128-08-5Relevant articles and documents
TIN(IV) MEDIATED SYNTHESIS OF N-HALO COMPOUNDS
Soundararajan, R.,Krishnamurthy, S.,Srinivasan, Vilanoor S.,Balasubramanian, T.R.
, p. 295 - 298 (1983)
Some representative N-halo compounds like N-bromosuccinimide, N-iodosuccinimide, N-bromophthalimide, N-iodophthalimide, N-iodobenzimidazole and N-iodobenzotriazole have been synthesised in good yields under neutral and mild conditions via an intermediate formed from the parent NH species and bis(tri-n-butyltin) oxide.The tin oxide is recovered as recyclable tri-n-butyltin halide.
Organic Synthesis Using Sodium Bromate. II. A Facile Synthesis of N-Bromo Imides and Amides Using Sodium Bromate and Hydrobromic Acid (or Sodium Bromide) in the Presence of Sulfuric Acid
Fujisaki, Shizuo,Hamura, Satoshi,Eguchi, Hisao,Nishida, Akiko
, p. 2426 - 2428 (1993)
The reaction of imides and amides in water (or aqueous acetic acid) with sodium bromate and hydrobromic acid (or sodium bromide) in the presence of sulfuric acid under mild conditions gave the corresponding N-bromides in high yields.
One-Electron Reduction of N-Bromosuccinimide. Rapid Expulsion of a Bromine Atom
Lind, Johan,Shen, Xinhua,Eriksen, Trygve E.,Merényi, Gábor,Eberson, Lennart
, p. 4629 - 4633 (1991)
By means of pulse radiolysis N-bromosuccinimide, SBr, was reduced to its radical anion, SBr?-. Evidence is presented that SBr?- rapidly fragments into the succinimide anion, S-, and a free bromine atom, Br?, which is converted into Br2?- by reacting with Br- present. The rate constant of hydrogen abstraction by Br? from 2-propanol and methanol have been determined. The carbon-centered radical of tert-butyl alcohol was also found to react with SBr yielding Br2?- in the presence of Br-.
A Practical Synthesis of N-Bromo Imides by Use of Sodium Bromite
Kajigaeshi, Shoji,Nakagawa, Takashi,Fujisaki, Shizuo,Nishida, Akiko
, p. 769 - 770 (1985)
N-Bromo imides can be readily prepared under mild conditions by a reaction of imides with sodium bromite in the presence of hydrobromic acid in fairly good yields.The scope and limitation are also presented.
Thiourea-Mediated Halogenation of Alcohols
Mohite, Amar R.,Phatake, Ravindra S.,Dubey, Pooja,Agbaria, Mohamed,Shames, Alexander I.,Lemcoff, N. Gabriel,Reany, Ofer
, p. 12901 - 12911 (2020/11/26)
The halogenation of alcohols under mild conditions expedited by the presence of substoichiometric amounts of thiourea additives is presented. The amount of thiourea added dictates the pathway of the reaction, which may diverge from the desired halogenation reaction toward oxidation of the alcohol, in the absence of thiourea, or toward starting material recovery when excess thiourea is used. Both bromination and chlorination were highly efficient for primary, secondary, tertiary, and benzyl alcohols and tolerate a broad range of functional groups. Detailed electron paramagnetic resonance (EPR) studies, isotopic labeling, and other control experiments suggest a radical-based mechanism. The fact that the reaction is carried out at ambient conditions, uses ubiquitous and inexpensive reagents, boasts a wide scope, and can be made highly atom economic, makes this new methodology a very appealing option for this archetypical organic reaction.
Triptycenyl Sulfide: A Practical and Active Catalyst for Electrophilic Aromatic Halogenation Using N-Halosuccinimides
Nishii, Yuji,Ikeda, Mitsuhiro,Hayashi, Yoshihiro,Kawauchi, Susumu,Miura, Masahiro
supporting information, p. 1621 - 1629 (2020/02/04)
A Lewis base catalyst Trip-SMe (Trip = triptycenyl) for electrophilic aromatic halogenation using N-halosuccinimides (NXS) is introduced. In the presence of an appropriate activator (as a noncoordinating-anion source), a series of unactivated aromatic compounds were halogenated at ambient temperature using NXS. This catalytic system was applicable to transformations that are currently unachievable except for the use of Br2 or Cl2: e.g., multihalogenation of naphthalene, regioselective bromination of BINOL, etc. Controlled experiments revealed that the triptycenyl substituent exerts a crucial role for the catalytic activity, and kinetic experiments implied the occurrence of a sulfonium salt [Trip-S(Me)Br][SbF6] as an active species. Compared to simple dialkyl sulfides, Trip-SMe exhibited a significant charge-separated ion pair character within the halonium complex whose structural information was obtained by the single-crystal X-ray analysis. A preliminary computational study disclosed that the πsystem of the triptycenyl functionality is a key motif to consolidate the enhancement of electrophilicity.
Esterification of aryl/alkyl acids catalysed by n-bromosuccinimide under mild reaction conditions
?ebular, Klara,Bo?i?, Bojan ?.,Stavber, Stojan
, (2018/09/10)
N-halosuccinimides (NXSs) are well-known to be convenient, easily manipulable and low-priced halogenation reagents in organic synthesis. In the present work, N-bromosuccinimide (NBS) has been promoted as the most efficient and selective catalyst among the NXSs in the reaction of direct esterification of aryl and alkyl carboxylic acids. Comprehensive esterification of substituted benzoic acids, mono-, di- and tri-carboxy alkyl derivatives has been performed under neat reaction conditions. The method is metal-free, air- and moisture-tolerant, allowing for a simple synthetic and isolation procedure as well as the large-scale synthesis of aromatic and alkyl esters with yields up to 100%. Protocol for the recycling of the catalyst has been proposed.
Preparation method of 2-amino-5-bromopyridine
-
Paragraph 0018; 0020; 0022, (2018/04/01)
The invention discloses a preparation method of 2-amino-5-bromopyridine. The preparation method is characterized in that 2-aminopyridine is used as the raw material, and two different bromination agents, namely bromine and N-bromo-succinimide (NBS), are sequentially added; the reaction temperature is strictly controlled, and thus 2-amino-5-bromopyridine can be quickly prepared with high yield andhigh purity; and the preparation method is applicable to industrial production. Additionally, a high-purity by-product, namely succinimide, is separated out in the preparation process and is brominated into high-purity NBS through potassium bromide, potassium bromate and sulfuric acid; and the NBS is applied to the synthesizing of 2-amino-5-bromopyridine in the method and has the same effect as the commercial NBS. According to the method, the quantity of used NBS is decreased, the raw material conversion rate is increased, and the bromination agents are recycled, so that the cost is greatly decreased; the main byproduct is only inorganic salt potassium sulfate; and the synthesizing method is green and environmentally friendly.
Pollution-free preparation method of N-bromosuccinimide
-
Paragraph 0011, (2017/08/27)
The invention discloses a pollution-free preparation method of N-bromosuccinimide. The preparation method comprises the following steps that 1, 1 mol of succinimide and 1.02-1.15 mol of sodium bromide are dissolved into 350 ml of water; 2, 1.0-1.13 mol of sodium hypochlorite and 1.03-1.16 mol of diluted hydrochloric acid are dropwise added while the reaction solution is stirred; 3, after dropwise adding is completed, the reaction solution is subjected to standing for 0.8-1.2 hours for reacting; 4, the reaction solution is stirred, cooled to 0 DEG C to 10 DEG C and then subjected to heat preservation and suction filtration, and a crude product is obtained; 5, the crude product is washed with ice water and dried, and N-bromosuccinimide is obtained. The pollution-free preparation method has the advantages that sodium hypochlorite and sodium bromide which are cheap and easy to obtain are utilized as bromine sources, the reaction is gentle and easy to control, the yield is high, the cost is low, and the technology is green and friendly to environment; usage of bromine which is high in toxicity, volatile and expensive in a traditional technology is avoided, and usage of high-cost sodium bromate in an improved technology is avoided.
PROCESS FOR THE PREPARATION OF ORGANIC BROMIDES
-
Paragraph 00114-00115, (2017/07/28)
The present invention provides a process for the preparation of organic bromides, by a radical bromodecarboxylation of carboxylic acids with a bromoisocyanurate.
