jeudi 8 février 2007


I will start this blog with a quite old but very interesting synthesis of pyrazine dicarboxylic acid.

This synthesis starts with the formation of quinoxaline, by the reaction of glyoxal and o-phenylendiamine in water with a 85-90% yield(1). Then the benzene fused ring is cleaved with a hot aqueous potassium permanganate solution (2), the mixture is cooled at room temperature and acidified with a 36% hydrochloric acid (3). The crude material is filtered off and recristallized in acetone to give the 2,3-pyrazinedicarboxylic acid with a 75-77% yield.

Interestingly, this synthesis can be applied to quinolines, isoquinolines and naphtalenes to provide the corresponding dicarboxylic derivatives.

For more information:


Organic Syntheses, Coll. Vol. 4, p.824 (1963); Vol. 30, p.86 (1950).

Reuben G. Jones and Keith C. McLaughlin.

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