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Seo U Lokelang ho se Tseba ka Pyridines

Seo U Lokelang ho se Tseba ka Pyridines

Sohle Seo U Lokelang ho se Tseba ka Pyridines

Pyridine ke tsa motheo heterocyclic mofuta oa mofuta oa azine. Pyridine e tsoa ho benzene ka ho nkela sebaka sa CH sebaka ke N-atom. Sebopeho sa Pyridine se tšoana le sebopeho sa benzene, hobane se amana le ho nkeloa sebaka ke sehlopha sa CH ka N. Phapang e khōlō e kenyeletsa:

  1. Ho tloha ho geometry e tloaelehileng e tloaelehileng ka nako e telele ka lebaka la ho ba teng ha hetero, ho hlaka, ho na le likarolo tse khutšoanyane tsa naetrojene-carbon,
  2. Ho kenngoa ha athomo ea haedrojene ka sefofaneng se nang le li-elektronike, joaloka sefofane sa mothapo, se nang le li-orbital sa sp2, ebile ha se amehe ka sextet ea p-elektronike e nkhang hamonate. Lekhasi lena la nitrogen le le leng le ikarabellang bakeng sa thepa ea motheo ea pyridines,
  3. Dipole e matla ka ho fetisisa e ka fumanoang liphatleng tse phahameng tsa elektronike ea athomo ea naetrojene e bapisoa le athomo ea carbon.

Lesale la Pyridine le hlaha likarolong tse 'maloa tsa bohlokoa, ho akarelletsa le livithamine niacin, pyridoxine, hammoho le tse ling.

Setsebi sa k'hemik'hale ea Scotland, Thomas Anderson o ile a qapa pyridine ka 1849 e le e 'ngoe ea metsoako e etsang oli ea bone. Ka mor'a lilemo tse peli, Anderson o ile a fumana pyridine e hloekileng ka lihlahisoa tse nyenyane tsa oli ea masapo. E na le metsi a nang le lero le chesang haholo, a se nang mobala, a nang le metsi a nang le alkaline a fokolang ka mokhoa o sa thabiseng, o kang monko oa tlhapi.

Pyridine e lula e sebelisoa e le selelekela ho meriana le lik'hemik'hale tsa lik'hemik'hale 'me e boetse e na le ts'ebetso ea bohlokoa haholo le ho rarolloa. Pyridine e ka eketsoa ho ethanol haeba u batla ho e etsa hore e se ke ea tšoanela batho ho e sebelisa. E boetse e sebetsa ha ho etsoa li-antihistaminic lithethefatsi mepyramine le tripelennamine, in vitro synthesis ea DNA, ho hlahisa sulfapyridine (meriana bakeng sa phekolo ea mafu a likokoana-hloko le mafu a baktheria), hammoho le bactericides, likokoana-hloko le liphoso tsa metsi.

Lik'hemik'hale tse ngata tsa lik'hemik'hale, le hoja li sa hlahisoe ho tloha pyridine, li na le mohaho oa lesale. Meriana e joalo e kenyelletsa li-vithamine tsa B tse kang pyridoxine le niacin, nikotine, lihlahisoa tse nang le limela tse nang le nitrojene, le lithethefatsi tse loantšang lefuba tse tsejoang e le isoniazid. Pyridine e ne e hlahisoa historing e le sehlahisoa sa khase ea mashala le ho tloha ka mashala a mashala. Leha ho le joalo, tlhokahalo e phahameng ea pyridine e lebisitse ho nts'etsopele ea lihlahisoa tsa moruo ho tsoa ho ammonia le acetaldehyde, 'me ho feta lithane tse 20,000 li hlahisoa selemo ka bophara.

Nomenclature ea pyridine

Lebitso le tloaelehileng la pyridine, ho ea ka lebitso la Hantzsch-Widman le hlalositsoeng ke IUPAC, ke azine. Empa mabitso a tloaelehileng bakeng sa metsoako ea motheo a sebelisoa ka seoelo; ho e-na le hoo, nomenclature ea heterocycles e latela mabitso a tloaelehileng a tloaelehileng. IUPAC ha e khothalletse tšebeliso ea azine ha u bua ka pyridine.

Ho baloa ha liathomo tsa mothapo ka li-azine ho qala ka nitrogen. Ho aroloa ha maemo a lengolo la Segerike sa alfabeta (α-γ) le mokhoa oa ho fetola lebitso la nomenclature o tloaelehileng ho tsamaiso ea homoaromatic (para ortho, pakane ea bona,) li sebelisoa ka linako tse ling. Mona α, β le γ li bua ka maemo a mabeli, a mararo le a mane, ka ho latellana.

Lebitso le tloaelehileng bakeng sa li-derivatives tsa pyridine ke pyridinyl, moo palo e etellang pele atom e 'ngoe e nkang sebaka e etelletsoeng ke palo. Empa lebitso la histori pyridyl e kgothaletswa ke IUPAC mme e sebelisitsoe hohle sebakeng sa lebitso le tsitsitseng. Se entsoeng ka ho eketsoa ha electrophile ho athomo ea naetrojene e tsejoa e le pyridinium.

4-bromopyridine

2,2'-bipyridine

Dipicolinic acid (pyridine-2,6-dicarboxylic acid)

Tsela ea motheo ea cation ea pyridinium

Ho hlahisa pyridine

Pyridine e fumanoe e le sehlahisoa sa khase ea mashala kapa e ntšoa ka lehlaka la mashala. Mokhoa ona o ne o se o lekaneng ebile o sebelisoa ke basebetsi: taala ea mashala e pota-potile 0.1 lekholong ea pyridine, kahoo ho hloekisoa ho hlahisa mehato e mengata, e leng se ileng sa fokotsa sehlahisoa. Kajeno, boholo ba pyridine bo etsoa ka mokhoa o sebetsang ka ho sebelisa mekhoa e 'maloa ea mabitso,' me lintho tse tloaelehileng ka ho fetisisa li tšohloa mona ka tlase.

Pyridine Synthesis ka Bohlmann-Rahtz

Pyridine Synthesis ka Bohlmann-Rahtz e lumella moloko oa li-pyridine tse nkeloeng sebaka ka mehato e 'meli e meholo. Ho ruruha ha li-enamine ho sebelisa li-ethynylketones ho fella ka motsoako oa aminodiene eo, ka mor'a hore e hlahisoe ke mocheso, o kenngoa ka cyclodehydration ho hlahisa pyridine ea 2,3,6-trisubstituted.

Pyridine Synthesis ka mokhoa oa Bohlmann-Rahtz

Mechine e amana le Hantzsch Dihydropyridine Synthesis e tsebahalang mooin situ-a hlahisa enamine le mefuta e mengata e hlahisang dihydropyridines. Le hoja Bohlmann-Rahtz Synthesis e fapane haholo, ho hloeka ha licheso tse phahameng le tse hlollang haholo ho hlokahala hore cyclodehydration e be liphephetso tse se nang thuso. Mathata a mangata a hlōtsoe, ho etsa hore Bohlmann-Rahtz Synthesis e be ea bohlokoa haholoanyane pyridine moloko.

Le hoja ho se ho entsoe lipatlisiso tsa mechine, li-intermediate li ka tšoaroa ke H-NMR. Sena se bontša hore sehlahisoa se seholo sa ho phaella ha Michael le pele ho fetisetsa proton e ka ba 2Z-4E-heptadien-6-e leng e nkiloeng le e hloekisitsoeng ka ho sebelisa chromatography ea kholu.

Ka hona ho hlokahala hore ho be le mocheso o phahameng haholo oa li-cycdehydration ho thusa Z/E li-isomerizations tseo e leng tsa bohlokoa bakeng sa heteroannelation.

Mekhoa e 'maloa e lumellang ho sebelisoa ha methapo ea tetra le pyrimin e hlalositsoeng ka mokhoa o le mong ho sa ntsane ho etsoa morao tjena. Ho e-na le ho sebelisa butynone e le substrate, Bagley o ile a lekoa ka litsela tse sa tšoaneng bakeng sa ho fetoha ha 4- (trimethylsilyl) e sa thekeseleng le e sa theko e tlaase empa e le theko e tlaase haholo-empa-3-yn-2-one. E ile ea bontšoa hore ke feela DMSO le EtOH tse nang le lintho tse ntle. EtOH e totobetse hore e na le sekhahla sa polar le protic le vs DMSO e le sekheo sa polar aprotic solvent. Li-solvents tse peli, protodesilylation e etsahetse feela. Bagley e boetse e bontšitse hore aciditi ea catalysis e lumella hore cyclodehydration e tsoele pele ka mocheso o tlaase.

Acid catalysis e boetse e matlafatsa le ho feta. Li-enamine tse fapa-fapaneng li ile tsa arabela ka ethynyl ketone ka (5: 1) motsoako oa asiti ea acetic le toluene ho fumana li-pyridine tse sebetsang hantle ka mohato o le mong lihlahisoa tse ntle.

Ka mor'a katleho ea Brønstedt acid acid catalysis, setsebi sa k'hemistri se ile sa batlisisa bokhoni ba Lewis acid catalysts. Melao e molemo ka ho fetisisa e sebelisitsoeng e ka bang mashome a mane a mol% ytterbium triflate kapa tse leshome le metso e mehlano mol% zinc bromide ka toluene ea refluxing. Le hoja lipatlisiso tsa tlhaho li sa ka tsa etsoa, ​​re ka nahana hore tšebelisano ea motsoako oa li-cycdehydration, Michael Addition le mehato ea isomerization.

Ho senyeha ke ho se lumellane ho lekanyelitsoeng le litšebelisano tse ntle tsa acid. Ka mohlala, ho senyeha ha acid e etsang hore li-enamine li senyehe li etsahala ka cyano le tert-butylester e le lihlopha tsa elektronike tse tlohang. Tsela e 'ngoe e bonolo ke ho sebelisoa ha Amberlyst-15 ion ho fapanyetsana reagent e mamella tert-butsoli.

Kaha li-enamine ha li fumaneha habonolo, 'me ho ntlafatsa mohaho oa ts'ebetso, mohato oa 3-motsoako o ile oa etsoa ho sebelisa ammonum acetate e le mohloli oa sehlopha sa amino. Mokhoa ona o atlehang, enamine e hlahisoa in situ e sebetsang le alkynone hona joale.

Tekong ea pele, ZnBr2 'me AcOH e ne e sebelisoa e le li-catalyst e eketsehileng ka toluene e le mokelikeli. Leha ho le joalo, ho tloha ka nako e 'ngoe ho se ho bontšitsoe hore litšebelisano tse nang le mahlaseli a acid li lula li sebetsana le tikoloho e bonolo le EtOH e le solvent.

Chichibabin Synthesis

Ts'ebetso ea Chichibabin pyridine e ile ea tlalehoa ka lekhetlo la pele ka 1924 'me e sa ntsane e le ts'ebetso e kholo ho indasteri ea lik'hemik'hale. Ke mokhoa oa ho etsa li-ring, o akarelletsang mokhoa oa condensation oa aldehydes, ketone, α, β-unsaturated carbonyl metsoako. Ho feta moo, mofuta o tloaelehileng oa karabelo e ka kenyelletsa leha e le efe motsoako oa lihlahisoa tse ka holimo ka ammonia e hloekileng kapa tse tsoang ho eona.

Ho thehoa Pyridine

Ho hlophisoa ha formaldehyde le acetaldehyde

Lintho tse tloaelehileng le li-acetaldehyde ke tsona mohloli oa li-pyridine tse sa tsitsang. Bonyane, li na le theko e tlaase ebile li fumaneha haholo.

  1. Mohato oa pele o kenyelletsa ho thehoa ha acrolein ho tloha formaldehyde le acetaldehyde ka Knoevenagel condensation.
  2. Sehlahisoa se qetellang se tlosoa ho acrolein le acetaldehyde le ammonia, ho etsa dihydropyridine.
  3. Mokhahlelo oa ho qetela ke mokhoa oa ho ts'oa ha li-oxidation le motsoako o tiileng oa naha ho hlahisa pyridine.
  4. Karabo e ka holimo e etsoa karolong ea khase e nang le mocheso oa 400-450 ° C. Sebopeho se entsoe se na le pyridine, picoline kapa methylated pyridines e bonolo, le lutidine. Leha ho le joalo, sebopeho se kenyeletsa ho sebelisoang habonolo le ka tsela e itseng, e fapana le litlhoko tsa moetsi. Ka tloaelo, motsoako ke sesebelisoa sa tšepe ea phetoho. Lintho tse tloaelehileng ka ho fetisisa ke manganese (II) fluoride kapa cadmium (II) fluoride, le hoja metsoako ea thallium le cobalt e ka ba mekhoa e meng.
  5. Pyridine e fumanoa lihlahisoa tse entsoeng ka litsela tse ngata. Sekhahla se seholo sa Chichibabin pyridine synthesis ke kotulo ea eona e tlase, e fetolelang hoo e ka bang 20% ea lihlahisoa tsa qetello. Ka lebaka lena, mefuta e sa tsejoeng ea likarolo tsena ha e atile haholo.

Bönnemann cyclization

Bönnemann cyclization ke sebopeho sa trimer ho kopanngoa le likarolo tse peli tsa acetylene molek'hule le karolo ea nitrile. Ha e le hantle, mokhoa ona ke phetoho ea Reppe synthesis.

Mechine e tsamaisoa ke mocheso o tsoang ho mocheso o phahameng le khatello kapa ka motlakase oa li-cycddition. Ha e kenyelitsoe ke leseli, Bönnemann cyclization e hloka CoCp2 (cyclopentadienyl, 1,5-cyclooctadiene) ho nka khato.

Mokhoa ona o ka hlahisa lihlahisoa tsa pyridine ho latela metsoako e sebelisoang. Ka mohlala, acetonitrile e tla fana ka 2-methylpyridine, e ka kenang dealkylation ho theha pyridine.

Mekhoa e meng

Kröhnke pyridine synthesis

Mokhoa ona o sebelisa pyridine e le reagent, le hoja e sa kenyelletsoa sehlahisoa sa ho fela. Ka lehlakoreng le leng, karabelo e tla hlahisa li-pyridine tse nkiloeng.

Ha o sebetsana le α-bromoesters, pyridine e tla ba le tsela e tšoanang le ea Michael-joaloka carbonyls e sa tsitsitseng e le hore e be sebaka sa pyridine le pyridium bromide. Karabelo ea eona e tšoaroa ka ammonia acetate ka har'a 20-100 ° C maemo a bonolo.

Rearrangement ea Ciamician-Dennstedt

Sena se akarelletsa ho atolosoa ha ringolo ea pyrrole le dichlorocarbene e theha 3-chloropyridine.

Gattermann-Skita synthesis

Ka karabelo ena, letsoai la senyesemane le itšoara le dichloromethylamine ka pel'a setsi.

Boger pyridine synthesis

Liketso tsa pyridine

Liphetoho tse latelang li ka boleloa esale pele bakeng sa pyridines ho tloha mohahong oa motlakase:

  1. Heteroatom e etsa hore pyridine e se ke ea sebetsana hantle le mekhoa e tloaelehileng ea phetoho e nkhang hamonate ea electrophilic. Ka lehlakoreng le leng, li-pyridine li ka hlaseloa ke likokoana-hloko. Li-Pyridine li etsa liphetoho tsa motlakase (electrophilic substitution substitution) (SEAr) ka mokhoa o tsitsitseng empa phetoho ea nucleophilic (SNAr) habonolo ho feta benzene.
  2. Ho hlaseloa ke li-réagents tsa electrophilic ka ho khetheha ho Natom le ho li-atom, ha li-reagents tsa nucleophilic li khetha li-a-le-cc-atom.

Motsoako oa Electrophilic ka Nitrogen

Liketsong tse amang moralo oa maiketsetso ho sebelisa li-elektronike tse le mong ho na le nitrojene, joaloka protonation le quaternization, pyridines e itšoara hantle joaloka li-aliphatic tse phahameng kapa li-amine tse nkhang hamonate.

Ha pyridine e nka e le motheo kapa nucleophile, e theha setopo sa pyridinium seo sextet e nkhang hamonate e bolokiloeng, 'me nitrogen e fumana tefiso e nepahetseng.

Protonation ka Nitrogen

Li-pyridines li etsa kristalline, hangata e ngata haholo, letsoai le nang le li-protic acid tse ngata.

Nitration ka Nitrogen

Sena se etsahala habonolo ka ho itšoara ha pyridine le letsoai la nitronium, tse kang nitronium tetrafluoroborate. Lisebelisoa tsa protic nitrating tse kang nitric acid, ha e le hantle, li lebisa feela ho N-protonation.

Acylation ho naetrojene

Li-chloride tsa acid le li-acryulphonic acid li sebetsa kapele ka pyridines tse hlahisang letsoai la 1-acyl le 1- arylsulfonylpyridinium ka tharollo.

Li-alkyl halides le sulfate li arabela habonolo ka pyridine tse fanang ka letsoai la quaternary pyridinium.

Li-Nucleophilic Substitutions

Ho fapana le benzene, mekhoa e mengata ea nucleophilic e ka etsoa ka katleho le ka mokhoa o atlehang ke pyridine. Ke hobane lesale le na le metsoako ea elektronike e tlase ea liathomo tsa carbon. Liphetoho tsena li kenyeletsa ho nkela sebaka ka ho tlosoa ha ion hydride le ho eketsa ho eketsa ho fumana mokhoa o ka hare oa aryne 'me hangata o tsoelapele ho 2- kapa 4-boemo.

Pyridine feela e ke ke ea fella ka ho thehoa ha mekhoa e mengata ea nucleophilic substitutions. Leha ho le joalo, phetoho ea pyridine le bromine, li-fragments tsa sulfonic acid, chlorine le fluorine li ka fella ka sehlopha se tlohang. Ho thehoa metsoako ea organolithium e ka fumanoa ho tsoa sehlopha se molemo ka ho fetisisa sa ho tsoa ha fluorine. Ha khatello e matla, li-coreucleic li ka sebetsana le li-alkoxides, li-thiolate, li-amine le metsoako ea ammonia.

Ke tse fokolang heterocyclic liketso li ka etsahala ka lebaka la ho sebelisa sehlopha se futsanehileng se tlohang, joaloka ion hydride. Matšeliso a Pyridine sebakeng sa 2 a ka fumanoa ka tsela ea Chichibabin. 2-aminopyridine e ka tsoela pele ho finyelloa ha amide ea sodium e sebelisoa e le nucleophile. Molek'hule ea haedrojene e thehoa ha protone ea sehlopha sa amino e kopana le ion hydride.

Joaloka benzene, pyridine li-intermediate tse kang heteroaryne li ka fumanoa ka likaroloana tsa nucleophilic ho pyridine. Tšebeliso ea li-alkaline tse matla tse kang sodium le potassium tert-butoxide e ka thusa ho felisa lihlahisoa tsa pyridine ha li sebelisa sehlopha se nepahetseng. Ka mor'a ho kenngoa ha nucleophile ho tlamahano e meraro, e theola khetho le ho lebisa ho thehoa ha motsoako o nang le li-adducts tse peli.

Mefuta ea Electrophilic

Mefuta e mengata ea pyridine electrophilic e ka 'na ea tsoela pele ka nako e itseng kapa ha e tsoele pele ka ho feletseng. Ka lehlakoreng le leng, karolo ea heteroaromatic e ka tsosoa ka ho sebetsana le monehelo oa elektronike. Mahlaseli a Friedel-Crafts (acylation) ke mohlala oa alkylations le acylations. Karolo eo e sa sebetsane le pyridine kaha e fella ka ho eketsoa ha athomo ea naetrojene. Li-substitution li etsahala ka ho khetheha libakeng tse tharo tseo e leng e 'ngoe ea liathomo tsa k'habone tse nang le li-electron tse fumanehang ka hare ho eona e etsang hore e khone ho eketsa motlakase.

Sebaka sa Pyridine N-Oxide

Likarolo tsa elektrophilic li ka fella ka phetoho ea boemo ba pyridine ho 2- kapa 4-boemo ka lebaka la bobebe bo sebetsang bo matla bo rarahaneng. Leha ho le joalo, mekhoa ea liteko e ka sebelisoa ha o ntse o etsa li-electrophilic substitution ho pyridine N-oxide. Hamorao ho lateloa ke athomo ea nitrojene ea deoxygenation. Ka hona, kenyelletso ea oksijene e tsejoa ho fokotsa boleng ba nitrogen le ho eketsa sebaka sa libaka tsa 2 le tsa 4-position.

Lik'hemik'hale tsa sulfur divalent kapa phosphorous e tloaelehileng e tsejoa hore li na le lik'hemik'hale tse ngata habonolo haholo li sebelisoa haholo ho tlosa athomo ea oksijene. Triphenylphosphine oxide ke motsoako o thehiloeng ka mor'a hore o sebelisoe ke lik'hemik'hale tsa Triphenylphosphine. Ke ntho e 'ngoe hape e ka sebelisoang ho felisa athomo ea oksijene e tsoang ho e' ngoe. Tlhahisoleseding e ka tlase e hlalosa kamoo ho tloaelehileng ho kenngoa ha electrophilic ho sebetsanang le pyridine.

Ho tsamaisa nitride ea pyridine e hloka maemo a mang a thata, 'me ka kakaretso ha e na chai e ngata. Karabelo ea lijo tse entsoeng ka khase ea pentexide le pyridine ka ho ba teng ha sodium e ka baka sebopeho sa 3-nitropyridine. Li-derivatives tsa pyridine li ka fumanoa ka nitration ea nitronium tetrafluoroborate (NO2BF4) ka ho khetha athomo ea naetrojene ka mokhoa o motlakase le ka motlakase. Tlhahiso ea metsoako e 'meli ea 6-dibromo pyridine e ka fella ka ho thehoa ha 3-nitropyridine ka mor'a hore ho tlosoe liathomo tsa bomo.

Direct nitration e nkoa e le e phutholohileng ho feta sulfonation e tobileng ea pyridine. Ho belisoa ha pyridine ka 320 ° C ho ka etsa hore pyridine-3-sulfonic acid e potlakele ho feta ho belisa acid e sulfuric lihatsimong tse tšoanang. Ho eketsoa ha sulfur element ho athomo ea naetrojene ho ka fumanoa ka ho sebetsana le sehlopha sa SO3 ka pel'a mercury (II) sulphate e sebetsang e le sebopeho.

Ho khantsa ka ho toba le ho bromine ho ka tsoelapele hantle ho fapana le nitration le sulfonation. 3-bromopyridine e ka fumanoa ka ho itšoara ha bromine ea limolek'hule ka sulfuric acid ka 130 ° C le pyridine. Ha ho etsoa chlorination, phello ea 3-chloropyridine e ka ba tlase ka pel'a aluminium chloride e sebetsang e le ntho ea bohlokoa ho 100 ° C. Karabelo e tobileng ea halogen le palladium (II) e ka fella ka 2-bromopyridine le 2-chloropyridine.

Likōpo tsa Pyridine

E 'ngoe ea lisebelisoa tsa thepa tse bohlokoa haholo ho liindasteri tsa lik'hemik'hale ke pyridine. Ka 1989, tlhahiso eohle ea pyridine lefatšeng ka bophara e ne e le lithane tse 26K. Ho latela 1999, 11 e tsoang libakeng tsa tlhahiso tsa 25 tse kholo tsa pyridine li ne li le Europe. Lihlahisoa tse kholo tsa pyridine li kenyeletsa Koei Chemical, Imperial Chemical Industries le Evonik Industries.

Lilemong tsa pele tsa 2000, tlhahiso ea pyridine e eketsehile ka tsela e phahameng. Ka mohlala, naha ea China feela e na le matla a selemo a tlhahiso ea li-tonne tsa 30,000. Kajeno, khoebo e kopanetsoeng pakeng tsa US le Chaena e fella ka tlhahiso e phahameng ka ho fetisisa lefatšeng ea pyridine.

Likokoana-hloko

Pyridine e sebelisoa ka ho khetheha e le selelekela ho mefuta e 'meli ea likokoana-hloko diquat le paraquat. Ha ho lokisetsoa li-fungicides tse nang le pyrithione, pyridine e sebelisoa e le motsoako oa motheo.

Karabelo pakeng tsa Zincke le pyridine e fella ka tlhahiso ea lik'hemik'hale tse peli - laurylpyridinium le cetylpyridinium. Ka lebaka la litšobotsi tsa bona tse sebelisoang ke likokoana-hloko, lik'hemik'hale tsena tse peli li kenngoa merianeng ea tlhokomelo ea meno le ea molomo.

Ho hlaseloa ke moemeli oa alkylating ho pyridine ho hlahisa litho tsa N-alkylpyridinium, cetylpyridinium chloride e le mohlala o mong.

Paraquat Synthesis

Solvent

Tšebeliso e 'ngoe eo pyridine e sebelisetsoang ho eona ke ho noa ha Knoevenagel, moo e sebelisoang e le mokhoa o tlase o sebetsang hantle, oa polar le oa motheo. Pyridine haholo-holo e ntle bakeng sa dehalogenation, moo e sebetsang e le motheo oa ho felisoa ha o ntse o kopanya motsoako oa hydrogen halide ho theha letsoai la pyridinium.

Ka li-acylation le li-acterification, Pyridine e sebelisa li-anhydrides kapa carboxylic acid halides. E sebetsang ka ho fetisisa liketsong tsena ke 4- (1-pyrrolidinyl) pyridine le 4-dimethylaminopyridine (DMAP), e leng lihlahisoa tsa pyridine. Ka tsela ea ho itšoara hantle, Pyridine e sebelisoa e le motheo.

Ho thehoa ha pyridinium ka ho felisoa ha lipere le pyridine

Pyridine e boetse e le ntho ea bohlokoa ka ho fetisisa indastering ea masela. Ntle le ho sebelisoa e le solvent ha ho etsoa rabara le dyes, e boetse e sebelisetsoa ho ntlafatsa bokhoni ba marang-rang a k'hothone.

Tsamaiso ea US Food and Drug Administration e lumella ho phaella ha pyridine ka bongata ho lijo ho ba fa tatso e bohloko.

Ha u rarolla tharollo, moeli oa ho hlahloba pyridine o haufi le 1-3 mmol·L-1 (79-237 mg · L-1). Ho ba setsi, pyridine e ka sebelisoa e le karabelo ea Karl Fischer. Leha ho le joalo, imidazole hangata e sebelisoa e le sebaka sa phetoho ea pyridine kaha e (imidazole) e na le monko o khathollang.

E etella pele ho Piperidine

Pyridine hydrogenation e nang le catalyst e thehiloeng mofuteng o bitsoang ruthenium-, cobalt-, kapa eickel, e hlahisa liphello tse ngata molemong oa ho hlahisa piperidine. Hona ke sebaka sa bohlokoa sa li-heterocycle ea nitrojene eo e leng mohaho oa bohlokoa oa ho haha.

Reagents e ikhethang e thehiloe ho Pyridine

Ka 1975, William Suggs le James Corey ba ntshetsa pele pyridinium chlorochromate. E sebelisoa ho kopanya joala bo bobebe ho ketone le ho noa joala ho aldehydes. Pyridinium chlorochromate e tloaelehile ho fumanoa ha pyridine e kenngoa pheletsong ea concentrated hydrochloric le chromic acid.

C5H5N + HCl + CrO3 → [C5H5NH] [CrO3Cl]

Ka chromyl chloride (CrO2Cl2) e le lefu la kankere, tsela e 'ngoe e ne e lokela ho batloa. E mong oa bona ke ho sebelisa pyridinium chloride ho tšoara chromium (VI) oxide.

[C5H5NH+] Cl- + CrO3 → [C5H5NH] [CrO3Cl]

Reagent ea Sarret (e rarahaneng ea chromium (VI) oxide e nang le heterocycle ea pyridine e pyridine), pyridinium chlorochromate (PCC), Cornforth reagent (pyridinium dichromate, PDC), le reagent ea Collins (e rarahaneng ea chromium (VI) oxide e nang le pyridine heterocycle ka dichloromethane) li tšoana le li-chromium-pyridine metsoako. Li boetse li sebelisoa bakeng sa khauta, joalo ka ho fetola li-alcohol tse bobeli le tse ka sehloohong ho ketone.

Li-reagents tsa Sarret le Collins ha li qhekellehe feela ho lokisetsa, empa li boetse li le kotsi. Li na le li-hygroscopic 'me li ka' na tsa hlaseloa ha li ntse li itokisetsoa. Ka hona, tšebeliso ea PDC le PCC e ile ea buelloa. Ha li-reagents tse peli li sebelisoa haholo ho 70 le 80s, ha li sebelisoe hangata ka lebaka la toxicity ea tsona 'me li tiisitsoe hore li na le kankere.

Sebopeho sa motsoako oa Crabtree

Ka khemistri e kopanetsoeng, pyridine e sebelisoa haholo joaloka ligand. E tsoa ho eona, joalo ka eona e tsoang ho 2,2'-bipyridine, e nang le limolek'hule tsa 2 pyridine tse kopantsoeng ke tlama e le 'ngoe, le terpyridine, molek'hule ea li-rings tsa 3 pyridine tse kopantsoeng hammoho.

Setsi sa Lewis se matla se ka sebelisoa e le sebaka sa phetolelo ea pyridine ligand eo e leng karolo ea metsoako ea tšepe. Tšobotsi ena e sebelisoa ka ho hloekisa polymerization le liketso tsa hydrogenation, ho sebelisa, ka mohlala, motsoako oa Carabtree. The pyridine Lingard e nkeloeng sebaka nakong ea karabelo e khutlisetsoa ka mor'a hore e phethoe.

References

Nomenclature ea Organic Chemistry: Litlhahiso tsa IUPAC le Mabitso a khethiloeng 2013 (Buka ea Blue). Cambridge: Royal Society of Chemistry. 2014. p. 141.

Anderson, T. (1851). "Ueber o hlahisa Producteur der trocknen Destillation thierischer Materien" [Ho lihlahisoa tsa distillation e omileng ea taba ea liphoofolo]. Annalen der Chemie le Pharmacie. 80: 44.

Sherman, AR (2004). "Pyridine". Paquette, L. Encyclopedia of Reagents bakeng sa Organic Synthesis. e-EROS (Encyclopedia of Reagents bakeng sa Organic Synthesis). New York: J. Wiley le Bara.

Behr, A. (2008). Angewandte homogene Katalyse. Weinheim: Wiley-VCH. p. 722.