THE FRIEDEL-CRAFTS ALKYLATION OF BENZENE

Inhaled benzene is primarily expelled unchanged through exhalation. In a human study 16.4 to 41.6% of retained benzene was eliminated through the lungs within five to seven hours after a two- to three-hour exposure to 47 to 110 ppm and only 0.07 to 0.2% of the remaining benzene was excreted unchanged in the urine. After exposure to 63 to 405 mg/m3 of benzene for 1 to 5 hours, 51 to 87% was excreted in the urine as phenol over a period of 23 to 50 hours. In another human study, 30% of absorbed dermally applied benzene, which is primarily metabolized in the liver, was excreted as phenol in the urine.

Converting some of the methylbenzene into benzene

As benzene is a human , most non-industrial applications have been limited.
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The cyclic nature of benzene was finally confirmed by the in 1929.

The methylbenzene is mixed with hydrogen at a temperature of between 550 and 650°C, and a pressure of between 30 and 50 atmospheres, with a mixture of silicon dioxide and aluminium oxide as catalyst.

Today, benzene and the methylbenzenes are primarily produced via:

Benzene is an important with the 66. The benzene molecule is composed of six carbon atoms joined in a ring with one hydrogen atom attached to each. As it contains only carbon and hydrogen atoms, benzene is classed as a .

3. To illustrate the importance of organic synthesis with real examples.
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Mercedes Benzene • r/chemistry - reddit

Even if it is not a common substrate for the metabolism, benzene can be oxidized by both and . In bacteria, enzyme can add an to the ring, and the unstable product is immediately reduced (by ) to a cyclic with two double bonds, breaking the aromaticity. Next, the diol is newly reduced by NADH to . The catechol is then metabolized to and , used by organisms mainly in the for energy production.

One of course was the "Mercedes Benzene".

Several tests can determine exposure to benzene. Benzene itself can be measured in breath, blood or urine, but such testing is usually limited to the first 24 hours post-exposure due to the relatively rapid removal of the chemical by exhalation or biotransformation. Most persons in developed countries have measureable baseline levels of benzene and other aromatic petroleum hydrocarbons in their blood. In the body, benzene is enzymatically converted to a series of oxidation products including , , , , and . Most of these metabolites have some value as biomarkers of human exposure, since they accumulate in the urine in proportion to the extent and duration of exposure, and they may still be present for some days after exposure has ceased. The current ACGIH biological exposure limits for occupational exposure are 500 μg/g creatinine for muconic acid and 25 μg/g creatinine for phenylmercapturic acid in an end-of-shift urine specimen.

Benzene - Sustainable Community Action

Benzenesulfonic acid, or a derivative thereof, is used as a synthetic intermediate for a number of chemical families of pharmaceuticals, pesticides, dyes, pigments, fluorescent brighteners, and other organic compounds.

Benzene and methylbenzenes - Essential Chemical …

Benzene is used mainly as an intermediate to make other chemicals, above all , , , nitrobenzene, and alkylbenzene. More than half of the entire benzene production is processed into ethylbenzene, a precursor to , which is used to make polymers and plastics like polystyrene and EPS. Some 20% of the benzene production is used to manufacture cumene, which is needed to produce and acetone for resins and adhesives. consumes ca. 10% of the world's benzene production; it is primarily used in the manufacture of nylon fibers, which are processed into textiles and engineering plastics. Smaller amounts of benzene are used to make some types of , , , , , , and . In 2013, the biggest consumer country of benzene was China, followed by the USA. Benzene production is currently expanding in the Middle East and in Africa, whereas production capacities in Western Europe and North America are stagnating.

Category:Reactions of benzene - Wikimedia Commons

Genetic polymorphisms in these enzymes may induce loss of function or gain of function. For example, mutations in CYP2E1 increase activity and result in increased generation of toxic metabolites. NQ01 mutations result in loss of function and may result in decreased detoxification. Myeloperoxidase mutations result in loss of function and may result in decreased generation of toxic metabolites. GSH mutations or deletions result in loss of function and result in decreased detoxification. These genes may be targets for genetic screening for susceptibility to benzene toxicity.