Ring transformation reactions of<i>C</i>-nucleosides: Facile synthesis of pyrazolo[1,5-<i>a</i>]pyrimidine and pyrazolo[1,5-<i>a</i>]triazine<i>C</i>-nucleosides
作者:C. K. Chu、J. J. Suh、M. Mesbah、S. J. Cutler
DOI:10.1002/jhet.5570230209
日期:1986.3
1,3-Dimethyluracil (1), a versatile synthon for the synthesis of various heterocycles, reacted readily with 3-aminopyrazoles 2 in sodium ethoxide to give pyrazolo[1,5-a]pyrimidines 3. Under similar conditions, 3-aminopyrazole C-nucleosides 4 and the synthon 1 gave a mixture of pyrazolo[1,5-a]pyrimidine C-nucleosides, which was separated on a silica gel column. Attempts to remove the protecting groups
1,3-二甲基尿嘧啶(1),用于合成各种杂环的通用合成子,在乙醇钠中容易与3-氨基吡唑2反应,得到吡唑并[1,5- a ]嘧啶3。在相似的条件下,3-氨基吡唑C-核苷4和合成子1得到吡唑并[1,5- a ]嘧啶C-核苷的混合物,将其在硅胶柱上分离。尝试去除保护基产生吡喃糖衍生物10。另一合成子1,3-二甲基-5-氮杂嘧啶和3-氨基吡唑12生成吡唑并[1,5- a ]三嗪13。在与3-氨基吡唑C-核苷4的类似反应中,得到相应的吡唑并[1,5- a ]-三嗪C-核苷14和15。