This book highlighted the methods used for the synthesis of some new pyrimidine compounds. The reactivity of pyrimidine and their synthetic importance were investigated. It also reported a good introduction for the literature survey of the chemistry of pyrimidine compounds. In this context, we reported herein the behavior of simple reagents in order to obtain some new pyrimidine ring systems and its reactivity towards different reagents for the constructions of heterocyclic derivatives containing a pyrimidine moiety. The methods of synthesis and the synthetic mechanisms of the aforementioned reactions were well presented and the structures of these compounds were assessed by analytical and spectral data. This book represents the ultra violet (UV) studies including synthesis and characterization of novel azobenzenesulfonamide dyes, the effect of solvent, effect of substituents and the effect of pH. The methods, analytical and spectral data of the investigated compounds were included.