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Acetoacetylation
Diketene is an organic compound with the molecular formula , and which is sometimes written as . It is formed by dimerization of ketene, . Diketene is a member of the oxetane family. It is used as a reagent in organic chemistry. It is a colorless liquid. Production Diketene is produced on commercial scale by dimerization of ketene. Reactions Heating or irradiation with UV light regenerates the ketene monomer: : Alkylated ketenes also dimerize with ease and form substituted diketenes. Diketene readily hydrolyzes in water forming acetoacetic acid. Its half-life in water is approximately 45 min. a 25 °C at . Certain diketenes with two aliphatic chains, such as alkyl ketene dimers (AKDs), are used industrially to improve hydrophobicity in paper. At one time acetic anhydride was prepared by the reaction of ketene with acetic acid: : ΔH = −63 kJ/mol Acetoacetylation Diketene also reacts with alcohols and amines to the corresponding acetoacetic acid deriv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acetoacetic Acid
Acetoacetic acid ( IUPAC name: 3-oxobutanoic acid, also known as acetonecarboxylic acid or diacetic acid) is the organic compound with the formula CHCOCHCOOH. It is the simplest beta- keto acid, and like other members of this class, it is unstable. The methyl and ethyl esters, which are quite stable, are produced on a large scale industrially as precursors to dyes. Acetoacetic acid is a weak acid. Biochemistry Under typical physiological conditions, acetoacetic acid exists as its conjugate base, acetoacetate: : Unbound acetoacetate is primarily produced by liver mitochondria from its thioester with coenzyme A (CoA): : The acetoacetyl-CoA itself is formed by three routes: *3-hydroxy-3-methylglutaryl CoA releases acetyl CoA and acetoacetate: *: *Acetoacetyl-CoA can come from beta oxidation of butyryl-CoA: *: *Condensation of pair of acetyl CoA molecules as catalyzed by thiolase. *: In mammals, acetoacetate produced in the liver (along with the other two " ketone bodies") is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organic Compound
Some chemical authorities define an organic compound as a chemical compound that contains a carbon–hydrogen or carbon–carbon bond; others consider an organic compound to be any chemical compound that contains carbon. For example, carbon-containing compounds such as alkanes (e.g. methane ) and its derivatives are universally considered organic, but many others are sometimes considered inorganic, such as certain compounds of carbon with nitrogen and oxygen (e.g. cyanide ion , hydrogen cyanide , chloroformic acid , carbon dioxide , and carbonate ion ). Due to carbon's ability to catenate (form chains with other carbon atoms), millions of organic compounds are known. The study of the properties, reactions, and syntheses of organic compounds comprise the discipline known as organic chemistry. For historical reasons, a few classes of carbon-containing compounds (e.g., carbonate salts and cyanide salts), along with a few other exceptions (e.g., carbon dioxide, and even ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Indane
Indane or indan is an organic compound with the formula C9H10. It is a colorless liquid hydrocarbon. It is a petrochemical, a bicyclic compound. It occurs at the level of about 0.1% in coal tar. It is usually produced by hydrogenation of indene.Karl Griesbaum, Arno Behr, Dieter Biedenkapp, Heinz-Werner Voges, Dorothea Garbe, Christian Paetz, Gerd Collin, Dieter Mayer, Hartmut Höke "Hydrocarbons" in Ullmann's Encyclopedia of Industrial Chemistry 2002 Wiley-VCH, Weinheim. Derivatives Derivatives include compounds such as 1-methylindane and 2-methylindane (where one methyl group is attached to the five carbon ring), 4-methylindane and 5-methylindane (where one methyl group is attached to the benzene ring), and various dimethylindanes. Other derivatives can be obtained indirectly, e.g. the reaction of diethyl phthalate with ethyl acetate, using metallic sodium and ethanol as a catalyst. The reaction yields indanedione ethyl ester, which can react with the sodium ions yielding ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pharmaceuticals
Medication (also called medicament, medicine, pharmaceutical drug, medicinal product, medicinal drug or simply drug) is a drug used to diagnose, cure, treat, or prevent disease. Drug therapy ( pharmacotherapy) is an important part of the medical field and relies on the science of pharmacology for continual advancement and on pharmacy for appropriate management. Drugs are classified in many ways. One of the key divisions is by level of control, which distinguishes prescription drugs (those that a pharmacist dispenses only on the medical prescription) from over-the-counter drugs (those that consumers can order for themselves). Medicines may be classified by mode of action, route of administration, biological system affected, or therapeutic effects. The World Health Organization keeps a list of essential medicines. Drug discovery and drug development are complex and expensive endeavors undertaken by pharmaceutical companies, academic scientists, and governments. As a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemical Intermediate
In chemistry, a reaction intermediate, or intermediate, is a molecular entity arising within the sequence of a stepwise chemical reaction. It is formed as the reaction product of an elementary step, from the reactants and/or preceding intermediates, but is consumed in a later step. It does not appear in the chemical equation for the overall reaction. For example, consider this hypothetical reaction: :A + B → C + D If this overall reaction comprises two elementary steps thus: :A + B → X :X → C + D then X is a reaction intermediate. The phrase ''reaction intermediate'' is often abbreviated to the single word ''intermediate'', and this is IUPAC's preferred form of the term. But this shorter form has other uses. It often refers to reactive intermediates. It is also used more widely for chemicals such as cumene which are traded within the chemical industry but are not generally of value outside it. IUPAC definition The IUPAC Gold Book defines an ''intermediate'' as a compound ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
AKD Synthesis 2
AKD or akd may refer to: Organisations * AKD Group, a financial institution in Pakistan, owner of AKD Securities * AKD motorcycles, Tyseley, Birmingham, UK * Alpha Kappa Delta, an international honor society of sociology * Aker Drilling, Oslo Stock Exchange symbol People * Anura Kumara Dissanayake, president of Sri Lanka since 2024. Transportation * Akdeniz Airlines (ICAO code), a former charter airline from Turkey * Akola Airport (IATA code), India * A US Navy hull classification symbol: Cargo ship dock (AKD) Other uses * Akpet language (ISO 639: akd) * Alkyl ketene dimer Alkyl ketene dimers (AKDs) are a family of organic compounds based on the 4-membered ring system of 2-oxetanone, oxetan-2-one, which is also the central structural element of propiolactone and diketene. Attached to the oxetane ring of technically ...; see Wet strength * Avian keratin disorder, a disorder involving deformities of the beak and claws in birds. See also * AKD-10, one of the Chinese air-to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Toluene
Toluene (), also known as toluol (), is a substituted aromatic hydrocarbon with the chemical formula , often abbreviated as , where Ph stands for the phenyl group. It is a colorless, water Water is an inorganic compound with the chemical formula . It is a transparent, tasteless, odorless, and Color of water, nearly colorless chemical substance. It is the main constituent of Earth's hydrosphere and the fluids of all known liv ...-insoluble liquid with the odor associated with paint thinners. It is a mono-substituted benzene derivative, consisting of a methyl group (CH3) attached to a phenyl group by a single bond. As such, its systematic IUPAC nomenclature of organic chemistry, IUPAC name is methylbenzene. Toluene is predominantly used as an industrial feedstock and a solvent. As the solvent in some types of paint thinner, permanent markers, contact cement and certain types of glue, toluene is sometimes used as a recreational inhalant and has the potential of causin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Triethylamine
Triethylamine is the chemical compound with the formula N(CH2CH3)3, commonly abbreviated Et3N. Like triethanolamine and the tetraethylammonium ion, it is often abbreviated TEA. It is a colourless volatile liquid with a strong fishy odor reminiscent of ammonia. Like diisopropylethylamine (Hünig's base), triethylamine is commonly employed in organic synthesis, usually as a base. Synthesis and properties Triethylamine is prepared by the alkylation of ammonia with ethanol: :NH3 + 3 C2H5OH → N(C2H5)3 + 3 H2O The pKa of protonated triethylamine is 10.75,David Evans Research Group and it can be used to prepare buffer solutions at that pH. The hydrochloride |
Thionyl Chloride
Thionyl chloride is an inorganic compound with the chemical formula . It is a moderately Volatility (chemistry), volatile, colourless liquid with an unpleasant acrid odour. Thionyl chloride is primarily used as a Halogenation, chlorinating reagent, with approximately per year being produced during the early 1990s, but is occasionally also used as a solvent. It is toxic, reacts with water, and is also List of Schedule 3 substances (CWC), listed under the Chemical Weapons Convention as it may be used for the production of chemical weapons. Thionyl chloride is sometimes confused with sulfuryl chloride, , but the properties of these compounds differ significantly. Sulfuryl chloride is a source of chlorine whereas thionyl chloride is a source of chloride ions. Production The major industrial synthesis involves the reaction of sulfur trioxide and sulfur dichloride. This synthesis can be adapted to the laboratory by heating oleum to slowly distill the sulfur trioxide into a cooled fla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stearic Acid
Stearic acid ( , ) is a saturated fatty acid with an 18-carbon chain. The IUPAC name is octadecanoic acid. It is a soft waxy solid with the formula . The triglyceride derived from three molecules of stearic acid is called stearin. Stearic acid is a prevalent fatty-acid in nature, found in many animal and vegetable fats, but is usually higher in animal fat than vegetable fat. It has a melting point of °C and a pKa of 4.50. Its name comes from the Greek word στέαρ "''stéar''", which means tallow. The salts and esters of stearic acid are called stearates. As its ester, stearic acid is one of the most common saturated fatty acids found in nature and in the food supply, following palmitic acid.Gunstone, F. D., John L. Harwood, and Albert J. Dijkstra "The Lipid Handbook with Cd-Rom. 3rd ed. Boca Raton: CRC Press, 2007. , Dietary sources of stearic acid include meat, poultry, fish, eggs, dairy products, and foods prepared with fats; beef tallow, lard, butterfat, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sizing
Sizing or size is a substance that is applied to, or incorporated into, other materials—especially papers and textiles—to act as a protective filler or glaze. Sizing is used in papermaking and textile manufacturing to change the absorption and wear characteristics of those materials. Sizing is used for oil-based surface preparation for gilding (sometimes called ''mordant'' in this context). It is used by painters and artists to prepare paper and textile surfaces for some art techniques. Sizing is used in photography to increase the sharpness of a print, to change the glossiness of a print, or for other purposes depending on the type of paper and printing technique. Fibers used in composite materials are treated with various sizing agents to promote adhesion with the matrix material. Sizing is used during paper manufacture to reduce the paper's tendency when dry to absorb liquid, with the goal of allowing inks and paints to remain on the surface of the paper and to dry t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
