Synthesis of Substituted 5‐aryl‐2,3‐dihydropyrazine 1,4‐dioxides Based on Condensation of N,N′‐(2,3‐dimethylbutane‐2,3‐diyl)bis(hydroxylamine) with Various Arylglyoxals

For the first time, a method for the synthesis of 2,3‐dihydropyrazine 1,4‐dioxide derivatives was devised. The presented approach is based on the reaction of N,N′‐(2,3‐dimethylbutane‐2,3‐diyl)bis(hydroxylamine) with α‐ketoaldehydes. A distinctive feature of the proposed protocol is the application of sulfate of the aforementioned bis‐hydroxylamine in the considered condensation. The advantages of the newly developed route are a one‐step synthetic procedure involving easily available starting materials, atom economy, and simple work‐up of the reaction mixture. The structure of one of the obtained products was confirmed by x‐ray analysis.