Phosphorus oxychloride → HCID 22756855, compound

HRID 65988Notes

Reaction equation

HRID 65988 reaction equation
[CH3:1][N:2]1[CH:10]=[C:9]2[C:4]([N:5]=[C:6]([C:12]3[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=3)[CH:7]=[C:8]2O)=[N:3]1.P(Cl)(Cl)([Cl:20])=O>>[Cl:20][C:8]1[C:9]2[C:4](=[N:3][N:2]([CH3:1])[CH:10]=2)[N:5]=[C:6]([C:12]2[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=2)[CH:7]=1

Participants

3

Reactant 2

HCID 24813Phosphorus oxychlorideHCID 178479971HCID 178479971, compound

Product 1

HCID 22756855HCID 22756855, compound

Procedure

39 g. of 2-methyl-6-phenyl-2H-pyrazolo[3,4-b]pyridin-4-ol (0.17 mol.) are refluxed in 195 ml. of phosphorus oxychloride for 90 minutes. The excess phosphorus oxychloride is removed in vacuo and the residue is poured onto ice. Concentrated aqueous ammonia is added under external cooling to adjust the mixture to pH 8-9. Stirring is continued for one additional hour. The collected 4-chloro-2-methyl-6-phenyl-2H-pyrazolo[3,4-b]pyridine is washed with water and dried at 70°, yield: 41 g. (100%); m.p. 177°-179°. Recrystallization from ethyl acetate gives a melting point of 189°-190°.

Workup

  1. customThe excess phosphorus oxychloride is removed in vacuo
  2. additionthe residue is poured onto ice
  3. additionConcentrated aqueous ammonia is added
  4. temperatureunder external cooling
  5. washThe collected 4-chloro-2-methyl-6-phenyl-2H-pyrazolo[3,4-b]pyridine is washed with water
  6. customdried at 70°
  7. customRecrystallization from ethyl acetate
  8. customgives a melting point of 189°-190°

Sources & evidence

ORD record
ord-519c1d9a9cdc4c52b19f56652c347634
Source dataset
uspto-grants-1978_12
Patent number
US04129738

Reaction notes

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