Pyrido[2, 3-d]pyrimidines were obtained by treatment of 6-allylaminouracils with PdCl2 at 60 °C, under which conditions the yields of the products were improved to a considerable extent as compared with our previously reported reaction. Pyrrolo[2, 3-d]pyrimidines were prepared under the above conditions from 6-(N-allyl-N-methylamino)uracils which were substituted with a methyl group at 6-NH of uracil. In addition, pyrido- and pyrrolo[2, 3-d]pyrimidine nucleosides were prepared from 6-(substituted allyl- or N-allyl-N-methylamino)uridines by adaptation of the above method. That is, the presence or absence of a substituent on the 6-amino group influences the size of ring formed. We proposed plausible pathways to explain why products having different ring sizes were formed.
Pyrido[2, 3-d]
嘧啶类化合物是通过将6-烯丙基
氨基尿
嘧啶与PdCl2在60°C下反应得到的,在这种条件下,产品的产率与我们之前报告的反应相比显著提高。根据上述条件,从6-(N-烯丙基-N-甲基
氨基)尿
嘧啶(其在尿
嘧啶的6-NH位点上有甲基取代)制备了
吡咯[2, 3-d]
嘧啶类化合物。此外,通过调整上述方法,从6-(取代的烯丙基或N-烯丙基-N-甲基
氨基)
尿苷中制备了
吡啶和
吡咯[2, 3-d]
嘧啶类核苷。也就是说,6-
氨基基团上取代基的有无影响形成的环的大小。我们提出了合理的路径来解释为什么产生了不同环大小的产品。