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Information about Catechol









Pyrocatechol
IUPAC namePyrocatechol
Other namescatechol
benzene-1,2-diol
2-hydroxyphenol
α-hydroxyphenol
o-benzenediol
o-hydroxyphenol
1,2-dihydroxybenzene
pyrocatechin
Identifiers
CAS number120-80-9
RTECS numberUX1050000
SMILESOc1c(O)cccc1
Properties
Molecular formulaC6H6O2
Molar mass110.1 g/mol
Appearancewhite solid
Density1.344 g/cm³, solid
Melting point 105 °C
Boiling point 245.5 °C
Solubility in water43 g/100 ml (? °C)
Hazards
EU classificationHarmful (Xn)
NFPA 704
1
2
0
 
R-phrasesR21/22, R36/38
S-phrasesS2, S22, S26, S37
Flash point127 °C
Related Compounds
Related benzenediolsResorcinol
Hydroquinone
Related compounds1,2-benzoquinone
Except where noted otherwise, data are given for
materials in their standard state
(at 25 C, 100 kPa)


Pyrocatechol, more commonly known as catechol, is a benzenediol, with the formula C6H4(OH)2.

Isolation, synthesis

Catechol was first isolated in 1839 by H. Reinsch by distilling catechin (the juice of Mimosa catechu (Acacia catechu L.f)); it occurs free in kino and in beechwood tar; its sulfonic acid is present in the urine of horse and man.

It results in the alkaline fusion of many resins and may be prepared by fusing ortho-phenolsulphonic acid, o-chlorphenol, o-bromophenol, and o-phenoldisulphonic acid with potash, or, better, by heating its methyl ether, guaiacol, C6H4(OH)(OCH3), a constituent of beechwood tar, with hydriodic acid.

Guaiacol may be obtained directly from beechwood tar, from pyrocatechin by methylation with potash and potassium methyl sulphate at 180, or from anisole by nitration, reduction of the ortho-nitroanisol to amino-anisol, which is then diazotized and boiled with water. It melts at 28 and boils at 250. It is employed in medicine as an expectorant. The dimethyl ether or veratrol is also used in medicine. Many other pyrocatechin derivatives have been suggested for therapeutic application. Guaiacol carbonate is known as duotal, the phosphate as phosphatol, the phosphite as guaiaco-phosphal; phosphotal is a mixture of the phosphites of creosote phenols. The valerianic ester of guaiacol is known as geosote, the henzoic as benzosol, the salicylic as guaiacolsalol, while the glycerin ether appears as guaiamar.

Ferric chloride gives a green coloration with the aqueous solution, whilst the alkaline solution rapidly changes to a green and finally to a black color on exposure to the air. It reduces silver solutions in the cold and alkaline copper on heating.

Catechol readily condenses to form heterocyclic compounds; cyclic esters are formed by phosphorus trichloride and oxychloride, carbonyl chloride, sulphuryl chloride, &c.; whilst ortho-phenylenediamine, o-aminophenol, and o-aminothiophenol give phenazine, phenoxazine and thiodiphenylamine, respectively.

Nomenclature

Pyrocatechol is the name recommended by the International Union of Pure and Applied Chemistry (IUPAC) in its 1993 Recommendations for the Nomenclature of Organic Chemistry.[1]

Occurrences

Urushiols are naturally existing organic compounds which have the catechol skeleton structure and diphenol functionality but with alkyl groups substituted onto the aromatic ring. Urushiols are the skin-irritating poisons found in plants like poison ivy, etc. Catecholamines are biochemically significant hormones/neurotransmitters which are phenethylamines where the phenyl group has a catechol skeleton structure. Two parts of a molecule of catechin, another natural compound which is found in tea, have the catechol skeleton structure in them.

Small amounts of catechol occur naturally in fruits and vegetables, along with the enzyme polyphenol oxidase. Upon exposure to air (as when a potato or apple is cut), the colorless catechol oxidizes to reddish-brown benzoquinone. This accounts for the browning of cut fruit and vegetables. The enzyme is inactivated by adding an acid, such as lemon juice, or by refrigeration. Excluding oxygen also prevents the browning reaction. Benzoquinone is said to be antimicrobial. which slows the spoilage of wounded fruits and other plant parts. The oxidation of catechol forms quinones and superoxide, which killed 50% of human glioblastoma cells treated with 0.23 mM of this compound in vitro (Pereira et al., 2004).

Uses

Pyrocatechol has been used as a film developing chemical.

Reference

  1. ^  Panico, R.; & Powell, W. H. (Eds.) (1994). A Guide to IUPAC Nomenclature of Organic Compounds 1993. Oxford: Blackwell Science. ISBN 0-632-03488-2. 
  • Barner, B. A. "Catechol" in Encyclopedia of Reagents for Organic Synthesis (Ed: L. Paquette) 2004, J. Wiley & Sons, New York. DOI: 10.1002/047084289.
Pereira, M.R.G.; de Oliveira, E. S.; de Villar, F. A. G. A.; Grangeiro, M. S.; Fonseca, J.; Silva, A. R.; Costa, M. F. D.; Costa, S. L.; El-Bachá, R. S., Cytotoxicity of catechol towards human glioblastoma cells via superoxide and reactive quinones generation. 2004, J. Bras. Patol. Med. Lab., v. 40, p. 280-285.

See also

References

External links

IUPAC nomenclature is a system of naming chemical compounds and of describing the science of chemistry in general. It is developed and kept up to date under the auspices of the International Union of Pure and Applied Chemistry (IUPAC).
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CAS registry numbers are unique numerical identifiers for chemical compounds, polymers, biological sequences, mixtures and alloys. They are also referred to as CAS numbers, CAS RNs or CAS #s.
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smiles

File extension: .smi
Type of format: chemical file format

The simplified molecular input line entry specification or SMILES
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A chemical formula is a concise way of expressing information about the atoms that constitute a particular chemical compound. A chemical formula is also a short way of showing how a chemical reaction occurs.
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Molar mass, symbol M,[1] is the mass of one mole of a substance (chemical element or chemical compound).[2] It is a physical property which is characteristic of each pure substance.
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In physics, density is mass m per unit volume V—how heavy something is compared to its size. A small, heavy object, such as a rock or a lump of lead, is denser than a lighter object of the same size or a larger object of the same weight, such as pieces of
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The melting point of a crystalline solid is the temperature range at which it changes state from solid to liquid. Although the phrase would suggest a specific temperature and is commonly and incorrectly used as such in most textbooks and literature, most crystalline compounds
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boiling point of a liquid is the temperature at which the vapor pressure of the liquid equals the environmental pressure surrounding the liquid.[1][2][3][4]
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Solubility is a physical property referring to the ability for a given substance, the solute, to dissolve in a solvent.[1] It is measured in terms of the maximum amount of solute dissolved in a solvent at equilibrium. The resulting solution is called a saturated solution.
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Water is a common chemical substance that is essential to all known forms of life.[1] In typical usage, water refers only to its liquid form or state, but the substance also has a solid state, ice, and a gaseous state, water vapor.
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Council Directive 67/548/EEC of 27 June 1967 on the approximation of laws, regulations and administrative provisions relating to the classification, packaging and labelling of dangerous substances (as amended) is the main European Union law concerning chemical safety.
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NFPA 704 is a standard maintained by the U.S. National Fire Protection Association. It defines the colloquial "fire diamond" used by emergency personnel to quickly and easily identify the risks posed by nearby hazardous materials.
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R-phrases (short for Risk Phrases) are defined in Annex III of European Union Directive 67/548/EEC: Nature of special risks attributed to dangerous substances and preparations.
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S-phrases are defined in Annex IV of European Union Directive 67/548/EEC: Safety advice concerning dangerous substances and preparations. The list was consolidated and republished in Directive 2001/59/EC , where translations into other EU languages may be found.
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The flash point of a flammable liquid is the lowest temperature at which it can form an ignitable mixture in air. At this temperature the vapor may cease to burn when the source of ignition is removed.
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Benzenediols or dihydroxybenzenes are aromatic chemical compounds and polyphenols in which two hydroxyl groups are substituted onto a benzene ring. Because they have at least one hydroxyl group covalently bonded directly to a carbon atom in a benzene ring, they are in a
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Resorcinol (or resorcin) is a chemical compound from the dihydroxy phenols. it is the 1,3-isomer of benzenediol. It is also known with a variety of other names, including: m-dihydroxybenzene, 1,3-benzenediol, 1,3-dihydroxybenzene, 3-hydroxyphenol, m-hydroquinone,
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Hydroquinone, also benzene-1,4-diol or quinol, is an aromatic organic compound which is a type of phenol, having the chemical formula C6H4(OH)2.
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1,2-Benzoquinone, also cyclohexa-3,5-diene-1,2-dione, is a ketone, with formula C6H4O2. It is one of the two isomers of quinone, the other being 1,4-benzoquinone. 1,2-Benzoquinone is produced on oxidation of catechol.

References


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standard state of a material is its state at 1 bar (100 kilopascals exactly). This pressure was changed from 1 atm (101.325 kilopascals) by IUPAC in 1990.[1] The standard state of a material can be defined at any given temperature, most commonly 25 degrees Celsius,
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Benzenediols or dihydroxybenzenes are aromatic chemical compounds and polyphenols in which two hydroxyl groups are substituted onto a benzene ring. Because they have at least one hydroxyl group covalently bonded directly to a carbon atom in a benzene ring, they are in a
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18th century - 19th century - 20th century
1800s  1810s  1820s  - 1830s -  1840s  1850s  1860s
1836 1837 1838 - 1839 - 1840 1841 1842

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Subjects:     Archaeology - Architecture -
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Catechins are polyphenolic antioxidant plant metabolites, specifically flavonoids called flavan-3-ols. Although present in numerous plant species, the largest source in the human diet is from various teas derived from the tea-plant Camellia sinensis.
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A. catechu

Binomial name
Acacia catechu
(L.) Willd., Oliv.

Range of Acacia catechu


Synonyms
  • Acacia catechu (L. f.) Willd. var.

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Kino may refer to:
  • Bahía Kino (Kino Bay), a town in Sonora, Mexico
  • Indian Kino Tree or Malabar Kino (Pterocarpus marsupium), a decidious tree
  • Kino (software), free video editing software

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Fagus
L.

Species

Fagus crenata - Japanese Beech
Fagus engleriana - Chinese Beech
Fagus grandifolia - American Beech
Fagus hayatae - Taiwan Beech
Fagus japonica - Japanese Blue Beech

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Sulfonic acid is a hypothetical acid with formula H-S(=O)2-OH. This compound is a less stable tautomer of sulfurous acid HO-S(=O)-OH, so sulfonic acid converts rapidly when it is formed.
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Urine is a liquid produced by animals through the kidney, and is collected in the bladder and excreted through the urethra.

Urine formation helps to maintain the balance of minerals and other substances in the body.
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Resin or Rosin (Oxford dictionary) is a hydrocarbon secretion of many plants, particularly coniferous trees, valued for its chemical constituents and uses such as varnishes, adhesives, as an important source of raw materials for organic synthesis, or for incense and
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2-Chlorophenol or ortho-chlorophenol has a medicinal taste and smell, and is a slightly acidic liquid (its Acid dissociation constant is 8.83). It is used as a disinfectant agent.
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