3-Phenylpropionic acid
[CAS# 501-52-0]

Identification

• Classification: Flavors and spices >> Synthetic spice >> Aromatic cinnamic acid, esters and derivatives
• Name: 3-Phenylpropionic acid
• Synonyms: Hydrocinnamic acid; 3-Phenylpropanoic acid; beta-Phenylpropionic acid
• Molecular Formula: C₉H₁₀O₂
• Molecular Weight: 150.18
• CAS Registry Number: 501-52-0
• EC Number: 207-924-5
• FEMA: 2889
• SMILES: C1=CC=C(C=C1)CCC(=O)O

Properties

• Density: 1.1±0.1 g/mL, Calc.^*, 1.071 g/mL (Expl.)
• Melting point: 45-48 °C (Expl.)
• Index of Refraction: 1.542, Calc.^*
• Boiling Point: 280.0 °C (760 mmHg), Calc.^*, 280 °C (Expl.)
• Flash Point: 170.0±13.9 °C, Calc.^*, 113 °C (Expl.)

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

Safety Data

• Hazard Symbols: GHS07 Warning
• Risk Statements: H315-H319-H335
• Safety Statements: P261-P305+P351+P338

Hazard Classification

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

Discovery and Applications

3-Phenylpropionic acid is an organic compound with the molecular formula C9H10O2. It is a derivative of propionic acid, where a phenyl group (C6H5) is attached to the β-carbon of the propionic acid chain. The compound appears as a white to light beige crystalline solid with a slightly sweet, aromatic odor.

The discovery and synthesis of 3-phenylpropionic acid date back to the early 20th century, with its structure and properties becoming more clearly understood through the development of organic chemistry. It is typically produced through various methods, including the Friedel-Crafts acylation of benzene with acetic acid or acetic anhydride in the presence of a catalyst, or by the catalytic hydrogenation of cinnamic acid.

3-Phenylpropionic acid has diverse applications in both the chemical and pharmaceutical industries. One of its most prominent applications is as a building block in the synthesis of more complex organic compounds. It is used in the production of various pharmaceuticals, where it serves as a precursor for compounds with antimicrobial, anti-inflammatory, and anti-cancer properties. Additionally, it is involved in the synthesis of various aromatic compounds that have utility in the production of polymers, fragrances, and plastics.

In the fragrance industry, 3-phenylpropionic acid is valued for its mild, floral, and sweet aroma, which can be used in the creation of perfumes, soaps, and cosmetic products. It is commonly used as a fixative to help extend the longevity of other fragrance components.

Beyond these applications, 3-phenylpropionic acid is also used in the synthesis of certain agrochemicals and specialty chemicals. It is an intermediate in the production of various herbicides and insecticides, contributing to crop protection products.

In terms of safety, 3-phenylpropionic acid is regarded as having low toxicity in its typical uses. It is essential, however, to adhere to safety guidelines when handling the compound, as prolonged exposure to high concentrations may cause irritation or adverse reactions.

In summary, 3-phenylpropionic acid is an important chemical with applications in pharmaceuticals, fragrances, agrochemicals, and other industries. Its role as a versatile building block in organic synthesis and its use in consumer products make it an important compound in the field of chemistry.

References

2019. Factors affecting intake, metabolism and health benefits of phenolic acids: do we understand individual variability? European Journal of Nutrition.
DOI: 10.1007/s00394-019-01987-6

2009. 3-Hydroxyphenylpropionate and Phenylpropionate Are Synergistic Activators of the MhpR Transcriptional Regulator from Escherichia coli. The Journal of biological chemistry.
DOI: 10.1074/jbc.m109.008243

2002. Synthesis of Cyclic Prodrugs of Aggrastat and Its Analogue with a Modified Phenylpropionic Acid Linker. Organic Letters.
DOI: 10.1021/ol010282n