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Hinsberg Oxindole Synthesis
The Hinsberg oxindole synthesis is a method of preparing oxindoles from the bisulfite additions of glyoxal. It is named after its inventor Oscar Hinsberg Oscar Heinrich Daniel Hinsberg (21 October 1857 – 13 February 1939) was a German chemist. Hinsberg was born in Berlin. In 1882 he obtained his doctorate in sciences at the University of Tübingen, later serving as a professor at the Universitie ....{{cite journal, author=Hinsberg, O. , journal=Ber. Dtsch. Chem. Ges., year=1908, volume=41, page= 1367, doi=10.1002/cber.190804101252, title=Über Glykokoll und Indol-derivate, url=https://zenodo.org/record/1426277 : See also * Friedel-Crafts alkylation * Stolle synthesis * Hinsberg reaction References Name reactions ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxindole
Oxindole (2-indolone) is an aromatic heterocyclic organic compound with the formula C6H4CHC(O)NH. It has a bicyclic structure, consisting of a six-membered benzene ring fused to a five-membered nitrogen-containing ring. Oxindole is a modified indoline with a substituted carbonyl at the second position of the 5-member indoline ring. Classified as a cyclic amide, it is a pale yellow solid. Formation and reactions Oxindole is derived in nature from tryptophan, formed by gut bacteria ("normal flora"). It is normally metabolized and detoxified from the body by the liver. In excess, it can cause sedation, muscle weakness, hypotension, and coma. Patients with hepatic encephalopathy have been recorded to have elevated serum oxindole levels. Treatment with phosphorus pentasulfide Phosphorus pentasulfide is the inorganic compound with the formula (monomer) or (dimer). This yellow solid is the one of two phosphorus sulfides of commercial value. Samples often appear greenish-gray due to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bisulfite Addition
The bisulfite ion (IUPAC-recommended nomenclature: hydrogensulfite) is the ion . Salts containing the ion are also known as "sulfite lyes". Sodium bisulfite is used interchangeably with sodium metabisulfite (Na2S2O5). Sodium metabisulfite dissolves in water to give a solution of Na+. :Na2S2O5 + H2O → 2Na SO3 Structure The bisulfite anion exists in solution as a mixture of two tautomers. One tautomer has the proton attached to one of the three oxygen centers. In the second tautomer the proton resides on sulfur. The S-protonated tautomer has ''C''3v symmetry. The O-protonated tautomer has only Cs symmetry. Reactions Tautomerization There exist two tautomers of bisulfite. They interconvert readily but can be characterized individually by various spectroscopic methods. They have been observed by 17O NMR spectroscopy: :HSO3− SO2(OH)− K = 4.2 Acid-base reactions Solutions of bisulfite are typically prepared by treatment of sulfur dioxide with aqueous base: :S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glyoxal
Glyoxal is an organic compound In chemistry, organic compounds are generally any chemical compounds that contain carbon-hydrogen or carbon-carbon bonds. Due to carbon's ability to catenate (form chains with other carbon atoms), millions of organic compounds are known. The ... with the chemical formula OCHCHO. It is the smallest dialdehyde (a compound with two aldehyde groups). It is a crystalline solid, white at low temperatures and yellow near the melting point (15 °C). The liquid is yellow, and the vapor is green.O'Neil, M.J. (2001): ''The Merck Index'', 13th Edition, page 803. Pure glyoxal is not commonly encountered because glyoxal is usually handled as a 40% aqueous solution (density near 1.24 g/mL). It forms a series of hydrates, including oligomers. For many purposes, these hydrated oligomers behave equivalently to glyoxal. Glyoxal is produced industrially as a precursor to many products. Production Glyoxal was first prepared and named by the German-British ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oscar Hinsberg
Oscar Heinrich Daniel Hinsberg (21 October 1857 – 13 February 1939) was a German chemist. Hinsberg was born in Berlin. In 1882 he obtained his doctorate in sciences at the University of Tübingen, later serving as a professor at the Universities of Freiburg and Geneva. He is known for research involving synthesis of oxindole, sulfone and thiophene. In 1890 he introduced the "Hinsberg reaction", a test used for differentiation of primary, secondary and tertiary amines. Publications * ''Ueber Oxalsäurederivate des Metanitroparatoluidins und des Metaparadiamidotoluols'', 1882. * ''Ueber die Wirkung des Acetphenetidins'', (with internist Alfred Kast 1856-1903). in Centralblatt für die medicinischen Wissenschaften, Berlin, 1887, 25: 145-148. - introduction of phenacetine. @ |
Stolle Synthesis , a type of cake
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Stolle is a surname. Notable people with the surname include: * Bruno Stolle (1915–2004), German pilot *Chris Stolle (born 1958), American politician * Fred Stolle (born 1938), Australian tennis player * Gerhard Stolle (born 1952), German athlete *Ken Stolle (born 1954), American politician * Michael Stolle (born 1974), German athlete *Philipp Stolle (1614–1675), German composer * Sandon Stolle (born 1970), Australian tennis player * Colin Stolle (born 1970), American politician See also * Stollé synthesis, a chemical reaction for the formation of oxindoles by combining anilines and α-haloacid chlorides (or oxalyl chloride) *Stol (other) * Stole (other) *Stoll (other) *Stollen Stollen ( or ) is a fruit bread of nuts, spices, and dried or candied fruit, coated with powdered sugar or icing sugar and often containing marzipan. It is a traditional German Christmas bread. During the Christmas season the cake-like loaves ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hinsberg Reaction
The Hinsberg reaction is a chemical test for the detection of primary, secondary and tertiary amines. The reaction was first described by Oscar Hinsberg in 1890. In this test, the amine is shaken well with Hinsberg reagent in the presence of aqueous alkali (either KOH or NaOH). A reagent containing an aqueous sodium hydroxide solution and benzenesulfonyl chloride is added to a substrate. A primary amine will form a soluble sulfonamide salt. Acidification of this salt then precipitates the sulfonamide of the primary amine. A secondary amine in the same reaction will directly form an insoluble sulfonamide. A tertiary amine will not react with the original reagent(benzene sulfonyl chloride) and will remain insoluble. After adding dilute acid this insoluble amine is converted to a soluble ammonium salt The ammonium cation is a positively-charged polyatomic ion with the chemical formula or . It is formed by the protonation of ammonia (). Ammonium is also a general name for positi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
