wiktionary mechanismMechanism may refer to Mechanism engineering , rigid bodies connected by joints in order to accomplish a desired force and or motion transmission Mechanism biology , explaining how a feature is created Mechanism philosophy , a theory that all natural phenomena can be explained by physical causes Mechanism sociology , a set of rules designed to bring about a certain outcome Mechanism band , a death metal band from Canada See also Machine Mechanism design , the art of designing rules of a game to achieve a specific outcome Mechanism of action , the means by which a drug exerts its biological effects Defence mechanism , unconscious mechanisms aimed at reducing anxiety Reaction mechanism , the sequence of reactions by which overall chemical change occurs Antikythera mechanism , an ancient Greek analog computer disambig cs Mechanismus de Mechanismus es Mecanismo desambiguaci n fr M canisme homonymie sk Mechanizmus ... more details
orphan date August 2008 In economics , optimal mechanism refers to the mechanism design mechanism which maximizes the seller s profit ref http research.microsoft.com hartline omd.pdf ref . References reflist Category Profit economics stub ... more details
The Bartell mechanism is a pseudorotation al mechanism similar to the Berry mechanism . It occurs only in molecules with a pentagonal bipyramidal molecular geometry , such as IF7 IF sub 7 sub . This mechanism was first predicted by H. B. Bartell . The mechanism exchanges the axial atoms with one pair of the equatorial atoms. Similarly to the Berry mechanism Berry mechanism Berry mechanism in square planar molecules in square planar molecules , the symmetry of the intermediary phase of the vibrational mode is chimeric ref name ch.ic.ac.uk cite web url http www.ch.ic.ac.uk rzepa bpr publisher ch.ic.ac.uk title Mechanisms that Interchange Axial and Equatorial Atoms in Fluxional processes accessdate 2008 01 22 ref of other mechanisms it displays characteristics of the Berry mechanism, a lever mechanism seen in pseudorotation of Seesaw chemistry disphenoidal molecules, and a turnstile mechanism which can be seen in trigonal bipyramidal molecules under certain conditions . in need of an image References Reflist See also Berry mechanism Pseudorotation Category Chemical bonding Category Molecular geometry Category Reaction mechanisms es Mecanismo de Bartell ... more details
Unreferenced stub auto yes date December 2009 In pharmacology , the term mechanism of action MOA refers to the specific biochemical interaction through which a Medication drug substance produces its pharmacological effect. A mechanism of action usually includes mention of the specific molecular targets to which the drug binds, such as an enzyme or receptor biochemistry receptor . For example, the mechanism of action of aspirin involves irreversible inhibition of the enzyme cyclooxygenase , which suppresses the production of prostaglandin s and thromboxane s, thereby reducing pain and inflammation. See also Pharmacodynamics Medicinal chemistry DEFAULTSORT Mechanism Of Action Category Pharmacology Category Medicinal chemistry Pharma stub ar pt Mecanismo de a o ... more details
Unreferenced date July 2009 Market mechanism is a term from economics referring to the use of money exchanged by buyers and sellers with an open and understood system of value and time trade offs to produce the best distribution of goods and services. The use of the market mechanism does not imply a free market there can be captive or controlled markets which seek to use supply and demand, or some other form of charging for scarcity, both in social situations and in engineering. See also Private sector Capitalism DEFAULTSORT Market Mechanism econ stub lt Rinkos mechanizmas pl Mechanizm rynkowy vi C ch th tr ng Category Markets customer bases ... more details
Orphan date February 2009 unreferenced date September 2007 The Western Mechanism is the debut album by United Kingdom British rock band Days of Worth . The album was released April 2005, by Visible Noise records. Track listing Standard Suburban Anthem State of me Street lights on heavy eyes It s a beautiful view Take me Through Youth Base Setter Narcolepsy Ladies and Gentlemen Takes more than distance The Western Mechanism DEFAULTSORT Western Mechanism, The Category 2005 albums Category Debut albums 2000s rock album stub ... more details
During the last decade there has been a growing interest in social mechanisms and mechanism based explanations, not only in sociology and the social sciences but also in philosophy of science , particularly philosophy of biology . Although many sociologists use the word mechanism they often use it in an off hand casual sense without any commitment to any type of mechanism based explanatory strategy. The core idea behind the mechanism approach has been expressed as follows by Jon Elster Elster 1989 3 4 To explain an event is to give an account of why it happened. Usually this takes the form of citing an earlier event as the cause of the event we want to explain . But to cite the cause is not enough the causal mechanism must also be provided, or at least suggested. There is no consensus on what is to be meant by a mechanism. Existing definitions differ a great deal from one another, but underlying them all is an emphasis on making intelligible the regularities being observed by specifying in detail how they were brought about. The currently most satisfactory discussion of the mechanism concept is found in Machamer, Darden and Craver 2000 . Following them, mechanisms can be said to consist of entities with their properties and the activities that these entities engage in, either by themselves or in concert with other entities. These activities bring about change, and the type of change brought about depends upon the properties and activities of the entities and the relations between them. A mechanism, thus defined, refers to a constellation of entities and activities that are organized such that they regularly bring about a particular type of outcome, and we explain an observed outcome by referring to the mechanism by which such outcomes are regularly brought about see also Peter Hedstrom Hedstr m and Ylikoski 2010 . References Elster, J. 1989. Nuts and Bolts for the Social Sciences . Cambridge Cambridge University Press. Hedstr m, P. and P. Ylikoski. 2010. Causal mechanisms ... more details
File Gears animation.gif thumb gear Gears are a type of mechanism. A mechanism is a combination of resistant bodies, so interconnected that by applying force or motion to one or more of those bodies, some of those bodies are caused to perform desired work accompanied by desired motions. Mechanisms are used to convert one type of motion into another. ref name hubbel cite book last Eckhardt first Homer title Kinematic Design of Machines and Mechanisms publisher McGrawHill isbn 0 07 018953 ref The connections present in a mechanism are called kinematic pairs. Kinematic pairs can be classified as higher pair or lower pair. A mechanism is usually a piece of a larger process or mechanical device. Sometimes an entire machine may be referred to as a mechanism. Examples are the Steering steering mechanism in a automobile car , or the winding mechanism of a watch wristwatch . Multiple mechanisms are machines. Lower pair A pair is said to be a lower pairs when the connections between two elements are through the area of contact. Some of the commonly used lower pairs are as follows Revolute pair Prismatic pair or Sliding pair Screw pair or Helical pair Cylindrical pair or Rolling pair Spheric pair Planar pair Example motion of piston in a cylinder of an engine, motion between nut and bolt. Higher pair A higher pair is defined as one in which the connection between two elements has only a point or line contact. Example Cam and followers, working of gears in gears box. External links http zhurnal.lib.ru s suhanow w n mehrichen.shtml Balanced hinge lever mechanism http www.scribd.com doc 441240 Five hundred and seven mechanical movements 507 Mechanical Movements a 1908 publication by Henry T. Brown References reflist 2 engineering stub Category Kinematics Category Mechanisms ar az Mexanizm be bg ca Mecanisme et Mehhanism es Mecanismo eo Mekanismo fa fr M canisme io Mekanismo it Meccanismo nl Mechanisme ja pl Mechanizm pt Mecanismo ro Mecanism ru ... more details
orphan date November 2009 Infobox Company name Mechanism Digital logo type Private foundation April 1996 location city New York , New York location country USA location br 118W 27th St br New York , New York 10001 locations key people Founder br Lucien Harriot area served industry services Visual Effects , Post production , Filmmaking Production Production , New Media revenue operating income net income num employees parent divisions subsid slogan homepage http www.mechanismdigital.com dissolved footnotes intl yes Mechanism Digital is a motion graphics production company in New York City . Mechanism specializes in Visual Effects and 3 D Animation . Founded in April 1996, Mechanism Digital produces graphics, 3 D animations, and visual effects for film, commercials, and television programming. Mechanism Digital s credits include Rome Engineering an Empire ref http www.vfxtalk.com forum particleillusion helps mechanism digital make last stand t9467.html?s 59118a3f98a26dfd65e49eb051963379& s 6e741635ab12c7f8574e7655d7140669& p 38764 ref , which won an Emmy in 2007, and an animated promo for the movie Juno film Juno airing on Cinemax , which won an Addy Awards ADDY award in 2009. References reflist External links http www.mechanismdigital.com Mechanism Digital website Category Companies based in New York City Visual effects companies Special effects companies Animation Studios Computer Animation Production ... more details
The fusion mechanism is the mechanism by which cell fusion takes place. Cell fusion is the formation of a hybrid cell from two different cells of different species. ref www.ncbiotech.org biotech101 glossary.cfm ref ref www.fao.org docrep 003 X3910E X3910E06.htm ref Cells from the same organism may fuse together as well. This is often observed during lytic viral infection, where alterations of the cell can be seen under a light microscope. These include changes in morphology, formation of vacuoles and fusion of cells to form Syncytium syncytia . The term cell fusion mechanism refers to the Receptor biochemistry receptors required for cells to fuse, whereas the term cell fusion refers to the action of formation of the new cell. One example of the cellular fusion mechanism is that of HIV infecting the body. HIV infects by fusing with the cell membrane membranes of White blood cell immune system cells . In order for HIV to fuse with a cell, it must be able to bind to the receptors CD4 , CCR5 , and CXCR4 . ref www.amfar.org cgi bin iowa bridge.html ref References reflist Category HIV AIDS Category Cell biology biology stub ... more details
Escape Mechanism is the title of a sound collage project instigated by Minneapolis based artist Jonathan Nelson. Using fragments of audio from a variety of previously recorded sound sources, the project is an experiment in recycled media. Escape Mechanism has taken many forms, since 1997. From solo studio releases and theatrical sound design, to a live ensemble and sound installation, the project is defined by its re use of sounds found in the broadcast media. Although essentially a studio project, Escape Mechanism experimented briefly 1999 2001 with live improvisation. Performing under the name Cast of Thousands with Escape Mechanism, the rotating ensemble also worked exclusively with bits and pieces of the media environment, performing at art venues and performances spaces such as Walker Art Center The Walker Art Center , the Soap Factory and First Avenue nightclub The First Avenue Main Room . Escape Mechanism has collaborated with artists such as Steev Hise, The Tape beatles and Wobbly, and mounted sound installations at art galleries such as The Blue Theater, Rosalux Gallery and The Rochester Art Center. Escape Mechanism proudly presents itself as 100 recycled, as every sound found in an Escape Mechanism composition is recycled from a previously recorded source. No original sounds are incorporated only original juxtapositions. Some Assembly Required Nelson is perhaps best known for his role as host and producer of the nationally syndicated radio program, Some Assembly Required . The show is a weekly exploration of works of appropriation , by artists who use samplers and other ... and Rosalux Gallery. Album Discography Box of Blue Paperclips 1997, out of print Escape Mechanism 1998 ... Cast of Thousands with Escape Mechanism 2004, Recombinations, REC003 Emphasis Added 2008, Recombinations, REC006 External links http www.escape mechanism.com Escape Mechanism website http www.mnartists.org ... Radio Feature Interview with Escape Mechanism s Jonathan Nelson on National Public Radio 2009 . http ... more details
which individual deformation mechanisms dominate for some materials in the form of deformation mechanism ... flow This is a mechanism that operates under low to moderate homologous temperature s, low confining ... of a pore fluid. Grain boundary sliding This mechanism must act with another to change the shapes of the grains so that they can slide past each other without creating significant voids. This mechanism ... Springer location Berlin year pages isbn 3 540 58713 6 oclc doi refend See also Deformation mechanism maps Creep deformation DEFAULTSORT Deformation Mechanism Category Structural geology Category ... more details
Image Geneva mechanism 6spoke animation.gif framed right Working principle of a Maltese cross or Geneva drive Image Moviecam schematic animation.gif thumb 320px right Animation of a rotating shutter . The film is transported one frame when the shutter is blocking illumination of the film. The intermittent mechanism or intermittent movement is the device by which film is regularly advanced and then held in place for a brief duration of time in a movie camera or movie projector . This is in contrast to a continuous mechanism, whereby the film is constantly in motion and the image is held steady by optical or electronic scanning methods. The reason the intermittent mechanism works for the viewer is because of a psychological phenomenon called persistence of vision . History Intermittent mechanisms were first used in sewing machines , in order for the fabric to be fed through correctly ensuring it is stationary as each stitch is made, while moving the required distance between stitches. Methods used The intermittent mechanism must be employed in concert with a rotating shutter photography shutter which blocks light transmittance during the motion of the film and allows light through while the film is held in place usually by one or more registration pin s. The intermittent mechanism can be accomplished in many ways, but most often, it is done with sprocket wheels, claws, or pins coupled to the camera or projector drive mechanism. In movie theater projectors, the intermittent movement is often produced by a Geneva drive Maltese cross mechanism. However, in a movie camera , it is done through a process by which a Shutter photography shutter opens exposing the film negative to light for a split second the standard for regular motion in North America is 1 48 of a second , then the shutter closes blocking light from reaching the negative. Once the shutter is completely closed, a claw pulls down the next frame of negative film by the sprocket holes into the film gate and the process ... more details
The book The Mechanism of Mind details the underpinning model of mind that leads to the many thinking skills developed by Edward de Bono , including lateral thinking . The Model The model detailed in the book, and referred to again in many of Edward de Bono s other books, is one of Neurones networked together by many stronger and weaker connections and activating as a result of input stimulus or stimulation from other neurones that are themselves active. Neurones that are active together form stronger connections and are more likely to activate together in the future. The model is a Self organizing system . It is not intended that the model be a detailed analysis of how human brains are structured but the broadest possible abstraction that can provide meaningful understanding of the nature of thinking. Nor is it intended to build a cohesive theory but to provide the reader with a collection of concepts that will illuminate further thinking about thinking. More detailed models and theories specifically about the brain can be found under the topic of Cognitive Science and connectionism . Behaviour of the Model The characteristic behaviour of the system is shown to create and reinforce patterns. The current set of patterns in the system determine how new experiences are integrated. Attention tends to flow along well worn paths and patterns have large catchment areas. Novel experiences are often lost as attention flows down old paths that are in some way similar to the new experience. Sometimes starting at a different point in an established pattern can lead to a jump out of that pattern ... limitations. From The Mechanism of Mind page 182 blockquote Cquote The limitations of the special ... External links and references DeBono, Edward The Mechanism of Mind ISBN 0224617095 January, 1969 Category Philosophy of mind literature Mechanism of the Mind Category 1969 books Mechanism of Mind, The Category Psychology books Mechanism of the Mind Category Consciousness studies Mechanism of the Mind ... more details
In quantum field theory , the GIM mechanism or Glashow Iliopoulos Maiani mechanism is the mechanism by which Flavor changing neutral current flavour changing neutral currents FCNCs are suppressed. It also explains why weak interaction s that change strangeness by 2 &Delta S 2 transitions are suppressed while those that change strangeness by 1 &Delta S 1 transitions are allowed. The mechanism was put forth by Sheldon Lee Glashow , John Iliopoulos and Luciano Maiani in their famous paper Weak Interactions with Lepton Hadron Symmetry published in Physical Review D in 1970. ref cite journal doi 10.1103 PhysRevD.2.1285 author S.L. Glashow, J. Iliopoulos, L. Maiani year 1970 title Weak Interactions with Lepton Hadron Symmetry journal Physical Review D volume 2 pages 1285 ref At the time the GIM mechanism was proposed, only three quark s up quark up , down quark down , and strange quark strange were thought to exist. Glashow and James Bjorken predicted a fourth quark in 1964, ref cite journal author B.J. Bjorken, S.L. Glashow year 1964 title Elementary particles and SU 4 journal Physics Letters volume 11 pages 255 257 doi 10.1016 0031 9163 64 90433 0 ref but there was little evidence for its existence. The GIM mechanism however, required the existence of a fourth quark, and the prediction of the charm quark is usually credited to Glashow, Iliopoulos, and Maiani. References reflist Further reading cite book author A. Das, T. Ferbel year 2003 chapter Standard Model and Confrontation with Data title Introduction to Nuclear and Particle Physics pages 345 ff edition 2nd publisher World Scientific isbn 981 238 744 7 cite journal author J. Iliopoulous year 2010 title Glashow Iliopoulos Maiani mechanism journal Scholarpedia volume 5 issue 5 pages 7125 doi 10.4249 scholarpedia.7125 cite web author B. Popescu date February 2006 title Weak Interactions 1 url http www.physics.uc.edu popescu ppt weak1.ppt work Physics 842 pages 45&ndash 48 publisher University of Cincinnati accessdate 2010 ... more details
Image NAMA Machine d Anticyth re 1.jpg right thumb 280px The Antikythera mechanism main fragment . The Antikythera mechanism pron en nt k r Respell ANT i ki THEER or pron en nt k r Respell ... project overview The Antikythera Mechanism Research Project , The Antikythera Mechanism Research Project. Retrieved 2007 07 01 Quote The Antikythera Mechanism is now understood to be dedicated ... Mechanism A Calendar Computer from ca. 80 B. C., Derek de Solla Price, Transactions of the American ... Mechanism Research Project Why is it so important? , Retrieved 2011 01 10 Quote The Mechanism ... of the Antikythera mechanism. Professor Michael Edmunds of Cardiff University who led the most recent study of the mechanism said This device is just extraordinary, the only thing of its kind. The design ... value, I have to regard this mechanism as being more valuable than the Mona Lisa . ref Cite ..., I have to regard this mechanism as being more valuable than the Mona Lisa. and One of the remaining ... The mechanism is the oldest known complex scientific calculator. It contains many gear s, and is sometimes ... around 100 BCE 150 100 BCE . Consensus among scholars is that the mechanism itself was made in the Greek speaking world. All the instructions of the mechanism are written in Koine Greek . ref ... who designed it since it contains a lunar mechanism which uses Hipparchus s theory for the motion of the Moon. However, the most recent findings of Antikythera mechanism The Antikythera Mechanism Research Project The Antikythera Mechanism Research Project , as published in the July 30, 2008, edition of Nature journal Nature alternatively suggest that the concept for the mechanism originated in the colonies ... of the artifact s mechanism. Function The device is remarkable for the level of miniaturization and for the complexity ... equilateral triangle s. When a date was entered via a crank now lost , the mechanism calculated the position ... universe Does it favor a Heliocentric, or Geocentric Universe? ref The mechanism has three main ... more details
In chemistry , a reaction mechanism is the step by step sequence of elementary reaction s by which overall chemical change occurs. ref JerryMarch ref Although only the net chemical change is directly observation observable for most chemical reaction s, experiment s can often be designed that suggest the possible sequence of steps in a reaction mechanism. Recently, electrospray ionization mass spectrometry ref Investigation of chemical reactions in solution using API MS Leonardo Silva Santos, Larissa ... ref has been used to corroborate the mechanism of several organic reaction proposals. Description A chemical mechanism describes in detail exactly what takes place at each stage of an overall ... and in what order . A complete mechanism must also account for all reactant s used, the function of a catalyst ... products and reactants in the mechanism s reaction steps. Reaction intermediates are often free ... small.png thumb center 540px SN2 reaction S sub N sub 2 reaction mechanism. Note the negatively ... a reaction mechanism for example, see the illustration of the mechanism for benzoin condensation in the following examples section. A reaction mechanism must also account for the order in which molecules ... 2 math . Therefore, a possible mechanism by which this reaction takes place is 2 NO sub 2 sub &rarr ... thumb 700px Benzoin condensation reaction mechanism . Cyanide ion CN sup sup acts as a catalyst ... A correct reaction mechanism is an important part of accurate predictive modelling . For many ... parameters. At the different stages of a reaction mechanism s elaboration, appropriate methods ... reaction Organic reactions by mechanism Organic reactions by mechanism under Organic reaction Nucleophilic acyl substitution Neighbouring group participation Finkelstein reaction Lindemann mechanism Electrochemical reaction mechanism Arrow pushing References Reflist Reaction mechanisms Category Chemical reactions Mechanism Category Reaction mechanisms Category Chemical kinetics Category Chemical ... more details
Infobox Album See Wikipedia WikiProject Albums Name Song Mechanism Type EP Artist Deadboy & the Elephantmen Cover Released 2004 Recorded Genre Rock music Swamp Rock Length 18 47 Label Self Released Distributed Last album If This Is Hell, Then I m Lucky br 2002 This album Song Mechanism br 2004 Next album We Are Night Sky br 2006 Originally distributed through Deadboy & the Elephantmen s website, and also by various local Louisiana music stores, Song Mechanism showcases four songs that were later included in Deadboy s second full length album We Are Night Sky . The extended play EP is no longer in print. Track listings How Long the Night Was small 2 42 small Blood Music small 5 30 small Dressed Up in Smoke small 4 52 small The Misadventures of Dope small 5 43 small Category Dax Riggs albums Category 2004 EPs ... more details
notability Music date February 2010 primarysources date February 2010 Mechanism is a death metal band from Canada Vancouver, British Columbia . Their debut album is called Inspired Horrific and combines death metal with progressive metal progressive . Line up Gene Hoglan Drums Devin Townsend , Daemon Dnk , Dark Angel band Dark Angel USA , Death , Dethklok , Forbidden USA , Just Cause , Meldrum , Naphobia , Old Man s Child , Phantasm , Pitch Black Forecast , Strapping Young Lad , Tenet , Testament band Testament , Unearth , Wargod USA , Zimmers Hole , Fear Factory Chris The Heathen Valagao Vocals Zimmers Hole , The Berzerker , The Kill Can Kris Schulz Guitar Bryan Somerville Guitar, Samples Markus McCallum Bass Discography 2009 Inspired Horrific References See Wikipedia Footnotes on how to create references using ref ref tags which will then appear here automatically Reflist External links http www.mechanismmetal.com Official website http www.myspace.com mechanismarmy Myspace page http www.metal archives.com band.php?id 3540273324 Mechanism Metal archives DEFAULTSORT Mechanism Band Category Canadian death metal musical groups ... more details
Unreferenced date August 2009 Expert subject Physics date February 2009 The misalignment mechanism is a hypothesized effect in the Peccei Quinn theory Peccei Quinn proposed solution to the strong CP problem in quantum mechanics . The effect occurs when a particle s field physics field has an initial value that is not at or near a potential minimum. This causes the particle s field to oscillate around the nearest minimum, eventually dissipating energy by decaying into other particles until the minimum is attained. and this coherent oscillation last as long as the dynamics allows this.... don t quite know what this is getting at In the case of hypothesized axion s created in the early universe , the initial values are random because of the masslessness of axions in the high temperature plasma physics plasma . Near the critical temperature of quantum chromodynamics , axions possess a temperature dependent mass that enters a damped oscillation until the potential minimum is reached. References Reflist DEFAULTSORT Misalignment Mechanism Category Astroparticle physics Phys stub ... more details
Orphan date November 2006 Context date October 2009 Overconstrained mechanisms are mechanism technology mechanisms , commonly Linkage mechanical linkage mechanisms , that exhibit full cycle mobility without satisfying the Chebychev Gr bler Kutzbach criterion . External links http scitation.aip.org getabs servlet GetabsServlet?prog normal&id JMDEDB000128000001000220000001&idtype cvips&gifs yes Mobility of Overconstrained Parallel Mechanisms Category Mechanisms ... more details
orphan date May 2008 In acoustics , Lighthill mechanism refers to the generation of sound by Turbulence turbulent fluid motions, as proposed by James Lighthill Sir Lighthill in 1952. See also Aeroacoustics References M. J. Lighthill, On Sound Generated Aerodynamically. I. General Theory, Proc. R. Soc. Lond. A 211 1952 pp. 564 587. M. J. Lighthill, On Sound Generated Aerodynamically. II. Turbulence as a Source of Sound, Proc. R. Soc. Lond. A 222 1954 pp. 1 32. Category Acoustics ... more details
The ANRORC mechanism in organic chemistry describes a special type of substitution reaction . ANRORC stands for A ddition of the N ucleophile, R ing O pening, and R ing C losure in nucleophilic attack on ring systems ref The SN ANRORC mechanism a new mechanism for nucleophilic substitution Henk C. Van der Plas Acc. Chem. Res. 1978 11 12 pp 462 468 DOI 10.1021 ar50132a005 ref ref cite journal title S N ANRORC reactions in azaheterocycles containing an inside leaving group author Vanderplas H. C. journal Advances in Heterocyclic Chemistry volume 74 pages 9 86 year 1999 id ISBN 978 0 12 020774 9 doi 10.1016 S0065 2725 08 60809 0 ref ref cite journal title S N ANRORC reactions in azaheterocycles containing an inside leaving group author Vanderplas H. C. journal Advances in Heterocyclic Chemistry volume 74 pages 87 151 year 1999 id ISBN 978 0 12 020774 9 doi 10.1016 S0065 2725 08 60810 7 ref and it helps to explain product formation and distribution in some nucleophilic substitution s especially in heterocyclic compound s. This reaction mechanism has been extensively studied in reactions of metal amide nucleophiles such as sodium amide and substituted pyrimidine s for instance 4 phenyl 6 bromopyrimidine 1 in ammonia at low temperatures. The main reaction product is 4 phenyl 6 aminopyrimidine 2 with the bromine substituent replaced by an amine . This rules out the formation of an aryne intermediate A which would also give the 5 substituted isomer. Image ANRORC overview.png center 450px ANRORC overview The exclusion of a second intermediate in this reaction, the Meisenheimer complex B in favor of the ring opened ANRORC intermediate is based on several pieces of evidence. With other amines such as piperidine the ring opened compound after loss of hydrogen bromide to the nitrile ... in the reaction product and this is again explained by the ANRORC mechanism where the ring opened intermediate ... nitrogen atom. The Zincke reaction is a named reaction involving an ANRORC mechanism. References ... more details
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