Synthesis of 5,6-, 5,8- and 7,8-Isoquinolinediones from the Corresponding Isoquinolinols and Dimethoxyisoquinolines.

Abstract

5, 8-Isopuinolinediones (12, 18, 25), 7, 8-isoquinolinediones (14, 19) and 5, 6-isoquinolinediones (26) were synthesized by oxidative demethylation of the corresponding dimethoxyisoquinolines with cerium(IV) ammonium nitrate or silver(II) oxide. 8-Dialkylamino-5, 6-isoquinolinediones (31) and 3, 5-bis(dialkylamino)-7, 8-isoquinolinediones (33) were prepared by copper(II)-catalyzed oxidation of the corresponding isoquinolinols with secondary amines. 5, 8-Isoquinolinediones (29, 34, 40) were also prepared.