Reaktion #56523

Reaktionsgleichung

2-chloro-5-nitro-benzotrifluoride

potassium hydroxide

hydrochloric acid

→

4-nitro-2-trifluoromethylphenol

Lösungsmittel

methanol

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigebeing kept at a maximum of 40° C.
2. 2
   Temperaturby cooling
3. 3
   workup.ADDITIONAbout 30 minutes after the addition
4. 4
   Temperaturcooled
5. 5
   ExtraktionThe mixture is extracted several times with 300 ml of methylene chloride each time
6. 6
   Trocknenthe organic phase is dried with sodium sulphate
7. 7
   SonstigeAbout 413 g of crude product, melting point: 90°-95° C., are obtained with a purity of about 95%
8. 8
   SonstigeAfter recrystallisation
9. 9
   workup.DISTILLATIONfrom toluene, or distillation under 0.5 mm

Vorschrift

450 g of 2-chloro-5-nitro-benzotrifluoride in 1,250 ml of methanol and 35 g of tetraethylammonium chloride are initially introduced. 1,000 g of an aqueous, 50% strength potassium hydroxide solution are then added dropwise (1 hour), the temperature being kept at a maximum of 40° C. by cooling. About 30 minutes after the addition has ended, the mixture is heated to 80° C. for 6 hours, cooled and rendered acid with concentrated hydrochloric acid. The mixture is extracted several times with 300 ml of methylene chloride each time, and the organic phase is dried with sodium sulphate and freed from the solvent under reduced pressure. About 413 g of crude product, melting point: 90°-95° C., are obtained with a purity of about 95% according to analysis by gas chromatography. After recrystallisation from toluene, or distillation under 0.5 mm, pure 4-nitro-2-trifluoromethylphenol is obtained, melting point: 134° C.

Quelle