Phosphorus trichloride → 3-Amino-6-methylpyrazine-2-carbonitrile

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Reaction Steps

The intermediate 2-amino-5-methylpyrazine is prepared stepwise, starting with 2-oxopropanal 1-oxime. This oxime is allowed to react with aminomalononitrile tosylate [prepared by the method of Ferris et al., J. Am. Chem. Soc. 88, 3829 (1966)], to yield 2-amino-3-cyano-5-methylpyrazine 1-oxide. The pyrazine 1-oxide prepared in this manner is allowed to react with phosphorous trichloride to yield 2-amino-3-cyano-5-methylpyrazine. This 2-amino-3-cyano-5-methylpyrazine is hydrolyzed with aqueous sodium hydroxide to yield 2-amino-3-carboxy-5-methylpyrazine, which, when heated in tetrahydronaphthalene, is decarboxylated to yield the desired 2-amino-5-methylpyrazine.

Provenance & Evidence