[Synthesis of antiviral agents acyclic nucleo-sides of 4-substituted pyrrolo [2,3-d] pyrimidine].
Naturally occurring nucleosides of pyrrolo [2,3-d] pyrimidine, tubercidin, sangivamycin and toyocamycin were known as antibodies not only for their potent antitumor activity but also for their significant antiviral effects. However, none of them was developed to be a useful drug due to their high toxicity. In order to reduce the toxicity of this kind of compounds and reveal the relationship between structure and biological activity, a series of acyclic analogues of tubercidin with varied 4-substituted amino groups were synthesized. 4-chlor-pyrrolo (2,3-d) pyrimidin was used as starting material which reacted with 1,3-dibenzyloxy-glycerol-2-chloro-methylether by direct sodium salt glycosylation procedure provided the key intermediate (IX). After hydrogenation, amination of compound IX gave the final free hydroxy products. All the compounds were tested in vitro against HSV-1 and Cox B6. Only three of them (XI6, XI7, XI9) showed certain activities against Cox B6.