2-pentyl cyclopentanone

2-pentyl cyclopentanone is a ketone chemical featuring the molecular formula C₁₀H₁₈O. It appears as a colorless to pale liquid notable for its complex floral odor, predominantly jasmine, combined with green, herbal, and lactonic hints. Also referred to by synonyms such as amyl cyclopentanone and by trade names like Delphone (Firmenich), it serves as a significant fragrance ingredient. Structural and chemical data are documented in public repositories such as PubChem. This compound derives mainly through synthetic organic methods targeting cyclopentanone derivatives, optimized for aroma applications. It finds use in creating nuanced floral and fruity scent profiles in perfumery.

2-pentyl cyclopentanone does not occur naturally in known biological sources but is valued in fragrance chemistry for its white floral enhancing characteristics. It has powerful diffusion and is used widely as a white floral booster in premium perfumes and fine fragrances. The compound also contributes beneficially to odor profiles like celery, fern, green notes, and subtle fruity nuances including peach and mango. It is recognized under the IFRA (Global) standard, which recommends usage levels up to one percent in fragrance concentrates for safety and regulatory compliance.

The compound exhibits moderate lipophilicity with an estimated log P around 2.87, indicating reasonable solubility in organic solvents and low aqueous solubility (~193 mg/L at 25°C). Its boiling range is narrowly defined between 216 and 217°C at atmospheric pressure (760 mm Hg), with a high flash point of 208°F, supporting stability under typical fragrance formulation conditions. Vapor pressure at 25°C is low (~0.13 mmHg), facilitating persistent scent release. Acid value is low, suggesting chemical stability and low acidity. Compatibility tests indicate trace-level application thresholds across various product categories like detergents and fine fragrances, reflecting controlled stability and limited degradation risk during use.

(IUPAC):	Atomic Weights of the Elements 2011 (pdf)
Videos:	The Periodic Table of Videos
tgsc:	Atomic Weights use for this web site
(IUPAC):	Periodic Table of the Elements
HMDB (The Human Metabolome Database):	Search
ChemSpider:	View

Safety information

Preferred SDS: View
European information :
Most important hazard(s):
Xi - Irritant
R 36/38 - Irritating to skin and eyes. S 02 - Keep out of the reach of children. S 24/25 - Avoid contact with skin and eyes. S 26 - In case of contact with eyes, rinse immediately with plenty of water and seek medical advice. S 37/39 - Wear suitable gloves and eye/face protection.
Hazards identification
Classification of the substance or mixture
GHS Classification in accordance with 29 CFR 1910 (OSHA HCS)
None found.
GHS Label elements, including precautionary statements
Pictogram
Hazard statement(s)
None found.
Precautionary statement(s)
None found.
Oral/Parenteral Toxicity:
Not determined
Dermal Toxicity:
Not determined
Inhalation Toxicity:
Not determined

Safety in use information

Category:
fragrance agents
RIFM Fragrance Material Safety Assessment: Search
IFRA Code of Practice Notification of the 49th Amendment to the IFRA Code of Practice
Recommendation for 2-pentyl cyclopentanone usage levels up to:
	1.0000 % in the fragrance concentrate.
Recommendation for 2-pentyl cyclopentanone flavor usage levels up to:
	not for flavor use.

Safety references

EPI System: View

AIDS Citations:Search

Cancer Citations:Search

Toxicology Citations:Search

EPA Substance Registry Services (TSCA):4819-67-4

EPA ACToR:Toxicology Data

EPA Substance Registry Services (SRS):Registry

Laboratory Chemical Safety Summary :20959

National Institute of Allergy and Infectious Diseases:Data

WGK Germany:2

2-pentylcyclopentan-1-one

Chemidplus:0004819674