Sulfuric Acid → 4-Bromo-2-ethyl-1-iodobenzene

Temperatur

60 °C

To a stirred mixture of 4-bromo-2-ethylaniline (80 g, 0.4 mol) in distilled water (400 ml) is added concentrated sulphuric acid (80 ml), followed by brief heating to 60° C. for 1 hour until dissolution is complete. The mixture is allowed to cool to room temperature then further cooled to approximately 0° C. in an ice/salt bath. To this slurry is added an aqueous solution of sodium nitrite (28 g, 0.4 mol) in distilled water (140 ml) dropwise over 15 minutes, maintaining the temperature below 5° C., followed by additional stirring for 30 minutes. The reaction mixture is allowed to come to room temperature and then a solution of aqueous potassium iodide (199 g, 1.2 mol) in distilled water (200 ml) is added 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 (1000 ml×3) and the organic phase is washed with 1M aqueous hydrochloric acid (500 ml) and aqueous sodium thiosulfate (2×250 ml). The organic phase is dried over anhydrous sodium sulphate, filtered and the filtrate is concentrated under reduced pressure. The residue is purified by column chromatography on silica gel to give 4-bromo-2-ethyl-1-iodobenzene (84.6 g) as an orange liquid.

1. temperatureto cool to room temperature
2. temperaturethen further cooled to approximately 0° C. in an ice/salt bath
3. temperaturemaintaining the temperature below 5° C.
4. customto come to room temperature
5. additionAfter the addition
6. temperatureis briefly heated to 80° C.
7. temperatureto cool to room temperature again
8. extractionThe reaction mixture is extracted with ethyl acetate (1000 ml×3)
9. washthe organic phase is washed with 1M aqueous hydrochloric acid (500 ml) and aqueous sodium thiosulfate (2×250 ml)
10. dry with materialThe organic phase is dried over anhydrous sodium sulphate
11. filtrationfiltered
12. concentrationthe filtrate is concentrated under reduced pressure
13. customThe residue is purified by column chromatography on silica gel

ORD-Eintrag

ord-71a88018292c42719973778f4708924c

Quelldatensatz

uspto-grants-2014_11

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US08895761B2