Hydrochloric Acid → 2-Ethylpyrazolo[1,5-a]pyridine-3-carboxylic acid

HRID 408799Notes

Reaction equation

HRID 408799 reaction equation
[CH2:1]([C:3]1[C:11]([C:12]([O:14]CC)=[O:13])=[C:6]2[CH:7]=[CH:8][CH:9]=[CH:10][N:5]2[N:4]=1)[CH3:2].[OH-].[Na+].Cl>CO.O>[CH2:1]([C:3]1[C:11]([C:12]([OH:14])=[O:13])=[C:6]2[CH:7]=[CH:8][CH:9]=[CH:10][N:5]2[N:4]=1)[CH3:2]

Participants

6

Reactant 3

HCID 313Hydrochloric AcidHCID 14798Sodium HydroxideHCID 137381512-Ethyl-pyrazolo[1,5-a]pyridine-3-carboxylic acid ethyl ester

Product 1

HCID 583793202-Ethylpyrazolo[1,5-a]pyridine-3-carboxylic acidYield 96%

Reagents, catalysts & solvents 2

HCID 887MethanolSolventHCID 962WaterSolvent

Conditions

Temperature
60 °C

Procedure

Ethyl 2-ethylpyrazolo[1,5-a]pyridine-3-carboxylate (5.0 g, 23 mmol) was stirred in methanol (200 mL) and a solution of sodium hydroxide in water (100 mL, 3 N) was added. The mixture was heated at 60° C. for 16 h. Evaporation gave a thick suspension which was treated with aqueous hydrogen chloride (100 mL, 3 N). The solids briefly dissolved and a new precipitate formed. The solid was filtered and washed with water to give the desired compound (4.1 g, 96%). LCMS for C10H11N2O2 (M+H)+: m/z=191.1. 1H NMR (300 MHz, DMSO-d6): δ 8.52 (m, 1H), 8.15 (m, 1H), 7.23 (m, 1H), 6.81 (m, 1H), 3.05 (m, 2H), 1.22 (m, 3H).

Workup

  1. customEvaporation
  2. customgave a thick suspension which
  3. dissolutionThe solids briefly dissolved
  4. customa new precipitate formed
  5. filtrationThe solid was filtered
  6. washwashed with water

Sources & evidence

ORD record
ord-db6d24439c144f50b3ad9024e8920c8f
Source dataset
uspto-grants-2014_06
Patent number
US08759359B2

Reaction notes

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