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Rathke Synthesis
In organic chemistry, isothiouronium is a functional group with the formula SC(NH2)2sup>+ (R = alkyl, aryl) and is the acid salt of isothiourea. The H centres can also be replaced by alkyl and aryl. Structurally, these cations resemble guanidinium cations. The CN2S core is planar and the C–N bonds are short. Synthesis Salts comprising these cations are typically prepared by alkylation of thiourea: :SC(NH2)2 + RX → SC(NH2)2sup>+X− Reactions Hydrolysis of isothiouronium salts gives thiols. : SC(NH2)2sup>+X− + NaOH → RSH + OC(NH2)2 + NaX Isothiouronium salts in which the sulfur has been alkylated, such as ''S''-methylisothiourea hemisulfate (CAS number: 867-44-7), will convert amines into guanidinium groups. This approach is sometimes called the Rathke synthesis after Bernhard Rathke Heinrich Bernhard Rathke (20 January 1840 in Königsberg – 14 August 1923 in Bad Reichenhall) was a German chemist. He was the son of embryologist Martin Rathke. He studied na ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
S-Ethylisothiouronium Diethylphosphate
''S''-Ethylisothiouronium diethylphosphate (brand name Difetur) is an ''S''-alkylisothiouronium derivative used as an antihypotensive drug. The ''S''-alkylisothiouronium compounds are used in processes of treating acute hypotension, which may result, for example, from shock or hemorrhage, and in processes for treating hyperoxic conditions, for example, oxygen poisoning. Indications It is used for increasing arterial blood pressure in cases of acute arterial hypotension due to surgical interference, trauma, poisoning, shock condition, hemorrhages; in conjunction with epidural anesthesia; in overdose of ganglion blockers, alpha-adrenergic blockers, neuroleptics, anesthetics; and in other conditions when adrenomimetics are contra-indicated or ineffective. Difetur was also found to possess oxygen protective activity and, thus, can be used as a medicament for protecting against oxygen poisoning conditions caused by hyperoxia. ''S''-Ethylisothiouronium diethylphosphate is also used for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thiourea
Thiourea () is an organosulfur compound with the formula and the structure . It is structurally similar to urea (), with the oxygen atom replaced by sulfur atom (as implied by the '' thio-'' prefix). The properties of urea and thiourea differ significantly. Thiourea is a reagent in organic synthesis. Thioureas are a broad class of compounds with the formula Structure and bonding Thiourea is a planar molecule. The C=S bond distance is 1.71 Å. The C-N distances average 1.33 Å. The weakening of the C-S bond by C-N pi-bonding is indicated by the short C=S bond in thiobenzophenone, which is 1.63 Å. Thiourea occurs in two tautomeric forms, of which the thione form predominates in aqueous solutions. The equilibrium constant has been calculated as ''K''eq is . The thiol form, which is also known as an isothiourea, can be encountered in substituted compounds such as isothiouronium salts. : Production The global annual production of thiourea is around 8,000 tonnes, mo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Functional Groups
In organic chemistry, a functional group is any substituent or moiety (chemistry), moiety in a molecule that causes the molecule's characteristic chemical reactions. The same functional group will undergo the same or similar chemical reactions regardless of the rest of the molecule's composition. This enables systematic prediction of chemical reactions and behavior of chemical compounds and the design of chemical synthesis. The Reactivity (chemistry), reactivity of a functional group can be modified by other functional groups nearby. Functional group interconversion can be used in retrosynthetic analysis to plan organic synthesis. A functional group is a group of atoms in a molecule with distinctive Chemical property, chemical properties, regardless of the other atoms in the molecule. The atoms in a functional group are linked to each other and to the rest of the molecule by covalent bonds. For repeating units of polymers, functional groups attach to their Chemical polarity, nonp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chelating Resins
Chelating resins are a class of ion-exchange resins. They are almost always used to bind cations, and utilize chelating agents covalently attached to a polymer matrix. Chelating resins have the same bead form and polymer matrix as usual ion exchangers. Their main use is for pre-concentration of metal ions in a dilute solution. Chelating ion-exchange resins are used for brine decalcification in the chlor-alkali industry, the removal of boron from potable water, and the recovery of precious metals in solutions. Properties and structure Chelating resins operate similarly to ordinary ion-exchange resins. Most chelating resins are polymers (copolymers to be precise) with reactive functional groups that chelate to metal ions. The variation in chelating resins arises from the nature of the chelating agents pendant from the polymer backbone. Dowex chelating resin A-1, also known as Chelex 100, is based on iminodiacetic acid in a styrene-divinylbenzene matrix. Dowex A-1 is available comme ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bernhard Rathke
Heinrich Bernhard Rathke (20 January 1840 in Königsberg – 14 August 1923 in Bad Reichenhall) was a German chemist. He was the son of embryologist Martin Rathke. He studied natural sciences at the University of Königsberg, and afterwards worked in Robert Bunsen's laboratory at Heidelberg. In 1867 he started work as an assistant at the chemical institute of the University of Halle, and two years later obtained his habilitation with a thesis on the history of selenium. From 1873 to 1876 he taught classes in chemistry and chemical engineering at the higher vocational school in Kassel. In 1876 he became an associate professor at Halle,Bernhard Rathke Catalogus Professorum Halensis during this time he published what became known as the [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amine
In chemistry, amines (, ) are organic compounds that contain carbon-nitrogen bonds. Amines are formed when one or more hydrogen atoms in ammonia are replaced by alkyl or aryl groups. The nitrogen atom in an amine possesses a lone pair of electrons. Amines can also exist as hetero cyclic compounds. Aniline is the simplest aromatic amine, consisting of a benzene ring bonded to an amino group. Amines are classified into three types: primary (1°), secondary (2°), and tertiary (3°) amines. Primary amines (1°) contain one alkyl or aryl substituent and have the general formula RNH2. Secondary amines (2°) have two alkyl or aryl groups attached to the nitrogen atom, with the general formula R2NH. Tertiary amines (3°) contain three substituent groups bonded to the nitrogen atom, and are represented by the formula R3N. The functional group present in primary amines is called the amino group. Classification of amines Amines can be classified according to the nature and number o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thiol
In organic chemistry, a thiol (; ), or thiol derivative, is any organosulfur compound of the form , where R represents an alkyl or other organic substituent. The functional group itself is referred to as either a thiol group or a sulfhydryl group, or a sulfanyl group. Thiols are the sulfur analogue of alcohols (that is, sulfur takes the place of oxygen in the hydroxyl () group of an alcohol), and the word is a blend of "''thio-''" with "alcohol". Many thiols have strong odors resembling that of garlic, cabbage or rotten eggs. Thiols are used as odorants to assist in the detection of natural gas (which in pure form is odorless), and the smell of natural gas is due to the smell of the thiol used as the odorant. Nomenclature Thiols are sometimes referred to as mercaptans () or mercapto compounds, a term introduced in 1832 by William Christopher Zeise and is derived from the Latin ('capturing mercury')''Oxford American Dictionaries'' (Mac OS X Leopard). because the thiolate grou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrolysis
Hydrolysis (; ) is any chemical reaction in which a molecule of water breaks one or more chemical bonds. The term is used broadly for substitution reaction, substitution, elimination reaction, elimination, and solvation reactions in which water is the nucleophile. Biological hydrolysis is the cleavage of Biomolecule, biomolecules where a water molecule is consumed to effect the separation of a larger molecule into component parts. When a carbohydrate is broken into its component sugar molecules by hydrolysis (e.g., sucrose being broken down into glucose and fructose), this is recognized as saccharification. Hydrolysis reactions can be the reverse of a condensation reaction in which two molecules join into a larger one and eject a water molecule. Thus hydrolysis adds water to break down, whereas condensation builds up by removing water. Types Usually hydrolysis is a chemical process in which a molecule of water is added to a substance. Sometimes this addition causes both the su ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alkylation
Alkylation is a chemical reaction that entails transfer of an alkyl group. The alkyl group may be transferred as an alkyl carbocation, a free radical, a carbanion, or a carbene (or their equivalents). Alkylating agents are reagents for effecting alkylation. Alkyl groups can also be removed in a process known as dealkylation. Alkylating agents are often classified according to their nucleophilic or electrophilic character. In oil refining contexts, alkylation refers to a particular alkylation of isobutane with alkene, olefins. For upgrading of petroleum, alkylation produces a premium blending stock for gasoline. In medicine, alkylation of DNA is used in chemotherapy to damage the DNA of cancer cells. Alkylation is accomplished with the class of drugs called alkylating antineoplastic agents. Nucleophilic alkylating agents Nucleophilic alkylating agents deliver the equivalent of an alkyl anion (carbanion). The formal "alkyl anion" attacks an electrophile, forming a new covalent bond ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organic Chemistry
Organic chemistry is a subdiscipline within chemistry involving the science, scientific study of the structure, properties, and reactions of organic compounds and organic matter, organic materials, i.e., matter in its various forms that contain carbon atoms.Clayden, J.; Greeves, N. and Warren, S. (2012) ''Organic Chemistry''. Oxford University Press. pp. 1–15. . Study of structure determines their structural formula. Study of properties includes Physical property, physical and Chemical property, chemical properties, and evaluation of Reactivity (chemistry), chemical reactivity to understand their behavior. The study of organic reactions includes the organic synthesis, chemical synthesis of natural products, drugs, and polymers, and study of individual organic molecules in the laboratory and via theoretical (in silico) study. The range of chemicals studied chemistry includes hydrocarbons (compounds containing only carbon and hydrogen) as well as compounds based on carbon, but a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Guanidinium
Guanidine is the compound with the formula HNC(NH2)2. It is a colourless solid that dissolves in polar solvents. It is a strong base that is used in the production of plastics and explosives. It is found in urine predominantly in patients experiencing renal failure. A guanidine moiety also appears in larger organic molecules, including on the side chain of arginine. Structure Guanidine can be thought of as a nitrogenous analogue of carbonic acid. That is, the C=O group in carbonic acid is replaced by a C=NH group, and each OH is replaced by a group. A detailed crystallographic analysis of guanidine was elucidated 148 years after its first synthesis, despite the simplicity of the molecule. In 2013, the positions of the hydrogen atoms and their displacement parameters were accurately determined using single-crystal neutron diffraction. Production Guanidine can be obtained from natural sources, being first isolated in 1861 by Adolph Strecker via the oxidative degradation of an a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isothiourea
In organic chemistry, thioureas are members of a family of organosulfur compounds with the formula and structure . The parent member of this class of compounds is thiourea (). Substituted thioureas are found in several commercial chemicals. Structure and bonding Thioureas have a trigonal planar molecular geometry of the core. The bond distance is near 1.71 Å, which is 0.1 Å longer than in normal ketones (). The C–N bond distances are short. Thioureas occurs in two tautomeric forms. : On the other hand, some compounds depicted as isothioureas and in fact thioureas, one example being mercaptobenzimidazole. Synthesis ''N'',''N''′-unsubstituted thioureas can be prepared by treating the corresponding cyanamide with hydrogen sulfide or similar sulfide sources. Organic ammonium salts react with potassium thiocyanate as the source of the thiocarbonyl (). Alternatively, ''N'',''N''′-disubstituted thioureas can be prepared by coupling two amines with thiophosgen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
