1,3-Dibromo-5,5-dimethylhydantoin, a useful reagent for aromatic bromination

1,3-dihalo-5,5-dimethylhydantoin/NaNO2 as an efficient heterogeneous system for the N-nitrosation of N,N-dialkylamines under mild conditions

“…E-mail: niknam@pgu.ac.ir Very recently, we and many others have demonstrated that the heterogeneous reagent systems have many advantages such as simple experimental procedures, mild reaction conditions and minimization of chemical waste as compared to the liquid phase counterparts [10][11][12][13][14][15]. In continuation of our studies in this regard, we have found that 1,3-dihalo-5,5-dimethylhydantoin, a cheap, commercially available reagent, recently used as an excellent reagent for analytical purposes [16][17][18], has thus far found little application in organic chemistry [19][20][21][22][23][24][25]. Therefore, we decided to apply DBDMH and DCDMH, sodium nitrite (I) and wet-SiO 2 as a heterogeneous system for the in situ generation of NOX (X = Br, Cl) in a non-aqueous medium and study its applications for the nitrosation of N,N-dialkyl amines.…”

Synthesis of a New Type of Glycosidic Linkage: Acetal‐Linked Disaccharides and Trisaccharides of Acyclic and Cyclic Sugars

“…We had recently found that 1,3-dibromo-5,5-dimethylhydantoin (DBDH) was able to act as a thiophilic activator to convert acyclic sugar dithioacetals into the alkyl glycofuranosides [40] and envisioned that DBDH, a cheap source for in situ generation of bromonium ion, might be a useful catalyst for the activation of sulfide to activate the dithioacetals in the presence of cyclic glycosyl acceptors towards the formation of acyclic glycosylidene acetals. DBDH has so far been utilized mainly as a free radical brominating agent [41] and as a source of bromonium ion, exploited in aromatic ring brominations, [42,43] but the full versatility of this reagent has not been well investigated. After a series of experiments regarding the quantity of activator, reaction solvent and other conditions, it was established that the use of 1.5 equivalent of DBDH was able to provide successful coupling of acyclic donors with the cyclic sugar derivatives through an acetal linkage at 0°C in CH 3 CN as solvent in a very short period of time and in excellent yields (Scheme 1, Table 1).…”

Sono-bromination of aromatic compounds based on the ultrasonic advanced oxidation processes

“…The most conventional brominating agent remains topically Br 2 , although it is hazardous and difficult in handling together with poor atom efficiency. A large panel of brominating reagents have been thus developed, including molecular bromine with or without catalysts [6][7][8][9], N-bromosuccinimide (NBS) [10-13], 1,3-dibromodimethylhydantoin (DBDMH) [13,14], N,N-dibromo-p-toluenesulfonamide (TsNBr 2 ) [15], KBrO 3 [16], or quaternary ammonium tribromide [17][18][19], etc. All of the aforementioned reagents are used in stoichiometry amount, more or less efficient, expensive, toxic, not commercially available and lead to large amounts of wastes at the end of the reaction.…”