Hydrochloric Acid → 1,4-Dihydro-2-(methylthio)-4-oxo-3-quinolinecarboxylic acid

HRID 1529594Notes

Reaction equation

HRID 1529594 reaction equation
C([O:3][C:4]([C:6]1[C:7]([S:17][CH3:18])=[N:8][C:9]2[C:14]([C:15]=1[OH:16])=[CH:13][CH:12]=[CH:11][CH:10]=2)=[O:5])C.Cl>[OH-].[Na+]>[CH3:18][S:17][C:7]1[NH:8][C:9]2[C:14]([C:15](=[O:16])[C:6]=1[C:4]([OH:5])=[O:3])=[CH:13][CH:12]=[CH:11][CH:10]=2

Participants

4

Reactant 2

HCID 313Hydrochloric AcidHCID 1784701074-Hydroxy-2-methylsulfanyl-quinoline-3-carboxylic acid ethyl ester

Product 1

HCID 465076311,4-Dihydro-2-(methylthio)-4-oxo-3-quinolinecarboxylic acidYield 85%

Reagents, catalysts & solvents 1

HCID 14798Sodium HydroxideSolvent

Procedure

4-Hydroxy-2-methylsulfanyl-quinoline-3-carboxylic acid ethyl ester (8 g, 30 mmol) was heated under reflux in NaOH solution (10%, 100 mL) for 1.5 h. After cooling, the mixture was acidified with concentrated HCl to pH 4. The resulting solid was collected via filtration, washed with water (100 mL) and MeOH (100 mL) to give 2-methylsulfanyl-4-oxo-1,4-dihydro-quinoline-3-carboxylic acid (A-16) as a white solid (6 g, 85%). 1H NMR (CDCl3) δ 16.4 (br s, 1H), 11.1 (br s, 1H), 8.19 (d, J=8 Hz, 1H), 8.05 (d, J=8 Hz, 1H), 7.84 (t, J=8, 8 Hz, 1H), 7.52 (t, J=8 Hz, 1H), 2.74 (s, 3H); ESI-MS 235.9 m/z (MH+).

Workup

  1. temperatureAfter cooling
  2. filtrationThe resulting solid was collected via filtration
  3. washwashed with water (100 mL) and MeOH (100 mL)

Sources & evidence

ORD record
ord-6ba57e76b0af4aa2a3b4a5fdc8cee78e
Source dataset
uspto-grants-2015_07
Patent number
US09090619B2

Reaction notes

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