Benzene

Benzene, also kanow as (6)Annulene, is clear colorless, highly flammable liquid with a petroleum-like odor. It evaporates into the air very quickly. Benzene is a natural constituent of crude oil, and is one of the most basic petrochemicals. It is widely used as solvent and precursor in a range of products. By substitution, addition reaction and benzene ring rupture reaction, many important chemical intermediates can be derived.

Benzene is insoluble in water. In addition to glycerol, ethylene glycol, diethylene glycol, 1,4 - butanediol and other polyols, Benzene can be miscible with alcohol, chloroform, ether, carbon tetrachloride, carbon disulfide, glacial acetic acid, acetone, toluene, xylene, aliphatic hydrocarbon and most organic solvents. With the exception of slightly dissolved iodine and sulfur, the inorganic substance is insoluble in benzene.

Preparation: The production and supply of benzene in different countries and regions are not the same. The United States is mainly get the benzene from the restructuring gasoline. The Western Europe is mainly from pyrolysis gasoline. And China is mainly from the restructuring gasoline and coking by-product.

1. Coking by-product: There is part of benzene in the high temperature tar of coking by-product. After some treamtent, benzene is obtained.

2. Pyrolysis gasoline: Benzene The pyrolysis gasoline generally contains about 40% -70% aromatic hydrocarbon. About 37% of aromatic hydrocarbon is benzene, about 14% is toluene, and about 5% is xylene. Benzene can be extracted by hydrogenation and dealkylation.

3. Benzene also can be prepared by toluene from hydrodealkylation. In this hydrogen-intensive process, toluene is mixed with hydrogen. Then in the presence of catalysts Chromium, Molybdenum or Platinum oxide, the reaction happens at 500–600 °C and 40–60 atm pressure. A typical reaction yield exceeds 95 %.
C₆H₅CH₃ + H2 → C₆H₆ + CH4

Uses: 1. Benzene is used as important raw material of synthetic dye, synthetic rubbers, synthetic resin, synthetic fiber, synthetic grain, plastics, pharmaceuticals, pesticides, photographic film and petrochemical products. Benzene has good solubility, so it is widely used as adhesive and industrial solvent such as lacquer thinner of varnish and nitrocellulose, paint remover, lubricant, grease, wax, celluloid, resin, leather.

2. Benzene is also used as standard sample in the measurment of refractive index. And it can be used as solvent and cleaning agent in precision optical instruments, electronics and so on.

3. It is used as solvent of cosmetics, paint, rubber, glue, etc. Today, benzene is used mainly as an intermediate to make other chemicals. For example: it can react with azidobenzene to get diphenylamine. This reaction needs reagent at temperature of 55 °C. The reaction time is 1 hours. The yield is 82%.

Safty: Benzene is toxic by inhalation, in contact with skin and if swallowed. Moreover, it is harmful that may cause lung damage if swallowed. In addition, Benzene has danger of very serious irreversible effects and serious damage to health by prolonged exposure that may cause heritable genetic damage. If you want to contact this product, you must wear suitable protective clothing and gloves. In case of accident or if you feel unwell, seek medical advice immediately (show the label whenever possible.) Please avoid exposure - obtain special instructions before use.

Structure Descriptors:
1. Smiles:c1ccccc1
2. InChI:InChI=1/C6H6/c1-2-4-6-5-3-1/h1-6H

Toxicity:

Organism	Test Type	Route	Reported Dose (Normalized Dose)	Effect	Source
cat	LCLo	inhalation	170000mg/m3 (170000mg/m3)		"Handbook of Toxicology," 4 vols., Philadelphia, W.B. Saunders Co., 1956-59Vol. 1, Pg. 324, 1955.
dog	LCLo	inhalation	146000mg/m3 (146000mg/m3)		"Handbook of Toxicology," 4 vols., Philadelphia, W.B. Saunders Co., 1956-59Vol. 1, Pg. 324, 1955.
dog	LDLo	oral	2gm/kg (2000mg/kg)		"Abdernalden's Handbuch der Biologischen Arbeitsmethoden." Vol. 4, Pg. 1313, 1935.
frog	LDLo	subcutaneous	1400mg/kg (1400mg/kg)		"Abdernalden's Handbuch der Biologischen Arbeitsmethoden." Vol. 4, Pg. 1313, 1935.
guinea pig	LD50	skin	> 9400uL/kg (9.4mL/kg)		Toxicology and Applied Pharmacology. Vol. 7, Pg. 559, 1965.
guinea pig	LDLo	intraperitoneal	527mg/kg (527mg/kg)		"Handbook of Toxicology," 4 vols., Philadelphia, W.B. Saunders Co., 1956-59Vol. 1, Pg. 42, 1955.
human	LCLo	inhalation	65mg/m3/5Y (65mg/m3)	BLOOD: OTHER CHANGES	Archiv fuer Geschwulstforschung. Vol. 44, Pg. 145, 1974.
human	LCLo	inhalation	2pph/5M (20000ppm)		Tabulae Biologicae. Vol. 3, Pg. 231, 1933.
human	TCLo	inhalation	100ppm (100ppm)	BEHAVIORAL: SOMNOLENCE (GENERAL DEPRESSED ACTIVITY) SKIN AND APPENDAGES (SKIN): "DERMATITIS, OTHER: AFTER SYSTEMIC EXPOSURE" GASTROINTESTINAL: NAUSEA OR VOMITING	Industrial Medicine. Vol. 17, Pg. 199, 1948.
mammal (species unspecified)	LCLo	inhalation	20000ppm/5M (20000ppm)		Naunyn-Schmiedeberg's Archiv fuer Experimentelle Pathologie und Pharmakologie. Vol. 138, Pg. 65, 1928.
mammal (species unspecified)	LD50	oral	5700mg/kg (5700mg/kg)		Gigiena i Sanitariya. For English translation, see HYSAAV. Vol. 39(4), Pg. 86, 1974.
mammal (species unspecified)	LDLo	intraperitoneal	1500mg/kg (1500mg/kg)	PERIPHERAL NERVE AND SENSATION: FLACCID PARALYSIS WITHOUT ANESTHESIA (USUALLY NEUROMUSCULAR BLOCKAGE) BEHAVIORAL: IRRITABILITY BEHAVIORAL: CONVULSIONS OR EFFECT ON SEIZURE THRESHOLD	American Journal of Hygiene. Vol. 7, Pg. 276, 1927.
man	LDLo	oral	50mg/kg (50mg/kg)		Gekkan Yakuji. Pharmaceuticals Monthly. Vol. 22, Pg. 883, 1980.
man	LDLo	unreported	194mg/kg (194mg/kg)		"Poisoning; Toxicology, Symptoms, Treatments," 2nd ed., Arena, J.M., Springfield, IL, C.C. Thomas, 1970Vol. 2, Pg. 73, 1970.
man	TCLo	inhalation	150ppm/1Y-I (150ppm)	BLOOD: OTHER CHANGES	Blut. Vol. 28, Pg. 293, 1974.
mouse	LC50	inhalation	9980ppm (9980ppm)	BEHAVIORAL: GENERAL ANESTHETIC BEHAVIORAL: MUSCLE WEAKNESS LUNGS, THORAX, OR RESPIRATION: DYSPNEA	Journal of Industrial Hygiene and Toxicology. Vol. 25, Pg. 366, 1943.
mouse	LD50	intraperitoneal	340mg/kg (340mg/kg)		Annals of the New York Academy of Sciences. Vol. 243, Pg. 104, 1975.
mouse	LD50	oral	4700mg/kg (4700mg/kg)		Hygiene and Sanitation Vol. 32(3), Pg. 349, 1967.
mouse	LD50	skin	48mg/kg (48mg/kg)		Raw Material Data Handbook, Vol.1: Organic Solvents, 1974. Vol. 1, Pg. 5, 1974.
rabbit	LCLo	inhalation	45000ppm/30M (45000ppm)		Journal of Industrial Hygiene and Toxicology. Vol. 26, Pg. 69, 1944.
rabbit	LD50	skin	> 9400uL/kg (9.4mL/kg)		Toxicology and Applied Pharmacology. Vol. 7, Pg. 559, 1965.
rabbit	LDLo	intravenous	88mg/kg (88mg/kg)	PERIPHERAL NERVE AND SENSATION: SPASTIC PARALYSIS WITH OR WITHOUT SENSORY CHANGE GASTROINTESTINAL: GASTRITIS SENSE ORGANS AND SPECIAL SENSES: HEMORRHAGE: EYE	Journal of Toxicology and Environmental Health. Vol. (Suppl,
rat	LC50	inhalation	10000ppm/7H (10000ppm)		"Toxicology and Biochemistry of Aromatic Hydrocarbons," Gerarde, H., New York, Elsevier, 1960Vol. -, Pg. 113, 1960.
rat	LD50	intraperitoneal	1100ug/kg (1.1mg/kg)		Acta Physiologica Polonica. Vol. 12, Pg. 173, 1961.
rat	LD50	oral	930mg/kg (930mg/kg)	BEHAVIORAL: TREMOR BEHAVIORAL: CONVULSIONS OR EFFECT ON SEIZURE THRESHOLD	Toxicology and Applied Pharmacology. Vol. 7, Pg. 767, 1965.