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Thiazolium Salt
Thiazole (), or 1,3-thiazole, is a 5-membered 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 Imidazole, imidazoles and Oxazole, oxazoles. Thiazole can also be considered a functional group when part of a larger molecule. Being planar thiazoles are characterized by significant pi-electron delocalization and have some degree of aromaticity, more so than the corresponding oxazoles. This aromaticity is evidenced by the proton NMR, 1H NMR chemical shift of the ring protons, which absorb between 7.27 and 8.77 ppm, indicating a strong diamagnetic ring current. The calculated pi-electron density marks C5 as the primary site for electrophi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heterocyclic Compound
A heterocyclic compound or ring structure is a cyclic compound that has atoms of at least two different elements as members of its ring(s). Heterocyclic organic chemistry is the branch of organic chemistry dealing with the synthesis, properties, and applications of organic heterocycles. Examples of heterocyclic compounds include all of the nucleic acids, the majority of drugs, most biomass (cellulose and related materials), and many natural and synthetic dyes. More than half of known compounds are heterocycles. 59% of US FDA-approved drugs contain nitrogen heterocycles. Classification The study of organic heterocyclic chemistry focuses especially on organic unsaturated derivatives, and the preponderance of work and applications involves unstrained organic 5- and 6-membered rings. Included are pyridine, thiophene, pyrrole, and furan. Another large class of organic heterocycles refers to those fused to benzene rings. For example, the fused benzene derivatives of py ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biomolecule
A biomolecule or biological molecule is loosely defined as a molecule produced by a living organism and essential to one or more typically biological processes. Biomolecules include large macromolecules such as proteins, carbohydrates, lipids, and nucleic acids, as well as small molecules such as vitamins and hormones. A general name for this class of material is ''biological materials''. Biomolecules are an important element of living organisms. They are often endogeny (biology), endogenous, i.e. produced within the organism, but organisms usually also need exogeny, exogenous biomolecules, for example certain nutrients, to survive. Biomolecules and their organic reaction, reactions are studied in biology and its subfields of biochemistry and molecular biology. Most biomolecules are organic compounds, and just four chemical element, elements—oxygen, carbon, hydrogen, and nitrogen—make up 96% of the human body's mass. But many other elements, such as the various biometal (b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Herz Reaction
The Herz reaction, named after the chemist Richard Herz, is the chemical conversion of an aniline to the benzo dithiazolium salt by its reaction with disulfur dichloride. The salt is called a Herz salt. Hydrolysis of this Herz salt give the corresponding sodium thiolate, which can be further converted to the 2-aminothiophenol. The 2-aminothiophenols are suitable for diazotization, giving benzothiadiazoles.{{cite journal , doi=10.1039/J39700002250 , title=1,2,3-Benzothiadiazoles. Part I. A simplified synthesis of 1,2,3-benzothiadiazoles , year=1970 , last1=Kirby , first1=P. , last2=Soloway , first2=S. B. , last3=Davies , first3=J. H. , last4=Webb , first4=Shirley B. , journal=Journal of the Chemical Society C: Organic , issue=16 , page=2250 Instead the sodium 2-aminothiophenolate can be converted to a 1,3-benzothiazole. : Dyes Aniline 5 is converted to compound 6, in three steps; # conversion to an ortho- aminothiol through the Herz-reaction (aniline 5 and disulfur dichlori ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carbon Disulfide
Carbon disulfide (also spelled as carbon disulphide) is an inorganic compound with the chemical formula and structure . It is also considered as the anhydride of thiocarbonic acid. It is a colorless, flammable, neurotoxic liquid that is used as a building block in organic synthesis. Pure carbon disulfide has a pleasant, ether- or chloroform-like odor, but commercial samples are usually yellowish and are typically contaminated with foul-smelling impurities.. History In 1796, the German chemist Wilhelm August Lampadius (1772–1842) first prepared carbon disulfide by heating pyrite with moist charcoal. He called it "liquid sulfur" (''flüssig Schwefel''). The composition of carbon disulfide was finally determined in 1813 by the team of the Swedish chemist Jöns Jacob Berzelius (1779–1848) and the Swiss-British chemist Alexander Marcet (1770–1822). Their analysis was consistent with an empirical formula of CS2. Occurrence, manufacture, properties Small amounts of carbon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chloroacetone
Chloroacetone is a chemical compound with the chemical formula, formula . At Standard temperature and pressure, STP it is a colorless liquid with a pungent odor. On exposure to light, it turns to a dark yellow-amber color. It was used as a lachrymatory agent, 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thioacetamide
Thioacetamide is an organosulfur compound with the formula C2 H5 N 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 coagulation, 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 of thioacetamide affords the corresponding metal s ... [...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 , where are any groups (typically organyl groups or hydrogen). Analogous to amides, thioamides exhibit greater multiple bond character along the C-N bond, resulting in a larger rotational barrier. Synthesis Thioamides are typically prepared by treating amides with phosphorus sulfides such as phosphorus pentasulfide, a reaction first described in the 1870s. An alternative to P2S5 is its more soluble analogue Lawesson's reagent. The Willgerodt-Kindler reaction can give benzylthioamides via an analogous process. These transformations can be seen in the synthesis of tolrestat. : The reaction of nitriles with hydrogen sulfide also affords thioamides: : Imidoyl chlorides react with hydrogen sulfide to produce thioamides. : Reactions A well-known thioamide is thioacetamide, which is used as a source of the sulfide ion. Thioamides are precursors to heterocycles. Such ap ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organic Synthesis
Organic synthesis is a branch of chemical synthesis concerned with the construction of organic compounds. Organic compounds are molecules consisting of combinations of covalently-linked hydrogen, carbon, oxygen, and nitrogen atoms. Within the general subject of organic synthesis, there are many different types of synthetic routes that can be completed including total synthesis, Enantioselective synthesis, stereoselective synthesis, automated synthesis, and many more. Additionally, in understanding organic synthesis it is necessary to be familiar with the methodology, techniques, and applications of the subject. Total synthesis A total synthesis refers to the complete chemical synthesis of molecules from simple, Precursor (chemistry), natural precursors. Total synthesis is accomplished either via a linear or convergent approach. In a Linear synthesis, ''linear'' synthesis—often adequate for simple structures—several steps are performed sequentially until the molecule is com ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cotton
Cotton (), first recorded in ancient India, 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 civilizat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anthroquinone
Anthraquinone, also called anthracenedione or dioxoanthracene, is an aromatic organic compound with formula . Several isomers exist but these terms usually refer to 9,10-anthraquinone (IUPAC: 9,10-dioxoanthracene) wherein the keto groups are located on the central ring. It is used as a digester additive to wood pulp for papermaking. Many anthraquinone derivatives are generated by organisms or synthesised industrially for use as dyes, pharmaceuticals, and catalysts. Anthraquinone 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
