Pyrimidine-fused derivatives traits the inextricable part of DNA and RNA, exhibit indispensable
role in numerous biological processes, possessing momentous chemical and biological importance.
Pyrimidine-condensed derivatives as the pharmacophore exhibit broad spectrum of biological
activities encompassing antitubercular, antibacterial, antifungal, antiviral, anti-inflammatory, antimalarial,
anticancer and anti-HIV. Several retrosynthetic approaches, are available for the synthesis
of pyrimidine-fused analogues which offers enormous scope in the field of medicinal chemistry. Ring
fused pyrimidine and their innumerable derivatives continue to hold the attention of chemists since
their presence in the biologically active resources have been known to elicit additive effects on the
bio-efficacy of the molecules. The present review is a concerted effort to congregate information
mainly focusing on the comprehensive categorization of pyrimidine ring based on their fusion with
five, six, seven and eight-membered ring(s). Moreover, it also puts forward their systematic nomenclature,
synthetic strategies, and bioactivities including SAR studies. This review is being put forwarded
with an incentive to provide researchers with a comprehensive and updated literature. In addition,
the manuscript also brings to light the various pharmacophore designs based on fusedpyrimidine
ring system, delving deeper into synthesis and the subsequent generation of new libraries
of pyrimidine-fused derivatives including their biological assessments.