2-Ethyl-3-methylpyrazine bromination

Bromination using NBS has been used to provide acetylpyrazine derivatives from the corresponding ethylpyrazines. Bromination of 2-ethyl-3-methylpyrazine gives 2-bromoethyl-3-methylpyrazine in quantitative yield this may be oxidized using the sodium salt of 2-nitropropane or with pyridine AT-oxide to yield 2-acetyl-3-methylpyrazine in yields of 66 and 25% respectively (Scheme 14). 

Conversion of pyrazinones into bromopyrazines is known (82MI2), as is side-chain bromination, particularly when NBS is used under conditions conducive to radical formation. Thus, 2-ethyl-3-methylpyrazine was converted into the l -bromoethyl derivative (72JOC511). 

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See also in sourсe #XX -- [ ]

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