2-isobutyl quinoline

2-Isobutyl quinoline is a chemical compound classified as a quinoline derivative, consisting of a quinoline ring substituted at the 2-position with an isobutyl group. It has the molecular formula C₁₃H₁₅N and appears as a colorless to pale liquid with a distinctive and potent odor profile. The compound exhibits an animalic, leather-like scent with woody, rooty, and tobacco notes, making it valued in fragrance applications. Synonyms include 2-(2-methylpropyl)quinoline, quinoline, 2-isobutyl-, and iso butylquinoline. It can be sourced synthetically, and is registered under several chemical databases such as PubChem, under CID 7130. Due to its intense aroma and long-lasting substantivity, it finds use primarily in perfumery rather than flavoring, despite some flavor notes being noted.

Although 2-isobutyl quinoline does not naturally occur in significant quantities, it is widely utilized as a synthetic fragrance ingredient in the perfume industry. It is particularly effective in chypre, leather, and woody fragrance compositions, contributing a strong animalic and leather character. Its long-lasting odor intensity makes it suitable for masculine colognes and complex accords involving tobacco, moss, and amber notes. The compound is included in the IFRA (Global) Code of Practice, which recommends usage limits to ensure safe formulation practices. It is not typically used for flavoring purposes, with its primary applications focused on perfuming agents and fragrance concentrates within cosmetic products.

2-Isobutyl quinoline has a molecular weight of approximately 185.27 g/mol and a boiling point range of 277 to 278°C at atmospheric pressure (760 mm Hg). Its flash point is relatively high at 232°F (about 111°C), suggesting moderate flammability under typical handling conditions. The compound has a low vapor pressure of 0.0013 mmHg at 20°C, indicating low volatility. It is soluble in alcohol and sparingly soluble in water, with a measured solubility of 225 mg/L at 20°C. The estimated partition coefficient (log P) is around 3.95, reflecting moderate lipophilicity that could affect its distribution in formulations. These properties influence its handling, formulation stability, and release characteristics in fragrance products.

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Safety information

European information :
Most important hazard(s):
Xi - Irritant
R 36/37/38 - Irritating to eyes, respiratory system, and skin. S 02 - Keep out of the reach of children. S 26 - In case of contact with eyes, rinse immediately with plenty of water and seek medical advice. S 36/37 - Wear suitable protective clothing and gloves.
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:
oral-rat LD50 1020 mg/kg Food and Cosmetics Toxicology. Vol. 14, Pg. 311, 1976.
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-isobutyl quinoline usage levels up to:
	2.0000 % in the fragrance concentrate.
Recommendation for 2-isobutyl quinoline flavor usage levels up to:
	not for flavor use.

Safety references

EPI System: View

AIDS Citations:Search

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Toxicology Citations:Search

EPA Substance Registry Services (TSCA):93-19-6

EPA ACToR:Toxicology Data

EPA Substance Registry Services (SRS):Registry

Laboratory Chemical Safety Summary :7130

National Institute of Allergy and Infectious Diseases:Data

WGK Germany:2

2-(2-methylpropyl)quinoline

Chemidplus:0000093196