Oxidation of Urazoles with 1,3-Dihalo-5,5-dimethylhydantoin, both in Solution and under Solvent-Free Conditions

Abstract

O x i d a t i o n o f U r a z o l e s w i t h 1 , 3 -D i h a l o -5 , 5 -d i m e t h y l h y d a n t o i n

Silica‐supported ICl as a novel heterogeneous system for the rapid oxidation of urazoles to triazolinediones

“…Examples are iodination of toluene [1b], α-iodination of β-ketosulfones [7], iodination of nitroarenes [1f], and other similar reports [1][2][3][4][5][6][7][8][9]. On the other hand, there are some reports on oxidation of the urazoles using the precursor of halonium species (with the suggested mechanism therein) such as 1,3-dihalo-5,5-dimethylhydantoin [14], silica sulfuric acid/KClO 3 or silica chloride/oxone ® systems [16b], and periodic acid or oxone ® /KBr system [16a]. Therefore, we propose a mechanism based on these previously reported results on the application of ICl (1) and oxidation of urazoles (see Scheme 5).…”

“…4-Substituted-1,2,4-triazoline-3,5-diones have been used in a variety of reactions such as ene SCHEME 1 reactions, electrophilic aromatic substitution, dehydrogenating properties, and oxidation of alcohols [12][13][14]. From the biochemical point of view, some of them have been identified as protein cross-linkers and conformational probes for some enzymes [15].…”

Recent progress in the application of N-halo reagents in the synthesis of heterocyclic compounds

“…74e77 DBH has also been used for the efficient oxidation of uraazoles and bis-urazoles to their corresponding triazolinediones in solution and under solvent-free conditions (Scheme 39). 78 Khoramabadi-Zad et al have described iodogen as a novel reagent for the efficient and practical oxidation of urazoles and bisurazoles under heterogeneous conditions. This system could be used for the oxidation of a range of urazoles under mild and safe conditions (Scheme 40).…”

The first report on the catalytic oxidation of urazoles to their corresponding triazolinediones via in situ catalytic generation of Br+ using periodic acid or oxone®/KBr system

“…Therefore, the oxidation reaction has been performed via in situ generation of Br + (Scheme 5). Scheme 6. This new catalytic system acts as such as 1,3-dibromo-5,5-dimethylhydantoin (DBH) via in situ generation of Br + [19].…”