Synthesis of (Z )-N-(2-amino-1,2-dicyanovinyl)formamide O-alkyloximes and a study of their cyclization in the presence of base
作者:Brian L. Booth、Flora A. T. Costa、Zahid Mahmood、Robin G. Pritchard、M. Fernanda Proença
DOI:10.1039/a901332f
日期:——
The title compounds (3) have been prepared in high yield by reaction of (Z)-N-(2-amino-1,2-dicyanovinyl)formimidate with an alkoxyamine NH2OR (R = CH2Ph, Me). These compounds cyclize to the corresponding 5-amino-4-cyanoimidazoles 4 by reaction with ethanolic NaOH solution. In ethyl acetate and using DBU as a base, amidoximes 3 follow an unexpected cyclization pathway leading to a pyrimidine structure
通过使(Z)-N-(2-氨基-1,2-二氰基乙烯基)甲酸酯与烷氧基胺NH 2 OR(R = CH 2 Ph,Me)反应,以高收率制备了标题化合物(3)。这些化合物通过与乙醇NaOH溶液反应而环化成相应的5-氨基-4-氰基咪唑4。在乙酸乙酯中,以DBU为碱,a胺肟3遵循意想不到的环化途径,导致嘧啶结构5。mid胺肟3a和嘧啶5a均获得了单晶X射线结构(R = CH 2Ph)。在固态和溶液中均发现的the胺肟结构中的强分子内氢键可能是这些化合物中观察到的异常环化模式的原因。