SYNTHESIS OF 2<i>H</i>-CHROMENO[2,3-<i>d</i>]PYRIMIDINE-2,4(3<i>H</i>)-DIONES (5-DEAZA-10-OXAFLAVINS) AS AN AUTORECYCLING OXIDIZING AGENT
作者:Fumio Yoneda、Ryoichi Hirayama、Machiko Yamashita
DOI:10.1246/cl.1980.1157
日期:1980.9.5
Treatment of 3-methyl-6-phenoxyuracils with the Vilsmeier reagent gave the corresponding 5-formyl-3-methyl-6-phenoxyuracils. Dehydrative cyclization of the above 5-formyluracils with polyphosphoric acid gave 3-methyl-2H-chromeno[2,3-d]pyrimidine-2,4(3H)-diones (3-methyl-5-deaza-10-oxaflavins). These 5-deaza-10-oxaflavins showed strong oxidizing power in oxidizing benzyl alcohol even under neutral conditions to give benzaldehyde, while they were hydrogenated to 1,5-dihydro-5-deaza-10-oxaflavins.
对3-甲基-6-苯氧基尿嘧啶进行维尔斯梅尔试剂处理,得到相应的5-甲醛-3-甲基-6-苯氧基尿嘧啶。上述5-甲醛尿嘧啶与聚磷酸的脱水环化反应生成3-甲基-2H-色烯[2,3-d]嘧啶-2,4(3H)-二酮(3-甲基-5-去氮-10-氧黄酮)。这些5-去氮-10-氧黄酮在中性条件下对苄醇显示出强的氧化能力,能够将其氧化为苯甲醛,同时它们被氢化生成1,5-二氢-5-去氮-10-氧黄酮。