Potassium Hydroxide → 7-(2-Chloro-4-methoxyphenyl)-2,6-dimethylpyrazolo[1,5-a]pyridine-3-carboxylic acid

HRID 859145Notes

Reaction equation

HRID 859145 reaction equation
[Cl:1][C:2]1[CH:7]=[C:6]([O:8][CH3:9])[CH:5]=[CH:4][C:3]=1[C:10]1[N:15]2[N:16]=[C:17]([CH3:24])[C:18]([C:19]([O:21]CC)=[O:20])=[C:14]2[CH:13]=[CH:12][C:11]=1[CH3:25].[OH-].[K+]>C(O)C.C1COCC1.O>[Cl:1][C:2]1[CH:7]=[C:6]([O:8][CH3:9])[CH:5]=[CH:4][C:3]=1[C:10]1[N:15]2[N:16]=[C:17]([CH3:24])[C:18]([C:19]([OH:21])=[O:20])=[C:14]2[CH:13]=[CH:12][C:11]=1[CH3:25]

Participants

6

Reactant 2

HCID 14797Potassium Hydroxide2×HCID 69588692Ethyl 7-(2-chloro-4-methoxyphenyl)-2,6-dimethylpyrazolo[1,5-a]pyridine-3-carboxylate

Product 1

HCID 695888007-(2-Chloro-4-methoxyphenyl)-2,6-dimethylpyrazolo[1,5-a]pyridine-3-carboxylic acidYield 79%

Reagents, catalysts & solvents 3

HCID 702EthanolSolventHCID 962WaterSolventHCID 8028TetrahydrofuranSolvent

Procedure

A solution of ethyl 7-(2-chloro-4-methoxyphenyl)-2,6-dimethylpyrazolo[1,5-a]pyridine-3-carboxylate (0.82 g, 2.3 mmol) in ethanol (14 mL), THF (8 mL) and H2O (8 mL) was treated with KOH (3.12 g, 55.6 mmol) and stirred at room temperature for 8 days adding more KOH periodically. The reaction was concentrated in vacuo and the residue partitioned between Et2O and H2O. The aqueous layer was acidified with concentrated HCl, extracted with ethyl aceatate, washed with brine, dried over MgSO4 and filtered. The filtrate was concentrated in vacuo to give a brown solid (0.60 g, 79%) as the title compound: 1H NMR (400 MHz, CDCl3) δ 8.18 (d, J=9.0 Hz, 1H), 7.43 (d, J=9.0 Hz, 1H), 7.30 (d, J=8.5 Hz, 1H), 7.16 (d, J=2.5 Hz, 1H), 7.04 (dd, J=8.5, 2.5 Hz, 1H), 3.93 (s, 3H), 2.67 (s, 3H), 2.19 (s, 3H); HRMS (FAB) calcd for C17H15N2O3Cl+H 331.0849. found 331.0853.

Workup

  1. concentrationThe reaction was concentrated in vacuo
  2. customthe residue partitioned between Et2O and H2O
  3. extractionextracted with ethyl aceatate
  4. washwashed with brine
  5. dry with materialdried over MgSO4
  6. filtrationfiltered
  7. concentrationThe filtrate was concentrated in vacuo

Sources & evidence

ORD record
ord-2ce6df5cb2b44b2cb892610dc32789f9
Source dataset
uspto-grants-2006_12
Patent number
US07151109B2

Reaction notes

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