Benzyl bromide stored over activated 4A molecular sieve burst

Comments · 129 Views

Benzyl bromide appears as a colorless liquid with an agreeable odor. Toxic by inhalation and by skin absorption. It is slightly soluble in water and denser than water

Benzyl bromide is an aromatic compound in which the benzene ring substituted with a bromomethyl group, and is produced by the reaction of toluene with bromine in the presence of an oxidizing agent. It is a combustible, colorless to yellow liquid with a pleasant odor. insoluble in water and easily soluble in most organic solvents. Has a strong tearing effect and unpleasant pungent odor, minimum irritant concentration of 4 mg/m3, intolerable concentration of 50-60 mg/m3.
Benzyl bromide is widely useful in organic synthesis as a benzyl protecting group for alcohols and carboxylic acids. It is used in the preparation of foaming and frothing agents, quaternary ammonium compounds, peniclins, photographic chemicals, synthetic resins, dyes and plasticizers and esters. It is also involved in the synthesis of (E)-(2-Iodovinyl)benzene by reacting it with diiodomethane.


Benzyl bromide is an aromatic halide that is mainly used as a protecting agent for protecting hydroxy group of alcohols via O-benzylation reaction. It has been used as an initiator in the synthesis of poly(styrene-b-methylmethacrylate) copolymers by atom transfer radical polymerization. It can undergo Menschutkin reaction with 1, 2-dimethylimidazole to form 3-benzyl-1, 2-dimethylimidazolium bromide.
Benzyl bromide is synthesized by toluene bromination. Toluene heated to 50°C, add bromine reaction, the reaction temperature of 75-80°C, reaction 6h, fractional distillation at atmospheric pressure to remove the fraction before 140°C, and then distillation under reduced pressure, collect 112-114°C(2.0kPa) fraction, to get benzyl bromide.
Benzyl bromide is a member of the class of benzyl bromides that is toluene substituted on the alpha-carbon with bromine. It has a role as a lachrymator.
Benzyl bromide appears as a colorless liquid with an agreeable odor. Toxic by inhalation and by skin absorption. It is slightly soluble in water and denser than water (density 1.44 g / cm3 (Aldrich)). A lachrymator. Corrosive to metals and tissue.
Benzyl bromide reacts with water, alcohols, common metals (except nickel and lead), bases, amines and oxidizing agents. . Benzyl bromide stored over activated 4A molecular sieve burst a bottle due to condensation-polymerization reaction with generation of HBr gas,
Reactivity with Water Reacts slowly generating hydrogen bromide (hydrobromic acid); Reactivity with Common Materials: Decomposes rapidly in the presence of all common metals except nickel and lead, liberating heat and hydrogen bromide; Stability During Transport: Stable; Neutralizing Agents for Acids and Caustics: Rinse with sodium bicarbonate or lime solution; Polymerization: Polymerizes with evolution of heat and hydrogen bromide when in presence with all common metals except nickel and lead; Inhibitor of Polymerization: None.

Comments