Introduction
By performing steam distillation we can isolate eugenol at lower temperature than its usual boiling point of 248 degree Celsius. Eugenol belongs to a category called essential oil. Many of these compounds are used as flavoring and perfumes and in the past were considered the essence of plant from which they were derived.
Structure of eugenol (clove oil) and eugenol acetate:
Reagents:
Eugenol, CH2Cl2, Br2, FeCl3, Methanol
Procedure:
Co-distillation
We first combine 15 mL of water with 1 g of crushed, ground cloves in a 25-mL round-bottom flask. Then added a spin bar to the 25-mL round-bottom flask and assembled the microscale distillation apparatus. We made certain that the ground cloves were well wetted. We maintained the temperature of the sand bath at approximately 130 °C and wrapped the bottom of the still with aluminum foil. Then periodically transfer the distillate from the Hickman head to a 15 mL screw cap centrifuge tube and continue the steam distillation until 5–8 mL of distillate have been collected. Then we started the extraction process by adding 2 mL of CH2Cl3 to the water–eugenol emulsion. Cap the tube and shake it frequently. We then allowed the layers to separate and transferred the CH2Cl2–eugenol solution to a clean, dry 5- mL conical vial. We made sure no water was transferred in this step. Then we added 1 mL of CH2Cl2 to the water–eugenol emulsion, cap and shake the tube. Allowed the layers to separate and transfer the CH2Cl2–eugenol solution to the 5-mL vial used previously and made certain that no water is transferred during this step. We then added 1 mL of CH2Cl2 to the water–eugenol emulsion and shook the tube. We allowed the layers to separate and transferred the CH2Cl2–eugenol solution to the 5-mL vial used in previous step. We made
References: Introduction to Organic Laboratory Techniques: A Microscale Approach. Pavia, Lampman, Kriz, and Engel. (1999) Saunders College Publishing.