Hydrochloric Acid → 2,4-Dimethoxyquinoline-3-carboxylic acid

HRID 73905Notes

Reaction equation

HRID 73905 reaction equation
[CH3:1][O:2][C:3]1[C:12]([C:13]([O:15]CC)=[O:14])=[C:11]([O:18][CH3:19])[C:10]2[C:5](=[CH:6][CH:7]=[CH:8][CH:9]=2)[N:4]=1.Cl>[OH-].[Na+]>[CH3:1][O:2][C:3]1[C:12]([C:13]([OH:15])=[O:14])=[C:11]([O:18][CH3:19])[C:10]2[C:5](=[CH:6][CH:7]=[CH:8][CH:9]=2)[N:4]=1

Participants

4

Reactant 2

HCID 313Hydrochloric AcidHCID 129326352,4-Dimethoxy-3-carbethoxyquinoline

Product 1

HCID 540834502,4-Dimethoxyquinoline-3-carboxylic acidYield 50.4%

Reagents, catalysts & solvents 1

HCID 14798Sodium HydroxideSolvent

Procedure

Ethyl 2,4-dimethoxyquinoline-3-carboxylate (1.5 g, 5.7 mmol) was heated at reflux in NaOH solution (10%, 100 mL) for 1 h. After cooling, the mixture was acidified with concentrated HCl to pH 4. The resulting precipitate was collected via filtration and washed with water and ether to give 2,4-dimethoxyquinoline-3-carboxylic acid (A-17) as a white solid (670 mg, 50%). 1H NMR (CDCl3) δ 8.01-8.04 (d, J=12 Hz, 1H), 7.66-7.76 (m, 2H), 7.42-7.47 (t, J=22 Hz, 2H), 4.09 (s, 3H). 3.97 (s, 3H); ESI-MS 234.1 m/z (MH+).

Workup

  1. temperatureAfter cooling
  2. filtrationThe resulting precipitate was collected via filtration
  3. washwashed with water and ether

Sources & evidence

ORD record
ord-b0089c3672c647cea00771390fc4b5a5
Source dataset
uspto-grants-2014_09
Patent number
US08829204B2

Reaction notes

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