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Urech Hydantoin Synthesis
The Urech hydantoin synthesis is the chemical reaction of amino acids with potassium cyanate and hydrochloric acid to give hydantoins. Reaction mechanism See also *Bucherer–Bergs reaction References {{Reflist External links English translation of 1873 German article 'on lactyl amino acids and lactyl ureas' by Friedrich Urech Friedrich may refer to: Names *Friedrich (surname), people with the surname ''Friedrich'' *Friedrich (given name), people with the given name ''Friedrich'' Other *Friedrich (board game), a board game about Frederick the Great and the Seven Years' ... Condensation reactions Nitrogen heterocycle forming reactions Heterocycle forming reactions Hydantoins Name reactions ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemical Reaction
A chemical reaction is a process that leads to the chemical transformation of one set of chemical substances to another. Classically, chemical reactions encompass changes that only involve the positions of electrons in the forming and breaking of chemical bonds between atoms, with no change to the nuclei (no change to the elements present), and can often be described by a chemical equation. Nuclear chemistry is a sub-discipline of chemistry that involves the chemical reactions of unstable and radioactive elements where both electronic and nuclear changes can occur. The substance (or substances) initially involved in a chemical reaction are called reactants or reagents. Chemical reactions are usually characterized by a chemical change, and they yield one or more products, which usually have properties different from the reactants. Reactions often consist of a sequence of individual sub-steps, the so-called elementary reactions, and the information on the precise course ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amino Acid
Amino acids are organic compounds that contain both amino and carboxylic acid functional groups. Although hundreds of amino acids exist in nature, by far the most important are the alpha-amino acids, which comprise proteins. Only 22 alpha amino acids appear in the genetic code. Amino acids can be classified according to the locations of the core structural functional groups, as Alpha and beta carbon, alpha- , beta- , gamma- or delta- amino acids; other categories relate to Chemical polarity, polarity, ionization, and side chain group type (aliphatic, Open-chain compound, acyclic, aromatic, containing hydroxyl or sulfur, etc.). In the form of proteins, amino acid '' residues'' form the second-largest component (water being the largest) of human muscles and other tissues. Beyond their role as residues in proteins, amino acids participate in a number of processes such as neurotransmitter transport and biosynthesis. It is thought that they played a key role in enabling ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Potassium Cyanate
Potassium cyanate is an inorganic compound with the formula KOCN (sometimes denoted KCNO). It is a colourless solid. It is used to prepare many other compounds including useful herbicide. Worldwide production of the potassium and sodium salts was 20,000 tons in 2006.Peter M. Schalke1, "Cyanates, Inorganic Salts" Ullmann's Encyclopedia of Industrial Chemistry2006, Wiley-VCH, Weinheim. . Article Online Posting Date: July 15, 2006 Structure and bonding The cyanate anion is isoelectronic with carbon dioxide and with the azide anion, being linear. The C-N distance is 121 pm, about 5 pm longer than for cyanide. Potassium cyanate is isostructural with potassium azide. Uses For most applications, the potassium and sodium salts can be used interchangeably. Potassium cyanate is often preferred to the sodium salt, which is less soluble in water and less readily available in pure form. Potassium cyanate is used as a basic raw material for various organic syntheses, including, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrochloric Acid
Hydrochloric acid, also known as muriatic acid, is an aqueous solution of hydrogen chloride. It is a colorless solution with a distinctive pungent smell. It is classified as a strong acid. It is a component of the gastric acid in the digestive systems of most animal species, including humans. Hydrochloric acid is an important laboratory reagent and industrial chemical. History In the early tenth century, the Persian physician and alchemist Abu Bakr al-Razi ( 865–925, Latin: Rhazes) conducted experiments with sal ammoniac ( ammonium chloride) and vitriol (hydrated sulfates of various metals), which he distilled together, thus producing the gas hydrogen chloride. In doing so, al-Razi may have stumbled upon a primitive method for producing hydrochloric acid, as perhaps manifested in the following recipe from his ("The Book of Secrets"): However, it appears that in most of his experiments al-Razi disregarded the gaseous products, concentrating instead on the color cha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydantoin
Hydantoin, or glycolylurea, is a heterocyclic organic compound with the formula CH2C(O)NHC(O)NH. It is a colorless solid that arises from the reaction of glycolic acid and urea. It is an oxidized derivative of imidazolidine. In a more general sense, hydantoins can refer to a groups and a class of compounds with the same ring structure as the parent. For example, phenytoin (mentioned below) has two phenyl groups substituted onto the number 5 carbon in a hydantoin molecule. Synthesis Hydantoin was first isolated in 1861 by Adolf von Baeyer in the course of his study of uric acid. He obtained it by hydrogenation of allantoin, hence the name. : Friedrich Urech synthesized 5-methylhydantoin in 1873 from alanine sulfate and potassium cyanate in what is now known as the Urech hydantoin synthesis. The method is very similar to the modern route using alkyl and arylcyanates. The 5,5-dimethyl compound can also be obtained from acetone cyanohydrin (also discovered by Urech: see ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Liebigs Ann
''Justus Liebigs Annalen der Chemie'' (often cited as just ''Liebigs Annalen'') was one of the oldest and historically most important journals in the field of organic chemistry worldwide. It was established in 1832 and edited by Justus von Liebig with Friedrich Wöhler and others until Liebig's death in 1873. In 1997 the journal merged with ''Recueil des Travaux Chimiques des Pays-Bas'' to form ''Liebigs Annalen/Recueil''. In 1998 it was absorbed by ''European Journal of Organic Chemistry'' by merger of a number of other national European chemistry journals. Title history * ''Annalen der Pharmacie'', 1832–1839 * ''Annalen der Chemie und Pharmacie'', 1840–1873 (, CODEN JLACBF) * ''Justus Liebig's Annalen der Chemie und Pharmacie'', 1873–1874 (, CODEN JLACBF) * ''Justus Liebig's Annalen der Chemie'', 1874–1944 & 1947–1978 (, CODEN JLACBF) * ''Liebigs Annalen der Chemie'', 1979–1994 (, CODEN LACHDL) * ''Liebigs Annalen'', 1995–1996 (, CODEN LANAEM) * ''Liebi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chem , a place in Finland
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Chem may refer to: * Chemistry practical waali mam * Chemistry * Chemical * ''Chem'' (journal), a scientific journal published by Cell Press *Post apocalyptic slang for "drugs", medicinal or otherwise in the Fallout video game series. In Ancient Egyptian usage: * ''Khem'' (also spelt ''Chem''), the Egyptian word for "black" * Min (god), in the past erroneously named ''Khem'' CHEM may refer to : *A metabolic panel: for instance, CHEM-7, which is the basic metabolic panel *CHEM-DT, a Canadian television channel See also *Chemo (other) *Kemi Kemi (; sme, Giepma ; smn, Kiemâ; sms, Ǩeeʹmm; Swedish (historically): ''Kiemi'') is a town and municipality of Finland. It is located very near the city of Tornio and the Swedish border. The distance to Oulu is to the south and to Rovani ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Urech Hydantoin Synthesis Scheme , it was named after Friedrich Urech, who published the reaction in 1873
{{Surname ...
Urech is a surname. Notable people with the surname include: * Christine Urech (born 1984), Swiss curler * Friedrich Urech (1844–1904), German chemist * Lisa Urech (born 1989), Swiss hurdler See also *Urech hydantoin synthesis The Urech hydantoin synthesis is the chemical reaction of amino acids with potassium cyanate and hydrochloric acid to give hydantoins. Reaction mechanism See also *Bucherer–Bergs reaction The Bucherer–Bergs reaction is the chemical reacti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bucherer–Bergs Reaction
The Bucherer–Bergs reaction is the chemical reaction of carbonyl compounds (aldehydes or ketones) or cyanohydrins with ammonium carbonate and potassium cyanide to give hydantoins. The reaction is named after Hans Theodor Bucherer. ''Overall Reaction'' Reaction Mechanism Following condensation of the carbonyl with the ammonium, the formed imine is attacked by the isocyanide to form the aminonitrile. Nucleophilic addition of aminonitrile to CO2 leads to cyano-carbamic acid, which undergoes an intramolecular ring closing to 5-imino-oxazolidin-2-one. The 5-imino-oxazolidin-2-one rearranges to form the hydantoin product via an isocyanate intermediate. History Reactions similar to the Bucherer–Bergs reaction were first seen in 1905 and 1914 by Ciamician and Silber, who obtained 5,5-dimethylhydantoin from a mixture of acetone and hydrocyanic acid after it had been exposed to sunlight for five to seven months. In 1929, Bergs issued a patent that described his own synthesis of a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Friedrich Urech
Friedrich may refer to: Names *Friedrich (surname), people with the surname ''Friedrich'' *Friedrich (given name), people with the given name ''Friedrich'' Other *Friedrich (board game), a board game about Frederick the Great and the Seven Years' War * ''Friedrich'' (novel), a novel about anti-semitism written by Hans Peter Richter *Friedrich Air Conditioning, a company manufacturing air conditioning and purifying products *, a German cargo ship in service 1941-45 See also *Friedrichs (other) *Frederick (other) *Nikolaus Friedreich Nikolaus Friedreich (1 July 1825 in Würzburg – 6 July 1882 in Heidelberg) was a German pathologist and neurologist, and a third generation physician in the Friedreich family. His father was psychiatrist Johann Baptist Friedreich (1796–1862 ... {{disambig ja:フリードリヒ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Condensation Reactions
In organic chemistry, a condensation reaction is a type of chemical reaction in which two molecules are combined to form a single molecule, usually with the loss of a small molecule such as water. If water is lost, the reaction is also known as a dehydration synthesis. However other molecules can also be lost, such as ammonia, ethanol, acetic acid and hydrogen sulfide. The addition of the two molecules typically proceeds in a step-wise fashion to the addition product, usually in equilibrium, and with loss of a water molecule (hence the name condensation). The reaction may otherwise involve the functional groups of the molecule, and is a versatile class of reactions that can occur in acidic or basic conditions or in the presence of a catalyst. This class of reactions is a vital part of life as it is essential to the formation of peptide bonds between amino acids and to the biosynthesis of fatty acids. Many variations of condensation reactions exist. Common examples include the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
