From Thiourea to Bicyclic Structures: An Original Route to Imidazo[2,1-<i>b</i>]thiazoles, 5<i>H</i>-Thiazolo[3,2-<i>a</i>]pyrimidines, 7<i>H</i>-Imidazo[2,1-<i>b</i>][1,3]thiazines, and 2<i>H</i>,6<i>H</i>-Pyrimido[2,1-<i>b</i>][1,3]thiazines
作者:Cyrille Landreau、David Deniaud、Jean Claude Meslin
DOI:10.1021/jo034381l
日期:2003.6.1
themselves undergoing cyclization reactions to yield imidazo[2,1-b]thiazoles, 5H-thiazolo[3,2-a]pyrimidines, 7H-imidazo[2,1-b][1,3]thiazines, and 2H,6H-pyrimido[2,1-b][1,3]thiazines without any regioisomeric ambiguity. This straightforward route represents an original and unambiguously regioselective pathway to these valuable heterocycles.
我们报告了一个有效的区域选择性合成使用硫脲作为原料的双杂环化合物的例子。实际上,通过将N,N-二甲基甲酰胺二甲基乙缩醛与硫脲双重缩合可轻松制得的N,N'-双(二甲基氨基亚甲基)硫脲(1)可以与卤代酮或丙烯酸二烯亲和剂反应生成噻唑类(2)和噻嗪类( 3)二氮杂二烯本身分别进行环化反应,生成咪唑并[2,1-b]噻唑,5H-噻唑并[3,2-a]嘧啶,7H-咪唑并[2,1-b] [1,3]噻嗪和2H,6H-嘧啶[2,1-b] [1,3]噻嗪,没有任何区域异构的歧义。这种简单的途径代表了通往这些有价值的杂环的原始且明确的区域选择性途径。