Jianchao Liu, H. He, Qingyun Ren
Jul 1, 2006
Citations
0
Influential Citations
14
Citations
Journal
Helvetica Chimica Acta
Abstract
A series of new, 2-substituted 3-aryl-8,9,10,11-tetrahydro-5-methyl[1]benzothieno[3′,2′ : 5,6]pyrido[4,3-d]pyrimidin-4(3H)-ones, compounds 5a–q, were designed and synthesized via the aza-Wittig reaction as the key step. The iminophosphorane 1 reacted with phenyl isocyanate (or 4-chlorophenyl isocyanate) to the carbodiimide 4, which was cyclized to 5 upon addition of different amines, EtOH, or phenols in the presence of a catalytic amount of EtONa or K2CO3 (Schemes 1 and 2). The structures of compounds 5 were confirmed by IR, 1H- and 13C-NMR, EI-MS, elemental analyses, and, in the case of 5l, by single-crystal X-ray diffraction (Figure).