Hydrochloric Acid → (4-Chloro-1-ethyl-1H-pyrazolo[3,4-b]pyridin-5-yl)methanol

HRID 1576813Notes

Reaction equation

HRID 1576813 reaction equation
C([O:3][C:4]([C:6]1[C:7]([Cl:17])=[C:8]2[CH:14]=[N:13][N:12]([CH2:15][CH3:16])[C:9]2=[N:10][CH:11]=1)=O)C.O1CCCC1.[H-].[Al+3].[Li+].[H-].[H-].[H-].Cl>O>[Cl:17][C:7]1[C:6]([CH2:4][OH:3])=[CH:11][N:10]=[C:9]2[N:12]([CH2:15][CH3:16])[N:13]=[CH:14][C:8]=12

Participants

6

Reactant 4

HCID 313Hydrochloric AcidHCID 8028TetrahydrofuranHCID 10491120ethyl 4-chloro-1-ethyl-1H-pyrazolo[3,4-b]pyridine-5-carboxylateHCID 21226445Aluminium lithium hydride

Product 1

HCID 20209064(4-Chloro-1-ethyl-1H-pyrazolo[3,4-b]pyridin-5-yl)methanol

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

10.02 g. of 4-Chloro-1-ethyl-1H-pyrazolo[3,4-b]pyridine-5-carboxylic acid ethyl ester (0.04 mol.) are dissolved in 100 ml. of anhydrous tetrahydrofuran. Nitrogen is passed through the flask and while stirring and cooling with tap water, 1.14 g. of lithium aluminium hydride is added a bit at a time in order to keep the reaction temperature at about 25°C. Stirring is continued for an additional two hours at room temperature. The reaction mixture is allowed to stand over night. Then 3 N-hydrochloric acid (60 ml) is added and the mixture is evaporated in vacuo. The residue is dissolved in water, neutralized with aqueous sodium hydroxide (10%) to pH 7 and extracted several times with ether. The combined etheral extracts are dried with sodium sulfate, evaporated and the residual oil (6.7 g. (79%)) is distilled in vacuo, b.p. 0.4 mm 137°-140°, providing a quickly crystallizing oil. The compound is recrystallized from hexane, to yield the 4-chloro-1-ethyl-1H-pyrazolo[3,4-b]pyridine-5-methanol, m.p. 56°.

Workup

  1. customat about 25°C
  2. stirringStirring
  3. waitto stand over night
  4. customthe mixture is evaporated in vacuo
  5. dissolutionThe residue is dissolved in water
  6. extractionextracted several times with ether
  7. dry with materialThe combined etheral extracts are dried with sodium sulfate
  8. customevaporated
  9. distillationthe residual oil (6.7 g. (79%)) is distilled in vacuo, b.p. 0.4 mm 137°-140°
  10. customproviding
  11. customa quickly crystallizing oil
  12. customThe compound is recrystallized from hexane

Sources & evidence

ORD record
ord-47c5f8fad78c498c8265b82ee72080e3
Source dataset
uspto-grants-1976_09
Patent number
US03983128

Reaction notes

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