This book highlighted the methods used for the syntheses of benzoxazinone and quinazolinone derivatives. The activity of benzoxazinones and their synthetic importance were investigated. It also reported a good introduction for the literature survey of lubricating oil additives including detergents dispersants additives and viscosity index improvers. In this context, we reported herein the behavior of benzoxazinone derivative towards some active reagents as a facile and convenient route to some heterocyclic derivatives containing benzoxazinone or quinazolinone moieties. The methods of synthesis and the synthetic mechanisms of the aforementioned reactions were well presented. This book evaluated the synthesized compounds as antioxidant additives for lubricating oil and corrosion inhibitors for Fe, Cu and Al metals. The investigated compounds possess excellent tribological performances.