A Facile Synthesis of (2-Oxo-1,2-dihydroquinoxalin-3-yl)-methyl Ketones and (Quinoxalin-2-yl)-methyl Ketones

Recent Advances on the Catalytic Functionalization of Quinoxalin- 2(1H)-ones via C-H Bond Activation

“…Although great achievements have been made, the synthesis of quinoxalin-2(1H)-ones bearing an alkyl substituent at C3 position via the direct C-H bond functionalization has rarely been reported. In 1983, Ramanathan and coworkers [5] reported a transition metal-free system for the oxidative cross-coupling reaction of quinoxalines with ketones in the presence of dimethyl sulphate (Scheme 1). When the reaction was conducted with equimolar quantities of quinoxalin-2(1H)-ones and the corresponding methyl ketones were refluxed in the presence of catalytic amount of anhydrous dimethyl sulphate to yield the quinoxalinyl ketones.…”

New opportunities for the synthesis of quinoxaline derivatives

“…The synthesis of (2-oxo-1,2-dihydroquinoxalin-3-yl)methyl ketones in reaction of quinoxalin-2-one with ketones in dimethyl sulfate is described earlier [17]. 3-Indolyl derivative of quinoxalin-2-one was prepared from its reaction with indole in the presence of acylating reagents [30].…”

“…Quinoxalylketenes were prepared as a result of substitution of the hydrogen upon heating of quinoxaline-2-ones with methylketenes in the presence of dimethyl sulfate [17]. Similarly, interaction of quino xaline-2-one with acetophenones in the presence of boron trifluoride leads to 3-(2-hydroxy-2-R-vinyl)quinoxalin-2-ones [18].…”

Copper‐Catalyzed Direct C‐3 Benzylation of Quinoxalin‐2(1H)‐ones with Methylarenes under Microwave Irradiation

“…Over the past decades, transition‐metal or transition‐metal‐free catalyzed direct C–H bond functionalization has proven to be a versatile step‐ and atom‐economic method in modern organic synthesis . In this field, the catalytic direct C3–H functionalization of quinoxalin‐2(1 H )‐ones has emerged as an attractive approach to 3‐substituted quinoxalin‐2(1 H )‐ones, which usually exhibit significant pharmaceutical properties . Recently, several important advances have been reported, including the radical C3–H arylation, phosphonylation, amination, acylation, and cyanoalkylation of quinoxalin‐2(1 H )‐ones (Scheme a).…”