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PBQ = 1,4-Benzoquinone
CAS NO:106-51-4
EC NO:203-405-2
General description
Free radical inhibitor
p-Benzoquinone (PBQ) is a cyclic conjugated diketone.
p-Benzoquinones high-resolution photoelectron spectrum has been reported. The visible and near ultraviolet spectra of PBQ have been recorded and analyzed.
p-Benzoquinones addition as coagent has been reported to enhance the crosslinking rate of polypropylene initiated by the pyrolysis of peroxides.
p-Benzoquinones impact on hemoglobin (Hb) has been investigated based on immunoblots and mass spectral analysis of a smoker′s blood.
Application
p-Benzoquinone may be used to form benzofuranone derivatives on reacting with anilides of β-aminocrotonic acids via Nenitzescu reaction.
Dienophile employed in Diels-Alder cycloadditions to form naphthoquinones, and 1,4-phenanthrenediones.
p-Benzoquinone, commonly known as para-quinone, is a chemical compound with the formula C6H4O2. In a pure state, it forms bright-yellow crystals with a characteristic irritating odor, resembling that of chlorine, bleach, and hot plastic or formaldehyde. This six-membered ring compound is the oxidized derivative of p-Benzoquinone. The molecule is multifunctional: it exhibits properties of a ketone, being able to form oximes; an oxidant, forming the dihydroxy derivative; and an alkene, undergoing addition reactions, especially those typical for α,β-unsaturated ketones.
p-Benzoquinone is sensitive toward both strong mineral acids and alkali, which cause condensation and decomposition of the compound.
Properties
Chemical formula C6H4O2
Molar mass 108.096 g·mol−1
Appearance Yellow solid
Odor Acrid, chlorine-like
Density 1.318 g/cm3 at 20 °C
Melting point 115 °C (239 °F; 388 K)
Boiling point Sublimes
Solubility in water 11 g/L (18 °C)
Solubility Slightly soluble in petroleum ether; soluble in acetone; 10% in ethanol, benzene, diethyl ether
Vapor pressure 0.1 mmHg (25°C)
Magnetic susceptibility (χ) -38.4·10−6 cm3/mol
Preparation
p-Benzoquinone is prepared industrially by oxidation of hydroquinone, which can be obtained by several routes. One route involves oxidation of diisopropylbenzene and the Hock rearrangement. The net reaction can be represented as follows:
C6H4(CHMe2)2 + 3 O2 → C6H4O2 + 2 OCMe2 + H2O
The reaction proceeds via the bis(hydroperoxide) and the hydroquinone. Acetone is a coproduct.
Another major process involves the direct hydroxylation of phenol by acidic hydrogen peroxide: C6H5OH + H2O2 → C6H4(OH)2 + H2O Both hydroquinone and catechol are produced. Subsequent oxidation of the hydroquinone gives the quinone.
Quinone was originally prepared industrially by oxidation of aniline, for example by manganese dioxide. This method is mainly practiced in PRC where environmental regulations are more relaxed.
Oxidation of hydroquinone is facile. One such method makes use of hydrogen peroxide as the oxidizer and iodine or an iodine salt as a catalyst for the oxidation occurring in a polar solvent; e.g. isopropyl alcohol.
When heated to near its melting point, p-Benzoquinone sublimes, even at atmospheric pressure, allowing for an effective purification. Impure samples are often dark-colored due to the presence of quinhydrone, a dark green 1:1 charge-transfer complex of quinone with hydroquinone.
Organic synthesis
p-Benzoquinone is used as a hydrogen acceptor and oxidant in organic synthesis.
p-Benzoquinone serves as a dehydrogenation reagent.
p-Benzoquinone is also used as a dienophile in Diels Alder reactions.
Benzoquinone reacts with acetic anhydride and sulfuric acid to give the triacetate of hydroxyquinol. This reaction is called the Thiele reaction or Thiele–Winter reaction after Johannes Thiele, who first described it in 1898, and after Ernst Winter, who further described its reaction mechanism in 1900. An application is found in this step of the total synthesis of Metachromin A:
Benzoquinone is also used to suppress double-bond migration during olefin metathesis reactions.
An acidic potassium iodide solution reduces a solution of benzoquinone to hydroquinone, which can be reoxidized back to the quinone with a solution of silver nitrate.
Due to its ability to function as an oxidizer, p-Benzoquinone can be found in methods using the Wacker-Tsuji oxidation, wherein a palladium salt catalyzes the conversion of an alkene to a ketone. This reaction is typically carried out using pressurized oxygen as the oxidizer, but benzoquinone can sometimes preferred.
p-Benzoquinone is also used as a reagent in some variants on Wacker oxidations.
p-Benzoquinone is used in the synthesis of Bromadol and related analogs.
p-Benzoquinone is the simplest member of the class of 1,4-benzoquinones, obtained by the formal oxidation of hydroquinone to the corresponding diketone.
p-Benzoquinone is a metabolite of benzene.
p-Benzoquinone has a role as a cofactor, a human xenobiotic metabolite and a mouse metabolite.
Benzoquinone appears as a yellowish-colored crystalline solid with a pungent, irritating odor. Poisonous by ingestion or inhalation of vapors. May severely damage skin, eyes and mucous membranes. Used to make dyes and as a photographic chemical.
p-Benzoquinone is a quinone imine.
p-Benzoquinone derives from a 1,4-benzoquinone.
p-Benzoquinone is used as a dienophile in Diels-Alder cycloadditions to prepare naphthoquinones and 1,4-phenanthrenediones.
p-Benzoquinone acts as a dehydrogenation reagent and an oxidizer in synthetic organic chemistry. In the Thiele-Winter reaction, it is involved in the preparation of triacetate of hydroxyquinol by reacting with acetic anhydride and sulfuric acid.
p-Benzoquinone is also used in the synthesis of bromadol and to suppress double- bond migration during olefin metathesis reactions.
p-Benzoquinone is used as a precursor to hydroquinone which finds application in photography and as a reducing agent and an antioxidant in rubber production.
Description
p-Benzoquinone exists as a large yellow, monoclinic prism with an irritating odour resembling that of chlorine.
p-Benzoquinone is extensively used as a chemical intermediate, a polymerisation inhibitor, an oxidising agent, a photographic chemical, a tanning agent, and a chemical reagent.
p-Benzoquinone was first produced commercially in 1919 and has since been manufactured in several European countries.
p-Benzoquinones major use is in hydroquinone production, but it is also used as a polymerisation inhibitor and as an intermediate in the production of a variety of substances, including rubber accelerators and oxidising agents.
p-Benzoquinone is used in the dye, textile, chemical, tanning, and cosmetic industries. In chemical synthesis for hydroquinone and other chemicals, quinone is used as an intermediate.
p-Benzoquinone is also used in the manufacturing industries and chemical laboratory associated with protein fibre, photographic film, hydrogen peroxide, and gelatin making. Occupational exposure to quinone may occur in the dye, textile, chemical, tanning, and cosmetic industries. Inhalation exposure to quinone may occur from tobacco smoke.
Chemical Properties
p-Benzoquinone is a yellow, crystalline material or large yellow, monoclinic prisms. Pungent, irritating odor.
1,4-Benzoquinone or p-benzoquinone is the basic structure of quinonoid compounds.They are widely distributed in the natural world, being found in bacteria, plants and arthropods and hence quinones are ubiquitous to living systems.
p-Benzoquinones play pivotal role in biological functions including oxidative phosphorylation and electron transfer.
Physical properties
Light yellow crystals with an acrid odor resembling chlorine. Odor threshold concentration is 84 ppb (quoted, Amoore and Hautala, 1983).
Uses
p-Benzoquinone is used in the manufactureof dyes, fungicide, and hydroquinone; fortanning hides; as an oxidizing agent; and inphotography.
Uses
Oxidizing agent; in photography; manufacture of dyes; manufacture of hydroquinone; tanning hides; making gelatin insoluble; strengthening animal fibers; as reagent.
Uses
As an oxidizing agent; in photography; tanning hides; intermediate in the manufacturing of dyes, fungicides, and hydroquinone.
Preparation
Preparation of Quinone (p-Benzoquinone) from Hydroquinone.
Principle: Hydroquinone can be readily oxidized to quinone by using oxidizing agent like potassium dichromate and conc. H2SO4 or KBrO3.
General Description
A yellowish-colored crystalline solid with a pungent, irritating odor. Poisonous by ingestion or inhalation of vapors. May severely damage skin, eyes and mucous membranes. Used to make dyes and as a photographic chemical.
p-Benzoquinone, commonly known as para-quinone or quinone, is a chemical compound with the formula C6H4O2.
p-Benzoquinone is found in barley, olive, and anise.
Formula: C6H4O2
Molecular mass: 108.1
Boiling point: ~180°C
Melting point: 116°C
Solubility in water: poor
Vapour pressure, Pa at 20°C: 12
Relative vapour density (air = 1): 3.7
Relative density of the vapour/air-mixture at 20°C (air = 1): 1.0
Flash point: 38-93°C
See Notes.
Auto-ignition temperature: 560°C
Octanol/water partition coefficient as log Pow: 0.2
p-Benzoquinone is used as a chemical intermediate, a polymerization inhibitor, an oxidizing agent, a photographic chemical, a tanning agent, and a chemical reagent.
p-Benzoquinones are oxidized derivatives of aromatic compounds and are often readily made from reactive aromatic compounds with electron-donating substituents such as phenols and catechols, which increase the nucleophilicity of the ring and contributes to the large redox potential needed to break aromaticity. (p-Benzoquinones are conjugated but not aromatic).
p-Benzoquinones are electrophilic Michael acceptors stabilised by conjugation. Depending on the quinone and the site of reduction, reduction can either rearomatise the compound or break the conjugation. Conjugate addition nearly always breaks the conjugation.
p-Benzoquinones usually are prepared by oxidation of aromatic amines, polyhydric phenols, and polynuclear hydrocarbons. The most important characteristic reaction of p-Benzoquinones is reduction to the corresponding dihydroxy form. In acidic solution, p-benzoquinone is reduced reversibly to hydroquinone (C6H6O2); the reaction is marked by a measurable electrical potential of a magnitude that depends upon the hydrogen ion concentration of the reaction medium and the benzoquinone and hydroquinone concentrations.
p-Benzoquinone is a precursor used in the synthesis of hydroquinone and is also used as a hydrogen acceptor and oxidant.
p-Benzoquinone exhibits anti-inflammatory and antibiotic activities.
p-Benzoquinone inhibits 5-lipoxygenase and prevents leukotriene synthesis. Additionally, this compound displays antibacterial efficacy against Staphylococcus, Salmonella, and Bacillus.
p-Benzoquinone is a major metabolite of benzene.
p-Benzoquinone has been found to generate H2O2 in cells.
p-Benzoquinone has been suggested that the peroxide reacts with Cu(I) to produce an active species that induces internucleosomal DNA fragmentation.
p-Benzoquinone is a specialty chemical intermediate that is useful for its oxidizing properties in organic synthesis.
p-Benzoqinone is often used in the production of pharmaceuticals, in photographic uchemistry, and in petrochemicals as a polymerization inhibitor.
p-Benzoquinone is closely related to Hydroquinone, another polymerization inhibitor useful for stabilizing acrylates.
CLASS
Specialty Chemicals, Chemical Intermediates, Toxic Release Inventory (TRI) Chemicals
FUNCTIONS
Intermediates, Polymerization Inhibitor , Chemical Intermediate
INDUSTRY
Industrial, Pharmaceutical, Oil and Gas Production, Petrochemistry, Specialty Chemicals
About this substance
Helpful information
p-Benzoquinone is registered under the REACH Regulation and is manufactured in and / or imported to the European Economic Area, at ≥ 10 to < 100 tonnes per annum.
p-Benzoquinone is used by consumers, by professional workers (widespread uses), in formulation or re-packing, at industrial sites and in manufacturing.
Consumer Uses
p-Benzoquinone is used in the following products: coating products and fillers, putties, plasters, modelling clay.
Other release to the environment of p-Benzoquinone is likely to occur from: indoor use and outdoor use resulting in inclusion into or onto a materials (e.g. binding agent in paints and coatings or adhesives).
Article service life
ECHA has no public registered data on the routes by which this substance is most likely to be released to the environment. ECHA has no public registered data indicating whether or into which articles the substance might have been processed.
Widespread uses by professional workers
p-Benzoquinone is used in the following products: coating products and fillers, putties, plasters, modelling clay.
ECHA has no public registered data on the types of manufacture using p-Benzoquinone.
Other release to the environment of p-Benzoquinone is likely to occur from: indoor use and outdoor use resulting in inclusion into or onto a materials (e.g. binding agent in paints and coatings or adhesives).
Formulation or re-packing
p-Benzoquinone is used in the following products: polymers and coating products.
Release to the environment of p-Benzoquinone can occur from industrial use: formulation of mixtures.
Uses at industrial sites
p-Benzoquinone is used in the following products: polymers, coating products, adhesives and sealants, fillers, putties, plasters, modelling clay and laboratory chemicals.
p-Benzoquinone has an industrial use resulting in manufacture of another substance (use of intermediates).
p-Benzoquinone is used for the manufacture of: plastic products and chemicals.
Release to the environment of p-Benzoquinone can occur from industrial use: as processing aid, as processing aid, in the production of articles and as an intermediate step in further manufacturing of another substance (use of intermediates).
Manufacture
Release to the environment of p-Benzoquinone can occur from industrial use: manufacturing of the substance.
Physical Properties
Physical Form
Crystalline Solid
Color
Bright Yellow
Odor
Acrid, chlorine-like
p-Benzoquinone (exists as a large yellow, monoclinic set with an odor.
p-Benzoquinone is widely used as a chemical intermediate, a polymerization inhibitor, a structuring agent, a photographic chemical, a tanning agent, and chemical reagent.
p-Benzoquinone was first commercially
p-Benzoquinone was acquired in 1919 and has been cultivated in Europe since. Re-use hydroquinone, but can also be used as a coupling inhibitor and including oxidizing agents. Used in the dye, textile, chemical, tanning and cosmetic industries. In chemical synthesis for hydroquinone and other chemicals, quinone is a Used as an intermediate.Also in industry and chemical laboratory assisted with protein fiber, photographic film, covert production.In the paint, textile, chemical, tanning and cosmetics industries, quinone exposure may occur.Use from quinone inhalation fumes,Used with 4-benzoquinone, fungicide and hydroquinone dye ; forgiving hides; as an oxidizing agent; and photography.
p-Benzoquinone is used as a catalyst in the preperation of allyl silyl ethers.
p-Benzoquinone is a superoxide scavenger that has been used in the characterization of carnation-like SnS2 nanostructure photocatalysts for photodegredation.
p-Benzoquinone is a toxic metabolite found in human blood.
p-Benzoquinone is primarily used as an intermediate in the production of hydroquinone, dyes, fungicides, as an oxidising agent and as a photographic chemical.
Application Areas:
Unsaturated Polyester Resins as Caring Agent
Unsaturated Polyester Resins as Cure inhibitor
Cosmetic Industry only for skin tanning creams
Pharma company as chemical reagent
SMC/DMC Auto composites manufacturing companies
Laboratory Reagents
Description:
p-Benzoquinone exists as a large yellow, monoclinic prism with an irritating odour resembling that of chlorine.
p-Benzoquinone is extensively used as a chemical intermediate, a polymerisation inhibitor, an oxidising agent, a photographic chemical, a tanning agent, and a chemical reagent.
p-Benzoquinone was first produced commercially in 1919 and has since been manufactured in several European countries.
p-Benzoquinones major use is in hydroquinone production, but it is also used as a polymerisation inhibitor and as an intermediate in the production of a variety of substances, including rubber accelerators and oxidising agents.
p-Benzoquinone is used in the dye, textile, chemical, tanning, and cosmetic industries. In chemical synthesis for hydroquinone and other chemicals, quinone is used as an intermediate.
p-Benzoquinone is also used in the manufacturing industries and chemical laboratory associated with protein fibre, photographic film, hydrogen peroxide, and gelatin making. Occupational exposure to quinone may occur in the dye, textile, chemical, tanning, and cosmetic industries. Inhalation exposure to quinone may, occur, from tobacco smoke.
p-Benzoquinone is used as a hydrogen acceptor and oxidant in organic synthesis.
p-Benzoquinone serves as a dehydrogenation reagent.
p-Benzoquinone is also uses as a dienophile in Diels Alder reactions.
IUPAC NAMES:
1,4-Benzoquinone
1,4-benzoquinone
1,4-benzoquinone
2,5-Cyclohexadiene-1,4-dione
[1,4]-benzoquinone
Benzoquinone
Benzoquinone
Cyclohexa-2,5-diene-1,4-dione
cyclohexa-2,5-diene-1,4-dione
p-Benzochinon
P-BENZOQUINONE
P-Benzoquinone
p-Benzoquinone
p-benzoquinone
p-benzoquinone
P-BENZOQUINONE]QUINONE
PARA BENZOQUINONE
quinone
Other names: 2,5-Cyclohexadiene-1,4-dione; p-Quinone; Chinone; Quinone; 1,4-Benzoquinone; 1,4-Cyclohexadienedione; Benzoquinone; Benzo-chinon; Chinon; Cyclohexadienedione; NCI-C55845; 1,4-Benzoquine; 1,4-Cyclohexadiene dioxide; 1,4-Diossibenzene; 1,4-Dioxy-benzol; p-Chinon; Rcra waste number U197; UN 2587; USAF P-220; Steara PBQ; NSC 36324
SYNONYMS:
1,4-Benzochinon [German] [ACD/IUPAC Name]
1,4-Benzoquinone [ACD/IUPAC Name]
1,4-Benzoquinone [French] [ACD/IUPAC Name]
1,4-Dihydrobenzoquinone
1,4-Diossibenzene [Italian]
106-51-4 [RN]
2,5-Cyclohexadiene-1,4-dione [ACD/Index Name]
203-405-2 [EINECS]
773967 [Beilstein]
Benzo-chinon [German]
benzoquinone [Wiki]
Cyclohexadiene-1,4-dione
MFCD00001591 [MDL number]
para-benzoquinone
para-quinone
p-Benzoquinone
p-dioxobenzene
p-quinone
1, 4-Benzoquinone
1,4-Benzoquine
1,4-Benzoquinone, 99%
1,4-Benzoquinone|2,5-cyclohexadiene-1,4-dione
1,4-Cyclohexadiene dioxide
1,4-Cyclohexadienedione
1,4-Dioxybenzene
1,4-Dioxy-benzol
1,4-quinone
1,4-苯醌 [Chinese]
19052-63-2 [RN]
2-(2,3-Dihydrobenzob1,4dioxin-6-yl)-4,4,5,5-tetramethyl-1,3,2-diox aborolane
2,5-Cyclohexadien-1-one, 4-carbonyl- [ACD/Index Name]
2,5-cyclohexadiene-1-4-dione
2237-14-1 [RN]
3225-29-4 [RN]
4-Benzochinone [German]
4-Benzoquinone 100 µg/mL in Cyclohexane
51226-74-5 [RN]
54560-36-0 [RN]
6-(4,4,5,5-Tetramethyl-1,3,2-dioxaborolan-2-yl)-1,4-benzodioxane
6-(4,4,5,5-Tetramethyl-1,3,2-dioxaborolan-2-yl)-2,3-dihydrobenzo-1,4-dioxine
benzo-1,4-quinone
cyclohexa-2,5-diene-1,4-dione
