I agree Our site saves small pieces of text information (cookies) on your device in order to deliver better content and for statistical purposes. You can disable the usage of cookies by changing the settings of your browser. By browsing our website without changing the browser settings you grant us permission to store that information on your device.
N-Bromosuccinimide is a chemical reagent used in electrophilic additions and radical substitution reactions in synthetic organic chemistry. In Wohl-Ziegler reaction, it is involved in allylic and benzylic bromination reaction. It is also used in the alfa-bromination of carbonyl derivatives. In the Hofmann rearrangement, it is used in the presence of a strong base, such as 1,8-Diazabicyclo[5.4.0]undec-7-ene (DBU) reacts with primary amides to produce a carbamate. It oxidizes silyl ethers to aldehydes in the presence of azobisisobutyronitrile. It is also used for the modification of ribosomal sulfhydryl groups.
Source of free-radical or positive bromine. For examples of radical benzylic bromination (Wohl-Ziegler), see: Org. Synth. Coll., 4, 921 (1963); 5, 145, 329, 825 (1973). The use of the ozone depleting solvent CCl4 has been avoided by the use of the ionic liquid 1-n-Butyl-3-methylimidazolium hexafluorophosphate, L19086 : Synlett, 702 (2003). Cleavage of carbohydrate benzyl ethers: J. Org. Chem., 55, 378 (1990), and of benzyl esters: Synlett, 219 (1994), occur under mild conditions; the benzyl group is converted to benzaldehyde. For allylic bromination, see e.g.: Org. Synth. Coll., 4, 108 (1963);.9, 112, 191 (1998) review: Chem. Rev., 43, 271 (1948).
For free-radical ɑ-bromination of a Boc glycine ester, see: Org. Synth. Coll., 9, 526 (1998).
Both aliphatic and aromatic aldehydes are converted to acyl bromides under free-radical conditions: Tetrahedron Lett., 3809 (1979); Synlett, 347 (1990); Tetrahedron Lett., 31, 7237 (1990).
In acetonitrile, NBS is a mild and regiospecific nuclear brominating agent for activated aromatics such as methoxybenzenes and naphthalenes: J. Org. Chem., 60, 5328 (1995). Deactivated aromatics, e.g. nitroarenes and benzotrifluorides, can be m-brominated under mild conditions in good yield with NBS in TFA, in the presence of H2SO4: Synlett, 1245 (1999).
In the presence of a phosphine or phosphite, converts alcohols to alkyl bromides with inversion: Tetrahedron Lett., 3937 (1973). For a review of this and related reactions, see: Org. React., 29, 1 (1983).
Alkenes undergo trans-addition reactions with NBS in combination with a nucleophile. For examples, see: Org. Synth. Coll., 6, 184, 560 (1988). With alcohols, bromohydrin ethers are formed. For use in the synthesis of cyclopropenone, see: Org. Synth. Coll., 6, 361 (1988):
In the presence of DBU in MeOH, amides rearrange to amines in good yields, providing a mild and efficient alternative to the classical Hofmann halogen/ caustic alkali conditions: J. Org. Chem., 62, 7495 (1997).
Examples of the use of NBS as a mild, selective oxidizing agent:
Sulfides to sulfoxides: J. Org. Chem., 37, 3976 (1968). Oximes to nitrile oxides: J. Org. Chem., 37, 436 (1968). Secondary alcohol in the presence of primary: Tetrahedron Lett., 2745 (1979). (In DMSO): Alkynes to ɑ-diketones: Can. J. Chem., 49, 1099 (1979).
(Free radical): Aldehydes to acyl bromides or amides: Tetrahedron Lett., 31, 7237 (1990). Benzyl silyl ethers to aldehydes: Synlett, 345 (1990). Aldehydes to esters: Synlett, 347 (1990).
For use as a mild catalyst in acetalization reactions, see Triethyl orthoformate, A13587 .
For a brief feature on uses in synthesis, see: Synlett, 498 (2006). See also 1,3-Dibromo-5,5-dimethylhydantoin, A15510 .
Guha, S.; Rajeshkumar, V.; Kotha, S. S.; Sekar, G. A Versatile and One-Pot Strategy to Synthesize alpha-Amino Ketones from Benzylic Secondary Alcohols Using N-Bromosuccinimide. Org. Lett. 2015, 17 (3), 406-409.
Wang, W. X.; Zhang, Q. Z.; Zhang, T. Q.; Li, Z. S.; Zhang, W.; Yu, W. N-Bromosuccinimide-Mediated Radical Cyclization of 3-Arylallyl Azides: Synthesis of 3-Substituted Quinolines. Adv. Synth. Catal. 2015, 357 (1), 221-226.
Hazard Statements: H302-H314-H318
Harmful if swallowed. Causes severe skin burns and eye damage. Causes serious eye damage.
Precautionary Statements: P260u-P303+P361+P353-P305+P351+P338-P301+P330+P331-P405-P501a
IF ON SKIN (or hair): Remove/Take off immediately all contaminated clothing. Rinse skin with water/shower. IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continue rinsing. IF SWALLOWED: Rinse mouth. Do NOT induce vomiting. Store locked up. Dispose of contents/container in accordance with local/regional/national/international regulations.