A rapid synthesis of quinoxalines starting from ketones

TsNBr2 Mediated Synthesis of 2‐Acylbenzothiazoles and Quinoxalines from Aryl Methyl Ketones under Metal Free Condition

“…Synthesis of quinoxalines in PEG‐400 mediated by hypervalent iodine(III) sulfonate was also reported . It can also be synthesized through one pot reaction of ketones via their α‐hydroxylimino ketone derivatives and condensation of the latter with 1,2‐diaminobenzene under microwave irradiation . Ketones can also be converted to corresponding qunoxalines via the formation of α‐tosyloxyketones with the aid of either [hydroxy(tosyloxy)iodo]benzene (HTIB) or a combination of iodobenzene, mCPBA and p ‐toluenesulfonic acid –.…”

Present status of quinoxaline motifs: Excellent pathfinders in therapeutic medicine

“…<<<<Scheme 2>>>> (c). The exposure of a well ground neat mixture of α-hydoxyimino ketone and o-phenylene diamine to microwave irradiation afforded the corresponding quinoxalines 20 as shown in Scheme 3a [43], while the plausible mechanism for the protonation of oxime group and intramolecular rearrangement was shown in Scheme 3b [43]. The α-hydoxyimino ketonic intermediate required for this study was acquired after slight modification of the earlier reported procedure by Rüedi and coworkers [44].…”

[4 + 2] Heterocyclization for Efficient Formation of Substituted Quinoxalines through Carbon–Oxygen Bonds Cleavage

“…Because of the preparation of 1,2‐dicarbonyl compounds, α‐hydroxy ketones or α‐haloketones requires multi‐steps involving benzoic condensation, oxidation reactions or halogenations, such reactions suffered from narrow substrate scopes, the use of expensive reagents/additives, or harsh reaction conditions, as well as the difficult experimental/work‐up procedures. In addition, there are some other oxidative approaches to synthesize quinoxaline derivatives . These shortcomings may limit the functional group compatibility and their application.…”