Extraction of Eugenol from Cloves Oil
Isolation of Acetyleugenol (Clove Oil) from Cloves
Purpose
In this experiment, you will obtain the essential oil from cloves by steam distillation.
You will then separate a component (acetyleugenol) from the oil by liquid-liquid extraction.
Finally, you will isolate the acetyleugenol by using a rotovap for reduced pressure distillation, which will remove the organic solvent (dichloromethane).
Background
Whole cloves contain between 14% and 20% by weight of essential oils, but only half of that can be isolated as acetyleugenol.
Clove oil contains two basic compounds: eugenol and acetyleugenol.
As a result of Dalton’s Law and Raoult’s Law, both of these substances can be removed from the cloves with a steam distillation.
Eugenol is polar due to the acidic hydroxyl (OH) group, but acetyleugenol is not polar.
As a result, they can be separated by extraction from a 5% aqueous NaOH solution. Acetyleugenol will dissolve in the organic CH2Cl2 layer, while eugenol remains in the aqueous base layer as a phenoxide. This can be seen in the reaction below (where ArOH is eugenol), because dissolved ions prefer the aqueous phase.
ArOH(aq) + OH-(aq) ArO-(aq) + H2O(Liq)
Acetyleugenol has no acid proton, and cannot ionize. So, it prefers the organic phase.
Essential oils from plant materials are used today for medicinal and other purposes.
Among these oils are camphor, quinine, oil of cloves, cedarwood, turpentine, cinnamon, gum benzoin, and myrrh. The U.S. FDA has declared clove oil to be the most effective remedy for a toothache. Substances
25 g whole cloves (350 g per lab section)
100 ml DI water (1.5 L per lab section)
10 ml 5% NaOH (150 ml per lab section)
45 ml CH2Cl2 (650 ml per lab section)
Mg SO4 or Na2SO4 (anhydrous)
Apparatus
Items in kit
250-ml round-bottomed flask distillation head thermometer adapter large bore condenser
Claisen adapter
125-ml separatory funnel
Items not in
Purpose
In this experiment, you will obtain the essential oil from cloves by steam distillation.
You will then separate a component (acetyleugenol) from the oil by liquid-liquid extraction.
Finally, you will isolate the acetyleugenol by using a rotovap for reduced pressure distillation, which will remove the organic solvent (dichloromethane).
Background
Whole cloves contain between 14% and 20% by weight of essential oils, but only half of that can be isolated as acetyleugenol.
Clove oil contains two basic compounds: eugenol and acetyleugenol.
As a result of Dalton’s Law and Raoult’s Law, both of these substances can be removed from the cloves with a steam distillation.
Eugenol is polar due to the acidic hydroxyl (OH) group, but acetyleugenol is not polar.
As a result, they can be separated by extraction from a 5% aqueous NaOH solution. Acetyleugenol will dissolve in the organic CH2Cl2 layer, while eugenol remains in the aqueous base layer as a phenoxide. This can be seen in the reaction below (where ArOH is eugenol), because dissolved ions prefer the aqueous phase.
ArOH(aq) + OH-(aq) ArO-(aq) + H2O(Liq)
Acetyleugenol has no acid proton, and cannot ionize. So, it prefers the organic phase.
Essential oils from plant materials are used today for medicinal and other purposes.
Among these oils are camphor, quinine, oil of cloves, cedarwood, turpentine, cinnamon, gum benzoin, and myrrh. The U.S. FDA has declared clove oil to be the most effective remedy for a toothache. Substances
25 g whole cloves (350 g per lab section)
100 ml DI water (1.5 L per lab section)
10 ml 5% NaOH (150 ml per lab section)
45 ml CH2Cl2 (650 ml per lab section)
Mg SO4 or Na2SO4 (anhydrous)
Apparatus
Items in kit
250-ml round-bottomed flask distillation head thermometer adapter large bore condenser
Claisen adapter
125-ml separatory funnel
Items not in