Reaktion #487560

Reaktionsgleichung

potassium iodide

sulfuric acid

5-bromo-2-ethylaniline

sodium nitrite

→

4-bromo-1-ethyl-2-iodobenzene

Lösungsmittel

water

water

water

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturby brief heating
2. 2
   Temperaturat reflux until dissolution
3. 3
   Sonstigeproducing a fine precipitate
4. 4
   Temperaturfurther cooled to approximately 0° C. in an ice/salt bath
5. 5
   Temperaturmaintaining a temperature below 5° C.
6. 6
   FiltrationThe reaction mixture is next filtered
7. 7
   workup.ADDITIONAfter the addition
8. 8
   Temperaturis briefly heated to 80° C.
9. 9
   Temperaturto cool to room temperature again
10. 10
    ExtraktionThe reaction mixture is extracted with ethyl acetate (3×50 ml)
11. 11
    Waschenthe organic phase is washed with 1M aqueous hydrochloric acid (30 ml) and aqueous sodium thiosulfate (2×30 ml)
12. 12
    TrocknenAfter drying over anhydrous magnesium sulfate and concentration in vacuo 4-bromo-1-ethyl-2-iodobenzene (4.90 g)
13. 13
    Sonstigeis furnished as an orange liquid

Vorschrift

To a stirred mixture of 5-bromo-2-ethylaniline (3.39 g, 200 mmol) in distilled water (110 ml) is added concentrated sulfuric acid (5.60 ml), followed by brief heating at reflux until dissolution. The mixture is allowed to cool to room temperature, producing a fine precipitate, then further cooled to approximately 0° C. in an ice/salt bath. To this slurry is added an aqueous solution of sodium nitrite (1.17 g, 16.94 mmol) in distilled water (10 ml) dropwise over 15 minutes, maintaining a temperature below 5° C., followed by additional stirring for 30 minutes. The reaction mixture is next filtered then added to a second solution of aqueous potassium iodide (8.44 g, 50.83 mmol) in distilled water (45 ml) dropwise at room temperature. After the addition is complete the solution is briefly heated to 80° C. then allowed to cool to room temperature again. The reaction mixture is extracted with ethyl acetate (3×50 ml), and the organic phase is washed with 1M aqueous hydrochloric acid (30 ml) and aqueous sodium thiosulfate (2×30 ml). After drying over anhydrous magnesium sulfate and concentration in vacuo 4-bromo-1-ethyl-2-iodobenzene (4.90 g) is furnished as an orange liquid.

Quelle