Cleavage of Pyrrolo[2,1-c][1,4]benzoxazine-1,2,4-triones with Thiocarbonohydrazide. Synthesis of Substituted 4-Amino-1,2,4-triazines
作者:A. I. Kobelev、E. E. Stepanova、M. V. Dmitriev、A. N. Maslivets
DOI:10.1134/s1070428019070182
日期:2019.7
4-dihydro-1,2,4-triazin-5(2H)-ones and 6-substituted 1,4-benzoxazine-2,3-diones which can be separated by fractional crystallization directly from the reaction mixture. The reaction is likely to involve a sequence of nucleophilic transformations with intermediate formation of spiro[pyrrole-2,6′-[1,2,4]triazines] which undergo cleavage of the C2-N1 bond in the pyrrole ring. The structure of the products
3-酰基吡咯并[ 2,1- c ] [1,4]苯并恶嗪-1,2,4-三酮与硫代碳酰肼反应生成4-氨基-6-(酰基甲基)-3-亚磺酰基-3,4-二氢的混合物-1,2,4-三嗪-5(2 H)-ones和6-取代的1,4-苯并恶嗪-2,3-二酮可以通过分级结晶直接从反应混合物中分离出来。该反应可能涉及亲核转化的序列,中间形成螺[吡咯-2,6'-[1,2,4]三嗪],该中间体经历C 2 -N 1的裂解在吡咯环上键合。通过X射线分析确定产物的结构,并通过UPLC / MS鉴定中间产物。1,2,4-三嗪衍生物也可以独立地与2,4-二氧代丁酸烷基酯或2-氧代丁二酸和硫代碳酰肼合成。由4-芳基-2,4-二氧代丁酸和硫代碳酰肼合成4-氨基-1,2,4-三嗪的已知程序已得到改进,以满足“绿色化学”原理。开发了两种合成取代的4-氨基-1,2,4-三嗪的新方法。所获得的化合物引起了药物化学,药理学和精细有机合成的兴趣。