5-methyl quinoxaline

5-methyl quinoxaline is an aromatic heterocyclic organic compound classified as a substituted quinoxaline with the molecular formula C₉H₈N₂. It appears as a colorless to pale-yellow liquid or solid depending on temperature, exhibiting a distinctive nutty and roasted aroma with sensory notes reminiscent of coffee, hazelnut, and roasted corn. This compound is also known by several synonyms including 5-methyl-1,4-benzodiazine and nutty oxaline. Its chemical structure links closely to pyrazine derivatives often found in flavor and fragrance chemistry. It is commercially sourced through synthetic routes and is found naturally in roasted almonds and coffee. The compound is indexed in chemical databases such as ChEBI and is recognized for its role in imparting nutty and roasted characteristics in various products.

5-methyl quinoxaline occurs naturally in foods such as roasted almonds and coffee, contributing to their characteristic nutty and roasted aromas. It is widely used in flavor and fragrance industries to enhance nutty notes reminiscent of almond, hazelnut, and peanut, as well as the roasted qualities found in coffee and corn. The compound is applicable in formulations requiring brown sugar, walnut, or yeast-like nuances, often utilized to create toasted and roasted outlines in complex flavor profiles. Its safety and usage levels are evaluated under standards such as FEMA (US), which assigns it the FEMA number 3203, and JECFA (international) which has reviewed it for food flavoring applications. These regulatory frameworks guide its controlled use in beverages, frozen dairy, gelatins, puddings, and confectionery, supporting its designation as suitable for flavoring purposes within defined limits.

5-methyl quinoxaline possesses a molecular weight of approximately 144.18 g/mol and a molecular formula of C₉H₈N₂. It has a melting point range near 20 to 21°C and a relatively low vapor pressure of 0.046 mmHg at 25°C, indicating moderate volatility under ambient conditions. The compound exhibits a specific gravity between 1.131 and 1.135 at 20°C and a refractive index range of 1.619 to 1.622 at the same temperature. Its flash point is about 110°C when converted from 230°F, suggesting moderate flammability risks during handling. It shows solubility in alcohols and limited water solubility, estimated near 1456 mg/L at 25°C, which influences its behavior in formulation matrices. The log P value of 2.04 indicates moderate lipophilicity, affecting its partitioning in flavor and fragrance systems and its evaporation rates when applied in product formulations.

	5-methylquinoxaline
NIST Chemistry WebBook:	Search Inchi
Canada Domestic Sub. List:	13708-12-8
Pubchem (cid):	61670
Pubchem (sid):	135017609

(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
FDA Substances Added to Food (formerly EAFUS):	View
CHEBI:	View
CHEMBL:	View
HMDB (The Human Metabolome Database):	HMDB33178
FooDB:	FDB011188
Export Tariff Code:	2933.99.9700
VCF-Online:	VCF Volatile Compounds in Food
ChemSpider:	View

Safety information

Preferred SDS: View
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 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:
flavor and 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 5-methyl quinoxaline usage levels up to:
	0.1000 % in the fragrance concentrate.
Maximised Survey-derived Daily Intakes (MSDI-EU):		22.00 (μg/capita/day)
Maximised Survey-derived Daily Intakes (MSDI-USA):		1.00 (μg/capita/day)
Structure Class:		III
Use levels for FEMA GRAS flavoring substances on which the FEMA Expert Panel based its judgments that the substances are generally recognized as safe (GRAS).
The Expert Panel also publishes separate extensive reviews of scientific information on all FEMA GRAS flavoring substances and can be found at FEMA Flavor Ingredient Library
publication number: 4
Click here to view publication 4
		average usual ppm	average maximum ppm
baked goods:		-	-
beverages(nonalcoholic):		-	10.00000
beverages(alcoholic):		-	-
breakfast cereal:		-	-
cheese:		-	-
chewing gum:		-	-
condiments / relishes:		-	-
confectionery froastings:		-	-
egg products:		-	-
fats / oils:		-	-
fish products:		-	-
frozen dairy:		-	10.00000
fruit ices:		-	10.00000
gelatins / puddings:		-	10.00000
granulated sugar:		-	-
gravies:		-	-
hard candy:		-	10.00000
imitation dairy:		-	-
instant coffee / tea:		-	-
jams / jellies:		-	-
meat products:		-	-
milk products:		-	-
nut products:		-	-
other grains:		-	-
poultry:		-	-
processed fruits:		-	-
processed vegetables:		-	-
reconstituted vegetables:		-	-
seasonings / flavors:		-	-
snack foods:		-	-
soft candy:		-	-
soups:		-	-
sugar substitutes:		-	-
sweet sauces:		-	-

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

Safety and efficacy of pyrazine derivatives including saturated ones belonging to chemical group 24 when used as flavourings for all animal species View page or View pdf

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EPA Substance Registry Services (TSCA):13708-12-8

EPA ACToR:Toxicology Data

EPA Substance Registry Services (SRS):Registry

Laboratory Chemical Safety Summary :61670

National Institute of Allergy and Infectious Diseases:Data

WGK Germany:3

5-methylquinoxaline

Chemidplus:0013708128