A practical one-pot procedure for the synthesis of pyrazino[2′,3′:4,5]thieno[3,2-d]pyrimidinones by a tandem aza-Wittig/heterocumulene-mediated annulation strategy
作者:Gerardo Blanco、Natalia Seguí、José M. Quintela、Carlos Peinador、Marcos Chas、Rosa Toba
DOI:10.1016/j.tet.2006.09.028
日期:2006.11
A simple one-pot and efficient method is described for the synthesis of pyrazino[2′,3′:4,5]thieno[3,2-d]pyrimidinone derivatives 6 via a tandem aza-Wittig/heterocumulene-mediated annulation process. The iminophosphorane 3 reacted with aryl isocyanates, followed by heterocyclization on addition of secondary amines to give the corresponding guanidine intermediates 5, which were cyclized in the presence
描述了一种简单的一锅高效方法,该方法可通过aza-Wittig /杂异丙苯介导的环空法合成吡嗪并[2',3':4,5]噻吩并[3,2- d ]嘧啶酮衍生物6。亚氨基磷烷3与芳基异氰酸酯反应,然后通过添加仲胺进行杂环化,得到相应的胍中间体5,在催化量的碳酸钾存在下将其环化成三环化合物6。类似地,亚氨基磷烷3与酚,苯硫酚或ROH反应生成2-芳基(烷基)氧基(硫代)吡嗪并[2',3':4,5]噻吩并[3,2- d ]嘧啶酮衍生物7丰产。可以分离和表征相应的碳二亚胺4c和胍型中间体化合物5,从而证实了建议的反应途径。然而,在亚氨基磷烷3与芳族异氰酸酯的反应中,以及随后在催化量的碳酸钾的存在下,与伯胺的反应中,可以产生两种异构的吡嗪并噻吩并嘧啶酮8和9。研究了亲核试剂和异氰酸酯对环化区域选择性的影响。