Sodium Hydroxide → 1H-Pyrazolo(4,3-b)pyridine-6-carboxylic acid

HRID 711054Notes

Reaction equation

HRID 711054 reaction equation
[NH:1]1[C:9]2[C:4](=[N:5][CH:6]=[C:7]([C:10]([O:12]C)=[O:11])[CH:8]=2)[CH:3]=[N:2]1.[OH-].[Na+]>CO.O>[NH:1]1[C:9]2[C:4](=[N:5][CH:6]=[C:7]([C:10]([OH:12])=[O:11])[CH:8]=2)[CH:3]=[N:2]1

Participants

5

Reactant 2

HCID 14798Sodium HydroxideHCID 60144275Methyl 1H-pyrazolo[4,3-B]pyridine-6-carboxylate

Product 1

HCID 671513391H-Pyrazolo(4,3-b)pyridine-6-carboxylic acidYield 21%

Reagents, catalysts & solvents 2

HCID 887MethanolSolventHCID 962WaterSolvent

Procedure

To a solution of methyl 1H-pyrazolo[4,3-b]pyridine-6-carboxylate (3.52 g, 20 mmol) in methanol (250 mL) and water (190 mL) at 0° C. was added aqueous sodium hydroxide (2M, 64 mL, 128 mmol), dropwise. The suspension was then allowed to warm to ambient temperature and stirred for 18 hours. The methanol was then removed in vacuo and the aqueous mixture extracted with ethyl acetate (250 mL). The aqueous layer was acidified (to pH 5-6) with 2 N aqueous hydrochloric acid (70 mL). The cream solid which had precipitated out was then filtered off and dried in a desiccator to yield the title compound (0.675 g, 21%). 1HNMR (400 MHz, DMSO-d6, δ): 8.97 (s, 1H), 8.45 (s, 1H), 8.39 (s, 1H).

Workup

  1. customThe methanol was then removed in vacuo
  2. extractionthe aqueous mixture extracted with ethyl acetate (250 mL)
  3. customThe cream solid which had precipitated out
  4. filtrationwas then filtered off
  5. customdried in a desiccator

Sources & evidence

ORD record
ord-1806240758984cd28199493b90daadf6
Source dataset
uspto-grants-2015_11
Patent number
US09181252B2

Reaction notes

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