The document describes the preparation of eugenol benzoate through the esterification of eugenol from clove oil with benzoyl chloride. The procedure involves: 1) dissolving clove oil in sodium hydroxide to deprotonate eugenol, 2) extracting the deprotonated eugenol with ether, 3) adding benzoyl chloride to form eugenol benzoate, 4) extracting the product with ether, and 5) recrystallizing eugenol benzoate from the ether solution. Percent yield of the product is calculated based on theoretical yield from the limiting reactant.

1. Preparation of
Eugenol Benzoate
(Steam Distillation Lab)

2. But first, a friendly reminder:
Wear them!
It's the LAW

3. Preparation of Eugenol Benzoate
Convert the eugenol present in clove oil to its benzoate ester:
O
O C O
OH
C Cl
OCH3 OCH3
+ NaOH
CH2CH=CH2 CH2CH=CH2
eugenol benzoyl chloride eugenol benzoate

4. Reaction Mechanism
O
+
O- Na
C Cl H3CO
OCH3
O
+ C O CH2CH=CH2
Cl
CH2CH=CH2
NaOH
H3CO
H
O O
OCH3 C O CH2CH=CH2
+ NaCl
CH2CH=CH2

5. Experimental Procedure
Step 1 – Acid/Base Reaction
OH +
O- Na
OCH3 OCH3
1) 1 mL H2O
+ other compounds + Other
2) NaOH
Compounds
(Unionized)
CH2CH=CH2 CH2CH=CH2
0.2 mL Convert to mass (g) by density. (Water soluble)
• Transfer 0.2 mL* of your clove oil into a clean, dry centrifuge tube.
• Add 1 mL of water to the centrifuge tube and then add 1M NaOH, drop by
drop, just until the oil dissolves.
• The solution may be cloudy, but no oil droplets should be visible.
* If you do not have enough clove oil, get some from your TA.

6. Experimental Procedure
Step 2 - Extraction of Salt
+ ether layer
O- Na other compounds
Discard in ether
OCH3 waste bottle
3 mL ether x 2
+ others +
O- Na
OCH3
CH2CH=CH2
aqueous layer
Ether layer
Remove it!
CH2CH=CH2
Aqueous layer
KEEP IT!!!!
(KEEP IT!)

7. Experimental Procedure
Step 3 – Extraction of Final Product
• TA adds 4-5 drops of benzoyl chloride to the centrifuge tube IN THE HOOD.
• Stopper and shake mixture thoroughly.
• Remove stopper and warm mixture for 5 minutes in hot water bath.
Use water aspirator to remove noxious fumes during heating.
(Your TA will show you how to set up a pipet aspirator.)
• After cooling, add 2 mL of ETHER to the centrifuge tube and shake.
• Allow the layers to separate. Ether layer KEEP IT!!
Aqueous layer
Discard!!!! Use
pipet to remove
• Dry ether layer with a small amount of Na2SO4.

8. Experimental Procedure
Step 4 – Recrystallization
• Filter the ether layer through a cotton plugged
pipet into another test tube.
• Add 1 mL methanol then reduce the solution
volume to ~0.5 mL by using a hot water bath.
• Cool the remaining solution and scratch
glass to crystallize.
• Collect and dry the crystals.
• Determine the mp and mass of eugenol
benzoate.
Remember!!!
Calculate % recovery of eugenol and determine mp and % yield of eugenol
benzoate. Submit your product in a sample vial as instructed by your TA.

9. Percent Yield
( Actual Mass / Theoretical Mass ) X 100% = % Yield
The theoretical yield value always relates to one of the reactants (the limiting one),
taking into account the molar relation of the reactants and the stoichiometry of the
reaction.
For this lab, you need to determine the mass of eugenol from its density:
Density = Mass / Volume >>> Mass = Density X Volume
O
O
OH C O
C Cl
OCH3 OCH3
+ NaOH
CH2CH=CH2 CH2CH=CH2
0.2 mL -> g -> mol mol -> g (Theoretical mass)