1. Preparation of N,N-Diethyl-m-toluamide
The Insect Repellent “OFF”

2. Reaction 1: Production of acid chloride
+ SOCl2
+ HCl + SO2
m-toluic acid thionyl m-toluoyl chloride
chloride

3. Reaction 2: Production of N,N-Diethyl-m-toluamide “OFF”+
+HCl
m-Toluoyl chloride Diethylamine N,N-Diethyl-m-toluamide

4. Special concerns All glassware must be dry!
Be sure you are using anhydrous ether.

5. safety concerns for using thionyl chloride and diethylamine
Dispense thionyl chloride and diethylamine in the hood.
Keep the bottles closed when not in use
Stopper test tubes when transferring chemicals to your hood
Cool diethylamine prior to using

6. Procedure Assemble apparatus in the hood
Add 1.81 g m-toluic acid (3-methylbenzoic acid) into a dry RBF
Use a dry graduated pipette to transfer 2.0 mL of thionyl chloride into a test tube. STOPPER THE TEST TUBE BEFORE BRINGING IT TO YOUR HOOD.
Remove the rubber septum and use a Pasteur pipet to add thionyl chloride to the RBF
Add a boiling stone, reattach the rubber septum them reflux the mixture for 15 minutes
Raise the apparatus from the heating mantle and let flask cool to RT

7. Procedure continued
Remove septum and add 25.0 mL of anhydrous ether to the reaction flask
Reattach septum and swirl mixture until it is homogeneous
Put 4.5 mL of ice-cold diethylamine in a small Erlenmeyer flask with 8 mL of anhydrous ether
Use a dry syringe to draw up diethylamine mixture and inject the solution into the RBF dropwise over minutes through the rubber septum
Swirl mixture occasionally
Once all the diethylamine is added swirl the mixture occasionally for 10 minutes.
Remove septum and add 14 mL 10% aqueous sodium hydroxide to the reaction flask in small portions.
Swirl the flask occasionally for 15 minutes

8. Procedure continued: Extraction of product
Disassemble glassware and transfer liquid to a separatory funnel
Invert funnel for 2-3 minutes
Remove and discard aqueous layer
Add another 14 mL of 10% sodium hydroxide to the funnel, shake for 2-3 minutes, remove and discard aqueous layer
Add 14 mL 10% HCl to the separatory funnel, shake, remove and discard aqueous layer
Add 14 mL water to the separatory funnel, shake, remove and discard aqueous layer
Transfer ether layer to a dry Erlenmeyer flask and dry with granular anhydrous sodium sulfate
Decant ether into another dry preweighed flask. Use a small amount of ether to rinse the drying agent.
Evaporate ether
Weight flask with product to determine yield

9. Column chromatography

11. How does column chromatography work?

12. Column chromatography
Clamp column vertically to wall of hood
Weigh out 7.3 grams of alumina
Place 14 mL hexane into a 125 mL Erylenmeyer flask
Swirl hexane while incrementally adding the 7.3 g alumina
Stir mixture with pipette then quickly pipette or pour slurry onto the column
Collect hexane in a flask
Preweigh collection beaker
Dissolve product in 2 mL hexane
When solvent level begins to enter alumina carefully add solution of N,N-diethyl-m- toluamide and hexane with a Pasteur pipette
Once mixture in on column add rinse product flask with 4 mL hexane and add to the column with pipette
Once wash mixture is on column add 14 mL hexane in small portions to the column to elute the N,N-diethyl-m- toluamide
Collect all the eluting liquid in the preweighed beaker
Evaporate hexane using a stream of air and heat
Determine yield and obtain an FTIR

13. Additional information
Remove a small amount of crude product prior chromatography for a back up FTIR.
Do not let column run dry!
Dispose of N,N-Diethyl-m-toluamide in the container provided.