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Thiazolium
Thiazole, or 1,3-thiazole, is a heterocyclic compound that contains both sulfur and nitrogen. The term 'thiazole' also refers to a large family of derivatives. Thiazole itself is a pale yellow liquid with a pyridine-like odor and the molecular formula C3H3NS. The thiazole ring is notable as a component of the vitamin thiamine (B1). Molecular and electronic structure Thiazoles are members of the azoles, heterocycles that include imidazoles and oxazoles. Thiazole can also be considered a functional group. Oxazoles are related compounds, with sulfur replaced by oxygen. Thiazoles are structurally similar to imidazoles, with the thiazole sulfur replaced by nitrogen. Thiazole rings are planar and aromatic. Thiazoles are characterized by larger pi-electron delocalization than the corresponding oxazoles and have therefore greater aromaticity. This aromaticity is evidenced by the chemical shift of the ring protons in proton NMR spectroscopy (between 7.27 and 8.77 ppm), clearly indicating ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Benzothiazole
Benzothiazole is an aromatic heterocyclic compound with the chemical formula . It is colorless, slightly viscous liquid. Although the parent compound, benzothiazole is not widely used, many of its derivatives are found in commercial products or in nature. Firefly luciferin can be considered a derivative of benzothiazole. Structure and preparation Benzothiazoles consist of a 5-membered 1,3-thiazole ring fused to a benzene ring. The nine atoms of the bicycle and the attached substituents are coplanar. Benzothiazoles are prepared by treatment of 2-mercaptoaniline with acid chlorides: :C6H4(NH2)SH + RC(O)Cl → C6H4(NH)SCR + HCl + H2O Uses Benzothiazole occurs naturally in some foods but is also used as a food additive. It has a sulfurous odor and meaty flavor. The European Food Safety Authority assessment had "no safety concern at estimated levels of intake as a flavouring substance". The heterocyclic core of the molecule is readily substituted at the unique methyne ce ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thiamine
Thiamine, also known as thiamin and vitamin B1, is a vitamin, an essential micronutrient, that cannot be made in the body. It is found in food and commercially synthesized to be a dietary supplement or medication. Phosphorylated forms of thiamine are required for some metabolic reactions, including the breakdown of glucose and amino acids. Food sources of thiamine include whole grains, legumes, and some meats and fish. Grain processing removes much of the vitamin content, so in many countries cereals and flours are enriched with thiamine. Supplements and medications are available to treat and prevent thiamine deficiency and disorders that result from it include beriberi and Wernicke encephalopathy. They are also used to treat maple syrup urine disease and Leigh syndrome. Supplements and medications are typically taken by mouth, but may also be given by intravenous or intramuscular injection. Thiamine supplements are generally well tolerated. Allergic reactions, including ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Luciferin
Luciferin (from the Latin ''lucifer'', "light-bearer") is a generic term for the light-emitting compound found in organisms that generate bioluminescence. Luciferins typically undergo an enzyme-catalyzed reaction with molecular oxygen. The resulting transformation, which usually involves splitting off a molecular fragment, produces an excited state intermediate that emits light upon decaying to its ground state. The term may refer to molecules that are substrates for both luciferases and photoproteins. Types Luciferins are a class of small-molecule substrates that react with oxygen in the presence of a luciferase (an enzyme) to release energy in the form of light. It is not known just how many types of luciferins there are, but some of the better-studied compounds are listed below. Because of the chemical diversity of luciferins, there is no clear unifying mechanism of action, except that all require molecular oxygen, The variety of luciferins and luciferases, their diver ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chloroacetone
Chloroacetone is a chemical compound with the formula . At STP it is a colourless liquid with a pungent odour. On exposure to light, it turns to a dark yellow-amber colour. It was used as a tear gas in World War I. Synthesis Chloroacetone may be synthesized from the reaction between chlorine and diketene, or by the chlorination of acetone. Applications Chloroacetone is used to make dye couplers for colour photography, and is an intermediate in chemical manufacturing. It is also used in the Feist-Benary synthesis of furans. *Reaction of phenoxide with chloroacetone gives phenoxyacetone, which is used to make a wide variety of different pharmaceuticals. A catalytic amount of potassium iodide is also necessary to facilitate a Finkelstein reaction. Purification Chloroacetone purchased from commercial suppliers contains 5% impurities including mesityl oxide, which is not removed by distillation. Mesityl oxide can be oxidized using acidified KMnO4 to form a diol (followed by s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thioacetamide
Thioacetamide is an organosulfur compound with the chemical formula, formula carbon, C2hydrogen, H5nitrogen, Nsulfur, S. This white crystalline solid is soluble in water and serves as a source of sulfide ions in the synthesis of organic and inorganic compounds. It is a prototypical thioamide. Research Thioacetamide is known to induce acute or chronic liver disease (fibrosis and cirrhosis) in the experimental animal model. Its administration in rat induces hepatic encephalopathy, metabolic acidosis, increased levels of transaminases, abnormal coagulopathy, and centrilobular necrosis, which are the main features of the clinical chronic liver disease so thioacetamide can precisely replicate the initiation and progression of human liver disease in an experimental animal model. Coordination chemistry Thioacetamide is widely used in classical qualitative inorganic analysis as an in situ source for sulfide ions. Thus, treatment of aqueous solutions of many metal cations to a solution ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thioamide
A thioamide (rarely, thionamide, but also known as thiourylenes) is a functional group with the general structure R–CS–NR′R″, where R, R′, and R″ are organic groups. They are analogous to amides but they exhibit greater multiple bond character along the C-N bond, resulting in a larger rotational barrier. One of the best-known thioamides is thioacetamide, which is used as a source of the sulfide ion and is a building block in heterocyclic chemistry. Thioamides or anti-thyroid drugs are also a class of drugs that are used to control thyrotoxicosis. Preparation and structure Thioamides are typically prepared by treating amides with phosphorus sulfides such as phosphorus pentasulfide, a reaction first described in the 1870s. Alternative routes include the use of Lawesson's reagent or the reaction of nitriles with hydrogen sulfide: The Willgerodt-Kindler reaction also affords benzylthioamides. The C2NH2S core of thioamides is planar. Using thioacetamide as represent ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Haloketone
In organic chemistry, an α-haloketone is a functional group consisting of a ketone group or more generally a carbonyl group with an α-halogen substituent. α-haloketones are alkylating agents. Prominent α-haloketones include phenacyl bromide and chloroacetone. Structure The general structure is RR′C(X)C(=O)R where R is an alkyl or aryl residue and X any one of the halogens. The preferred conformation of a haloketone is that of a cisoid with the halogen and carbonyl sharing the same plane as the steric hindrance with the carbonyl alkyl group is generally larger. Haloketone synthesis Haloketones and halo carbonyl compounds in general are synthesized by reaction of carbonyl compounds with sources of X+ (X = halogen), which is provided using halogens: :RC(O)CH3 + X2 → RC(O)CH2X + HX Specialized sources of electrophilic halogenating agents include ''N''-Bromosuccinimide and 1,3-dibromo-5,5-dimethylhydantoin (DBDMH). In the Nierenstein reaction an acyl chloride re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organic Synthesis
Organic synthesis is a special branch of chemical synthesis and is concerned with the intentional construction of organic compounds. Organic molecules are often more complex than inorganic compounds, and their synthesis has developed into one of the most important branches of organic chemistry. There are several main areas of research within the general area of organic synthesis: ''total synthesis'', ''semisynthesis'', and ''methodology''. Total synthesis A total synthesis is the complete chemical synthesis of complex organic molecules from simple, commercially available petrochemical or natural precursors. Total synthesis may be accomplished either via a linear or convergent approach. In a ''linear'' synthesis—often adequate for simple structures—several steps are performed one after another until the molecule is complete; the chemical compounds made in each step are called synthetic intermediates. Most often, each step in a synthesis refers to a separate rea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cotton
Cotton is a soft, fluffy staple fiber that grows in a boll, or protective case, around the seeds of the cotton plants of the genus ''Gossypium'' in the mallow family Malvaceae. The fiber is almost pure cellulose, and can contain minor percentages of waxes, fats, pectins, and water. Under natural conditions, the cotton bolls will increase the dispersal of the seeds. The plant is a shrub native to tropical and subtropical regions around the world, including the Americas, Africa, Egypt and India. The greatest diversity of wild cotton species is found in Mexico, followed by Australia and Africa. Cotton was independently domesticated in the Old and New Worlds. The fiber is most often spun into yarn or thread and used to make a soft, breathable, and durable textile. The use of cotton for fabric is known to date to prehistoric times; fragments of cotton fabric dated to the fifth millennium BC have been found in the Indus Valley civilization, as well as fabric remnants dated back ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anthroquinone
Anthraquinone, also called anthracenedione or dioxoanthracene, is an aromatic organic compound with formula . Isomers include various quinone derivatives. The term anthraquinone however refers to the isomer, 9,10-anthraquinone (IUPAC: 9,10-dioxoanthracene) wherein the keto groups are located on the central ring. It is a building block of many dyes and is used in bleaching pulp for papermaking. It is a yellow, highly crystalline solid, poorly soluble in water but soluble in hot organic solvents. It is almost completely insoluble in ethanol near room temperature but 2.25 g will dissolve in 100 g of boiling ethanol. It is found in nature as the rare mineral hoelite. Synthesis There are several current industrial methods to produce 9,10-anthraquinone: # The oxidation of anthracene. Chromium(VI) is the typical oxidant. # The Friedel-Crafts reaction of benzene and phthalic anhydride in presence of AlCl3. o-Benzoylbenzoic acid is an intermediate. This reaction is useful for producing ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
