Phosphorus oxychloride → Ethyl 4-chloro-3-methyl-1-(2-pyridinyl)-1H-pyrazolo[3,4-b]pyridine-5-carboxylate

HRID 497935Notes

Reaction equation

HRID 497935 reaction equation
O[C:2]1[C:7]([C:8]([O:10][CH2:11][CH3:12])=[O:9])=[CH:6][N:5]=[C:4]2[N:13]([C:17]3[CH:22]=[CH:21][CH:20]=[CH:19][N:18]=3)[N:14]=[C:15]([CH3:16])[C:3]=12.P(Cl)(Cl)([Cl:25])=O>>[Cl:25][C:2]1[C:7]([C:8]([O:10][CH2:11][CH3:12])=[O:9])=[CH:6][N:5]=[C:4]2[N:13]([C:17]3[CH:22]=[CH:21][CH:20]=[CH:19][N:18]=3)[N:14]=[C:15]([CH3:16])[C:3]=12

Participants

3

Reactant 2

HCID 24813Phosphorus oxychlorideHCID 178469580HCID 178469580, compound

Product 1

HCID 22320120Ethyl 4-chloro-3-methyl-1-(2-pyridinyl)-1H-pyrazolo[3,4-b]pyridine-5-carboxylateYield 54.3%

Conditions

Temperature
100 °C

Procedure

A solution of ethyl 4-hydroxy-3-methyl-1-(2-pyridinyl)-1H-pyrazolo[3,4-b]pyridine-5-carboxylate (3.0 g, 0.01 mol) in phosphorous oxychloride (7.7 g, 0.05 mol) was heated and stirred at 100° C. for 1 hour. After the solution was allowed to cool to room temperature, the reaction solvent was evaporated under reduced pressure, and the residue water was added to iced water. After neutralization by the addition of an aqueous sodium hydroxide solution, organic matter was extracted with chloroform. The extract was washed with saturated brine and water, and dried over anhydrous magnesium sulfate, and the solvent was evaporated under reduced pressure. Purification of the residue by silica gel chromatography (ethyl acetate) gave the title compound (1.72 g, 54% yield).

Workup

  1. temperatureto cool to room temperature
  2. customthe reaction solvent was evaporated under reduced pressure
  3. additionthe residue water was added to iced water
  4. additionAfter neutralization by the addition of an aqueous sodium hydroxide solution, organic matter
  5. extractionwas extracted with chloroform
  6. washThe extract was washed with saturated brine and water
  7. dry with materialdried over anhydrous magnesium sulfate
  8. customthe solvent was evaporated under reduced pressure
  9. customPurification of the residue by silica gel chromatography (ethyl acetate)

Sources & evidence

ORD record
ord-ce2eda86178b4775a79333105439c9f8
Source dataset
uspto-grants-2005_09
Patent number
US06949648B2

Reaction notes

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