Efficient Synthesis of Fused Pyrimidine Derivatives with Biological Activity via Aza-Wittig Reaction

Pyrimidine derivatives have played an important role in the chemistry of biological systems. This review focuses on recent work of our studies on the synthesis and biological activity of fused pyrimidine derivatives including pyrido[4,3-d]pyrimidine-4(3H)- ones; 3,4-dihydro-pyrido[4,3-d]pyrimidine-8-carbonitriles; pyrazolo[3,4-b]pyrido[4,3-d]-pyrimidine-4-ones; thieno[3',2'-5,6]pyrido [4,3- d]pyrimidin-4(3H)-ones; 1,2,3-triazolo[4,5-d]pyrimidin-7-ones; 1,2,4-triazolo[1,5-a]pyrimidin-10(3H)-ones; thiazolo[4,5-d]pyrimidin- 4(3H)-ones and pyrazolo[4',3':5,6]pyrano[2,3-d]pyrimidin-4(3H)-ones. The different approaches for the syntheses of these fused pyrimidine derivatives are described and reviewed. Parts of other researchers' most relevant work were also included in this review.