What is 1-phenyl cyclopentane carboxylic acid?
1-Phenylcyclopentanecarboxylic acid (abbreviated PCCA), CAS 77-55-4, is a carboxylic acid with the acid functionality and a phenyl group both attached to the same quaternary carbon atom of a cyclopentane ring. The carboxylic acid functional group allows conversion of PCCA into pentoxyverine, the active pharmaceutical ingredient.
It is not an active pharmaceutical ingredient itself. Instead, it is a pharmaceutical intermediate, a compound that is chemically modified during the production process to obtain the active pharmaceutical ingredient.
Chemical properties
1-Phenylcyclopentanecarboxylic acid contains a carboxylic acid functional group, which means it can undergo a wide range of different reactions. It can undergo esterification with alcohols, react with bases to form carboxylate salts and be reduced to the corresponding aldehyde or alcohol. The cyclopentane ring adds rigidity to the molecule, which influences how it reacts compared to linear carboxylic acids. The compound is soluble in organic solvents such as ethanol, ether and acetone. It has limited solubility in water.
Applications of PCCA
The primary application of PCCA is as an intermediate in the synthesis of pentoxyverine. Pentoxyverine is a non-opioid cough suppressant used for dry cough caused by colds and bronchitis. During the synthesis process, the acid chloride of PCCA is coupled with 2-[2-(diethylamino)ethoxy]ethanol to obtain pentoxyverine. Beyond pentoxyverine, PCCA is also used as a precursor in the development of other pharmacologically active structures, including isoxazole and isoxazoline derivatives.
For more information about the synthesis of pentoxyverine and the role of PCCA, read our blog: What is pentoxyverine and what role does PCCA play in its synthesis?
Read more about pharmaceutical intermediates and API production in our blog: What is a pharmaceutical intermediate and how is PCCA used in production?
PCCA is used as a building block in organic synthesis. Its cyclopentane ring and carboxylic acid group make it a useful starting material for producing a range of organic compounds, including agrochemicals and specialty chemicals. In order to achieve the desired reactivity during synthesis, PCCA is first converted into its acid chloride, usually with thionyl chloride (SOCl₂), oxalyl chloride (C₂O₂Cl₂) or phosphorus oxychloride (POCl₃).
PCCA is sometimes used to functionalise specialty polymers. For example, cellulose diacetate, a green polymer, has been functionalised with PCCA to enhance thermoplasticity and lower the glass transition temperature.[1]
Reference:
[1] M. Boulven et al., Carbohydrate Polymers 2019, 206, 674-684
PCCA is used in laboratory settings as a model compound for studying the reactivity of cyclic carboxylic acids. It is a standard reference material for researchers working on cyclopentane-based chemistry.
Technical specifications
| Property | Value |
|---|---|
| Chemical name | 1-Phenyl-1-cyclopentanecarboxylic acid |
| CAS number | 77-55-4 |
| Molecular formula | C₁₂H₁₄O₂ |
| Molecular weight | 190.24 g/mol |
| Purity | ≥ 98.0% |
| Melting range | 159–161°C |
| Solubility | Clear solution in DMF (2.5%) |
| Product form | Powder |
| Dangerous goods | No |
Safety and handling
PCCA is not classified as a dangerous good. Standard laboratory and industrial hygiene practices apply. Avoid prolonged skin contact and inhalation of dust. Wear gloves and safety glasses when handling the powder. Work in a well-ventilated area. Store in a cool, dry place, away from strong oxidizing agents. Keep containers tightly closed.
A Safety Data Sheet (SDS) is available upon request.
Frequently asked questions
PCCA is primarily used as a pharmaceutical intermediate in the synthesis of pentoxyverine, a cough suppressant. It is also used in organic synthesis, polymer chemistry and laboratory research.
No. Cyclopentanecarboxylic acid (CAS 3400-45-1) is a simpler compound with only a cyclopentane ring and a carboxylic acid group. PCCA (CAS 77-55-4) also has a phenyl group attached to the same carbon as the carboxylic acid group. This makes them chemically different compounds with different applications.
Partners in Chemicals supplies PCCA at a minimum purity of 98.0%.
PCCA is supplied as a powder with a melting range of 159–161°C.
No. PCCA is not classified as a dangerous good under standard storage and transport conditions.
No. PCCA is a pharmaceutical intermediate, not an active pharmaceutical ingredient (API). It is used in the production process and is chemically modified before it reaches the final formulation.
Disclaimer
The information provided on this page is based on current knowledge and intended for general guidance. 1-Phenylcyclopentanecarboxylic acid (PCCA) should be tested in the specific application to confirm suitability, performance and compliance with regulatory requirements. While every effort has been made to ensure accuracy, Partners in Chemicals makes no representations or warranties regarding the completeness, reliability or suitability of the content. Users should verify details and consult official datasheets or regulatory guidance when making technical or industrial decisions.