1,3-Dibromopropane → 4,5,6,7-Tetrahydropyrazolo[1,5-a]pyrimidine-3-carbonitrile

HRID 349555

Reaction equation

HRID 349555 reaction equation
[NH2:1][C:2]1[NH:6][N:5]=[CH:4][C:3]=1[C:7]#[N:8].C(N(CC)CC)C.Br[CH2:17][CH2:18][CH2:19]Br>O1CCOCC1>[N:5]1[N:6]2[CH2:17][CH2:18][CH2:19][NH:1][C:2]2=[C:3]([C:7]#[N:8])[CH:4]=1

Participants

5

Reactant 3

HCID 80011,3-DibromopropaneHCID 8471TriethylamineHCID 855155-Amino-4-cyanopyrazole

Product 1

HCID 1356713724,5,6,7-Tetrahydropyrazolo[1,5-a]pyrimidine-3-carbonitrile

Reagents, catalysts & solvents 1

HCID 312751,4-DioxaneSolvent

Conditions

Temperature
95 °C

Procedure

To a solution of 5-aminopyrazole-4-carbonitrile (102 g) and triethylamine (316 ml) in 1,4-dioxane (2000 ml) was added 1,3-dibromopropane (115 ml), and the mixture was stirred at 95° C. for 5 days. The insoluble materials were removed by filtration, and the filtrate was concentrated in vacuo. To the residue was added 10% aqueous citric acid solution, and the mixture was extracted with chloroform. The extract was dried over anhydrous magnesium sulfate, filtered, and concentrated in vacuo. The residue was triturated with 2-propanol and dried in vacuo to give 4,5,6,7-tetrahydropyrazolo[1,5-a]pyrimidine-3-carbonitrile (8.0 g) as a solid.

Workup

  1. customThe insoluble materials were removed by filtration
  2. concentrationthe filtrate was concentrated in vacuo
  3. additionTo the residue was added 10% aqueous citric acid solution
  4. extractionthe mixture was extracted with chloroform
  5. dry with materialThe extract was dried over anhydrous magnesium sulfate
  6. filtrationfiltered
  7. concentrationconcentrated in vacuo
  8. customThe residue was triturated with 2-propanol
  9. customdried in vacuo

Sources & evidence

ORD record
ord-912c718fea374522827ed71adc7db813
Source dataset
uspto-grants-2007_02
Patent number
US07179801B2

Linked notes

Loading…