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

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• 作者：Pascal Dao ; Christiane Garbay ; Huixiong Chen ; ^{huixiong.chen@parisdescartes.fr}
• 关键词：Nitrogen heterocycles ; Cyclization ; Regioselectivity ; Reaction mechanisms
• 刊名：Tetrahedron
• 出版年：2013
• 出版时间：13 May, 2013
• 年：2013
• 卷：69
• 期：19
• 页码：3867-3871
• 全文大小：449 K

文摘

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 dicyandiamide and the corresponding arylamines. Mechanistic studies for the subsequent cyclocondensation 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.