A new facet of the reaction of nitro heteroaromatic compounds with ethyl isocyanoacetate
作者:Takashi Murashima、Ken-ichi Fujita、Kazuo Ono、Takuji Ogawa、Hidemitsu Uno、Noboru Ono
DOI:10.1039/p19960001403
日期:——
heteroarenes react with ethyl isocyanoacetate in the presence of 1,8-diazabicyclo[5.4.0]undecene (DBU) to give pyrroles or pyrimidine N-oxide depending on the structure of the starting nitro compounds. For example, 4-nitro-2,1,3-benzothiadiazole 3a reacted with ethyl isocyanoacetate to give ethyl 2,1,3-benzothiadiazole[3,4-c]pyrrole-2-carboxylate 4a (33%), while a similar reaction with 5-nitro-2,1,3-benzothiadiazole
在1,8-二氮杂双环[5.4.0]十一碳烯(DBU)存在下,硝基杂芳烃与异氰基乙酸乙酯反应生成吡咯或嘧啶N-氧化物,具体取决于起始硝基化合物的结构。例如,4-硝基-2,1,3-苯并噻二唑3a与异氰基乙酸乙酯反应生成2,1,3-苯并噻二唑[3,4- c ]吡咯-2-羧酸乙酯4a(33%),与5-硝基-2,1,3-苯并噻二唑3b反应,得到相应的化合物4b(21%),为唯一产物。提出了这些反应的合理机制。