Ethyl benzoate and p-Cymene

November 22, 2021
We’re all about the berries.
What molecules are we?
Image of Ethyl benzoate

November is flavor and aroma month at MOTW!

It’s almost Thanksgiving! Among the holiday treats that most of us enjoy is cranberry sauce, whether it’s full of whole berries or simply a wiggly gelatin. What compounds are in cranberries that make the sauce taste so good?

According to the Science and Food program at the University of California, Los Angeles, the primary flavor compounds are ethyl benzoate, p-cymene, α-terpineol, and 1,8-cineole (aka eucalyptol). The latter two are former Molecules of the Week, so the first two take center stage this year.

Ethyl benzoate is a simple ester of benzoic acid with a sweet, fruity aroma. It has been known since the late 19th century; it is found in fruits such as apples, bananas, cherries, and of course, cranberries. Synthetic ethyl benzoate is made by esterifying benzoic acid and ethanol with an acid catalyst such as hydrochloric or sulfuric acid. It is used as an ingredient in perfumes and artificial fruit-flavoring agents.

p-Cymene is a dialkyl aromatic hydrocarbon. In addition to being a flavor component in cranberries, it is abundant in several essential oils, notably the oils of cumin and thyme. Its aroma and flavor have been described as having hints of citrus, earth, and wood. It can be synthesized from petrochemicals (e.g., the alkylation of toluene with propylene) or from natural terpenes (e.g., by microwave irradiation of limonene). Like ethyl benzoate, p-cymene is used as a flavoring agent; but it also has medicinal uses (in cough syrup) and as a starting material for manufacturing pesticides.

Needless to say, while you’re enjoying your Thanksgiving dinner, you won’t be focusing on any of this. Have a happy holiday!

Ethyl benzoate hazard information

Hazard class* GHS code and hazard statement
Flammable liquids, category 4 H227—Combustible liquid Chemical Safety Warning
Short-term (acute) aquatic hazard, category 2 H401—Toxic to aquatic life

p-Cymene hazard information**

Hazard class* GHS code and hazard statement
Flammable liquids, category 3 H226—Flammable liquid and vapor Chemical Safety Warning
Aspiration hazard, category 1 H304—May be fatal if swallowed and enters airways  Chemical Safety Warning
Skin corrosion/irritation, category 2 H315—Causes skin irritation Chemical Safety Warning
Serious eye damage/eye irritation, category 2A H319—Causes serious eye irritation Chemical Safety Warning
Specific target organ toxicity, single exposure, respiratory tract irritation category 3 H335—May cause respiratory irritation Chemical Safety Warning
Reproductive toxicity, category 2 H361—Suspected of damaging fertility or the unborn child Chemical Safety Warning
Short-term (acute) aquatic hazard, category 2 H401—Toxic to aquatic life
Long-term (chronic) aquatic hazard, category 2 H411—Toxic to aquatic life with long-lasting effects

*Globally Harmonized System (GHS) of Classification and Labeling of Chemicals. Explanation of pictograms.

**Compilation of selected safety data sheets.

These molecules were suggested by readers. We present almost all of the molecules suggested by our readers. If you have a molecule you would like us to consider, please send an e-mail to motw@acs.org. And thank you for your interest in Molecule of the Week! —Ed.


Ethyl benzoate 
fast facts

CAS Reg. No. 93-89-0
SciFinder
nomenclature
Benzoic acid, ethyl ester
Empirical formula C9H10O2
Molar mass 150.17 g/mol
Appearance Colorless liquid
Boiling point 212° C
Water solubility 0.7 g/L


p-Cymene 
fast facts

CAS Reg. No. 99-87-6
SciFinder
nomenclature
Benzene, 1-methyl-4-(1-methylethyl)-
Empirical formula C10H14
Molar mass 134.22 g/mol
Appearance Colorless liquid
Boiling point 177° C
Water solubility 23 mg/L
Chemical Abstract Service - a division of ACS

Learn more about this molecule from CAS, the most authoritative and comprehensive source for chemical information.

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