Preparation of Artificial Flavorings and Fragrances

Kammin, Sandra Resurrection Lutheran School

Objectives 1. To ignite the spark of learning which is latent in the depths of the student's mind. 2. To allow the students an opportunity to learn the practical aspects of Chemistry. 3. The students will be able to correctly write a laboratory report. 4. The student will prepare several kind of fragrant ester molecules. 5. The student will develop the skill of naming esters. Apparatus Needed: 1. Salicylic acid (C7H6O3).
2. Butyric acid (C4H8O2).
3. Glacial acetic acid (100% acetic acid CH3COOH).
4. b-Naphthol or 2-Naphthol (C10H8O).
5. Sulfuric acid (H2SO4).
6. n-Amyl alcohol (1-pentanol, C5H11OH).
7. n-Octyl alcohol (1-octanol, C8H17OH).
8. Methyl alcohol (methanol, CH3OH).
9. Ethyl alcohol (ethanol, C2H5OH).
10. Beaker for water bath.
11. Test tubes.
12. Graduated cylinders, 10 mL.
13. Hot plate.
14. Labels.
15. Stirring rods.
16. Test tube holders.
17. Droppers.

Recommended Strategy: Caution: Be careful with the acetic and sulfuric acids. Wear gloves and goggles. Also extinguish all flames in the room because the alcohols are flammable. 1. Prepare a water bath by filling a 250 mL beaker half full with water and heating it. 2. Look at the table to find an acid and an alcohol that you will combine. ---------------------------------------------------------------------- TUBE ALCOHOL ACID ESTER FRAGRANCE ---------------------------------------------------------------------- 1 n-amyl alcohol butyric acid apricot 2 n-amyl alcohol salicylic acid pineapple 3 n-amyl alcohol glacial acetic acid banana 4 n-octyl alcohol glacial acetic acid fruity 5 methyl alcohol salicylic acid wintergreen 6 methyl alcohol 2-naphthol perfume 7 ethyl alcohol butyric acid apple 8 ethyl alcohol glacial acetic acid fruity 3. Place 2 mL of the alcohol from the table for each ester chosen in a test tube. Label the tube. 4. If the acid is a liquid, add 2 mL of it to the alcohol in the tube. If it is a solid, add 1g of it. 5. The teacher will add 1 mL of concentrated sulfuric acid to the tube. 6. Stir slightly and then place the test tube in a boiling water bath. 7. After a few minutes check the tubes for fragrances by waving a little of the vapor toward you. If you fail to detect an odor, pour the content of the test tube into a beaker containing 25 to 50 mL of warm water. REACTION: An ester molecule is formed when an alcohol molecule and an organic acid molecule come together and a water molecule is released: RCOOH + HOR'-------> RCOOR' + H2O
organic acid alcohol ester water

The carbon group R stands for the rest of the acid molecule, and
the carbon group R' stands for the rest of the alcohol molecule.
Esters are named by first giving the alcohol name and then the
acid name, which is changed to have an ATE suffix instead of an
IC suffix. For example, ethyl alcohol with acetic acid produces
ethyl acetate.
Read the labels on artificially flavored foods and candies to
find additives that are esters.


1. Describe the odor of the ester produced in each tube you tested.
2. Use the guide in the Reaction section to write the reaction for
the ester you produced.
3. Name the ester you produced.
4. Why was sulfuric acid used?

References: Bird, Harold, Jr. Laboratory Studies in General, Organic and Biological Chemistry, Freeman 1972 pp. 407-11.

Jarvis, Bruce and Paul Mazzocchi, Form and Function: An Organic Module. Harper and Row: New York, 1978 pp. 68-70.
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