Thionyl Chloride → 4-Ethoxy-1-ethyl-1H-pyrazolo[3,4-b]pyridine-5-carboxylic acid chloride

HRID 596763Notes

Reaction equation

HRID 596763 reaction equation
[CH2:1]([O:3][C:4]1[C:9]([C:10](O)=[O:11])=[CH:8][N:7]=[C:6]2[N:13]([CH2:16][CH3:17])[N:14]=[CH:15][C:5]=12)[CH3:2].S(Cl)([Cl:20])=O>>[CH2:1]([O:3][C:4]1[C:9]([C:10]([Cl:20])=[O:11])=[CH:8][N:7]=[C:6]2[N:13]([CH2:16][CH3:17])[N:14]=[CH:15][C:5]=12)[CH3:2]

Participants

3

Reactant 2

HCID 24386Thionyl ChlorideHCID 130729804-Ethoxy-1-ethyl-1H-pyrazolo[3,4-b]pyridine-5-carboxylic acid

Product 1

HCID 218238814-Ethoxy-1-ethyl-1H-pyrazolo[3,4-b]pyridine-5-carboxylic acid chloride

Procedure

117.5 g. of 4-ethoxy-1-ethyl-1H-pyrazolo[3,4-b]pyridine-5-carboxylic acid (0.5 mol.) are slowly added with stirring to 300 ml. of thionyl chloride. The mixture is refluxed for 4 hours, excess thionyl chloride is removed in vacuo and the residue dissolved in 500 ml. anhydrous diethylether. The undissolved material is filtered off and the filtrate intensively cooled. The acid chloride precipitates; it is filtered under suction and washed well with cold water. Yield 105 g. (80%), m.p. 72°-73°.

Workup

  1. temperatureThe mixture is refluxed for 4 hours
  2. customexcess thionyl chloride is removed in vacuo
  3. dissolutionthe residue dissolved in 500 ml
  4. filtrationThe undissolved material is filtered off
  5. temperaturethe filtrate intensively cooled
  6. customThe acid chloride precipitates
  7. filtrationit is filtered under suction
  8. washwashed well with cold water

Sources & evidence

ORD record
ord-ba06d75bf9c149eb951d2f46c19b49f1
Source dataset
uspto-grants-1977_03
Patent number
US04012373

Reaction notes

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