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Sulfonation
Aromatic sulfonation is an organic reaction in which a hydrogen atom on an arene is replaced by a sulfonic acid functional group in an electrophilic aromatic substitution. Aryl sulfonic acids are used as detergents, dye, and drugs. Stoichiometry and mechanism Typical conditions involve heating the aromatic compound with sulfuric acid: :C6H6 + H2SO4 → C6H5SO3H + H2O Sulfur trioxide or its protonated derivative is the actual electrophile in this electrophilic aromatic substitution. To drive the equilibrium, dehydrating agents such as thionyl chloride can be added. :C6H6 + H2SO4 + SOCl2 → C6H5SO3H + SO2 + 2 HCl Chlorosulfuric acid is also an effective agent: :C6H6 + HSO3Cl → C6H5SO3H + HCl In contrast to aromatic nitration and most other electrophilic aromatic substitutions this reaction is reversible. Sulfonation takes place in concentrated acidic conditions and desulfonation is the mode of action in a dilute hot aqueous acid. The reaction is very useful in protecting th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Piria Reaction
Aromatic sulfonation is an organic reaction in which a hydrogen atom on an arene is replaced by a sulfonic acid functional group in an electrophilic aromatic substitution. Aryl sulfonic acids are used as detergents, dye, and drugs. Stoichiometry and mechanism Typical conditions involve heating the aromatic compound with sulfuric acid: :C6H6 + H2SO4 → C6H5SO3H + H2O Sulfur trioxide or its protonated derivative is the actual electrophile in this electrophilic aromatic substitution. To drive the equilibrium, dehydrating agents such as thionyl chloride can be added. :C6H6 + H2SO4 + SOCl2 → C6H5SO3H + SO2 + 2 HCl Chlorosulfuric acid is also an effective agent: :C6H6 + HSO3Cl → C6H5SO3H + HCl In contrast to aromatic nitration and most other electrophilic aromatic substitutions this reaction is reversible. Sulfonation takes place in concentrated acidic conditions and desulfonation is the mode of action in a dilute hot aqueous acid. The reaction is very useful in protecting t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sulfonic Acid
In organic chemistry, sulfonic acid (or sulphonic acid) refers to a member of the class of organosulfur compounds with the general formula , where R is an organic alkyl or aryl group and the group a sulfonyl hydroxide. As a substituent, it is known as a sulfo group. A sulfonic acid can be thought of as sulfuric acid with one hydroxyl group replaced by an organic substituent. The parent compound (with the organic substituent replaced by hydrogen) is the parent sulfonic acid, , a tautomer of sulfurous acid, . Salts or esters of sulfonic acids are called sulfonates. Preparation Aryl sulfonic acids are produced by the process of sulfonation. Usually the sulfonating agent is sulfur trioxide. A large scale application of this method is the production of alkylbenzenesulfonic acids: :RC6H5 + SO3 -> RC6H4SO3H In this reaction, sulfur trioxide is an electrophile and the arene is the nucleophile. The reaction is an example of electrophilic aromatic substitution. Alkylsulfonic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrophilic Aromatic Substitution
Electrophilic aromatic substitution is an organic reaction in which an atom that is attached to an aromatic system (usually hydrogen) is replaced by an electrophile. Some of the most important electrophilic aromatic substitutions are aromatic nitration, aromatic halogenation, aromatic sulfonation, and alkylation and acylation Friedel–Crafts reaction. Illustrative reactions The most widely practised example of this reaction is the ethylation of benzene. :: Approximately 24,700,000 tons were produced in 1999. (After dehydrogenation and polymerization, the commodity plastic polystyrene is produced.) In this process, acids are used as catalyst to generate the incipient carbocation. Many other electrophilic reactions of benzene are conducted, although on a much smaller scale; they are valuable routes to key intermediates. The nitration of benzene is achieved via the action of the nitronium ion as the electrophile. The sulfonation with fuming sulfuric acid gives benzenesul ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sodium Polystyrene Sulfonate
Polystyrene sulfonates are a group of medications used to treat high blood potassium. Effects generally take hours to days. They are also used to remove potassium, calcium, and sodium from solutions in technical applications. Common side effects include loss of appetite, gastrointestinal upset, constipation, and low blood calcium. These polymers are derived from polystyrene by the addition of sulfonate functional groups. Sodium polystyrene sulfonate was approved for medical use in the United States in 1958. A polystyrene sulfonate was developed in the 2000s to treat Clostridium ''difficile'' associated diarrhea under the name Tolevamer, but it was never marketed. Medical uses Polystyrene sulfonate is usually supplied in either the sodium or calcium form. It is used as a potassium binder in acute and chronic kidney disease for people with hyperkalemia (abnormal high blood serum potassium levels). However, it is unclear if it is beneficial and there is concern about poss ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Desulfonation Reaction
In organic chemistry, the desulfonation reaction is the hydrolysis of sulfonic acids: :RC6H4SO3H + H2O → RC6H5 + H2SO4 The reaction applied to aryl and naphthylsulfonic acids. It is the reverse of sulfonation.Otto Lindner, Lars Rodefeld "Benzenesulfonic Acids and Their Derivatives" in Ullmann's Encyclopedia of Industrial Chemistry 2005, Wiley-VCH, Weinheim. The temperature of desulfonation correlates with the ease of the sulfonation. Applications in synthesis This reactivity is exploited in the regiospecific preparation of many di- and tri-substituted aromatic compounds. 2-Chlorotoluene for example can be prepared by chlorination of p-toluenesulfonic acid ''p''-Toluenesulfonic acid (PTSA or ''p''TsOH) or tosylic acid (TsOH) is an organic compound with the formula CH3 C6H4 SO3H. It is a white extremely hygroscopic solid that is soluble in water, alcohols, and other polar organic solvents. The CH3C ..., followed by hydrolysis. The method is also useful for the preparation of 2 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sulfur Trioxide
Sulfur trioxide (alternative spelling sulphur trioxide, also known as ''nisso sulfan'') is the chemical compound with the formula SO3. It has been described as "unquestionably the most important economically" sulfur oxide. It is prepared on an industrial scale as a precursor to sulfuric acid. Sulfur trioxide exists in several forms - gaseous monomer, crystalline trimer, and solid polymer. Sulfur trioxide is a solid at just below room temperature with a relatively narrow liquid range. Gaseous SO3 is the primary precursor to acid rain. Molecular structure and bonding Monomer The molecule SO3 is trigonal planar. As predicted by VSEPR theory, its structure belongs to the D3h point group. The sulfur atom has an oxidation state of +6 and may be assigned a formal charge value as low as 0 (if all three sulfur-oxygen bonds are assumed to be double bonds) or as high as +2 (if the Octet Rule is assumed). When the formal charge is non-zero, the S-O bonding is assumed to be delocalized. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amino Sulfonic Acid Synthesis V
In chemistry, amines (, ) are compounds and functional groups that contain a basic nitrogen atom with a lone pair. Amines are formally derivatives of ammonia (), wherein one or more hydrogen atoms have been replaced by a substituent such as an alkyl or aryl group (these may respectively be called alkylamines and arylamines; amines in which both types of substituent are attached to one nitrogen atom may be called alkylarylamines). Important amines include amino acids, biogenic amines, trimethylamine, and aniline; Inorganic derivatives of ammonia are also called amines, such as monochloramine (). The substituent is called an amino group. Compounds with a nitrogen atom attached to a carbonyl group, thus having the structure , are called amides and have different chemical properties from amines. Classification of amines Amines can be classified according to the nature and number of substituents on nitrogen. Aliphatic amines contain only H and alkyl substituents. Aroma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Raffaele Piria
Raffaele Piria ( Scilla 20 August 1814 – Turin 18 July 1865) was an Italian chemist from Scilla, who lived in Palmi. He converted the substance Salicin into a sugar and a second component, which on oxidation becomes salicylic acid, a major component of the analgesic drug Aspirin ( acetylsalicylic acid). Other reactions discovered by Piria were the conversion of aspartic acid Aspartic acid (symbol Asp or D; the ionic form is known as aspartate), is an α-amino acid that is used in the biosynthesis of proteins. Like all other amino acids, it contains an amino group and a carboxylic acid. Its α-amino group is in the pro ... to malic acid by action of nitrogen dioxide, and the reaction of aromatic nitro compounds with sulfite towards aminosulfonic acids. References {{DEFAULTSORT:Piria, Raffaele Italian chemists People from Scilla, Calabria People from Palmi 1814 births 1865 deaths University of Pisa faculty ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ion Exchange Resin
An ion-exchange resin or ion-exchange polymer is a resin or polymer that acts as a medium for ion exchange. It is an insoluble matrix (or support structure) normally in the form of small (0.25–1.43 mm radius) microbeads, usually white or yellowish, fabricated from an organic polymer substrate. The beads are typically porous, providing a large surface area on and inside them where the trapping of ions occurs along with the accompanying release of other ions, and thus the process is called ion exchange. There are multiple types of ion-exchange resin. Most commercial resins are made of polystyrene sulfonate.François Dardel and Thomas V. Arden "Ion Exchangers" in Ullmann's Encyclopedia of Industrial Chemistry, 2008, Wiley-VCH, Weinheim. . Ion-exchange resins are widely used in different separation, purification, and decontamination processes. The most common examples are water softening and water purification. In many cases ion-exchange resins were introduced in such p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polystyrene
Polystyrene (PS) is a synthetic polymer made from monomers of the Aromatic hydrocarbon, aromatic hydrocarbon styrene. Polystyrene can be solid or foamed. General-purpose polystyrene is clear, hard, and brittle. It is an inexpensive resin per unit weight. It is a poor barrier to oxygen and water vapour and has a relatively low melting point. Polystyrene is one of the most widely used plastics, the scale of its production being several million tonnes per year. Polystyrene can be naturally Transparency (optics), transparent, but can be colored with colorants. Uses include protective packaging (such as Foam peanut, packing peanuts and in the Optical disc packaging#Jewel case, jewel cases used for storage of optical discs such as CDs and occasionally DVDs), containers, lids, bottles, trays, tumblers, disposable cutlery, in the making of models, and as an alternative material for phonograph records. As a thermoplastic polymer, polystyrene is in a solid (glassy) state at room tempe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Allura Red AC Structural Formula V1
Allura may refer to: * Allura, Karnataka, a village in Bidar district, Karnata, India * Apache Allura, software * Princess Allura, a fictional character * Allura Red AC Allura Red AC is a red azo dye that goes by several names, including FD&C Red 40. It is used as a food dye and has the E number E129. It is usually supplied as its red sodium salt, but can also be used as the calcium and potassium salts. These ..., a dye See also * Alura (other) * Allure (other) {{Disambiguation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sulfonamide (medicine)
Sulfonamide is a functional group (a part of a molecule) that is the basis of several groups of drugs, which are called sulphonamides, sulfa drugs or sulpha drugs. The original antibacterial sulfonamides are synthetic (nonantibiotic) antimicrobial agents that contain the sulfonamide group. Some sulfonamides are also devoid of antibacterial activity, e.g., the anticonvulsant sultiame. The sulfonylureas and thiazide diuretics are newer drug groups based upon the antibacterial sulfonamides. Allergies to sulfonamides are common. The overall incidence of adverse drug reactions to sulfa antibiotics is approximately 3%, close to penicillin; hence medications containing sulfonamides are prescribed carefully. Sulfonamide drugs were the first broadly effective antibacterials to be used systemically, and paved the way for the antibiotic revolution in medicine. Function In bacteria, antibacterial sulfonamides act as competitive inhibitors of the enzyme dihydropteroate synth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
