Benzyl bromide
Encyclopedia
Benzyl bromide, or α-bromotoluene, is an organic compound
consisting of a benzene
ring substituted with a bromomethyl group. It can be prepared by the bromination of toluene
at room temperature in air, using manganese(IV) oxide as a heterogeneous catalyst. It is a colorless liquid that is decomposed slowly in water.
Benzyl bromide is used in organic synthesis
for the introduction of the benzyl protecting group
for alcohol
s and carboxylic acid
s.
Benzyl bromide is a strong lachrymator
and is also intensely irritating to skin and mucous membranes. Because of these properties, it has been used as a war gas.
under conditions suitable for a free radical halogenation
:
N-Bromosuccinimide
may also be used in place of elemental bromine.
Organic compound
An organic compound is any member of a large class of gaseous, liquid, or solid chemical compounds whose molecules contain carbon. For historical reasons discussed below, a few types of carbon-containing compounds such as carbides, carbonates, simple oxides of carbon, and cyanides, as well as the...
consisting of a benzene
Benzene
Benzene is an organic chemical compound. It is composed of 6 carbon atoms in a ring, with 1 hydrogen atom attached to each carbon atom, with the molecular formula C6H6....
ring substituted with a bromomethyl group. It can be prepared by the bromination of toluene
Toluene
Toluene, formerly known as toluol, is a clear, water-insoluble liquid with the typical smell of paint thinners. It is a mono-substituted benzene derivative, i.e., one in which a single hydrogen atom from the benzene molecule has been replaced by a univalent group, in this case CH3.It is an aromatic...
at room temperature in air, using manganese(IV) oxide as a heterogeneous catalyst. It is a colorless liquid that is decomposed slowly in water.
Benzyl bromide is used in organic synthesis
Organic synthesis
Organic synthesis is a special branch of chemical synthesis and is concerned with the construction of organic compounds via organic reactions. Organic molecules can often contain a higher level of complexity compared to purely inorganic compounds, so the synthesis of organic compounds has...
for the introduction of the benzyl protecting group
Protecting group
A protecting group or protective group is introduced into a molecule by chemical modification of a functional group in order to obtain chemoselectivity in a subsequent chemical reaction...
for alcohol
Alcohol
In chemistry, an alcohol is an organic compound in which the hydroxy functional group is bound to a carbon atom. In particular, this carbon center should be saturated, having single bonds to three other atoms....
s and carboxylic acid
Carboxylic acid
Carboxylic acids are organic acids characterized by the presence of at least one carboxyl group. The general formula of a carboxylic acid is R-COOH, where R is some monovalent functional group...
s.
Benzyl bromide is a strong lachrymator
Lachrymatory agent
Tear gas, formally known as a lachrymatory agent or lachrymator , is a non-lethal chemical weapon that stimulates the corneal nerves in the eyes to cause tears, pain, and even blindness...
and is also intensely irritating to skin and mucous membranes. Because of these properties, it has been used as a war gas.
Synthesis
Benzyl bromide can be synthesized by the bromination of tolueneToluene
Toluene, formerly known as toluol, is a clear, water-insoluble liquid with the typical smell of paint thinners. It is a mono-substituted benzene derivative, i.e., one in which a single hydrogen atom from the benzene molecule has been replaced by a univalent group, in this case CH3.It is an aromatic...
under conditions suitable for a free radical halogenation
Free radical halogenation
In organic chemistry, free-radical halogenation is a type of halogenation. This chemical reaction is typical of alkanes and alkyl-substituted aromatics under application of heat or UV light. The reaction is used for the industrial synthesis of chloroform , dichloromethane , and hexachlorobutadiene...
:
N-Bromosuccinimide
N-Bromosuccinimide
N-Bromosuccinimide or NBS is a chemical reagent which is used in radical substitution and electrophilic addition reactions in organic chemistry. NBS can be considered a convenient source of cationic bromine.-Preparation:...
may also be used in place of elemental bromine.