Synthesis of nitrogen-containing heterocycles. 7 Reaction of aliphatic diaminomethylenehydrazones with hindered ethoxymethylenecyanoacetate
作者:Yoshiko Miyamoto、Chiji Yamazaki
DOI:10.1002/jhet.5570330447
日期:1996.7
along with 3. When the alkylidene moiety was bulky, 1e and 1f, the similar reaction gave 3 in high yields without any cyclized product. Upon exposure to acid, compound 3 yielded 6-oxo-1,6-dihydropyrimidines 6, [1,2,4]triazolo[1,5-c]pyrimidine-8-carboxylate 5 and N-alkenyl-1,2,4-triazoles 9 in addition to 7 and 8 in proportions dictated by the nature of the substituents of 1. The structural assignment
脂族diaminomethylenehydrazones 1用2-氰基-3-乙氧基-2-戊烯酸反应2根据取代模式和取代基的大小,得到了一些在低杂环至适中的产率,。当1在末端氮上带有一个甲基时,它优先给出6- N-(1,6-dihydropyrimidines)4,将N(4)结合到环中。相反,1c或1d与2之间的反应导致6-亚氨基-和6-氧代-1、6-二氢嘧啶7和8以及3。亚烷基部分大时,1e和1f,相似的反应在没有任何环化产物的情况下以高收率得到3。暴露于酸后,化合物3产生6-氧代-1,6-二氢嘧啶6,[1,2,4]三唑并[1,5 - c ]嘧啶-8-羧酸盐5和N-烯基-1,2,4除7和8以外的-三唑9的比例由1的取代基的性质决定。讨论了结构分配和反应机理。