Ethyl 3-phenylpropionate
[CAS# 2021-28-5]

Identification

• Classification: Flavors and spices >> Synthetic spice >> Carboxylic acid and ester perfume >> Aromatic carboxylic acid ester
• Name: Ethyl 3-phenylpropionate
• Synonyms: 3-Phenylpropionic acid ethyl ester; Ethyl hydrocinnamate
• Molecular Formula: C₁₁H₁₄O₂
• Molecular Weight: 178.23
• CAS Registry Number: 2021-28-5
• EC Number: 217-966-6
• FEMA: 2455
• SMILES: CCOC(=O)CCC1=CC=CC=C1

Properties

• Density: 1.0±0.1 g/cm³ Calc.^*, 1.015 g/mL (Expl.)
• Boiling point: 245.9±9.0 ºC 760 mmHg (Calc.)^*, 247 - 248 ºC (Expl.)
• Flash point: 107.8 ºC (Calc.)^*, 108 ºC (Expl.)
• Solubility: water <0.1 g/100 mL (25 ºC) (Expl.)
• Index of refraction: 1.499 (Calc.)^*, 1.494 (Expl.)

^* Calculated using Advanced Chemistry Development (ACD/Labs) Software.

Safety Data

• Hazard Symbols: GHS07 Warning
• Hazard Statements: H302
• Precautionary Statements: P280-P305+P351+P338

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Specific target organ toxicity - single exposure	STOT SE	3	H335
Skin irritation	Skin Irrit.	2	H315
Eye irritation	Eye Irrit.	2	H319

Discovory and Applicatios

Ethyl 3-phenylpropionate is an aromatic ester belonging to the family of phenylpropanoate derivatives. Structurally, it consists of a benzene ring attached to a three-carbon propionate chain, which is then esterified with an ethyl group. The compound is a colorless to pale yellow liquid with a pleasant, sweet, fruity odor that resembles honey, floral notes, and balsamic undertones. Its fragrance profile and stability have made it an important substance in the flavor and fragrance industries.

The compound was first identified during early research into phenylpropanoic acid derivatives and their esters, as scientists investigated how structural variations influenced odor characteristics. By the mid-20th century, ethyl 3-phenylpropionate was being widely adopted in perfumery and food flavorings due to its natural, sweet scent and low volatility, which allows it to provide lasting notes in formulated products.

In practical applications, ethyl 3-phenylpropionate is primarily used in perfumes, soaps, detergents, and cosmetic products. Its aroma profile makes it a popular choice for floral, fruity, and oriental fragrance compositions, often used to impart honey- and jasmine-like effects. In addition to perfumery, it is employed as a flavoring agent in foods, beverages, and confectionery, where it contributes to sweet, fruity nuances at very low concentrations.

From a chemical perspective, ethyl 3-phenylpropionate is synthesized through esterification of 3-phenylpropionic acid with ethanol, typically catalyzed by an acid such as sulfuric acid. Alternative synthetic routes involve enzymatic esterification using lipases, which offer high selectivity and operate under milder conditions. These biocatalytic approaches have gained attention in recent years as more sustainable methods of producing esters for use in the fragrance and flavor industries.

The chemical stability of ethyl 3-phenylpropionate is one of the reasons for its popularity in product formulations. It resists hydrolysis under neutral conditions, although strong acids or bases can cleave the ester bond to regenerate 3-phenylpropionic acid and ethanol. Its aromatic structure contributes to stability against oxidation, allowing the compound to retain its olfactory properties over time.

Toxicological studies indicate that ethyl 3-phenylpropionate is generally safe for use in consumer products at regulated concentrations. It has been evaluated for dermal and oral exposure, showing low acute toxicity and minimal sensitization potential when used within established safety guidelines. Regulatory organizations, including the Flavor and Extract Manufacturers Association (FEMA) and the International Fragrance Association (IFRA), recognize the compound as safe for use in flavors and fragrances under controlled conditions.

Beyond its industrial use in perfumery and food products, ethyl 3-phenylpropionate has also served as a useful chemical intermediate in organic synthesis. Its ester group allows for transformations such as hydrolysis, reduction, and transesterification, while the phenylpropyl moiety offers a framework for further functionalization. These properties make it a versatile starting material in the preparation of more complex organic molecules, including analogues of bioactive compounds.

Through its discovery, characterization, and broad adoption in multiple industries, ethyl 3-phenylpropionate has established itself as both a practical and versatile substance. Its pleasant odor, ease of synthesis, stability, and safety profile continue to secure its role in fragrances, flavors, and as a building block in organic chemistry.

References

2023. The LOTUS Initiative for Open Natural Products Research: frozen dataset union wikidata (with metadata).
DOI: 10.5281/zenodo.5794106

2024. Volatile compositions and sensorial properties of strawberry fruit wines fermented with Torulaspora delbrueckii and Saccharomyces cerevisiae in sequential and simultaneous inoculations. European Food Research and Technology.
DOI: 10.1007/s00217-024-04581-1

2025. Metabolomics in Food Fermentation and Designing Functional Foods. Microbial Metabolomics.
DOI: 10.1007/978-981-96-4824-5_11