Heterocycles in general and nitrogen heterocycles in particular constitute the lion's part of the classical divisions of organic chemistry and are of immense importance biologically, industrially, and indeed to the healthy functioning of any developed society. The majority of pharmaceuticals/ biologically significant/ agrochemicals/ commercially used available entities are heterocyclic compounds. They are available in living systems, viz. DNA-RNA bases, vitamins, enzymes, hormones etc. which play a crucial role in the biochemical processes. Relevant to the proposed project are the nitrogen heterocycles, which normally form the basic skeleton of alkaloids. To be specific, this proposed project involves the works on pyrimidines - the RNA nucleobase, whose biochemical role is well known. This book entitled "Pyrimidine Chemistry: Synthesis, Structure and Bioactivity of some Uracil Derivatives" comprises of seven Chapters. Each chapter is divided into sections namely Introduction, Materials and Methods, Results and Discussion (including Bioactivity test), Conclusion, Experimental Section and References respectively (excluding Chapters 1 & 7).