Pyrrolodiazines with a Bridgehead Nitrogen

Abstract

The general class of pyrrolodiazines with a bridgehead nitrogen atom includes four distinct heterocyclic systems. This chapter presents an overview of the primary literature on these four hetrocyclic systems in order to systematically compare and contrast their chemistry and compile spectral data of value in making structural assignments for derivatives of these compounds. In the context of pyrrolo[1,2-a]pyrimidines, the methods for preparing this ring system are essentially divided into three categories—namely, syntheses starting with the pyrimidine portion of the bicyclic system preformed, syntheses starting with the pyrrole portion of the molecule preformed, and syntheses employing only acyclic precursors. Few functional group transformations, such as etherification and nitrile hydrolysis, are reported for derivatives of the completely unsaturated pyrrolo[1,2-a]pyrimidine nucleus. However, the reactions reported for pyrrolo[1,2-c]pyrimidines are of three main types—namely, electrophilic attack, addition reactions, and ring opening reactions. Electrophilic reactions on this compound produce 7-substituted derivatives.