[Synthesis and antibacterial properties of pyrido[2,3-b]pyrazine derivatives]

Novel pyrido[2,3-b]pyrazine 1,4-dioxide and pyrido [2,3-b]pyrazine 1-oxide derivatives were synthesized from furazano [4,5-b]pyridine 3-oxide and the enolic form of 1,3-diketones or beta-ketoesters catalyzed by silica gel or molecular sieves. Their antibacterial activities were evaluated. As the results of anti-bacterial screening tests in vitro, pyrido[2,3-b]pyrazine 1,4-dioxide derivatives revealed strong activities, but pyrido[2,3-b]pyrazine 1-oxide derivatives revealed no activities.