Synthesis and Regioselective N- and O-Alkylation of 1<i>H</i>- or 3<i>H</i>-[1,2,3]Triazolo[4,5-<i>d</i>]pyrimidine-5,7(4<i>H</i>,6<i>H</i>)-diones (8-Azaxanthines) and Transformation of Their 3-Alkyl Derivatives into 1-Alkyl Isomers
作者:Tomohisa Nagamatsu、Rafiqul Islam
DOI:10.1055/s-2006-950337
日期:——
alkylating agents, for example alkyl halides and dimethyl sulfate, were employed in aprotic Solvents Under a variety of conditions for the alkylation of mono- and disubstituted 1H- or 3H-[1,2,3]triazolo[4,5-d]pyrimidine-5,7(4H,6H)-diones, which were prepared by cyclization of the appropriate 5,6-diaminouracils with nitrous acid. The alkylation on the triazole ring in the presence of anhydrous potassium carbonate
在非质子溶剂中使用了几种烷基化剂,例如卤代烷和硫酸二甲酯 在各种条件下用于单取代和双取代的 1H-或 3H-[1,2,3]三唑并[4,5-d]的烷基化嘧啶-5,7(4H,6H)-二酮,通过适当的 5,6-二氨基尿嘧啶与亚硝酸的环化制备。在无水碳酸钾存在下,三唑环上的烷基化同时在 1 位和 2 位发生,优先在 2 位烷基化。用等价的烷基化试剂在嘧啶环上进行类似的烷基化仅在 4 位发生。3,6-二取代衍生物在室温下烷基化导致5-O-烷基化伴随4-N-烷基化,但在高温下仅发生4-N-烷基化。3,4的反应,