Studies on pyrazines. 7. The synthesis of 5-chloropyrazinecarboxylic acid

The titled carboxylic acid ( 1 ) was prepared by condensation of 2-furylglyoxal with aminoacetamide followed by chlorination of the resulting 2-hydroxy-5-(2′-furyl)pyrazine ( 2 ) and permanganate oxidation. The acid was further converted into methyl ester and 5-hydroxypyrazinecarboxylic acid.