Quinoxaline Derivatives. XI. The Reaction of Quinoxaline 1,4-Dioxide and Some of its Derivatives with Acetyl Chloride

Abstract

Quinoxaline 1,4-dioxide (Ia) with acetyl chloride gives 6-chloroquinoxaline 1-oxide (Ila). On heating, and progressively increasing the time of reaction, the yield of Ila increases, and 3-chloroquinoxaline 1-oxide (Illa) and 6,7-dichloroquinoxaline appear as additional products. 7-Ethoxy- (lb), 7-methoxy- (Ic), and 7-methylquinoxa-line 1,4-dioxides (Id) show a similar behavior, giving corresponding 6-chloro (Ilb-d) and 3-chloro derivatives (Illb-d), as main products. Further increase in the reaction time results in the formation of 2,6-dichloro (Vb-d) and 2,3-dichloro (VIb-d) compounds as additional products. However none of the 2-chloro 4-oxide derivatives (IVb-d) were isolated. The mechanisms for these transformations have been proposed and discussed. © 1973, American Chemical Society. All rights reserved.