Synthesis and electrochemistry of pyrimidoquinazoline-5, 10-diones. Design of hydrolytically stable high potential quinones and new reductive alkylation systems
EB Skibo, JH Gilchrist
文献索引：Skibo, Edward B.; Gilchrist, James H. Journal of Organic Chemistry, 1988 , vol. 53, # 18 p. 4209 - 4218
DMF at room temperature afforded the half-cyclized product 9, which cannot be cyclized to the pyrimido [4, 5-glquinazoline system even under harsh conditions (refluxing concentrated HC1). The closure of the first pyrimidinone ring is favored due to electron withdrawal by the nitro group from the acetamido group undergoing nucleophilic attack. On the other hand, this nitro group precludes cyclization of the second pyrimidinone ring by electron withdrawal ...
