2-acetyl-5-methyl pyrazine

2-acetyl-5-methyl pyrazine is a pyrazine derivative with molecular formula C₇H₈N₂O and a molecular weight of approximately 136.15 g/mol. It appears as a low-volatility compound characterized by a distinct nutty aroma, contributing notable odor notes predominantly recognized in popcorn and coffee. Its synonyms include 1-(5-methylpyrazin-2-yl)ethanone and ethanone, 1-(5-methyl-2-pyrazinyl)-, reflecting its heterocyclic structure with acetyl and methyl substitutions. This compound is sourced primarily through chemical synthesis and sometimes isolated from roasted food matrices where it naturally forms via Maillard reactions. For additional chemical information, it is catalogued under PubChem CID 30915, providing access to standard reference data. Its applications mainly encompass flavoring agent use to mimic or enhance sensory profiles in diverse food products.

2-acetyl-5-methyl pyrazine occurs naturally in roasted coffee, measurable at up to 0.3 mg/kg, and in popcorn aromas where it significantly contributes to the characteristic nutty sensory impression. Functionally, it is utilized as a flavoring agent to impart roasted, nut-like notes in food products, leveraging its potent odor profile. Such usage conforms with standards including FEMA (US), which governs flavoring substances for food and beverage applications. Regulatory bodies recognize its safety for inclusion in foodstuffs when applied within prescribed limits. It finds applications in aromatic enhancement for coffee flavor formulations, savory snacks like popcorn, and can be present in composite foods requiring roasted aroma notes.

2-acetyl-5-methyl pyrazine exhibits a boiling range between 226 to 228°C at atmospheric pressure, indicating moderate thermal stability relevant to food processing conditions. Its estimated logP value of approximately 0.45 suggests moderate hydrophobicity, which influences its distribution in lipid versus aqueous systems within formulations. The compound's vapor pressure at 25°C is low (around 0.07 mmHg), consistent with limited volatility and a controlled release of aroma under ambient conditions. Solubility characteristics reveal suitability for incorporation in alcohol-containing matrices and limited water solubility, affecting formulation choices. The flash point near 95°C (converted from 203°F) denotes safety considerations during handling and processing under elevated temperature. Collectively, these properties inform the design and stability of flavor delivery systems involving this pyrazine derivative.

	1-(5-methylpyrazin-2-yl)ethanone
NIST Chemistry WebBook:	Search Inchi
Pubchem (cid):	30915
Pubchem (sid):	134993898

(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
VCF-Online:	VCF Volatile Compounds in Food
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:
flavoring agents
Recommendation for 2-acetyl-5-methyl pyrazine usage levels up to:
	not for fragrance use.
Maximised Survey-derived Daily Intakes (MSDI-EU):		0.0024 (μg/capita/day)
Modified Theoretical Added Maximum Daily Intake (mTAMDI):		270 (μg/person/day)
Threshold of Concern:		540 (μg/person/day)
Structure Class:		II
Food categories according to Commission Regulation EC No. 1565/2000 (EC, 2000) in FGE.06 (EFSA, 2002a). According to the Industry the "normal" use is defined as the average of reported usages and "maximum use" is defined as the 95th percentile of reported usages (EFSA, 2002i).
Note: mg/kg = 0.001/1000 = 0.000001 = 1/1000000 = ppm.
		average usage mg/kg	maximum usage mg/kg
Dairy products, excluding products of category 02.0 (01.0):		0.40000	2.00000
Fats and oils, and fat emulsions (type water-in-oil) (02.0):		0.10000	0.50000
Edible ices, including sherbet and sorbet (03.0):		0.40000	2.00000
Processed fruit (04.1):		0.40000	2.00000
Processed vegetables (incl. mushrooms & fungi, roots & tubers, pulses and legumes), and nuts & seeds (04.2):		-	-
Confectionery (05.0):		1.00000	5.00000
Chewing gum (05.3):		-	-
Cereals and cereal products, incl. flours & starches from roots & tubers, pulses & legumes, excluding bakery (06.0):		0.20000	1.00000
Bakery wares (07.0):		1.00000	5.00000
Meat and meat products, including poultry and game (08.0):		0.10000	0.50000
Fish and fish products, including molluscs, crustaceans and echinoderms (MCE) (09.0):		0.10000	0.50000
Eggs and egg products (10.0):		-	-
Sweeteners, including honey (11.0):		-	-
Salts, spices, soups, sauces, salads, protein products, etc. (12.0):		0.10000	0.50000
Foodstuffs intended for particular nutritional uses (13.0):		0.20000	1.00000
Non-alcoholic ("soft") beverages, excl. dairy products (14.1):		0.20000	1.00000
Alcoholic beverages, incl. alcohol-free and low-alcoholic counterparts (14.2):		1.00000	5.00000
Ready-to-eat savouries (15.0):		1.00000	5.00000
Composite foods (e.g. casseroles, meat pies, mincemeat) - foods that could not be placed in categories 01.0 - 15.0 (16.0):		0.20000	1.00000

Safety references

European Food Safety Athority(EFSA):Flavor usage levels; Subacute, Subchronic, Chronic and Carcinogenicity Studies; Developmental / Reproductive Toxicity Studies; Genotoxicity Studies...

European Food Safety Authority (EFSA) reference(s):

Opinion of the Scientific Panel on food additives, flavourings, processing aids and materials in contact with food (AFC) on a request from the Commission related to Flavouring Group Evaluation 17 (FGE.17): Pyrazine derivatives from chemical group 24 (Commission Regulation (EC) No 1565/2000 of 18 July 2000) View page or View pdf

Flavouring Group Evaluation 50 (FGE.50): Consideration of pyrazine derivatives evaluated by JECFA (57th meeting) structurally related to pyrazine derivatives evaluated by EFSA in FGE.17 (2005) (Commission Regulation (EC) No 1565/2000 of 18 July 2000) - Opinion of the Scientific Panel on Food Additives, Flavourings, Processing Aids and Materials in contact with Food (AFC) View page or View pdf

Flavouring Group Evaluation 17, Revision 1 (FGE.17Rev1): Pyrazine derivatives from chemical group 24 - Opinion of the Scientific Panel on Food Additives, Flavourings, Processing Aids and Materials in contact with Food (AFC) [1] View page or View pdf

Scientific Opinion on Flavouring Group Evaluation 17, Revision 2 (FGE.17Rev2): Pyrazine derivatives from chemical group 24 View page or View pdf

Scientific Opinion on Flavouring Group Evaluation 50, Revision 1 (FGE.50Rev1): Consideration of pyrazine derivatives evaluated by JECFA (57th meeting) structurally related to pyrazine derivatives evaluated by EFSA in FGE.17Rev2 (2010) View page or View pdf

Scientific Opinion on Flavouring Group Evaluation 17, Revision 3 (FGE.17Rev3): Pyrazine derivatives from chemical group 24 View page or View pdf

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 :30915

National Institute of Allergy and Infectious Diseases:Data

1-(5-methylpyrazin-2-yl)ethanone

Chemidplus:0022047274