Catalytic hydrogenation of pyrazinecarboxylic acids was written by Felder, E.;Maffei, S.;Pietra, S.;Pitre, D.. And the article was included in Helvetica Chimica Acta in 1960.Quality Control of Ethyl pyrazine-2-carboxylate This article mentions the following:
Reduction of several pyrazinecarboxylic acids and derivatives over Pd-C generally gave piperazines. Reduction of 3.1 g. pyrazine-2-carboxylic acid (I) in 200 ml. H2O containing 1.6 g. KOH at 50° and atm. pressure over 10% Pd-C gave in 90 min. 94% piperazine-2-carboxylic acid (II), resolved into optical isomers through its 1:2 salt with (+)-10-camphorsulfonic acid; (-)-II camphorsulfonate m. 264-5° (decomposition), [α]25D 14.9° (c 5, H2O); (-)-II m. 291-3° (decomposition), [α]20D -3.9° (c 6.5, H2O), obtained by anion exchange of the salt. Similar reduction of pyrazine-2,3-dicarboxylic acid (di-Et ester b2 138-40°) gave 83% piperazine-2,3-dicarboxylic acid (III); resolution through the 1:1 salt with (+)-10-camphorsulfonic acid gave (+)-III camphorsulfonate, m. 233° (decomposition), [α]22D 14.08° (c 6, H2O); (+)-III, m. 296° (decomposition), [αa]20D 0.32° (c 21, N NH4OH). In similar reductions were prepared the following piperazines (substituents, m.p., and % yield given): 2,5-(CO2H)2, 205-7°, 93 [di-HCl salt m. 278° (decomposition)]; 2,6-(CO2H)2, 305-6°, 96 [di-HCl salt m. 242-3° (decomposition)]; 2,3-(CO2Me)2, -, 50 (di-HCl salt m. 199°; picrate m. 192°); 2,3-(CO2Et)2, 55°, 57 (picrate m. 182°); 2-CONH2, 143-4° (decomposition), 83 [di-HCl salt m. 132-4° (decomposition)]; 2 (or 3)-CO2H, 3 (or 2)-CONH2 (IV), 189-90°, 74; 2,3-(CONH2)2, 204-8° (decomposition), 65. Reduction in EtOH of pyrazine-2,3-dicarboxylic acid imide gave 50% tetrahydropyrazine-2,3-dicarboxylic acid imide, red solid, m. 217-18° (decomposition), reduced in alk. solution to IV. I Me ester and I Et ester, m. 49°, b6 120-2, gave no isolable reduction products. Pyrazine-2,3-dicarboxamide gave the monoamide, m. 170-1°, by partial saponification with NaOH solution In the experiment, the researchers used many compounds, for example, Ethyl pyrazine-2-carboxylate (cas: 6924-68-1Quality Control of Ethyl pyrazine-2-carboxylate).
Ethyl pyrazine-2-carboxylate (cas: 6924-68-1) belongs to pyrazine derivatives. Pyrazine is an N-heterocyclic moiety, and it can be easily prepared from ethylenediamine and 1,2-diketone, α-hydroxyketone, α-methyl ketone. Substituted pyrazines have been found as subunits of multiple synthetically constructed therapeutic agents, as well as several natural products.Quality Control of Ethyl pyrazine-2-carboxylate