[Heterocyclics fused to pyrazine-1,4-dioxide. 3. Synthesis and antibacterial effect of substituted pteridine--5,8-dioxides].

The synthesis of substituted pteridine-5,8-dioxides (6) via reaction of furoxanes (5) with enolizing carbonyl compounds is described. Compounds 5 are obtained either through reaction of chloro pyrimidines 1 with sodium azide, or through diazotization of hydrazino pyrimidine 2 and subsequent thermal decomposition of 3 or through nucleophilic displacement of methoxy against amino groups in 5. The antibacterial activity of the compounds 6a and 6c is directed against some gramnegative organisms, i.e. E. coli, Klebsiella spp. and Proteus spp., with MIC values and ED50 values which do not exceed those of the corresponding pyridol [2,3-b]pyrazine-1,4-dioxides.