108-90-7 Usage
General Description
A colorless to clear, yellowish liquid with a sweet almond-like odor. Flash point 84°F. Practically insoluble in water and somewhat denser than water (9.2 lb / gal). Vapors heavier than air. Used to make pesticides, dyes, and other chemicals.
Purification Methods
The main impurities are likely to be chlorinated impurities originally present in the *benzene used in the synthesis of chlorobenzene, and also unchlorinated hydrocarbons. A common purification procedure is to wash it several times with conc H2SO4 then with aqueous NaHCO3 or Na2CO3, and water, followed by drying with CaCl2, K2CO3 or CaSO4, then with P2O5, and distilling. It can also be dried with Linde 4A molecular sieve. Passage through, and storage over, activated alumina has been used to obtain low conductance material. [Flaherty & Stern J Am Chem Soc 80 1034 1958, Beilstein 5 H 199, 5 IV 640.]
Uses
Chlorobenzene is a halogenated benzene used in chemical toxicity QSAR research for agricultural pollution.
Health Hazard
Irritating to skin, eyes and mucous membranes. Repeated exposure of skin may cause dermatitis due to defatting action. Chronic inhalation of vapors or mist may result in damage to lungs, liver, and kidneys. Acute vapor exposures can cause symptoms ranging from coughing to transient anesthesia and central nervous system depression.
Limited information is available on the acute (short-term) effects of chlorobenzene. Acute inhalation exposure of animals to chlorobenzene produced narcosis, restlessness, tremors, and muscle spasms. Chronic (long-term) exposure of humans to chlorobenzene affects the central nervous system (CNS). Signs of neurotoxicity in humans include numbness, cyanosis, hyperesthesia (increased sensation), and muscle spasms. No information is available on the carcinogenic effects of chlorobenzene in humans. EPA has classified chlorobenzene as a Group D, not classifiable as to human carcinogenicity.
Description
Chlorobenzene is a monocyclic aromatic compound with one hydrogen atom on the benzene ring substituted with one chlorine. It is produced by chlorination of benzene in the liquid phase with a catalyst. Chlorobenzene is a colourless, flammable liquid with a sweet almond-like odor, at ambient temperature with a relatively high vapour pressure, moderate octanol-water partition coefficient (log 2.8) and moderate to low water solubility (497.9 mg/L @ 25℃). Chlorobenzene has a high solubility in nonpolar solvents, however, it is almost insoluble in water. Technical grade Chlorobenzene is typically 99% pure with < 0.05% benzene and < 0.1% dichlorobenzenes as contaminants. It is a common solvent and a widely used intermediate in the manufacture of other chemicals. Rhodococcus phenolicus is a bacterium species able to degrade chlorobenzene as sole carbon sources.
Definition
ChEBI: The simplest member of the class of monochlorobenzenes, that is benzene in which a single hydrogen has been substituted by a chlorine.
Toxicity
The toxic effects of chlorobenzene on humans were exhaustion, nausea, lethargy, headache and irritation to the upper respiratory tract and eye. Contact of chlorobenzene with the skin induced irritation. No reports were obtained on sensitization by chlorobenzene in this investigation.
The oral LD50 values of chlorobenzene were 1,445 mg/kg in mice, 1,427 to 3,400 mg/kg in rats and 2,250 to 2,830 mg/kg in rabbits. The LC50s following 6-hr inhalation exposure were 1,889 ppm in mice and 2,968 ppm in rats.
Air & Water Reactions
Highly flammable. Insoluble in water.
Reactivity Profile
Chlorobenzene undergoes a sometimes explosive reaction with powdered sodium or phosphorus trichloride + sodium. May react violently with dimethyl sulfoxide. Reacts vigorously with oxidizing agents. Attacks some forms of plastic, rubber and coatings. Forms a shock sensitive solvated salt with silver perchlorate. .
Chemical Properties
colourless liquid, Chlorination of benzene in the presence of a catalyst (FeCl3 or AICI3) yields chlorobenzene as the first product. Substitution with a second CI yields ortho, para, or meta dichlorobenzene, Eventually all the hydrogens can be substituted to give hexachlorobenzene, C6C16. In the presence ofultraviolet light, the chlorinationofbenzene yields benzene hexachloride, C6H6C~, a derivative ofcyclohexane.
Uses
- Chlorobenzene is used primarily as raw material for the synthesis of o- and p-nitrochlorobenzene and 2,4-dinitrochlorobenzene.Important quantitative chemical conversions other than the production of nitrochlorobenzenes are the production of diphenyl oxide and diphenyldichlorosilane.
- Chlorobenzene is mainly used as raw material for the synthesis of chemicals including triphenylphosphine (catalyst for organic synthesis), phenylsilane, and thiophenol (pesticide and pharmaceutical intermediate). It is also used as raw material for the synthesis of solvent for organic synthesis reactions including methylenediphenyldiisocyanate, urethane raw material, agricultural adjuvants, paint and ink, and cleaning solvent for electronics.
- manufacture of phenol, aniline, DDT; solvent for paints; heat transfer medium.
- Chlorobenzene is used as a process solvent in the production of isocyanates such as MDI and TDI and as a solvent in various crop protection formulations. It is further used as a solvent in condensation reactions in the dyes industry.
- Chlorobenzene is a basic substance used in chemical syntheses with 95% of the quantity used converted in closed systems to intermediate and final products.
- It is used as a process solvent in the manufacture of three indigoid dyes and pigments. All the pigments and dyes are thioindigoid colors.
- Chlorobenzene is an example of haloarenes which is formed by mono substitution of benzene ring. When chlorobenzene is fused with sodium hydroxide at 623K and 320 atm sodium phenoxide is produced. Finally, sodium phenoxide on acidification gives phenols.
InChI:InChI=1/C6H6.ClH/c1-2-4-6-5-3-1;/h1-6H;1H/p-1
