13925-07-0

Basic information

• Product Name: 3,5-DIMETHYL-2-ETHYLPYRAZINE
• Synonyms: 2,6-dimethyl-3-ethyl-pyrazin;2-ethyl-3,5-dimethyl-pyrazin;3,5-dimethyl-2-ethyl-pyrazin;3-Ethyl-2,6-dimethylpyrazine;FEMA 3150;fema3150;Pyrazine, 2,6-dimethyl-3-ethyl-;Pyrazine, 2-ethyl-3,5-dimethyl-
• CAS NO: 13925-07-0
• Molecular Formula: C₈H₁₂N₂
• Molecular Weight: 136.19428
• EINECS: 237-694-1
• Product Categories: Heterocyclic Compounds;Heterocycles
• Mol File: 13925-07-0.mol
• Article Data: 9

Chemical Properties

• Melting Point: 64-66 °C
• Boiling Point: 182°C
• Flash Point: 182°C
• Appearance: Yellow oil
• Density: 0.96
• Vapor Pressure: 0.814mmHg at 25°C
• Refractive Index: 1.5015
• Storage Temp.: Sealed in dry,Room Temperature
• PKA: 2.73±0.10(Predicted)
• Water Solubility: Not miscible or difficult to mix in water. Soluble in alcohol, chloroform and dichloromethane.
• CAS DataBase Reference: 3,5-DIMETHYL-2-ETHYLPYRAZINE(CAS DataBase Reference)
• NIST Chemistry Reference: 3,5-DIMETHYL-2-ETHYLPYRAZINE(13925-07-0)
• EPA Substance Registry System: 3,5-DIMETHYL-2-ETHYLPYRAZINE(13925-07-0)

Safety Data

• TSCA: Yes
• Hazardous Substances Data: 13925-07-0(Hazardous Substances Data)

Usage

Chemical Properties

Yellow Oil

Occurrence

Reported found in the basic fractions of whiskey and rum, in roasted peanuts, in roasted barley, in coffee, filberts, potato and soy products, fried pork, cocoa, tea, oatmeal, asparagus, shrimps, clam, squid, grilled beef and wheaten bread

Uses

3,5-Dimethyl-2-ethylpyrazine is an odorant of coffee brews.

Preparation

By alkylation of 2,6-dimethylpyrazine with ethyllithium

Aroma threshold values

15 ppm in water

InChI:InChI=1/C8H12N2/c1-4-8-7(3)10-6(2)5-9-8/h5H,4H2,1-3H3

Upstream product

• 133129-03-0 C₁₀H₁₆N₂O₃ 
• 38557-72-1 2-chloro-3,5-dimethylpyrazine 
• 74-96-4 ethyl bromide 
• 50-99-7 D-glucose 
• 59-51-8 DL-methionine 
• 108-50-9 2,6-dimethylpyrazine 
• 123-38-6 propionaldehyde 
• 997-62-6 Gly-L-Lys-OH 
• 78-98-8 2-oxopropanal 
• 56-87-1 L-lysine 
• 56-40-6 glycine 
• 72-18-4 L-valine 
• 492-62-6 alpha-D-glucopyranose 
• 556-50-3 glycylglycine 

Relevant articles and documents

Comparison of pyrazines formation in methionine/glucose and corresponding Amadori rearrangement product model

The generation of pyrazines in a binary methionine/glucose (Met/Glc) mixture and corresponding methionine/glucose-derived Amadori rearrangement product (MG-ARP) was studied. Quantitative analyses of pyrazines and methional revealed that MG-ARP generated more methional compared to Met/Glc, whereas lower content and fewer species of pyrazines were observed in the MG-ARP model. Comparing the availability of α-dicarbonyl compounds generated from the Met/Glc model, methylglyoxal (MGO) was a considerably effective α-dicarbonyl compound for the formation of pyrazines during MG-ARP degradation, but glyoxal (GO) produced from MG-ARP did not effectively participate in the corresponding formation of pyrazines due to the asynchrony on the formation of GO and recovered Met. Diacetyl (DA) content was not high enough to form corresponding pyrazines in the MG-ARP model. The insufficient interaction of precursors and rapid drops in pH limited the formation of pyrazines during MG-ARP degradation. Increasing reaction temperature could reduce the negative inhibitory effect by promoting the content of precursors.

Alkylations and hydroxymethylations of pyrazines via green minisci-type reactions

A new general methodology utilizing Minisci-type chemistry has been developed that cleanly and efficiently prepares alkyl- and (hydroxymethyl) pyrazines. The new methods eliminate toxic catalysts and halogenated solvents, providing a greatly improved route to these natural products which are prevalent in many natural systems as bacterial volatiles, plant volatiles, and insect pheromones.

Formation of pyrazines in maillard model systems of lysine-containing dipeptides

Whereas most studies concerning the Maillard reaction have focused on free amino acids, little information is available on the impact of peptides and proteins on this important reaction in food chemistry. Therefore, the formation of flavor compounds from the model reactions of glucose, methylglyoxal, or glyoxal with eight dipeptides with lysine at the N-terminus was studied in comparison with the corresponding free amino acids by means of stir bar sorptive extraction (SBSE) followed by GC-MS analysis. The reaction mixtures of the dipeptides containing glucose, methylglyoxal, and glyoxal produced 27, 18, and 2 different pyrazines, respectively. Generally, the pyrazines were produced more in the case of dipeptides as compared to free amino acids. For reactions with glucose and methylglyoxal, this difference was mainly caused by the large amounts of 2,5(6)-dimethylpyrazine and trimethylpyrazine produced from the reactions with dipeptides. For reactions with glyoxal, the difference in pyrazine production was rather small and mostly unsubstituted pyrazine was formed. A reaction mechanism for pyrazine formation from dipeptides was proposed and evaluated. This study clearly illustrates the capability of peptides to produce flavor compounds that can differ from those obtained from the corresponding reactions with free amino acids.