Reaktion #322777

Reaktionsgleichung

sulfuric acid

5,6,7-Trimethylquinoline-8-carboxaldehyde n-Butyl lithium

8-bromo-5,6,7-trimethylquinoline

N-formylpiperidine

potassium carbonate

→

5,6,7-trimethylquinoline-8-carboxaldehyde

Lösungsmittel

THF

THF

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturthe mixture was warmed to room temperature
2. 2
   Extraktionwas then extracted with ether
3. 3
   TrocknenThe dried (MgSO4) organic fraction
4. 4
   Sonstigewas evaporated
5. 5
   Sonstigethe residue was purified by column chromatography over alumina with carbon tetrachloride/dichloromethane (1:1 v/v) elution

Vorschrift

5,6,7-Trimethylquinoline-8-carboxaldehyde n-Butyl lithium (2.1 equiv; 1.55M in hexane) was added slowly to a suspension of 8-bromo-5,6,7-trimethylquinoline (4.2 g) in anhydrous THF (40 ml) under nitrogen at -90° C. After 3 hr a solution of N-formylpiperidine (2.1 equiv) in anhydrous THF (10 ml) was added and the mixture was warmed to -40° C. over ca. 2 hr. A dilute sulfuric acid solution (1N; 20 ml) was added and the mixture was warmed to room temperature. The mixture was made basic by the addition of potassium carbonate and was then extracted with ether. The dried (MgSO4) organic fraction was evaporated and the residue was purified by column chromatography over alumina with carbon tetrachloride/dichloromethane (1:1 v/v) elution to give 5,6,7-trimethylquinoline-8-carboxaldehyde as a pale yellow solid, mp 162° C. Pmr spectrum (CDCl3 ; δ in ppm): 2.48 (3H,s); 2.68 (3H,s); 2.74 (3H,s); 7.43-8.96 (3H,m); 11.61 (1H,s).

Quelle