Regioselective synthesis of imidazo[1,2-a][1,3,5]triazines and 3,4-dihydroimidazo[1,2-a][1,3,5]triazines from [1,3,5]triazin-2,4-diamines
作者:Pascal Dao、Christiane Garbay、Huixiong Chen
DOI:10.1016/j.tet.2013.03.039
日期:2013.5
An efficient and practical procedure was developed to prepare novel imidazo[1,2-a][1,3,5]triazines and 3,4-dihydroimidazo[1,2-a][1,3,5]triazines with a good regioselectivity and high yields, starting from di-cyandiamide and the corresponding arylamines. Mechanistic studies for the subsequent cyclo-condensation with chloroacetaldehyde support a pathway, which begins with the displacement of the chloro atom activated by an adjacent CO group, followed by cyclization and dehydration. (C) 2013 Elsevier Ltd. All rights reserved.