2-methyl-5-propyl thiophene

2-methyl-5-propyl thiophene is a heterocyclic organic compound belonging to the thiophene family. Its molecular formula is C₈H₁₂S, indicating a sulfur-containing five-membered ring with alkyl substituents at the 2 and 5 positions, specifically a methyl group and a propyl group, respectively. The compound appears as a colorless liquid with a characteristic alliaceous odor reminiscent of onions, aligning it with sulfur-containing flavor compounds. Synonymously known as 2-methyl-5-propylthiophene or thiophene, 2-methyl-5-propyl-, it is classified under organosulfur compounds with notable olfactory properties. Industrially and scientifically, it is primarily sourced via chemical synthesis as part of research into thiophene derivatives. Further detailed chemical information can be accessed through controlled-vocabulary resources such as PubChem.

This compound occurs as a synthetic organosulfur material with an alliaceous sensory profile. It does not naturally occur in significant amounts in biological sources but is studied for its distinctive sensory characteristics similar to those found in onions and related vegetables. The current documented applications of 2-methyl-5-propyl thiophene are informational and research-related; it is not used commercially in fragrance or flavor formulations. According to regulatory standards such as FEMA (US), it has no recognized status for such uses. Due to absence of established usage levels or approvals, this compound serves primarily as a reference substance rather than a functional additive in consumer products.

2-methyl-5-propyl thiophene exhibits physical and chemical properties typical of substituted thiophenes bearing alkyl groups. It has a boiling point range of approximately 179 to 180°C at standard atmospheric pressure, indicating moderate volatility suitable for laboratory handling under controlled conditions. The estimated octanol-water partition coefficient (log P) around 3.5 reflects moderate hydrophobicity, influencing its solubility and interaction in formulations. Vapor pressure at 25°C is low, about 1.296 mmHg, suggesting limited volatility relative to lighter solvents. It shows solubility in alcohols and slight solubility in water (~39.8 mg/L at 25°C estimated), important for understanding its behavior in different solvents. Flash point measurement of approximately 42°C reflects its flammability risk. These properties shape its stability profile and suitability for experimental usage, while also dictating safety precautions.

	2-methyl-5-propylthiophene
NIST Chemistry WebBook:	Search Inchi
Pubchem (cid):	36628
Pubchem (sid):	134998722

(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

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:
information only not used for fragrances or flavors
Recommendation for 2-methyl-5-propyl thiophene usage levels up to:
	not for fragrance use.
Recommendation for 2-methyl-5-propyl thiophene flavor usage levels up to:
	not for flavor use.

Safety references

EPI System: View

AIDS Citations:Search

Cancer Citations:Search

Toxicology Citations:Search

EPA ACToR:Toxicology Data

EPA Substance Registry Services (SRS):Registry

Laboratory Chemical Safety Summary :36628

National Institute of Allergy and Infectious Diseases:Data

2-methyl-5-propylthiophene

Chemidplus:0033933732