Phosphorus pentachloride → 7-Chloro-1-ethyl-3,5-dimethyl-1H-pyrazolo[4,3-d]pyrimidine

HRID 2417675Notes

Reaction equation

HRID 2417675 reaction equation
[CH3:1][C:2]1[C:6]2[N:7]=[C:8]([CH3:12])[N:9]=[C:10](O)[C:5]=2[N:4]([CH2:13][CH3:14])[N:3]=1.P(Cl)(Cl)(Cl)(Cl)[Cl:16]>P(Cl)(Cl)(Cl)=O>[Cl:16][C:10]1[C:5]2[N:4]([CH2:13][CH3:14])[N:3]=[C:2]([CH3:1])[C:6]=2[N:7]=[C:8]([CH3:12])[N:9]=1

Participants

4

Reactant 2

HCID 24819Phosphorus pentachlorideHCID 178463054HCID 178463054, compound

Product 1

HCID 133384097-Chloro-1-ethyl-3,5-dimethyl-1H-pyrazolo[4,3-d]pyrimidineYield 85.8%

Reagents, catalysts & solvents 1

HCID 24813Phosphorus oxychlorideSolvent

Procedure

A mixture of 16 g (0.083 mol) of 3,5-dimethyl-1-ethyl-7-hydroxy-1H-pyrazolo[4,3-d]pyrimidine and 18.5 g (0.087 mol) of phosphorus pentachloride in 120 ml of phosphorus oxychloride is stirred under reflux five hours. The solution is evaporated in vacuo. The residue is redissolved in ether and percolated over neutral alumina to yield 15 g of 7-chloro-3,5-dimethyl-1-ethyl-1H-pyrazolo[4,3-d]pyrimidine, a low-melting waxy solid (40°-50° C.).

Workup

  1. temperatureunder reflux five hours
  2. customThe solution is evaporated in vacuo
  3. dissolutionThe residue is redissolved in ether

Sources & evidence

ORD record
ord-57ae5a7d463b4160bb087936308b3936
Source dataset
uspto-grants-1984_09
Patent number
US04469868

Reaction notes

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