Optimizing reaction efficiency: Microwave-supported synthesis of quinoxaline-based compounds

Abstract

The chemistry of chloroquinoxalines has garnered significant interest owing to the potential applications of this nitrogen-containing heterocyclic class in various fields. This manuscript delves into the investigation of heteroaromatic nucleophilic substitution reactions (SNAr) involving quinoxaline substrates, specifically 2-chloroquinoxaline and 2-chloro-3-methylquinoxaline, in the presence of thiols (mercaptan). The documented findings present the outcome of these reactions, which proceed experimentally under mild and metal-free conditions and lead to the selective formation of mono- and di-substituted products with commendable yields. Employing microwave-assisted synthesis for the preparation of compounds 1, 4, and 5 was crucial for optimizing reaction efficiency and maximizing product formation. The experimental findings revealed an increase in the overall yield of compounds 1, 4, and 5 by approximately 15–20%, accompanied by a significant reduction in reaction time by 75%.

Keywords

• Chloroquinoxalines
• SNAr
• Microwave synthesis
• Thioethers
• C-S bond formation