Recent Advancement in the Conversion of 1,2,3‐Benzotriazin‐4(3 H )‐One to Other Heterocyclic Systems and Their Applications: A Concise Review

Abstract The nitrogen containing 1,2,3‐benzotriazin‐4(3 H )‐one is structurally worthwhile system for its notable applications in the synthesis of N─ , O ─ and S─ heterocycles bears pivotal significant usage in the pharmaceutical and industrial chemicals. Today most of common items like dyes, cosmetics, sanitizers, insecticides and plastics are based on heterocyclic moieties. Different starting materials are used industrially for the formation of diverse heterocycles but 1,2,3‐benzotriazin‐4(3 H )‐one is a valuable structure used to prepare numerous valuable products. These conversions are radiation or metal‐catalyzed denitrogenation annulation type reactions provide easy, one‐step and atom‐economical route. The vast applications of heterocycles and significance of their cheap synthesis make this subject interesting for scientific researchers and industrialists. This mini review summarizes the recent developments in the transformation of 1,2,3‐benzotriazin‐4(3 H )‐one ring to various other structures like phenanthridinones, isoquinolones, coumarin‐1‐imines, benzamides, pyrroloquinazolinones, indolin‐1‐ones, 1,2‐benzisoselenazol‐3(2 H )‐ones and benzofuranones. Some emerging drugs like ebselen, losartan, irbesartan, luotonin A, deoxyvasicinone and mackinazolinone have been successfully synthesized from differently substituted benzotriazinones.