A New Access to 2-(Alkylamino)- and 2-(Arylamino)pyrroles by Addition of Isocyanides to Protonated 1-Azabutadienes
作者:Evelyne Marchand、Georges Morel、Sourisak Sinbandhit
DOI:10.1002/(sici)1099-0690(199907)1999:7<1729::aid-ejoc1729>3.0.co;2-s
日期:1999.7
A number of 5-(alkylamino)- or 5-(arylamino)-2H-pyrrolium salts 3 or 5 have been obtained by treating the 1-aza-1,3-diene hydrochlorides 2 with isocyanides R4NC in refluxing acetonitrile or chloroform for a few hours. Depending on the experimental conditions, deprotonation of these species can occur in the reaction medium to furnish the corresponding 2-aminopyrroles 4 and 6. Insertion of isocyanide
通过在回流的乙腈或乙腈中用异氰酸酯R 4 NC处理1-氮杂-1,3-二烯盐酸盐2获得了许多5-(烷基氨基)-或5-(芳基氨基)-2 H-吡咯鎓盐3或5。氯仿几个小时。取决于实验条件,这些物质的去质子化可在反应介质中发生,以提供相应的2-氨基吡咯4和6。在吡咯盐的碳氢键中插入异氰化物也会导致生成(吡咯-2-基)亚甲基亚胺氯化物7 – 9。在类似条件下,治疗与过量的叔丁基异氰酸酯将质子化的α-氯肉桂二胺2j,k转化为5-(叔丁基氨基)吡咯-2-腈13。所有环加合物的结构均基于其NMR光谱特性进行了确定,尤其是在NOEDIFF实验中观察到的效果。建议的机制解释了在大气氧下吡咯4和6的闭环反应和自氧化,从而得到5-亚氨基-2-吡咯啉酮17和18。