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Wilhelm Lossen
Wilhelm Clemens Lossen (8 May 1838 in Kreuznach – 29 October 1906 in Aachen) was a German chemist. He was the brother of geologist Karl August Lossen. From 1857 he studied chemistry at the University of Giessen, then continued his education at Göttingen as a pupil of Friedrich Wöhler. After graduation, he worked as an assistant to Karl Weltzien at the polytechnic in Karlsruhe and as an assistant under Wilhelm Heinrich Heintz at the University of Halle. In 1870 he became an associate professor at Heidelberg, then in 1877 accepted a position as professor of chemistry at the University of Königsberg. He is largely known for his work with hydroxylamines; their preparations, properties and derivatives. The eponymous Lossen rearrangement, refers to the decomposition of hydroxamic acids or their derivatives to yield isocyanates. While a student at Göttingen, he conducted research of cocaine with Albert Niemann. After the untimely death of Niemann in 1861, he continued rese ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wilhelm Lossen
Wilhelm Clemens Lossen (8 May 1838 in Kreuznach – 29 October 1906 in Aachen) was a German chemist. He was the brother of geologist Karl August Lossen. From 1857 he studied chemistry at the University of Giessen, then continued his education at Göttingen as a pupil of Friedrich Wöhler. After graduation, he worked as an assistant to Karl Weltzien at the polytechnic in Karlsruhe and as an assistant under Wilhelm Heinrich Heintz at the University of Halle. In 1870 he became an associate professor at Heidelberg, then in 1877 accepted a position as professor of chemistry at the University of Königsberg. He is largely known for his work with hydroxylamines; their preparations, properties and derivatives. The eponymous Lossen rearrangement, refers to the decomposition of hydroxamic acids or their derivatives to yield isocyanates. While a student at Göttingen, he conducted research of cocaine with Albert Niemann. After the untimely death of Niemann in 1861, he continued rese ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lossen Rearrangement
The Lossen rearrangement is the conversion of a hydroxamate ester to an isocyanate. Typically O-acyl, sulfonyl, or phosphoryl O-derivative are employed. The isocyanate can be used further to generate ureas in the presence of amines or generate amines in the presence of H2O. Reaction mechanism The mechanism below begins with an O-acylated hydroxamic acid derivative that is treated with base to form an isocyanate that generates an amine and CO2 gas in the presence of H2O. The hydroxamic acid derivative is first converted to its conjugate base by abstraction of a hydrogen by a base. Spontaneous rearrangement releases a carboxylate anion to produce the isocyanate intermediate. The isocyanate is then hydrolyzed in the presence of H2O. Finally, the respective amine and CO2 are generated by abstraction of a proton with a base and decarboxylation. Hydroxamic acids are commonly synthesized from their corresponding esters. Historical references * * * See also *Curtius rearrangemen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of Göttingen Alumni
A university () is an institution of higher (or tertiary) education and research which awards academic degrees in several academic disciplines. Universities typically offer both undergraduate and postgraduate programs. In the United States, the designation is reserved for colleges that have a graduate school. The word ''university'' is derived from the Latin ''universitas magistrorum et scholarium'', which roughly means "community of teachers and scholars". The first universities were created in Europe by Catholic Church monks. The University of Bologna (''Università di Bologna''), founded in 1088, is the first university in the sense of: *Being a high degree-awarding institute. *Having independence from the ecclesiastic schools, although conducted by both clergy and non-clergy. *Using the word ''universitas'' (which was coined at its foundation). *Issuing secular and non-secular degrees: grammar, rhetoric, logic, theology, canon law, notarial law.Hunt Janin: "The university i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of Giessen Alumni
A university () is an institution of higher (or tertiary) education and research which awards academic degrees in several academic disciplines. Universities typically offer both undergraduate and postgraduate programs. In the United States, the designation is reserved for colleges that have a graduate school. The word ''university'' is derived from the Latin ''universitas magistrorum et scholarium'', which roughly means "community of teachers and scholars". The first universities were created in Europe by Catholic Church monks. The University of Bologna (''Università di Bologna''), founded in 1088, is the first university in the sense of: *Being a high degree-awarding institute. *Having independence from the ecclesiastic schools, although conducted by both clergy and non-clergy. *Using the word ''universitas'' (which was coined at its foundation). *Issuing secular and non-secular degrees: grammar, rhetoric, logic, theology, canon law, notarial law.Hunt Janin: "The university i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Academic Staff Of Heidelberg University
An academy (Attic Greek: Ἀκαδήμεια; Koine Greek Ἀκαδημία) is an institution of secondary or tertiary higher learning (and generally also research or honorary membership). The name traces back to Plato's school of philosophy, founded approximately 385 BC at Akademia, a sanctuary of Athena, the goddess of wisdom and skill, north of Athens, Greece. Etymology The word comes from the ''Academy'' in ancient Greece, which derives from the Athenian hero, ''Akademos''. Outside the city walls of Athens, the gymnasium was made famous by Plato as a center of learning. The sacred space, dedicated to the goddess of wisdom, Athena, had formerly been an olive grove, hence the expression "the groves of Academe". In these gardens, the philosopher Plato conversed with followers. Plato developed his sessions into a method of teaching philosophy and in 387 BC, established what is known today as the Old Academy. By extension, ''academia'' has come to mean the accumulation, de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Academic Staff Of The University Of Königsberg
An academy (Attic Greek: Ἀκαδήμεια; Koine Greek Ἀκαδημία) is an institution of secondary or tertiary higher learning (and generally also research or honorary membership). The name traces back to Plato's school of philosophy, founded approximately 385 BC at Akademia, a sanctuary of Athena, the goddess of wisdom and skill, north of Athens, Greece. Etymology The word comes from the ''Academy'' in ancient Greece, which derives from the Athenian hero, ''Akademos''. Outside the city walls of Athens, the gymnasium was made famous by Plato as a center of learning. The sacred space, dedicated to the goddess of wisdom, Athena, had formerly been an olive grove, hence the expression "the groves of Academe". In these gardens, the philosopher Plato conversed with followers. Plato developed his sessions into a method of teaching philosophy and in 387 BC, established what is known today as the Old Academy. By extension, ''academia'' has come to mean the accumulation, d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1906 Deaths
Nineteen or 19 may refer to: * 19 (number), the natural number following 18 and preceding 20 * one of the years 19 BC, AD 19, 1919, 2019 Films * ''19'' (film), a 2001 Japanese film * ''Nineteen'' (film), a 1987 science fiction film Music * 19 (band), a Japanese pop music duo Albums * ''19'' (Adele album), 2008 * ''19'', a 2003 album by Alsou * ''19'', a 2006 album by Evan Yo * ''19'', a 2018 album by MHD * ''19'', one half of the double album ''63/19'' by Kool A.D. * ''Number Nineteen'', a 1971 album by American jazz pianist Mal Waldron * ''XIX'' (EP), a 2019 EP by 1the9 Songs * "19" (song), a 1985 song by British musician Paul Hardcastle. * "Nineteen", a song by Bad4Good from the 1992 album '' Refugee'' * "Nineteen", a song by Karma to Burn from the 2001 album ''Almost Heathen''. * "Nineteen" (song), a 2007 song by American singer Billy Ray Cyrus. * "Nineteen", a song by Tegan and Sara from the 2007 album '' The Con''. * "XIX" (song), a 2014 song by Slipk ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1838 Births
Events January–March * January 10 – A fire destroys Lloyd's Coffee House and the Royal Exchange in London. * January 11 – At Morristown, New Jersey, Samuel Morse, Alfred Vail and Leonard Gale give the first public demonstration of Morse's new invention, the telegraph. * January 11 - A 7.5 earthquake strikes the Romanian district of Vrancea causing damage in Moldavia and Wallachia, killing 73 people. * January 21 – The first known report about the lowest temperature on Earth is made, indicating in Yakutsk. * February 6 – Boer explorer Piet Retief and 60 of his men are massacred by King Dingane kaSenzangakhona of the Zulu people, after Retief accepts an invitation to celebrate the signing of a treaty, and his men willingly disarm as a show of good faith. * February 17 – Weenen massacre: Zulu impis massacre about 532 Voortrekkers, Khoikhoi and Basuto around the site of Weenen in South Africa. * February 24 – U.S. Representatives William J. Graves of K ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mucous Membrane
A mucous membrane or mucosa is a membrane that lines various cavities in the body of an organism and covers the surface of internal organs. It consists of one or more layers of epithelial cells overlying a layer of loose connective tissue. It is mostly of endodermal origin and is continuous with the skin at body openings such as the eyes, eyelids, ears, inside the nose, inside the mouth, lips, the genital areas, the urethral opening and the anus. Some mucous membranes secrete mucus, a thick protective fluid. The function of the membrane is to stop pathogens and dirt from entering the body and to prevent bodily tissues from becoming dehydrated. Structure The mucosa is composed of one or more layers of epithelial cells that secrete mucus, and an underlying lamina propria of loose connective tissue. The type of cells and type of mucus secreted vary from organ to organ and each can differ along a given tract. Mucous membranes line the digestive, respiratory and reproductive trac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Albert Niemann (chemist)
Albert Friedrich Emil Niemann (May 20, 1834 – January 19, 1861) was a German chemist. In 1859 - about the same time as Paolo Mantegazza - he isolated cocaine, and he published his finding in 1860. Life Niemann was born in Goslar, then in the Kingdom of Hanover, the son of a school principal. In 1849 he began an apprenticeship at the town hall pharmacy in Göttingen, where, starting in 1852, he was a Ph.D. student at the George August University. Cocaine In the 19th century, there was great interest among European chemists in the effects of coca leaves discovered in Latin America. In 1855 the chemist Friedrich Gaedcke had published a treatise on an active alkaloid extract of the coca leaf he called ''erythroxyline'', after the genus ''Erythroxylum'', from which cocaine-rich leaves are obtained. This extract was benzoylmethylecgonine, or cocaine, though it lacked in purity. He published a description in the journal ''Archiv der Pharmazie''. Friedrich Wöhler, Ordinary Pro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cocaine
Cocaine (from , from , ultimately from Quechuan languages, Quechua: ''kúka'') is a central nervous system (CNS) stimulant mainly recreational drug use, used recreationally for its euphoria, euphoric effects. It is primarily obtained from the leaves of two Coca species native to South America, ''Erythroxylum coca'' and ''Erythroxylum novogranatense''. After extraction from coca leaves and further processing into cocaine hydrochloride (powdered cocaine), the drug is often Insufflation (medicine), snorted, applied topical administration, topically to the mouth, or dissolved and injection (medicine), injected into a vein. It can also then be turned into free base form (crack cocaine), in which it can be heated until sublimated and then the vapours can be smoking, inhaled. Cocaine stimulates the mesolimbic pathway, reward pathway in the brain. Mental effects may include an euphoria, intense feeling of happiness, sexual arousal, psychosis, loss of contact with reality, or psychomo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isocyanate
In organic chemistry, isocyanate is the functional group with the formula . Organic compounds that contain an isocyanate group are referred to as isocyanates. An organic compound with two isocyanate groups is known as a diisocyanate. Diisocyanates are manufactured for the production of polyurethanes, a class of polymers. Isocyanates should not be confused with cyanate esters and isocyanides, very different families of compounds. The cyanate (cyanate ester) functional group () is arranged differently from the isocyanate group (). Isocyanides have the connectivity , lacking the oxygen of the cyanate groups. Structure and bonding In terms of bonding, isocyanates are closely related to carbon dioxide (CO2) and carbodiimides (C(NR)2). The C−N=C=O unit that defines isocyanates is planar, and the N=C=O linkage is nearly linear. In phenyl isocyanate, the C=N and C=O distances are respectively 1.195 and 1.173 Å. The C-N=C angle is 134.9° and the N=C=O angle is 173.1°. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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