Studies on pyrazine derivatives. Part V. Synthesis and tuberculostatic activity of some 6-(beta-aminoethoxy)-pyrazine-2-carboxylic acids.

In the reaction of 2-cyano-6-chloropyrazine with sodium beta-aminoethanolates a mixture of nitriles 1 and imidoesters 2 is formed in relation depending on the reaction conditions. Compounds 1 and 2 with H2S and triethylamine give thioamides 3, which were converted into amides 4 and amidoximes 5. Alkaline hydrolysis of the derivatives of 6-(beta-aminoethoxy)-pyrazine-2-carboxylic acid of type 1,2,3 and 5 gave 6-ethoxypyrazine-2-carboxylic acid. The highest antituberculous activity (62-5-125 mug/cm3) showed thioamides 3a and 3b.