In other cases, impure NBS (slightly yellow in color) may give unreliable results.

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.

[3] Formation of a bromonium ion and immediate attack by water gives strong Markovnikov addition and anti stereochemical selectivities.

[5] Standard conditions for using NBS in allylic and/or benzylic bromination involves refluxing a solution of NBS in anhydrous CCl4 with a radical initiator—usually azobisisobutyronitrile (AIBN) or benzoyl peroxide, irradiation, or both to effect radical initiation.

[7][8] The carbon tetrachloride must be maintained anhydrous throughout the reaction, as the presence of water may likely hydrolyze the desired product.

[16] NBS, in the presence of a strong base, such as DBU, reacts with primary amides to produce a carbamate via the Hofmann rearrangement.

non-oxidative PLP dependent decarboxylation) NBS is a weaker equivalent to bromine in its dangers.