Nitration

Locker # Compound Locker # Compound
1, 10, 20, 4 Bromobenzene 6, 16, 11 Chlorobenzene
2, 12, 22, 9 1,4-Dichlorobenzene 7, 17, 21 1,4-Dibromobenzene
3, 13, 23, 19 1,3-Dichlorobenzene 8, 18, 14 1,2 Dichlorobenzene
5, 15, 24 1-Bromo-4-chlorobenzene    


WEAR GLOVES


  1. Set-up a yellow hot plate in the hood and prepare an ice-water bath.
  2. In a 500mL Erlenmeyer flask add 20mL of nitric acid and 20mL of sulfuric acid, place your glass thermometer into the flask.
  3. If needed, adjust the temperature to 300 to 400C using the ice-water bath.
  4. Now slowly, with swirling, add 0.1 mole of the halobenzene. Keep the temperature between 300 and 600C.
  5. Heat the mixture on the hot plate for 30 minutes keeping the temperature between 600 and 1000C.
  6. Allow the mixture to cool to room temperature. You may use the ice-water bath to speed up the process.
  7. Put 150mL of water and 50mL of ice into a 400mL beaker.
  8. Carefully pour the contents of the 500mL Erlenmeyer flask into the 400mL beaker containing the cold water while stirring it with a glass rod.
  9. At this point you should see solid forming in the 400mL beaker. If not inform the instructor.
  10. Collect the solid using vacuum filtration and a small Buchner funnel.
  11. Wash the solid well with water.
  12. Recrystallize the solid by dissolving it in a minimum amount of boiling solvent and allowing the solution to cool slowly.
  13. Collect the crystals in a small Buchner funnel, scrape the crystals off the filter paper onto a watch glass and leave them in your drawer to dry.
  14. Do thin-layer chromatography on your solid.
    1. Dissolve a small amount of the product in acetone.
    2. Draw a line of origin on your tlc plate and spot the plate with your product and at least two known compounds.
    3. Develop the plate in hexane:chloroform.
    4. Read the plate in a UV light box and circle the spots.
    5. Calculate the Rf values for your products.
    6. Leave the crystals in your drawer to dry.
  15. Next Week: get the weight and determine the melting point range of your product,  compare it with the theoretical value.
  1. Package your product in a properly labeled sample vial and place it in the box.
  2. See "The Report" link on the web site for direction.

© Dr. Noel Sturm 2008