The pyrazine ring was developed in a pyrimidine and in a benzene by Isay type condensations under microwave irradiation to afford pterin and quinoxaline systems. Interestingly, the desired isomerically free 6-substituted pterins including pterin sugar derivatives were synthesised in moderate to good yields whereas mixtures of both 6- and 7-isomers (major) are generally obtained using conventional Isay
吡嗪环在微波辐射下通过Isay型缩合在
嘧啶和苯中显影,得到蝶呤和
喹喔啉系统。有趣的是,以中等至良好的产率合成了所需的不含异构体的6-取代的蝶呤,包括蝶呤糖衍
生物,而通常使用常规的Isay型缩合反应获得6-和7-异构体的混合物(主要)。