3-a]pyrimidine 3a,b, with formic acid, and carbon disulphide to give pyrido[2,3-d][1,2,4]traizolo[4,3-a]pyrimidine 4, 5. Reaction of 1 with nitrous acid afforded tetrazolo[1,5-a]pyrido[2,3-d]pyrimidine 6, which was reduced by zinc dust to give 2-amino-pyrido-[2,3-d]pyrimidine 7. Finally the reaction of 2-hydrazino 1 with D-xylose or D-glucose afforded the acyclic N-nucleoside 8,11 which were converted into tetra/penta
吡啶并
嘧啶与芳香醛反应得到芳基腙 2a,b,它可以与
甲酸环化成
吡啶并[2,3-d][1,2,4]三唑并[4,3-a]
嘧啶 3a,b,和
二硫化碳得到
吡啶并[2,3-d][1,2,4]三唑并[4,3-a]
嘧啶4, 5。1与
亚硝酸反应得到
四唑并[1,5-a]
吡啶并[2 ,3-d]
嘧啶 6,被
锌粉还原得到 2-
氨基-
吡啶并-[2,3-d]
嘧啶 7。最后 2-
肼基 1 与
D-木糖或
D-葡萄糖反应得到无环 N-核苷 8,11 在
乙酸酐/
吡啶中转化为四/五 O-
乙酸酯无环 C-核苷 9, 12。化合物 9、12 的去乙酰化得到 C-核苷 10、13。