反応 #487560

反応方程式

potassium iodide

sulfuric acid

5-bromo-2-ethylaniline

sodium nitrite

→

4-bromo-1-ethyl-2-iodobenzene

溶媒

water

water

water

反応条件

後処理

1. 1
   温度by brief heating
2. 2
   温度at reflux until dissolution
3. 3
   その他producing a fine precipitate
4. 4
   温度further cooled to approximately 0° C. in an ice/salt bath
5. 5
   温度maintaining a temperature below 5° C.
6. 6
   ろ過The reaction mixture is next filtered
7. 7
   workup.ADDITIONAfter the addition
8. 8
   温度is briefly heated to 80° C.
9. 9
   温度to cool to room temperature again
10. 10
    抽出The reaction mixture is extracted with ethyl acetate (3×50 ml)
11. 11
    洗浄the organic phase is washed with 1M aqueous hydrochloric acid (30 ml) and aqueous sodium thiosulfate (2×30 ml)
12. 12
    乾燥After drying over anhydrous magnesium sulfate and concentration in vacuo 4-bromo-1-ethyl-2-iodobenzene (4.90 g)
13. 13
    その他is furnished as an orange liquid

実験手順

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.

出典