N-Bromo Succinimide (NBS)

 

N-Bromo Succinimide (NBS) is a chemical reagent. In organic chemistry, N-bromo succinimide serves as a chemical reagent commonly employed in radical substitution, electrophilic substitution, & electrophilic addition processes.

 

AD PHARMACHEM is known for manufacturer of N-Bromo Succinimide (NBS) intermediates.

N-Bromo Succinimide (NBS) is a versatile chemical reagent widely used in organic chemistry, particularly for bromination reactions.

 

N-Bromo succinimide (NBS) appears as a crystalline powder, ranging in color from white to slightly yellow. 

 

N-Bromo succinimide (NBS) is commercially available, but it can also be synthesized in the laboratory. N-Bromo succinimide (NBS) is synthesized by combining succinimide, sodium hydroxide, and bromine in an ice-water solution. Through filtration, the precipitated NBS product can be gathered.

 

Crude NBS tends to give a better yield in the Wohl–Ziegler reaction. However, in other applications, impure NBS (which appears slightly yellow) may produce unreliable results. To purify NBS, it can be recrystallized from water at a temperature of 90 to 95 °C, using 10 grams of NBS for every 100 mL of water.


N-Bromo Succinimide (NBS) acts as an effective brominating and oxidizing agent, widely used as a bromine source in radical processes like allylic bromination and in various electrophilic addition reactions. When substrates such as alcohols and amines undergo bromination with NBS, followed by the removal of HBr in the presence of a base, the reaction yields oxidation products where bromine is not integrated into the final structure.

N-Bromo Succinimide Physical and Chemical Properties:

1. Appearance : Crystalline powder, white to slightly yellow in color. 

2. Melting Range : 176°C – 182°C. 

 

3. Loss on Drying (LOD) : Not more than 0.1% when dried at 60°C for 3 hours.

 

4. Solubility : Sparingly Soluble in: Methanol, Soluble in: Acetone, Acetic Acid, Sodium Hydroxide.

 

 

5. Identification : By IR Spectroscopy: The infrared absorption spectrum of the substance being examined must be concordant with the IR spectrum obtained from a working standard.

 

6. Assay : By Titration: NBS must contain not less than 98.0% of the active substance.

N-Bromo Succinimide

Application of N-Bromo Succinimide

NBS is primarily used in organic synthesis for selective bromination of alkenes, alkynes, and aromatic compounds. Its specific applications include:

1. Bromination of Alkenes: NBS is widely used to brominate alkenes at the allylic position. The reaction typically involves radical intermediates and is initiated by light or a radical initiator.

 

Example: 

R-CH=CH₂ + NBS→R-CH=CHBr

 

2. Bromination of Aromatic Compounds: NBS can brominate aromatic rings, usually at the position para to an electron-donating group.

 

Example: 

Ph-OH + NBS→Ph-OH(p-Br) 

 

3. Oxidation Reactions: NBS can act as an oxidizing agent in various organic transformations, such as the conversion of alcohols to carbonyl compounds. 

 

Example: 

R-CH₂OH + NBS→R-CHO  

 

4. Halolactonization: NBS is used in the halolactonization of alkenoic acids, where a halogen and a lactone are introduced in the same molecule.