Reaktion #552586

Reaktionsgleichung

4-acetylamino-2,5-dichlorophenol

potassium hydroxide

hexafluoropropylene

→

4-acetylamino-2,5-dichloro-1-(1,1,2,3,3,3-hexafluoropropyloxy)benzene

Lösungsmittel

dimethylformamide

Reaktionsbedingungen

Aufarbeitung

1. 1
   TemperaturAfter cooling
2. 2
   Einengenthe mixture is concentrated by rotary evaporation
3. 3
   workup.DISSOLUTIONthe residue is dissolved in methylene chloride
4. 4
   WaschenThe resultant solution is washed with water
5. 5
   Trocknendried over Na2SO4
6. 6
   Einengenconcentrated
7. 7
   SonstigeThe crude product obtained as residue
8. 8
   Sonstigeis chromatographed through a column of silica gel (length: 1 m; diameter: 10 cm)
9. 9
   Wascheneluted with an 11:1 mixture of toluene and acetone

Vorschrift

47 g of 4-acetylamino-2,5-dichlorophenol together with 154 g of 90% potassium hydroxide solution and 130 ml of dimethylformamide are stirred in an autoclave. 75.8 g of hexafluoropropylene are then pressed into the closed autoclave. The mixture is stirred for 20 hours at 70° C. under the pressure existing in the autoclave. After cooling, the mixture is concentrated by rotary evaporation and the residue is dissolved in methylene chloride. The resultant solution is washed with water, dried over Na2SO4 and concentrated. The crude product obtained as residue is chromatographed through a column of silica gel (length: 1 m; diameter: 10 cm) eluted with an 11:1 mixture of toluene and acetone, affording 4-acetylamino-2,5-dichloro-1-(1,1,2,3,3,3-hexafluoropropyloxy)benzene in the form of pale yellow crystals (m.p.: 93°-95° C.), 26 g of which are kept for 10 hours under reflux with 110 ml of ethanol and 35.6 ml of 37% hydrochloric acid. The reaction mixture is then concentrated, diluted with ice/water and made weakly alkaline. The product is extracted from the mixture with methylene chloride. The organic extract phase is washed with water, dried over Na2SO4 and concentrated. The residue is purified by distillation, thus affording the title compound of the formula ##STR12## as a colourless liquid with a boiling point of 81°-83° C./0.05 torr.

Quelle