Conversion of Pyridine<i>N</i>-Oxides to Tetrazolopyridines
作者:Shanshan Liu、Dieter Lentz、C. Christoph Tzschucke
DOI:10.1021/jo500231m
日期:2014.4.4
An efficient and convenient procedure for the conversion of pyridineN-oxides to tetrazolopyridines by treatment with 4-toluene sulfonyl chloride and sodium azide in toluene at elevated temperature is described.
unexpectedly, in stead of pyrido[2,3-d]pyrimidine derivatives, by the intermolecular aza-Wittig reaction of methyl 2-(N-triphenylphosphoranylidene)aminonicotinate 3 with aryl isocyanates followed by attempted heterocyclization by use of prim-amines. A novel sequential aza-Wittig / cycloaddition / ring-transformation mechanism for the formation of 10 has been reported based on the isolation and characterization
通过分子间的氮杂-Wittig反应,意外地获得了(2-氧-1,2-二氢吡啶-3-基)-1,3,5-三嗪衍生物10,而不是吡啶并[2,3- d ]嘧啶衍生物。 2-(N-三苯基正膦亚基)氨基烟酸甲酯3与芳基异氰酸酯的反应,然后尝试使用伯胺进行杂环化。一种新颖的顺序氮杂维蒂希/环加成/环变换机构,用于形成10已经报道基于所述隔离和关键中间体的表征,吡啶并[1,2一个] [1,3,5]三嗪15形成的通过 最初生产的碳二亚胺与异氰酸芳基酯的[4 + 2]环加成反应。