N-bromosuccinimide

N-Bromosuccinimide

Names
IUPAC name 1-Bromo-2,5-pyrrolidinedione
Other names N-bromosuccinimide; NBS
Identifiers
CAS Number	128-08-5 Y
3D model (Jmol)	Interactive image
ChEBI	CHEBI:53174 Y
ChemSpider	60528 Y
ECHA InfoCard	100.004.435
InChI InChI=1S/C4H4BrNO2/c5-6-3(7)1-2-4(6)8/h1-2H2 Y Key: PCLIMKBDDGJMGD-UHFFFAOYSA-N Y InChI=1/C4H4BrNO2/c5-6-3(7)1-2-4(6)8/h1-2H2 Key: PCLIMKBDDGJMGD-UHFFFAOYAS
SMILES O=C1N(Br)C(=O)CC1
Properties
Chemical formula	C4H4BrNO2
Molar mass	177.99 g·mol−1
Appearance	White solid
Density	2.098 g/cm3 (solid)
Melting point	175 to 178 °C (347 to 352 °F; 448 to 451 K)
Boiling point	339 °C (642 °F; 612 K)
Solubility in water	14.7 g/L (25 °C)
Solubility in CCl4	Insoluble (25 °C)
Hazards
Main hazards	Irritant
Safety data sheet	[1]
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Y  (what is YN ?)
Infobox references

N-Bromosuccinimide or NBS is a chemical reagent used in radical substitution and electrophilic addition reactions in organic chemistry. NBS can be a convenient source of Br^•, the bromine radical.

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).

NBS will react with alkenes 1 in aqueous solvents to give bromohydrins 2. The preferred conditions are the portionwise addition of NBS to a solution of the alkene in 50% aqueous DMSO, DME, THF, or tert-butanol at 0 °C. Formation of a bromonium ion and immediate attack by water gives strong Markovnikov addition and anti stereochemical selectivities.

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.