Cyclohexene is a cyclic olefin, and is a colorless, flammable liquid with a special pungent odor at room temperature. Long-term placement in the air it can be oxidated into peroxide by air. Naturally present in coal tar, soluble in acetone, carbon tetrachloride, benzene, ether, hexane, ethanol and other organic solvents, can form binary azeotrope with lower alcohols, acetic acid, etc. Cyclohexene has the general nature of olefin, decomposes rapidly in the presence of uranium salts under sunlight or ultraviolet rays, is constant as being heated in a sealed tube at 200 ℃ for a long time, forms benzene and naphthalene at 400~500 ℃.
It is obtained by dehydration of cyclohexanol at high temperature in the presence of an acid catalyst in industrial. It is obtained by sulfated dehydration of cyclohexanol in the laboratory.
Figure 1 is the chemical reaction equation of sulfated dehydration of cyclohexanol to obtain cyclohexene.
Cyclohexene is an important chemical raw materials, used for the production of adipic acid, adipic aldehyde, maleic acid, Cyclohexane acid, cyclohexane aldehyde, maleic acid, cyclohexyl carboxylic acid, cyclohexanecarboaldehyde in industry. It is also used as the extraction agent, the stabilizer having a high-octane gasoline. Inhalation can cause mild poisoning.
Here are some of these important compounds prepared by cyclohexene, (1)chlorinated cyclohexane is made, useful as pharmaceutical intermediates, a solvent and rubber additives. (2) cyclohexanone is made from cyclohexene, can be used as intermediates raw materials of medicine, pesticides, perfumes, and dyes, as polymer modifiers. (3) cyclohexyl acetate is made, used as a plastic solvent. (4) cyclohexanone phenol is made, can be used as raw materials medicine and pesticides. (5) aminocyclohexanol is made, can be used as surfactants and emulsifiers. (6) The product can also be used directly as organic intermediates, solvents and additives when spices are prepared. It can be used in the preparation of butadiene in the laboratory.
The above information were edited and collated by Yan Yanyong of Chemicalbook.
Explosive hazardous characteristics
It can be explosive mixed with air.
Colorless flammable liquid. Insoluble in water, soluble in ether.
Dry powder, dry sand, carbon dioxide, foam, 1211 fire extinguishing agent.
1. Used in organic synthesis, it is also used as a solvent.
2. It is used as organic synthetic raw materials, such as synthetic raw materials for lysine, cyclohexanone, phenol, polycycloolefin resin, chlorinated cyclohexane, rubber additives, cyclohexanol, etc. It is also used as a catalyst solvent and petroleum extraction agent, high octane gasoline stabilizer.
3. It is used for Preparation of adipic acid, maleic acid, hexahydro benzoic acid and acetaldehyde, preparation of butadiene in the laboratory. It is used as high-octane gasoline stabilizer.
A colorless liquid. Insoluble in water and less dense than water. Flash point 20°F. Vapors heavier than air. Inhalation of high concentrations may have a narcotic effect. Used to make other chemicals.
May cause toxic effects if inhaled or absorbed through skin. Inhalation or contact with material may irritate or burn skin and eyes. Fire will produce irritating, corrosive and/or toxic gases. Vapors may cause dizziness or suffocation. Runoff from fire control or dilution water may cause pollution.
HIGHLY FLAMMABLE: Will be easily ignited by heat, sparks or flames. Vapors may form explosive mixtures with air. Vapors may travel to source of ignition and flash back. Most vapors are heavier than air. They will spread along ground and collect in low or confined areas (sewers, basements, tanks). Vapor explosion hazard indoors, outdoors or in sewers. Runoff to sewer may create fire or explosion hazard. Containers may explode when heated. Many liquids are lighter than water.
Flammability hazard characteristics
In case of fire, high temperature, oxidant, it is flammable, burning produces irritant smoke.
Cyclohexanol is heated to generate cyclohexene in the presence of sulfuric acid catalyst, distilled to obtain crude products. Washed with a fine saturated salt solution, then sodium sulfate solution is used to neutralize traces of acid, then washed with water, layered, dried, filtration, distillation, collecting 82-85 ℃ distillate products to obtain cyclohexene.
Cyclohexene may react vigorously with strong oxidizing agents. May react exothermically with reducing agents to release hydrogen gas. In the presence of various catalysts (such as acids) or initiators, may undergo exothermic addition polymerization reactions. Oxidizes readily in air to form unstable peroxides that may explode spontaneously [Bretherick, 1979 p.151-154].
ChEBI: A cycloalkene that is cylohexane with a single double bond.
Free cyclohexene from peroxides by washing with successive portions of dilute acidified ferrous sulfate, or with NaHSO3 solution, then with distilled water, drying with CaCl2 or CaSO4, and distilling under N2. Alternative methods for removing peroxides include passage through a column of alumina, refluxing with sodium wire or cupric stearate (then distilling from sodium). The diene is removed by refluxing with maleic anhydride before distilling under vacuum. Treatment with 0.1moles of MeMgI in 40mL of diethyl ether removes traces of oxygenated impurities. Other purification procedures include washing with aqueous NaOH, drying and distilling under N2 through a spinning band column, redistilling from CaH2, storing under sodium wire, and passing through a column of alumina, under N2, immediately before use. Store it at <0o under argon. [Coleman & Johnstone Org Synth Coll Vol I 83 1955, Carson & Ipatieff Org Synth Coll Vol II 152 1943, Woon et al. J Am Chem Soc 108 7990 1986, Wong et al. J Am Chem Soc 109 3428 1987.] [Beilstein 5 IV 218.]
Treasury ventilation low-temperature drying, stored separately from oxidants and acids. Not long storage to prevent polymerization.
TWA 1015 mg/cubic meter.
Air & Water Reactions
Highly flammable. Insoluble in water.
Inhalation-Rats TCL0: 600 PPM/6 hrs/26 weeks.
Alkylation component. In the manufacture of adipic acid, maleic acid, hexahydrobenzoic acid and aldehyde. To prepare butadiene in the laboratory. Has been suggested for the synthesis of maleic acid and as stabilizer for high octane gasoline.