In the Laboratory
Cinnamaldehyde by Steam Distillation of Cinnamon Douglass F. Taber* and Andrew J. Weiss Department of Chemistry, University of Delaware, Newark, DE 19716
Steam distillation has commonly been used in the undergraduate organic chemistry laboratory to separate the volatile components of cumin, cloves, and caraway (1). We have wanted to add cinnamon to this list, in order to obtain its essential oil, cinnamaldehyde (1), but have found that this spice foams badly on attempted distillation. O H
1
We thought that the foaming might be due to the open pore structure of the bark as opposed to the dense seed matter and/or leaves and berries of the other spices. Indeed, we have now found evacuating the flask containing the water and cinnamon mixture draws the air out of the pores; on release of the vacuum, water flows in to take its place. The resulting treated cinnamon slurry is then ready to be distilled.
Procedure Ten grams of cinnamon was placed in the boiling flask and a tight-fitting ground-glass hose adapter was placed in the neck with a hose attached to the aspirator vacuum and the flask. The pump was turned on, and the flask was lightly agitated to produce foaming of the mixture. As soon as the foaming reached the top of the flask, the vacuum was released. The contents were allowed to settle, and then the process was repeated until no foaming was observed. The steam distillation could then be performed without incident. The impure cinnamaldehyde can be further characterized as its semicarbazone, mp 215 °C (2). Literature Cited 1. Bell, C.; Clark, A.; Taber, D.; Rodig, O. Organic Chemistry Laboratory: Standard and Microscale Experiments, 2nd ed.; Saunders College: Philadelphia, 1996; pp 153–165. 2. Fieser, L. F. Organic Experiments; Heath: Boston, 1964; p 99.
*Corresponding author.
JChemEd.chem.wisc.edu • Vol. 75 No. 5 May 1998 • Journal of Chemical Education
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