Synthesis of quinoxaline derivatives from substituted acetanilides through intramolecular quaternization reactions

The cyclization of 2-dialkylamino-2′-halogeno- and 2-chloro-2′-(dialkylamino)acetanilides to quinoxaline derivatives has been studied in detail. These reactions proceed, respectively, through intramolecular aromatic nucleophilic or aliphatic nucleophilic substitution reactions and depending on the substituents and the experimental conditions, they lead to 3-oxoquinoxalinium salts or, after an alkyl chloride elimination, to quinoxalin-2-ones. Some new cases of the little known intramolecular quaternization of tertiary amines with aryl halides are described.