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

HRID 2404272Notes

Reaction equation

HRID 2404272 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) before being acidified (to pH 5-6) with aqueous hydrochloric acid (2 M, 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, 4.16 mmol, 21% yield). 1HNMR (400 MHz, DMSO-d6): 8 ppm 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-26906df897564b798fc91ba9e4f83d00
Source dataset
uspto-grants-2014_08
Patent number
US08802690B2

Reaction notes

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