Sodio-2-methylpyrazine

Methylpyrazine heated with paraformaldehyde at 165° for 4.5 hours formed 2-(2 -hydroxyethyl)pyrazine (38%) (470,722), and with benzophenone and sodium amide gave 2-(2-hydroxy-2, 2 -diphenylethyl)pyrazine (705). A series of substituted 2-(2 -hydroxyethyl)pyrazines (e.g., 23) have been prepared from sodio-2-methylpyrazine (22) (from methylpyrazine and sodium in liquid ammonia) and aldehydes or ketones (706). Similarly 2-methyl-6-pyrazinylmethylsodium with aldehydes and ketones undergoes aldol-type condensations to give the corresponding secon-... 

Sodio-2-methylpyrazine with methyl picolinate afforded a mixture containing 2-(pyridin-2 -ylcarbonylmethyl)pyrazine (42.6%) (24) and 2-pyridinylbis(pyrazinyl-methyl)carbinol (22.8%), and with ethyl formate gave only bis(pyrazinylmethyl> carbinol (642). 

The sodio derivative of methylpyrazine (20) reacts with aldehydes and ketones to give secondary and tertiary pyrazine carbinols, respectively.175, 178 Yields in the range 21-99% are obtained when the molar ratio of methylpyrazine sodamide carbonyl compound used is 2 2 1. Oppenauer oxidation of 1-phenyl-2-pyrazylethand (21), the aldol addition product of methylpyrazine and benzaldehyde, gives phenacylpyrazine (22) in 18% yield.176... 

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... 

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See also in sourсe #XX -- [ ]

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