2- Methoxy-6-methylpyrazine

The aposematic beetle, Metriorrhynchus rhipidius, contains three pyrazines as warning odor components and two amides as bitter principles (Tables III, V, and VIII) (97). Of the three components with the beetlelike odor, the most characteristic is 2-methoxy-3-isopropylpyrazine (24b). The other two components are 2-methoxy-3-methylpyrazine (24a) and 2-methoxy-3-sec-butylpyrazine (24d). It would seem likely that these compounds will occur in the defensive systems of the aposematic beetles. The two amide components, detectable in the hemo-lymph exuded by adult beetles, are 3-phenylpropanamide (130) and l-methyl-2-quinolone (57), the latter being the major component. It seems likely that these bitter principles contribute to distastefulness to potential predators. 

Alkyl-2-methoxypyrazines exhibit a base peak at miz 124 in the mass spectrum. The peak corresponds to a molecular ion in 2-methoxy-3-methylpyrazine (24a) and to a fragment ion, resulting from a McLafferty rearrangement of an alkyl group, in 3-isopropyl-2-methoxypyrazine (24b) and 3-5cc-butyl-2-methoxy pyrazine (24d) (97). 

MethyIbutyl)-2-methoxy- -3-methylpyrazine och3 CH3 CH2CH(Ch l3)C2H5... 

The reaction of the sodium derivative of methylpyrazine with alkyl halides in liquid ammonia gives good yields (44-81%) of mono-alkylated products phenylation has been achieved by reaction with benzyne (generated from bromobenzene and sodamide in liquid ammonia) and gives 53% benzylpyrazine.178 The alkylation of the sodio derivative of 2-methoxy-3-methylpyrazine with methyl iodide, and of the product with ethyl bromide, gives 2-methoxy-3-sec-butylpyrazine (25) a constituent of galbanum oil.31... 

Alkoxy groups again direct attack to the more remote nitrogen site, probably for steric reasons. Thus, 2-ethoxypyrazine gave 45% and 2-methoxy-3-methylpyrazine 82% of the 4-oxides (64JOC2623). Isolation of an almost quantitative yield of 4-oxide from 2-methoxy-3-phenylpyrazine oxidation... 

C6H7N02 N-methylpyrrole-2-carboxylic acid 6973-60-0 453.15 39.402 2 7349 C6H8N20 2-methoxy-3-methylpyrazine 2847-30-5 579.00 51.524 2... 

Both 2-methylpyrazine 1- and 4-oxides (625) (obtained by oxidation of 2-methyl-pyrazine with peroxyacetic acid) on treatment with phosphoryl chloride have been claimed to give 2-chloro-3-methylpyrazine(626)but the 2-methylpyrazine-4-oxide used is now known to have been a mixture of the 1- and 4-isomers (734). More recently other workers (735, 736) have claimed that the mixed 2-methylpyrazine 7V-oxides with phosphoryl chloride gave a mixture of 2-chloro-3-, -5-, and -6-methylpyrazine but Nakel and Haynes (686) have shown that 2-methylpyrazine 1-oxide with phosphoryl chloride followed by sodium methoxide gave 2-methoxy-3-methylpyrazine and 6-methoxy-2-methylpyrazine, and 2-methylpyrazine 4-oxide (3-methylpyrazine 1-oxide) similarly treated gave only 2-methoxy-6-methylpyrazine. 3-Trifluoromethylpyrazine 1-oxide with benzenesulfonyl chloride at 1(X)° has been shown to give 2-chloro-6-trifluoromethylpyrazine (44%) (759). 

Pyrazine, 2-methoxy-3-methyl-, 2-methoxy-3-methylpyrazine, 2-methyl-3-methoxypyrazine [2847-30-5] FEMA 3183... 

Methoxy-3-methylpyrazine. See 2-Methoxy-3(5)-methylpyrazine 2-Methoxy-3(5)-methylpyrazine CAS 2847-30-5 EINECS/ELINCS 220-651-6 FEMA 3183... 

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