Substituted pyrazine-2,5-dicarboxamides: Synthesis, Hydrophobicity Parameters, and Antimycobacterial Evaluation

Substituted pyrazine derivatives were synthesized and tested against Mycobacterium tuberculosis strain H37Rv. The hydrophobicity of all the pyrazines was determined using the reversed phase high performance liquid chromatography (RP-HPLC) method (isocratic elution with methanol as an organic modifier in the mobile phase, end-capped non-polar C18 stationary RP column). Experimentally derived Log K values (the logarithm of capacity factor K) were that compared with Log P values calculated by commercially available programmes. The synthetic approach, analytical, spectroscopic, lipophilicity and biological data of ten newly synthesized compounds are presented. Structure—activity relationships among the chemical structure, the anti-mycobacterial activity of the evaluated compounds are discussed. 3-(3-Methylphenyl)-aminopyrazine-2,5-dicarboxamide (7) has shown the highest activity against M. tuberculosis H37Rv (63% inhibition).