Nucleophilic Substitution of Oxazino-/Oxazolino-/Benzoxazin- 32-bindazoles: An Effective Route to 1 H-Indazolones

摘要

A variety of nucleophiles – thiolates, alkoxides, amines, iodide, and cyanide – react with oxazino-, oxazolino-, and benzoxazin[3,2-b]indazoles under microwave conditions to yield a diverse set of 2-substituted 1 H-indazolones. The synthetic utility of these indazoles is further demonstrated by ANRORC (Addition of the Nucleophile, Ring Opening, and Ring Closure) reactions to yield isomeric pyrazoloindazolones by a process wherein iodide acts first as a nucleophile and subsequently as a leaving group.