Reaktion #1475722

Reaktionsgleichung

potassium dichromate

sulfuric acid

2-chloro-5-(trifluoromethylthio) benzyl alcohol

→

2-chloro-5-(trifluoromethylthio)benzaldehyde

Ausbeute 86.2%

Lösungsmittel

water

dichloromethane

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.WAITto stand overnight
2. 2
   SonstigeThe aqueous layer is then separated
3. 3
   Waschenthe organic layer washed with water
4. 4
   Trocknena 5% sodium hydroxide solution, dried with magnesium sulfate
5. 5
   Sonstigeevaporated
6. 6
   workup.DISTILLATIONThe residue is distilled in vacuo

Vorschrift

Triethylbenzylammonium chloride (3.6 g) is added to a solution of 39.9 g of crude 2-chloro-5-(trifluoromethylthio) benzyl alcohol in 400 ml of dichloromethane and the mixture is treated dropwise at 15°-20° C. with a solution of 20.6 g of potassium dichromate in 270 ml of water containing 135 ml of sulfuric acid. The mixture is stirred for 4 hours at room temperature and allowed to stand overnight. The aqueous layer is then separated and the organic layer washed with water and a 5% sodium hydroxide solution, dried with magnesium sulfate and evaporated. The residue is distilled in vacuo. There are obtained 34.1 g of crude 2-chloro-5-(trifluoromethylthio)benzaldehyde boiling at 120°-130° C./2 kPa. According to the 1H-NMR spectrum the product consists of approximately 80% of the named compound and the remainder is the position isomer. In this state the substance is suitable for further processing.

Quelle