92508-08-2

Usage

Uses

Used in Wine Industry:
2-Methoxy-3,5-dimethylpyrazine is used as a contaminant indicator for assessing the quality of wines with cork stoppers. Its presence can be a concern due to the strong unpleasant smell it imparts to the wine, potentially affecting consumer perception and preference. Efforts are made to minimize its occurrence in wines to ensure a better sensory experience for consumers.

Upstream product

• 67-56-1 methanol 
• 108-50-9 2,6-dimethylpyrazine 
• 186581-53-3 diazomethane 
• 60187-00-0 3-hydroxy-2,6-dimethylpyrazine 
• 38557-72-1 2-chloro-3,5-dimethylpyrazine 
• 31396-38-0 3,5-dimethyl-pyrazine-1-oxide 

Relevant academic research and scientific papers

Novel pyrazines from the myxobacterium Chondromyces crocatus and marine bacteria

The volatiles released by two strains of the myxobacterium Chondromyces crocatus and seven strains of marine Alpha-proteobacteria from the North Sea were collected using the CLSA or SPME headspace methods and analysed by GC-MS. In the extracts of C. crocatus 27 pyrazines were identified, belonging to different classes. 2,5-Dialkylpyrazines and related 3-methoxy-2,5- dialkylpyrazines dominated. Several pyrazines like 2-(1-methylethenyl)-5-(1- methylethyl)-pyrazine (7) and 3-methoxy-2,5-dialkylpyrazines with methyl, isopropyl, isobutyl or sec-butyl side-chains were obtained from natural sources for the first time. It was essential for the identification to rely on synthetic reference materials, which were obtained using Fuerstner's iron-catalysed coupling of chloropyrazines with Grignard reagents or condensation of azido ketones as key steps. The synthetic material allowed the identification of two previously unknown attractants of bacterial origin for the pineapple beetle Carpophilus humeralis, namely 3-methoxy-2-(1-methylpropyl)-5-(2-methylpropyl) pyrazine (17) and 3-methoxy-2,5-bis(1-methylpropyl)pyrazine (52). Several 2,5-dialkylpyrazines were identified in the extracts of the marine Alphaproteobacteria. The unique 2,5-dimethyl-3-(methylsulfanyl)pyrazine (67) represents a new type of natural pyrazine. Our results, together with literature reports, show that pyrazines are an important class of bacterial volatiles which might be more widespread than previously thought. Wiley-VCH Verlag GmbH & Co. KGaA, 2005.

Isolation and identification of 2-methoxy-3,5-dimethylpyrazine, a potent musty compound from wine corks

The compound responsible for a fungal must taint evident in industry assessments of wine corks was identified as 2-methoxy-3,5- dimethylpyrazine. The identification was made on the basis of gas chromatography/odor analyses, collection of material using micropreparative techniques, determination of chemical properties of collected material, and comparison by gas chromatography/mass spectrometry with an authentic sample, synthesized from 2-hydroxy-3,5-dimethylpyrazine. 2-Methoxy-3,5-dimethylpyrazine is an extremely potent compound with an unpleasant, musty, moldy aroma and an aroma threshold in a white wine of 2.1 ng/L. While its contribution to the frequency and intensity of cork taint in bottled wine is yet to be established, it has been assessed by some wine industry personnel as second only to 2,4,6-trichloroanisole as a cause of cork taint in Australian wine.

Potent odorants of raw Arabica coffee. Their changes during roasting

Aroma extract dilution analysis of raw Arabica coffee revealed 3- isobutyl-2-methoxypyrazine (I), 2-methoxy-3,5-dimethylpyrazine (II), ethyl 2- methylbutyrate (III), ethyl 3-methylbutyrate (IV), and 3-isopropyl-2- methoxypyrazine (V) as potent odorants. T