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

HRID 2417659Notes

Reaction equation

HRID 2417659 reaction equation
[CH3:1][N:2]1[C:10]2[C:9](O)=[N:8][C:7]([CH3:12])=[N:6][C:5]=2[C:4]([CH3:13])=[N:3]1.P(Cl)(Cl)(Cl)(Cl)[Cl:15]>P(Cl)(Cl)(Cl)=O>[Cl:15][C:9]1[C:10]2[N:2]([CH3:1])[N:3]=[C:4]([CH3:13])[C:5]=2[N:6]=[C:7]([CH3:12])[N:8]=1

Participants

4

Reactant 2

HCID 24819Phosphorus pentachlorideHCID 178433418HCID 178433418, compound

Product 1

HCID 133384077-Chloro-1,3,5-trimethyl-1H-pyrazolo[4,3-d]pyrimidineYield 98%

Reagents, catalysts & solvents 1

HCID 24813Phosphorus oxychlorideSolvent

Procedure

A mixture of 30.5 g (0.17 mol) of 1,3,5-trimethyl-1H-pyrazolo[4,3-d]pyrimidin-7-ol and 37 g (0.18 mol) of phosphorus pentachloride in 350 ml of phosphorus oxychloride is stirred under reflux for seven hours and the resulting solution is evaporated in vacuo. The solid residue is redissolved in 300 ml of methylenedichloride and stirred with 200 ml of a saturated aqueous solution of sodium bicarbonate. The organic layer is dried over MgSO4 and evaporated in vacuo to give 30 g (98%) of 7-chloro-1,3,5-trimethyl-1H-pyrazolo[4,3-d]pyrimidine, mp 91°-93° C. from ethyl acetate-pet ether.

Workup

  1. temperatureunder reflux for seven hours
  2. customthe resulting solution is evaporated in vacuo
  3. dissolutionThe solid residue is redissolved in 300 ml of methylenedichloride
  4. stirringstirred with 200 ml of a saturated aqueous solution of sodium bicarbonate
  5. dry with materialThe organic layer is dried over MgSO4
  6. customevaporated in vacuo

Sources & evidence

ORD record
ord-b4185639f7834fcd95dd23cbffdf0b11
Source dataset
uspto-grants-1984_09
Patent number
US04469868

Reaction notes

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