THE CHEMISTRY OF 2'-AMINO ANALOGS OF 2'-HYDROXYCHALCONE AND ITS DERIVATIVES

The cyclization of 2'-aminochalcone (2a) and its side-chain additives has been studied for the development of syntheses of 2-aryl-4-quinolones. 2a and its 2-acetamido 2b and 2-benzenesulfonamido 2c derivatives underwent acid- or base-catalyzed cyclization to 1,2,3,4-tetrahydro-4-quinolones. The ɑ,ß-dibromides of 2b and 2c cyclized to cis-3-bromo-4-quinolones as did the corresponding α-bromochalcones and the ɑ-bromo-ß-methoxyadditive of 2c. 2-Acetamido-a-bromochalcone was cyclized by acid to 1,4-dihydro-2-phenyl-4-quinolone. 2'-Aminochalcone formed a stable epoxide which, with acid, gave ds-3-hydroxy-1,2,3,4-tetrahydro-3-phenyl-4-quinolone. 2'-Aminochalcones 2a-c and their additives, such as dibromide and epoxide, are useful, readily available precursors of various 2-aryl-4-quinolones. © 1990, American Chemical Society. All rights reserved.