Phosphorus oxychloride → 4-chloro-1,3-dimethyl-6-phenyl-1H-pyrazolo[3,4-b]pyridine

HRID 1764095Notes

Reaction equation

HRID 1764095 reaction equation
[CH3:1][N:2]1[C:6]2=[N:7][C:8]([C:12]3[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=3)=[CH:9][C:10](O)=[C:5]2[C:4]([CH3:18])=[N:3]1.P(Cl)(Cl)([Cl:21])=O>>[Cl:21][C:10]1[CH:9]=[C:8]([C:12]2[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=2)[N:7]=[C:6]2[N:2]([CH3:1])[N:3]=[C:4]([CH3:18])[C:5]=12

Participants

3

Reactant 2

HCID 24813Phosphorus oxychlorideHCID 178433989HCID 178433989, compound

Product 1

HCID 227705064-chloro-1,3-dimethyl-6-phenyl-1H-pyrazolo[3,4-b]pyridine

Procedure

73 gms. of 1,3-dimethyl-4-hydroxy-6-phenyl-1H-pyrazolo[3,4-b]pyridine (0.31 mol.) are refluxed in 800 ml. of phosphorus oxychloride for 6 hours. The excess phosphorus oxychloride is removed in vacuo and the oily residue is treated with ice-water by which operation the compound becomes solid. The compound is extracted with ether, washed with an aqueous sodium carbonate solution (10%) and again with water. Evaporation of the dried (Na2SO4) and charcoal treated ethereal extract provides 4-chloro-1,3 -dimethyl-6-phenyl-1H-pyrazolo[3,4-b]-pyridine which is washed with absolute ethanol, yield: 55.6 gms. (69.8%) of white product melting at 89°-90° C.

Workup

  1. customThe excess phosphorus oxychloride is removed in vacuo
  2. additionthe oily residue is treated with ice-water by which operation the compound
  3. extractionThe compound is extracted with ether
  4. washwashed with an aqueous sodium carbonate solution (10%) and again with water
  5. customEvaporation of the
  6. dry with materialdried (Na2SO4) and charcoal treated ethereal
  7. extractionextract

Sources & evidence

ORD record
ord-22cf88fcf58b4feb9eb58d6987952e55
Source dataset
uspto-grants-1978_09
Patent number
US04115394

Reaction notes

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