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Synthesis of quinoxalinediones

Recent Literature

Whereas the cyclocondensation of 2-aminothiophenols with 1,2-biselectrophiles such as ethyl glyoxalate and diethyl oxalate in aqueous medium leads to the formation of benzothiazole-2-carboxylates via a 5-endo-trig process contrary to Baldwin’s rule, the reaction of 2-aminophenols/anilines produced the corresponding benzazine-3-ones or benzazine-2,3-diones via a 6-exo-trig process in compliance with Baldwin’s rule.
T. M. Dhameliya, S. S. Chourasiya, E. Mishra, P. S: Hadhavar, P. V. Bharatam, A. K. Chakraborti, J. Org. Chem., 2017, 82, 10077-10091.

An unprecedented metal-free reaction of o-aminobenzamides with CO2 provides N-unsubstituted and N3-substituted quinazoline-2,4(1H,3H)-diones at room temperature. This eco-friendly protocol tolerates a broad range of functional groups (including alkyl, aryl, and heterocycle groups) at the N3-position.
L. Zhang, Q. Chen, L. Li, N. Ma, J. Tian, H. Sun, Q. Xu, Y. Yang, C. Li, Org. Lett., 2023, 25, 2471-2475.

A visible-light-promoted oxidation of quinoxalin-2(1H)-ones provides various quinoxalinediones in very good yields under an ambient air atmosphere using recyclable graphitic carbon nitride (g-C3N4) as a heterogeneous photocatalyst. Importantly, the heterogeneous catalyst can be used at least six times without significant loss of activity.
L.-Y. Xie, Q.-X. Xie, Y.-D. Chen, J.-Y. Zhou, S. Peng, Synthesis, 2023, 55, 443-450.

Visible light mediates a metal-free oxygenation of quinoxalin-2(1H)-one to quinoxaline-2,3-diones in very good yields by employing Mes-Acr-MeClO4 as a photocatalyst without using any additive or cocatalyst. O2 serves as the eco-friendly and green oxidant source for this conversion. In addition, this sustainable approach tolerates a broad range of functional groups.
S. Sau, P. Mal, J. Org. Chem., 2022, 87, 14565-14579.