluble material was filtered off, and the filtrate was evaporated under reduced pressure to give 4,5,6,7-tetrahydropyrazolo[1,5-a]pyrimidine (5.1 g).

Workup

  1. temperatureThe mixture was refluxed
  2. stirringunder stirring for 4 hours
  3. temperatureThe reaction mixture was cooled to 0°-5° C. in an ice-bath
  4. stirringstirred for 30 minutes
  5. filtrationAn insoluble material was filtered off
  6. customthe filtrate was evaporated under reduced pressure

Sources & evidence

ORD record
ord-e06215942935458284c9792a7fe4189f
Source dataset
uspto-grants-1994_11
Patent number
US05366970

Reaction notes

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