General Description
Mobile clear colorless liquid with a pungent odor. Flash point 124°F. Denser than water and insoluble in water. Hence sinks in water. Vapors are heavier than air. A skin irritant.
Reactivity Profile
BROMOBENZENE(108-86-1) may be sensitive to light. May react with oxidizing agents .
Air & Water Reactions
Flammable. Insoluble in water.
Hazard
Skin irritant. Moderate fire risk.
Health Hazard
Contact with liquid causes irritation of eyes and mild irritation of skin. Ingestion causes mild irritation of mouth and stomach.
Fire Hazard
Special Hazards of Combustion Products: Irritating hydrogen bromide and other gases may be produced in fire.
Description
Bromobenzene is a flammable, clear, colorlessmobile liquid with a pleasant odor. Molecularweight=157.02. Specific gravity (H2O:1)=1.48; Boilingpoint=156℃; Freezing/Melting point=2 31℃; Flashpoint=51℃; Autoignition temperature=565℃. Explosivelimits in air: LEL=6%; UEL=36.5%[icsc]. HazardIdentification (based on NFPA-704 M Rating System):Health 2, Flammability 2, Reactivity 0. Very slightly soluble in water; solubility=0.04% at 25℃.
Chemical Properties
colourless liquid
Physical properties
Mobile, clear, colorless to pale yellow liquid with an aromatic odor. The reported odor threshold is
4.6 ppm (Mateson, 1955).
Uses
Bromobenzene is a colorless, flammable liquid with a density
greater than water and with an aromatic odor. It is synthesized
by the reaction of bromide with benzene in the presence of iron
powder. It is used for organic synthesis, particularly in the
production of the intermediate phenylmagnesium bromide.
Bromobenzene is an additive to motor oils and used as a crystallizing
solvent. Bromobenzene is used as an ingredient in the
manufacture of phencyclidine, a recreational drug.
Uses
In organic synthesis, especially to make phenyl magnesium bromide; as solvent, especially for crystallizations on a large scale and where a heavy liquid is desirable; as additive to motor oils.
Uses
The compound is employed as a starting material in organic
syntheses in which a Grignard intermediate (phenyl magnesium
bromide) is used. The material is a chemical precursor
for certain agricultural products and has been used as
an additive to motor oils. Bromobenzene has also been
used as a high-density solvent for chemical recrystallization
processes.
Application
The compound is employed as a starting material in organic syntheses in which a Grignard intermediate (phenyl magnesium bromide) is used. The material is a chemical precursor for certain agricultural products and has been used as an additive to motor oils. Bromobenzene has also been used as a high-density solvent for chemical recrystallization processes. especially for crystallizations on a large scale and where a heavy liquid is desirable.
Definition
ChEBI: Bromobenzene is the simplest member of the class of bromobenzenes, that is benzene in which a single hydrogen has been substituted by a bromine. A liquid at room temperature (m.p. -30℃; b.p.760 156℃), it is used as a solvent, particularly for large-scale crystallisations, and for the introduction of phenyl groups in organic synthesis. It has a role as a non-polar solvent, a hepatotoxic agent and a mouse metabolite. It is a member of bromobenzenes, a bromoarene and a volatile organic compound.
Preparation
Bromobenzene is obtained by reacting benzene with bromine. First add iron powder and benzene into the reactor, slowly add bromine under stirring, keep the reaction at 70-80°C for 1 h after adding, the obtained crude product is washed with water and 5% sodium hydroxide solution, left to stand for stratification, distillation, Drying, filtering, and finally fractional distillation under constant pressure, taking the fraction at 155-157°C to obtain the finished product.
Chemical Reactivity
Reactivity with Water No reaction; Reactivity with Common Materials: No reactions; Stability During Transport: Stable; Neutralizing Agents for Acids and Caustics: Not pertinent; Polymerization: Not pertinent; Inhibitor of Polymerization: Not pertinent.
Biochem/physiol Actions
Bromobenzene induces hepatic necrosis via the formation of a reactive metabolite that arylates vital cellular macromolecules.
Potential Exposure
Mutagen.Bromobenzene is used as an intermediate in organic synthesis,and as an additive in motor oil and fuels. During chlorination water treatment, bromobenzene can be formed insmall quantities.
First aid
If this chemical gets into the eyes, remove anycontact lenses at once and irrigate immediately for at least15 min, occasionally lifting upper and lower lids. Seekmedical attention immediately. If this chemical contactsthe skin, remove contaminated clothing and wash immediately with soap and water. Seek medical attention immediately. If this chemical has been inhaled, remove fromexposure, begin rescue breathing (using universal precautions, including resuscitation mask) if breathing hasstopped and CPR if heart action has stopped. Transferpromptly to a medical facility. When this chemical hasbeen swallowed, get medical attention. Give large quantities of water and induce vomiting. Do not make an unconscious person vomit.
Source
No MCLs, MCLGs, or DWELs have been proposed (U.S. EPA,
2000).
Storm water runoff, waste motor oils, improper disposal of laboratory solvent containing
bromobenzene (quoted, Verschueren, 1983)
Environmental Fate
Biological. In activated sludge, 34.8% of the applied bromobenzene mineralized to carbon
dioxide after 5 d (Freitag et al., 1985).
Photolytic. A carbon dioxide yield of 19.7% was achieved when bromobenzene adsorbed on
silica gel was irradiated with light (λ >290 nm) for 17 h (Freitag et al., 1985). Irradiation of
bromobenzene in air containing nitrogen oxides gave phenol, 4-nitrophenol, 2,4-dinitrophenol, 4-
bromophenol, 3-bromonitrobenzene, 3-bromo-2-nitrophenol, 3-bromo-4-nitrophenol, 3-bromo-6-nitrophenol, 2-bromo-4-nitrophenol, and 2,6-dibromo-4-nitrophenol (Nojima et al., 1980).
Chemical/Physical. Bromobenzene will not hydrolyze to any reasonable extent. In the
laboratory, no change in concentration was observed after 29 d at 85 °C in 0.1M NaOH and 0.1M
HCl (Kollig, 1995).
Augusti et al. (1998) conducted kinetic studies for the reaction of bromobenzene (0.2 mM) and
other monocyclic aromatics with Fenton’s reagent (8 mM hydrogen peroxide; [Fe+2] = 0.1 mM) at
25 °C. They reported a reaction rate constant of 0.0740/min.
Metabolic pathway
Bromobenzene and chlorobenzene are metabolized by
human and mouse hepatic microsomes to two
different epoxide intermediates, which rearrange to
form either o- or p-bromo- and o- or p-chlorophenols,
respectively. Humans preferentially metabolize
halobenzenes through the hepatotoxic 3,4-epoxide
pathway, suggesting that humans may be more
susceptible than mice to halobenzene-induced
hepatotoxicity.
storage
Color Code—Red: Flammability Hazard: Store ina flammable liquid storage area or approved cabinet awayfrom ignition sources and corrosive and reactive materials.Prior to working with bromobenzene you should be trainedon its proper handling and storage. Store in tightly closedcontainers in a refrigerated area away from incompatiblematerials listed above. Protect from light. Metal containers involving the transfer of this chemical should begrounded and bonded. Drums must be equipped with selfclosing valves, pressure vacuum bungs, and flame arresters.Use only nonsparking tools and equipment, especiallywhen opening and closing containers of this chemical.Sources of ignition, such as smoking and open flames, areprohibited where this chemical is used, handled, or storedin a manner that could create a potential fire or explosionhazard.
Shipping
Bromobenzene requires a “FLAMMABLELIQUID” label. It falls in Hazard Class 3 and PackingGroup II.
Purification Methods
Wash bromobenzene vigorously with conc H2SO4, then 10% NaOH or NaHCO3 solutions, and H2O. Dry it with CaCl2 or Na2SO4, or pass it through activated alumina, before refluxing with, and distilling from, CaH2, using a glass helix-packed column. [Beilstein 5 IV 670.]
Toxicity evaluation
Bromobenzene will volatilize from dry surfaces, due to its vapor
pressure of 4.18mmHg at 25°C, and therefore will exist as
a vapor in the environment. Bromobenzene will undergo little
hydrolysis in water and little biodegradation by aquatic
microorganisms. Bromobenzene is not expected to adsorb to
sediment from water due to its soil sorption constant (Koc) of
150 and water solubility of 446 mg l-1. It is also expected
to have a high mobility in soil and volatilize easily from
moist surfaces due to its Henry’s law constant of 2.47×10-3
atmm3 mol-1 at 25°C. Bioconcentration factors range from
low values of 8.8 in carp to moderately high values of 190 in
algae.
Toxicology
The acute toxicity of bromobenzene is lowin test animals. The toxic symptoms includesomnolence, respiratory stimulation, and muscle contraction. The oral LD50 value in rats is2700 mg/kg.
Incompatibilities
Forms explosive mixture with air.Incompatible with strong oxidizers, alkaline earth metals(barium, calcium, magnesium, strontium, etc.), metallicsalts; with risk of violent reactions. May accumulate staticelectrical charges; may cause ignition of its vapors.