New Azacycles by One‐Pot Three‐Component Hantzsch‐Like Synthesis of Tetra(hexa)azacyclopenta[a]anthracenes, Tetraazaindeno[5,4‐b]fluorenes, and Oxatetraazacyclopenta[m]tetraphenes

Abstract

AbstractNew Azacycles by One‐Pot Three‐Component Hantzsch‐Like Synthesis of Tetra(hexa)azacyclopenta[a]anthracenes, Tetraazaindeno[5,4‐b]fluorenes, and Oxatetraazacyclopenta[m]tetraphenes (H. Butenschön, I. A. Abdelhamid et al.) #OpenAccessMulticomponent reactions (MCRs) are envisaged as an entry point for the synthesis of heterocyclic compounds with interesting biological activities. An efficient approach to annelated tetra(hexa)azacyclopenta[a]anthracenes, tetraazaindeno[5,4‐b]fluorenes, and oxatetraazacyclopenta[m]tetraphene was accomplished using a three‐component reaction involving 7‐amino‐2‐methyl‐3‐phenylpyrazolo[1,5‐a]pyrimidin‐5‐one with aromatic aldehydes and the corresponding active 1,3‐dicarbonyl compounds (namely, dimedone, 1,3‐dimethylbarbituric acid, 1,3‐indanedione, and 4‐hydroxycoumarine). The reactions were conducted in glacial acetic acid at reflux for 5 h to give the desired products in good yields (62–83 %). The chemical constitutions of all new products were confirmed spectroscopically.