Phosphorus oxychloride → 3-(3-Chloropyridazin-6-yl)-2-phenylpyrazolo[1,5-a]pyridine

HRID 703988Notes

Reaction equation

HRID 703988 reaction equation
O=[C:2]1[CH:7]=[CH:6][C:5]([C:8]2[C:9]([C:17]3[CH:22]=[CH:21][CH:20]=[CH:19][CH:18]=3)=[N:10][N:11]3[CH:16]=[CH:15][CH:14]=[CH:13][C:12]=23)=[N:4][NH:3]1.P(Cl)(Cl)([Cl:25])=O>>[Cl:25][C:2]1[N:3]=[N:4][C:5]([C:8]2[C:9]([C:17]3[CH:22]=[CH:21][CH:20]=[CH:19][CH:18]=3)=[N:10][N:11]3[CH:16]=[CH:15][CH:14]=[CH:13][C:12]=23)=[CH:6][CH:7]=1

Participants

3

Reactant 2

HCID 24813Phosphorus oxychlorideHCID 105894183(2H)-Pyridazinone, 6-(2-phenylpyrazolo[1,5-a]pyridin-3-yl)-

Product 1

HCID 151581443-(3-Chloropyridazin-6-yl)-2-phenylpyrazolo[1,5-a]pyridine

Procedure

A mixture of 3-(3-oxo-2,3-dihydropyridazin-6-yl)-2-phenylpyrazolo[1,5-a]pyridine (2.91 g) and phosphorus oxychloride (10 ml) was heated under reflux for 1 hour. Phosphorus oxychloride was evaporated in vacuo. The residue was neutralized by saturated aqueous solution of sodium hydrogen carbonate and extracted with chloroform (30 ml×3). The combined extract was washed with a saturated aqueous solution of sodium chloride (20 ml) and dried over magnesium sulfate. The solvent was evaporated in vacuo and the residue was triturated with ethanol, collected by filtration, washed with ethanol and dried to give crystals of 3-(3-chloropyridazin-6-yl)-2-phenylpyrazolo[1,5-a]pyridine (2.42 g).

Workup

  1. temperaturewas heated
  2. temperatureunder reflux for 1 hour
  3. customPhosphorus oxychloride was evaporated in vacuo
  4. extractionextracted with chloroform (30 ml×3)
  5. extractionThe combined extract
  6. washwas washed with a saturated aqueous solution of sodium chloride (20 ml)
  7. dry with materialdried over magnesium sulfate
  8. customThe solvent was evaporated in vacuo
  9. customthe residue was triturated with ethanol
  10. filtrationcollected by filtration
  11. washwashed with ethanol
  12. customdried

Sources & evidence

ORD record
ord-58f4c44257874adfb3ee149f90d42bcd
Source dataset
uspto-grants-1991_01
Patent number
US04985444

Reaction notes

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