NBS is commercially available. It can also be synthesized in the laboratory. To do so, sodium hydroxide and bromine are added to an ice-water solution of succinimide. The NBS product precipitates and can be collected by filtration.
Crude NBS gives better yield in the Wohl-Ziegler reaction. In other cases, impure NBS (slightly yellow in color) may give unreliable results. It can be purified by recrystallization from 90–95 °C water (10 g of NBS for 100 mL of water).
Side reactions include the formation of α-bromoketones and dibromo compounds. These can be minimized by the use of freshly recrystallized NBS.
With the addition of nucleophiles, instead of water, various bifunctional alkanes can be synthesized.
Allylic and benzylic bromination
Standard conditions for using NBS in allylic and/or benzylic bromination involves refluxing a solution of NBS in anhydrousCCl4 with a radical initiator—usually azobisisobutyronitrile (AIBN) or benzoyl peroxide, irradiation, or both to effect radicalinitiation. The allylic and benzylic radical intermediates formed during this reaction are more stable than other carbon radicals and the major products are allylic and benzylic bromides. This is also called the Wohl–Ziegler reaction.
In the above reaction, while a mixture of isomeric allylic bromide products are possible, only one is created due to the greater stability of the 4-position radical over the methyl-centered radical.
Bromination of carbonyl derivatives
NBS can α-brominate carbonyl derivatives via either a radical pathway (as above) or via acid-catalysis. For example, hexanoyl chloride 1 can be brominated in the alpha-position by NBS using acid catalysis.
The reaction of enolates, enol ethers, or enol acetates with NBS is the preferred method of α-bromination as it is high-yielding with few side-products.
NBS electrophilically brominates the amine, which is followed by decarboxylation and release of an imine. Further hydrolysis will yield an aldehyde and ammonia. (cf. non-oxidative PLP dependent decarboxylation)
Although NBS is easier and safer to handle than bromine, precautions should be taken to avoid inhalation. NBS should be stored in a refrigerator. NBS will decompose over time giving off bromine. Pure NBS is white, but it is often found to be off-white or brown colored by bromine.
In general, reactions involving NBS are exothermic. Therefore, extra precautions should be taken when used on a large scale.
^Beger, J. (1991). "Präparative Aspekte elektrophiler Dreikomponentenreaktionen mit Alkenen" [Preparative aspects of electrophilic three-component reactions with alkenes]. J. Prakt. Chem.333 (5): 677–698. doi:10.1002/prac.19913330502.
^Ziegler, K.; Schenck, G.; Krockow, E. W.; Siebert, A.; Wenz, A.; Weber, H. (1942). "Die Synthese des Cantharidins" [The synthesis of cantharidin]. Justus Liebig's Annalen der Chemie. 551: 1–79. doi:10.1002/jlac.19425510102.
^Binkley, R. W.; Goewey, G. S.; Johnston, J. (1984). "Regioselective ring opening of selected benzylidene acetals. A photochemically initiated reaction for partial deprotection of carbohydrates". J. Org. Chem.49 (6): 992. doi:10.1021/jo00180a008.
^Stotter, P. L.; Hill, K. A. (1973). "α-Halocarbonyl compounds. II. Position-specific preparation of α-bromoketones by bromination of lithium enolates. Position-specific introduction of α,β-unsaturation into unsymmetrical ketones". J. Org. Chem.38 (14): 2576. doi:10.1021/jo00954a045.
^Lichtenthaler, F. W. (1992). "Various Glycosyl Donors with a Ketone or Oxime Function next to the Anomeric Centre: Facile Preparation and Evaluation of their Selectivities in Glycosidations". Synthesis. 1992: 179–84. doi:10.1055/s-1992-34167.
^Mitchell, R. H.; Lai, Y. H.; Williams, R. V. (1979). "N-Bromosuccinimide-dimethylformamide: a mild, selective nuclear monobromination reagent for reactive aromatic compounds". J. Org. Chem.44 (25): 4733. doi:10.1021/jo00393a066.