Reaktion #6775

Reaktionsgleichung

2-(Methoxycarbonyl)-4-oxo-6,8-dichloro-7-methylquinoline

LiOH.H2O

→

2-carboxy-4-oxo-7-methylquinoline

Ausbeute 98.8%

Lösungsmittel

methanol

water

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeThe resulting reaction mixture
2. 2
   Sonstigethe resulting reaction mixture
3. 3
   FiltrationThe reaction mixture was filtered
4. 4
   Einengenconcentrated under reduced pressure
5. 5
   Sonstigeto remove methanol
6. 6
   workup.ADDITIONdiluted with water (300 mL)
7. 7
   FiltrationThe precipitate was collected by filtration
8. 8
   Waschenwashed with water
9. 9
   Sonstigedried

Vorschrift

2-(Methoxycarbonyl)-4-oxo-6,8-dichloro-7-methylquinoline (28.5 g, 99.6 mmol) was suspended in methanol (1 L) and a solution of LiOH.H2O (20.5 g, 0.5 mol) in water (200 mL) was added to the solution. The resulting reaction mixture was stirred at ambient temperature for 0.5 hours. Pd/C (5.8 g) was added to the reaction mixture and the resulting reaction mixture was shaken under 50 Psi hydrogen overnight. The reaction mixture was filtered, concentrated under reduced pressure to remove methanol, diluted with water (300 mL) and the pH was adjusted to between pH 3 and pH 4 by 2N HCl. The precipitate was collected by filtration, washed with water and dried to afford a white solid, 2-carboxy-4-oxo-7-methylquinoline (20 g, 90%); NMR (DMSO-d6) 2.40 (s, 3), 6.60 (s, 1), 7.20 (d, 1), 7.68 (s, 1), 7.96 (d, 1) ppm.

Quelle