Utilizing the mouse test as an assay method for antituberculous agents, we showed in 1948, 2 the role of nicotinamide and its derivatives in the chemotherapy of tuberculosis. As a sequence to the study of pyridine derivatives, many pyrazine analogs were synthesized which led ultimately to the discovery of pyra~ inamide~~(Aldinamide3b), an effective, clinical, chemotherapeutic agent. Pyrazinamide in combination with isoniazid now ap-
