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M-Cresol
''meta''-Cresol, also 3-methylphenol, is an organic compound with the formula CH3C6H4(OH). It is a colourless, viscous liquid that is used as an intermediate in the production of other chemicals. It is a derivative of phenol and is an isomer of ''p''-cresol and ''o''-cresol. Production Together with many other compounds, ''m''-cresol is traditionally extracted from coal tar, the volatile materials obtained in the production of coke from (bituminous) coal. This residue contains a few percent by weight of phenol and isomeric cresols. In the cymene–cresol process, toluene is alkylated with propylene to give isomers of cymene, which can be oxidatively dealkylated analogous to the cumene process. Another method, involves carbonylation of a mixture of methallyl chloride and acetylene in the presence of nickel carbonyl. Applications ''m''-Cresol is a precursor to numerous compounds. Important applications include: * pesticides such as fenitrothion and fenthion * synthetic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
O-Cresol
''ortho''-Cresol, also called 2-methylphenol, or 2-hydroxytoluene, is an organic compound with the formula CH3C6H4(OH). It is a colourless solid that is widely used intermediate in the production of other chemicals. It is a derivative of phenol and is an isomer of ''p''-cresol and ''m''-cresol.Helmut Fiegein "Cresols and Xylenols" in Ullmann's Encyclopedia of Industrial Chemistry" 2007; Wiley-VCH, Weinheim. Natural occurrences ''o''-Cresol is one of the chemical compounds found in castoreum. This compound is gathered from the beaver's castor glands and found in the white cedar consumed by the beaver. ''o''-Cresol is a constituent of tobacco smoke. Production Together with many other compounds, ''o''-cresol is traditionally extracted from coal tar, the volatile materials obtained in the production of coke from coal. A similar source material is petroleum residues. These residue contains a few percent by weight of phenol and isomeric cresols. In addition to the materials ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
P-Cresol
''para''-Cresol, also 4-methylphenol, is an organic compound with the formula CH3C6H4(OH). It is a colourless solid that is widely used intermediate in the production of other chemicals. It is a derivative of phenol and is an isomer of ''o''-cresol and ''m''-cresol. Production Together with many other compounds, ''p''-cresol is conventionally extracted from coal tar, the volatilized materials obtained in the roasting of coal to produce coke. This residue contains a few percent by weight of phenol and cresols. Industrially, ''p''-cresol is currently prepared mainly by a two-step route beginning with the sulfonation of toluene: :CH3C6H5 + H2SO4 → CH3C6H4SO3H + H2O Basic hydrolysis of the sulfonate salt gives the sodium salt of the cresol: :CH3C6H4SO3H + 2 NaOH → CH3C6H4OH + Na2SO3 + H2O Other methods for the production of ''p''-cresol include chlorination of toluene followed by hydrolysis. In the cymene-cresol process, toluene is alkylated with propene to give ''p''- c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thymol
Thymol (also known as 2-isopropyl-5-methylphenol, IPMP), , is a natural monoterpenoid phenol derivative of ''p''-Cymene, isomeric with carvacrol, found in oil of thyme, and extracted from ''Thymus vulgaris'' (common thyme), ajwain, and various other plants as a white crystalline substance of a pleasant aromatic odor and strong antiseptic properties. Thymol also provides the distinctive, strong flavor of the culinary herb thyme, also produced from ''T. vulgaris''. Thymol is only slightly soluble in water at neutral pH, but it is extremely soluble in alcohols and other organic solvents. It is also soluble in strongly alkaline aqueous solutions due to deprotonation of the phenol. Its dissociation constant ( p''K''a) is . Thymol absorbs maximum UV radiation at 274 nm. Chemical synthesis Thymol is produced by the alkylation of ''m''-cresol and propene: : History Ancient Egyptians used thyme for embalming. The ancient Greeks used it in their baths and burned it as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Miscible
Miscibility () is the property of two substances to mix in all proportions (that is, to fully dissolve in each other at any concentration), forming a homogeneous mixture (a solution). The term is most often applied to liquids but also applies to solids and gases. For example, water and ethanol are miscible because they mix in all proportions. By contrast, substances are said to be immiscible if there are certain proportions in which the mixture does not form a solution. For one example, oil is not soluble in water, so these two solvents are immiscible. As another example, butanone (methyl ethyl ketone) is significantly soluble in water, but these two solvents are also immiscible because in some proportions the mixture will separate into two phases. Organic compounds In organic compounds, the weight percent of hydrocarbon chain often determines the compound's miscibility with water. For example, among the alcohols, ethanol has two carbon atoms and is miscible with water, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fenitrothion
Fenitrothion (IUPAC name: ''O'',''O''-dimethyl ''O''-(3-methyl-4-nitrophenyl) phosphorothioate) is a phosphorothioate (organophosphate) insecticide that is inexpensive and widely used worldwide. Trade names include ''Sumithion'', a 94.2% solution of fenitrothion. Health effects Fenitrothion at sublethal doses affected the motor movement of marsupials, and at acute dose levels it reduced the energy of birds. In chronic (low) dose tests, unexpectedly only the lowest concentration (0.011 microgram/liter) of fenitrothion depressed the growth of an algae, though all of the chronic dose levels used were toxic in other ways to the algae. Just half of fenitrothion's minimally effective dose altered the thyroid structure of a freshwater murrel (the snakehead fish). Cases of non-specific encephalopathy and fatty visceral changes (Reye's syndrome) in children living in the vicinity of fenitrothion-spraying operations invoked the research described latterly in ''Science'', and originally ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Propene
Propylene, also known as propene, is an unsaturated organic compound with the chemical formula CH3CH=CH2. It has one double bond, and is the second simplest member of the alkene class of hydrocarbons. It is a colorless gas with a faint petroleum-like odor. Production Steam cracking The dominant technology for producing propylene is steam cracking. The same technology is applied to ethane to ethylene. These two conversions are the #2 and #1 processes in the chemical industry, as judged by their scale. In this process, propane undergoes dehydrogenation. The by-product is hydrogen: :CH3CH2CH3 → CH3CH=CH2 + H2 The yield of propene is about 85 m%. By-products are usually used as fuel for the propane dehydrogenation reaction. Steam cracking is one of the most energy-intensive industrial processes. The feedstock is naphtha or propane, especially in the Middle East, where there is an abundance of propane from oil/gas operations. Propene can be separated by fractional di ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Total Synthesis
Total synthesis is the complete chemical synthesis of a complex molecule, often a natural product, from simple, commercially-available precursors. It usually refers to a process not involving the aid of biological processes, which distinguishes it from semisynthesis. Syntheses may sometimes conclude at a precursor with further known synthetic pathways to a target molecule, in which case it is known as a formal synthesis. Total synthesis target molecules can be natural products, medicinally-important active ingredients, known intermediates, or molecules of theoretical interest. Total synthesis targets can also be organometallic or inorganic, though these are rarely encountered. Total synthesis projects often require a wide diversity of reactions and reagents, and subsequently requires broad chemical knowledge and training to be successful. Often, the aim is to discover a new route of synthesis for a target molecule for which there already exist known routes. Sometimes, however, no ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Insulin
Insulin (, from Latin ''insula'', 'island') is a peptide hormone produced by beta cells of the pancreatic islets encoded in humans by the ''INS'' gene. It is considered to be the main anabolic hormone of the body. It regulates the metabolism of carbohydrates, fats and protein by promoting the absorption of glucose from the blood into liver, fat and skeletal muscle cells. In these tissues the absorbed glucose is converted into either glycogen via glycogenesis or fats (triglycerides) via lipogenesis, or, in the case of the liver, into both. Glucose production and secretion by the liver is strongly inhibited by high concentrations of insulin in the blood. Circulating insulin also affects the synthesis of proteins in a wide variety of tissues. It is therefore an anabolic hormone, promoting the conversion of small molecules in the blood into large molecules inside the cells. Low insulin levels in the blood have the opposite effect by promoting widespread catabolism, especial ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polyaniline
Polyaniline (PANI) is a conducting polymer and organic semiconductor of the semi-flexible rod polymer family. The compound has been of interest since the 1980s because of its electrical conductivity and mechanical properties. Polyaniline is one of the most studied conducting polymers. Historical development Polyaniline was discovered in the 19th century by F. Ferdinand Runge (1794–1867), Carl Fritzsche (1808–1871), John Lightfoot (1831–1872), and Henry Letheby (1816–1876). Lightfoot studied the oxidation of aniline, which had been isolated only 20 years previously. He developed the first commercially successful route to the dye called Aniline black. The first definitive report of polyaniline did not occur until 1862, which included an electrochemical method for the determination of small quantities of aniline. From the early 20th century on, occasional reports about the structure of PANI were published. Polymerized from the inexpensive aniline, polyaniline can be found ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polymer
A polymer (; Greek '' poly-'', "many" + ''-mer'', "part") is a substance or material consisting of very large molecules called macromolecules, composed of many repeating subunits. Due to their broad spectrum of properties, both synthetic and natural polymers play essential and ubiquitous roles in everyday life. Polymers range from familiar synthetic plastics such as polystyrene to natural biopolymers such as DNA and proteins that are fundamental to biological structure and function. Polymers, both natural and synthetic, are created via polymerization of many small molecules, known as monomers. Their consequently large molecular mass, relative to small molecule compounds, produces unique physical properties including toughness, high elasticity, viscoelasticity, and a tendency to form amorphous and semicrystalline structures rather than crystals. The term "polymer" derives from the Greek word πολύς (''polus'', meaning "many, much") and μέρος (''meros'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solvent
A solvent (s) (from the Latin '' solvō'', "loosen, untie, solve") is a substance that dissolves a solute, resulting in a solution. A solvent is usually a liquid but can also be a solid, a gas, or a supercritical fluid. Water is a solvent for polar molecules and the most common solvent used by living things; all the ions and proteins in a cell are dissolved in water within the cell. The quantity of solute that can dissolve in a specific volume of solvent varies with temperature. Major uses of solvents are in paints, paint removers, inks, and dry cleaning. Specific uses for organic solvents are in dry cleaning (e.g. tetrachloroethylene); as paint thinners ( toluene, turpentine); as nail polish removers and solvents of glue (acetone, methyl acetate, ethyl acetate); in spot removers ( hexane, petrol ether); in detergents ( citrus terpenes); and in perfumes (ethanol). Solvents find various applications in chemical, pharmaceutical, oil, and gas industries, including in chemic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amylmetacresol
Amylmetacresol (AMC) is an antiseptic used to treat infections of the mouth and throat. It is used as an active pharmaceutical ingredient in Strepsils, Cēpacol, Gorpils and Lorsept throat lozenges, typically in combination with dichlorobenzyl alcohol, another antiseptic. Medical uses The lozenges are used to treat sore throat and minor mouth and throat infections including pharyngitis and gingivitis.. Accessed 20 May 2021. A 2017 meta-analysis found that the combination of AMC with dichlorobenzyl alcohol has a modest advantage over un-medicated lozenges regarding pain relief. Contraindications No contraindications are known apart from hypersensitivity to the substance. Adverse effects Amylmetacresol sometimes causes soreness of the tongue. Hypersensitivity reactions are very rare and show symptoms such as nausea or dyspepsia, although it is not entirely clear which side effects are caused by AMC and which by dichlorobenzyl alcohol or other ingredients of the lozenges. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
