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Konke Okufuneka Ukwazi NgePyridines

Konke Okufuneka Ukwazi NgePyridines

Konke Okufuneka Ukwazi Ngawo Pyridines

I-Pyridine iyona siseko heterocyclic uhlobo lwe-azine uhlobo. I-Pyridine ivela kwi-benzene ngokutshintshwa kweqela le-CH nge-N-athomu. Isakhiwo sePyridine sifana nesakhiwo se-benzene, kuba idibene nokutshintshwa kweqela le-CH nge-N. Ulwahluko olukhulu luquka:

  1. Ukusuka kwi-geometry eqhelekileyo engama-hexagonal ekhoyo ngenxa yobukho be-hetero i-athomu, ukucaca, i-nitrogen-carbon bonds,
  2. Ukutshintshwa kwe-athomu ye-hydrogen kwinqanaba lomngqingili kunye nombini ongatshitshisiweyo we-electron, njengendiza yendandatho, e-sp2 hybrid orbital, kwaye ingabandakanyeki kwi-sextet enamakha e-p-electron. Le nxalenye ye-nitrojeni yedwa ijongene nezakhiwo eziphambili ze-pyridines,
  3. I-dipole engapheliyo elandelwayo kwi-atron ephezulu ye-nitrogen xa ifaniswe ne-athomu ye-carbon.

I-ring yePyridine ivela kwiinqununu ezininzi ezibalulekileyo, kuquka iivithamini niacin, pyridoxine, kunye nama-azines.

I-chemistry yaseScotland, uTom Anderson waqulunqa i-pyridine kwi-1849 njengenye yezinto ezibandakanya ioli. Emva kweminyaka emibini, u-Anderson ufumana i-pyridine ecocekileyo nge-fractional distillation yamathambo esithambo. Ingumbane onokutsha, ongenakubalabala, ongenamanzi, onobuthakathaka obuthakathaka obunobumba obunqabileyo, obunjengeentlanzi.

I-Pyridine isoloko isetyenziselwa njengophambili kumachiza kunye ne-agrochemicals kunye neyona nto ibaluleke kakhulu kwaye isisombululo. I-Pyridine inokudibaniswa kwi-ethanol ukuba ufuna ukuyenza ingafanelanga ukusetyenziswa kwabantu. Kukwasebenza kwakhona kwimveliso yamachiza e-antihistaminic i-mepyramine kunye ne-tripelennamine, i-In vitro ukuhlanganiswa kweDNA, kwimveliso ye-sulfapyridine (unyango lokunyanga izifo zentsholongwane kunye nokusuleleka kubaktheriya), kunye ne-bactericides, i-herbicides, kunye nokuhlaselwa kwamanzi.

Uninzi lwamakhemikhali, nangona lungakhange luveliswe kwi-pyridine, luqulethe isakhiwo sendandatho. Ezi zinto ziquka i-vithamini B efana ne-pyridoxine kunye ne-niacin, i-nicotine, imveliso yezityalo eziqukethe i-nitrogen, kunye neziyobisi ezichasayo ezibizwa ngokuba yi-isoniazid. I-Pyridine yaveliswa ngokomlando njengemveliso ye-charity gasification kunye ne-tar coal. Nangona kunjalo, ukufunwa kwamanzi nge-pyridine kwakhokelela ekuphuhliseni iindlela zokwenza imali ezivela kwi-ammonia kunye ne-acetaldehyde, kwaye ngaphezu kweetoni ze-20,000 zenziwa ngonyaka.

ISetyinamente pyridine

Igama elichanekileyo le-pyridine, ngokwe-Hantzsch-Widman igama eliphakanyisiweyo eliphakanyiswe yi-IUPAC, azine. Kodwa amagama asemgangathweni kwiimpawu ezisisiseko zisetyenziselwa ngokuqhelekileyo; kunoko, ukutyunjwa kwamagama angama-heterocycle kulandela amagama aqhelekileyo asetyenziswayo. IUPAC ayikhuthazi ukusebenzisa azine xa e bhe kisela pyridine.

Ukubalwa kwee-atom ze-ring kwi-azine kuqala nge-nitrogen. Ulwabiwo lwezikhundla ngee-alfabhethi incwadi (α-γ) kunye nomzekelo wesimboli sokumelwa kwegama lomnxekto oqhelekileyo kwiinkqubo ze-homoaromatic (ortho, meta,) kusetyenziswa ngamanye amaxesha. Nantsi α, β kunye γ ibhekisela kwizikhundla zombini, ezintathu, nezine, ngokulandelanayo.

Igama elichanekileyo kwii-derivatives ze-pyridine pyridinyl, apho inomboro ilandele i-atom engena endaweni elandelwe ngenani. Kodwa igama lembali pyridyl Kunconywa yi-IUPAC kwaye isetyenziswa ngokubanzi endaweni yegama elichanekileyo. I-derivative eyenziwe ngokongezwa kwe-electrophile kwi-athomu ye-nitrogen iyaziwa pyridinium.

4-bromopyridine

2,2'-bipyridine

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

Ifom ye siseko ye-pyridinium cation

Ukuveliswa kwe pyridine

I-Pyridine yafunyanwa njengemveliso ye-charity gasification okanye ephuma kwi-tar yemalahle. Le ndlela yayingasebenzi kakuhle kwaye iyasebenza: i-tar yamalahle ijikeleze i-0.1 yepesenti ye-pyridine, kwaye ngoko ke kufuneka kuhlanjululwe amanqanaba amaninzi, okwenyusa umphumo. Namhlanje, ininzi i-pyridine yenziwe ngokukodwa ngokusetyenziswa kwamagama amaninzi, kwaye ezi ziqhelekileyo zixutyushwa apha ngezantsi.

Pyridine Synthesis ngeBohlmann-Rahtz

I-Pyridine Synthesis ngeBohlmann-Rahtz ivumela isizukulwana sama pyridines asetyenzisiweyo ngamanyathelo amabini amakhulu. Ukunciphisa i-enamines usebenzisa i-ethynylketones kubangela ukuba phakathi kwe-aminodiene ephakathi, emva kwe-isomerization eshushu, ihamba nge-cyclodehydration ukuvelisa i-pyridines ye-2,3,6-trisubstituted.

I-Pyridine Synthesis ngokusebenzisa indlela ye-Bohlmann-Rahtz

Le ndlela ihambelana ne-Hantzsch Dihydropyridine Synthesis ethandwayo aphoin situe-generated enamine kunye neentlobo zezilwanyana zivelisa i-dihydropyridines. Nangona i-Bohlmann-Rahtz Synthesis ixhaphake kakhulu, ukuhlanjululwa kwamaqondo okushisa aphezulu kunye nenyukayo okufunekayo ukuba i-cyclodehydration yiingxaki eziye zinciphisa ukusetyenziswa kwayo. Ininzi yemingeni iyanqotshwa, okwenza iBohlmann-Rahtz Synthesis ibaluleke kakhulu pyridines isizukulwana.

Nangona kungekho uphando lwezinto eziye zenziwe, abadibanisi bangabonakaliswa yi-H-NMR. Oku kubonisa ukuba umkhiqizo omkhulu we-First Additional Addition and the following proton transfer can be a 2Z-4E-heptadien-6-enye ekhishwe kwaye ihlanjululwe ngokusebenzisa i-column chromatography.

Kufuneka ke ukushisa ukushisa kwe-cyclodehydration ephakamileyo Z/E i-isomerizations efunekayo kwi-hetero.

Izindlela eziliqela ezivumela ukuhlanganiswa kwe-tetra kunye neepriridines ezihlambulukileyo kwinkqubo enye-nyathelo ziye zaphuhliswa kutshanje. Esikhundleni sokusebenzisa i-butynone njenge-substrate, i-Bagley yavavanya i-solvents ehlukeneyo yokuguqulwa kwe-4- (trimethylsilyl) engancinci kwaye engabiziyo kodwa -3-yn-2-enye. Kwaboniswa ukuba i-DMSO kuphela ne-EtOH kuphela zi-solvents ezifanelekileyo. I-EtOH icatshulwa ngokucacileyo njenge-polar kunye ne-protic solvent kunye ne-DMSO njenge-solder aprotic solvent. Kwimizimbini ye-solvents, i-protodesilylation yenzeke ngokukhawuleza. UBarley uye wabonisa ukuba i-acid catalysis ivumela ukuba i-cyclodehydration iqhubeke kwiqondo lokushisa elisezantsi.

I-acid catalysis nayo ikhuthaza ukudibanisa i-conjugate. Uhlobo oluninzi lwe-enamine lwenziwa ngama-ethynyl ketoni kwi-5: 1) umxube we-acetic acid kunye ne-toluene ukufumana i-pyridines esebenzayo kwisinyathelo esinye kwisithamo esihle.

Emva kokuphumelela kwe-Brønstedt acid catalysis, isazi samakhemikhali sasiphenya ngekhono lika-Lewis acid catalysts. Iimeko ezigqwesileyo ezisetyenziselwa i-mol% ye-ytterbium triflate okanye i-15 ye-mol% zinc bromide kwi-toluene ye-reflux. Nangona uphando lwezobugcisa aluzange lwenzeke, sinokucinga ukuba ukulungelelaniswa ngumbonakalo ukhawuleza ngee-cyclodehydration, uMichael Addition, kunye namanyathelo okusikwa kwe-isomerization.

Ukuphazamiseka kukuhambelana okulinganiselwe kunye ne-substrates ezikhuselekileyo ze-asidi. Ngokomzekelo, i-acid-catalyzed decomposition ye-enamines iyenzeka nge-cyano kunye mhlaba-buttyterter njengamaqela okukhangela ama-electron. Enye enye indlela ebumnene kusetyenziselwa i-Amberlyst-15 ion yokutshintshiselana ne-reagent ebekezelayo mhlaba-abalinganiswa.

Ekubeni i-enamine ayifumaneki ngokulula, kwaye ukuphucula isikhokelo senkqubo, i-3-inxalenye yempendulo yenziwa nge-acetate ye-ammonium njengomthombo weqela le-amino. Kule nkqubo efanelekileyo, i-enamine yenziwe in situ osebenzayo kunye ne-alkynone.

Kwilingo lokuqala, iZnBr2 kunye ne-AcOH zenziwa njengezixhobo ezongezelelekileyo nge-toluene njengoluhlu olusisiseko. Nangona kunjalo, bekuye kwaboniswa ukuba i-substrates ezikhuselekileyo ze-acid zihlala zisabela kwimeko enobume kunye ne-EtOH njengesisombululo.

Chichibabin Synthesis

Intetho yeChichibabin pyridine yaqala ukuxelwa kwi-1924 kwaye isisicelo esikhulu kwi-shishini likhemikhali. Yimpendulo eyenziwe ngokukhawuleza, okubandakanya ukuphendulwa kwe-aldehydes, i-ketones, i-α, β-unsaturated compounds. Ngaphezu koko, ifom epheleleyo yempendulo ingabandakanya nayiphi na intlangano yeemveliso ezingentla apha kwi-ammonia ecocekileyo okanye eziphuma kuyo.

Ukuqulunqwa Pyridine

Ukumiselwa kwe-formaldehyde kunye ne-acetaldehyde

I-formaldehyde kunye ne-acetaldehyde yimiba yemithombo ye-pyridine engagqitywanga. Ubuncinane, zifikeleleka kwaye zifikeleleke.

  1. Isinyathelo sokuqala siquka ukwakheka kwe-acrolein kwi-formaldehyde kunye ne-acetaldehyde ngokusebenzisa ukulungiswa kwe-Knoevenagel.
  2. Umkhiqizo wokuphela uxoxwa kwi-acrolein nge-acetaldehyde kunye ne-ammonia, eyenza i-dihydropyridine.
  3. Inkqubo yokugqibela yindlela yokusabela ngayo i-oxidation ne-catalyst yesimo esomeleleyo sokunika i-pyridine.
  4. Ukusabela oku ngasentla kwenziwa kwisigaba segesi kunye neqondo lokushisa lwe-400-450 ° C. I-compound eyenziwe ibandakanya i-pyridine, i-picoline okanye i-pyridine e-methylated elula, kunye ne-lutidine. Nangona kunjalo, ukubunjwa kukuxhomekeke kwintsebenziswano kunye nakwezinga elithile, lihluka kunye neemfuno zomenzi. Ngokuqhelekileyo, i-catalyst iyityuwa yentsimbi yenguqu. Izona ziqhelekileyo ziyi-manganese (II) i-fluoride okanye i-cadmium (II) i-fluoride, nangona i-thallium kunye ne-cobalt i-compounds ingaba ezinye iindlela.
  5. I-pyridine ifunyenwe kwii-by-product kwinkqubo ye-multistage. Umlinganiselo omkhulu we-Chichibabin synthesis of pyridine isivuno esiphantsi, ukuguqulela malunga ne-20% yemveliso ekupheleni. Ngenxa yesi sizathu, iifom ezingahambelaniyo zeli candelo zingaphantsi.

Bönnemann cyclization

I-Bönnemann i-cyclization yindlela yokwakha i-trimer ukusuka ekuhlanganisweni kweengxenye ezimbini ze-acetylene molecule kunye nenxalenye ye-nitrile. Enyanisweni, le nkqubo yenguqu ye-Reppe synthesis.

Indlela leyo iququzelelwa ngubushushu obuvela kumaqondo aphezulu aphezulu kunye noxinzelelo okanye ngokusebenzisa i-cycloaddition ekhutshwe ngefoto. Xa isebenze ngokukhanya, i-Bönnemann cyclization idinga iCocp2 (i-cyclopentadienyl, i-1,5-cyclooctadiene) ukuba ibe yinto ehamba phambili.

Le ndlela inokuvelisa i-chain of derivatives e-pyridine ngokuxhomekeke kwiimveliso ezisetyenziswayo. Ngokomzekelo, i-acetonitrile iya kuvelisa i-2-methylpyridine, enokuthi ifake i-dealkylation ukwenza i-pyridine.

Ezinye iindlela

I-Kröhnke pyridine synthesis

Le ndlela isebenzisa i-pyridine njenge-reagent, nangona ayiyi kubandakanywa kwimveliso yokugqibela. Ngokwahlukileyo, impendulo iya kuvelisa i-pyridines engena endaweni.

Xa sithatha i-α-bromoesters, i-pyridine iya kufana nokuphendula kukaMichael kunye ne-carbonyls engabonakaliyo ukwenza i-pyridine kunye ne-pyridium bromide endaweni. Impendulo ithathwa nge-acetate ye-ammonia ngaphakathi kwe-20-100 ° C izimo ezintle.

Ukulungiswa kwakhona kwe-Ciamician-Dennstedt

Oku kubandakanya ukongezwa kwe-pyrrole kunye ne-dichlorocarbene eyenza i-3-chloropyridine.

Isitatimende seGattermann-Skita

Kule mpendulo, i-calonate ester iyancipha ne-dichloromethylamine phambi kwesiseko.

I-Boger pyridine synthesis

Ukuphendula pyridines

Ukuphendula okulandelayo kunokuqikelelwa kwiipriridines kwisakhiwo sogesi:

  1. I-heteroatom yenza i-pyridines ingasebenzi kwiindawo eziqhelekileyo zokutshintshwa kwe-electrophilic. Ngokuchasene, iipyridines ziyakwazi ukuhlaselwa kwe-nucleophilic. AmaPyridines aphantsi kweempembelelo zokufaka endaweni ye-electrophilic (SEAr) ngaphezulu kokungathandabuzeki kodwa ukutshintshwa kwe-nucleophilic (SNAr) ngokulula ngaphezu kwe-benzene.
  2. Ukuhlaselwa kwe-reagents ye-electrophilic ngokukhethekileyo kwi-Natom nakwi-bc-atom, ngelixa i-reagents i-nucleophilic ikhetha i-at-na-cc-atom.

Ukongezwa kwe-Electrophilic kwiNitrogen

Kwiimpendulo ezibandakanya ukubunjwa kwebhondi usebenzisa i-electron idilesi enye kwi-nitrogen ye-nitrogen, njenge-protonation kunye ne-quaternization, i-pyridines iziphatha ngendlela efana ne-aliphatic ephakamileyo okanye amamin amnandi.

Xa i-pyridine ithatha njengesiseko okanye i-nucleophile, yenza i-pyridinium cation apho i-sextet enamakha igcinwa khona, kwaye i-nitrogen ithola inkokhelo ehlelekile.

Iprotonation kwiNitrogen

Iipyridines zenza i-crystalline, rhoqo i-hygroscopic, i-salts eninzi iprotic acid.

Nitration kwiNitrogen

Oku kwenzeka ngokukhawuleza ngokuphendulwa kwama-pyridines ne-nitronium salts, njenge-nitronium tetrafluoroborate. I-protic nitrating agents ezinjenge-nitric acid, ngokuqinisekileyo, zikhokelela kuphela kwi-N-protonation.

Acylation kwi nitrogen

I-acid chloride kunye ne-arylsulfonic acids zenza ngokukhawuleza ngeepridrid ezenza i-1-acyl- kunye ne-1- arylsulfonylpyridinium isalathisi.

I-alkyl halides kunye ne-sulphure isabela ngokulula ngama-pyridines enikeza i-quaternary i-pyridinium salts.

Nucleophilic Substitutions

Ngokungafani ne-benzene, iinguqu ezininzi ze-nucleophilic zinokusetyenziswa ngokufanelekileyo nangempumelelo ngepriridine. Kungenxa yokuba indandatho ine-electron ephantsi kwee-athomu ze-carbon. Ezi mpendulo ziquka ukutshintshwa kwe-hydride ion kunye nezongezo zokuqeda ukufumana ukucwangciswa kwe-aryne ephakathi kwaye ngokuqhelekileyo kuqhubela kwi-2- okanye kwi-4-isikhundla.

I-Pyridine yodwa ayinakuphumela ekubunjweni kwamanyathelo amaninzi e-nucleophilic. Nangona kunjalo, ukuguqulwa kwe-pyridine kunye ne-bromine, i-sulphonic acid fragments, i-chlorine, kunye ne-fluorine kunokubangela iqela elishiya. Ukubunjwa kwe-organicololum compounds kungabuyiselwa kwiqela elihamba phambili lokuphuma kwefrijini. Xa uxinzelelo oluphezulu, i-nucleophilic inokuyithatha i-alkoxides, i-thiolates, i-amines kunye ne-ammonia.

Bambalwa heterocyclic iimpendulo zingenzeka ngenxa yokusebenzisa iqela elihlwempuzekileyo elishiya njenge-hydride ion. Izixhobo ezivela kwi-Pyridine kwi-2-isikhundla zingatholakala kwi-Chichibabin yokusabela. I-2-aminopyridine ingaqhubeka iphumelele xa i-amide ye-sodium isetyenziswa njenge-nucleophile. I-molecule ye-hydrogen yenziwa xa iiprotoni zeqela le-amino zidibanisa ne-hydride ion.

Efana ne-benzene, pyridines Iziphambili ezifana ne-heteroaryne zifumaneka kwiindawo ezingenayo i-nucleophilic ukuya kwi-pyridine. Ukusetyenziswa kwama-alkali anamandla afana ne-sodium ne-potassium tert-butoxide kunokunceda ukulahla iimveliso ze-pyridine xa usebenzisa ilungelo lokushiya iqela. Ukulandela ukuqaliswa kwe-nucleophile kwisibophelelo esithathu, sinciphisa ukhetho kwaye kukhokelela ekubunjweni komxube onokubakho kwezi zimbini.

Izixhobo ze-Electrophilic

Amashishini athile e-pyridine asetyenzisiweyo angakwazi ukuqhubeka ukuya kwindawo ethile okanye aqhubekeki ngokupheleleyo. Ngakolunye uhlangothi, inxalenye ye-heteroaromatic ingakhuthazwa ngokusebenza komnikelo we-electron. I-alkylation ye-Friedel-Crafts (acylation) ngumzekelo we-alkylations kunye nama-acylation. Imbono ihluleka ukungena kwi-pyridine kuba igalelo le-atrojeni. Ukutshintshwa ngokutsha kubakho ngokukodwa kwindawo elinezikhundla ezintathu, enye enye i-athomu ye-carbon elineetronksi elinekhampani eyenza ibe yinto enokungeniswa kwe-electrophilic.

Ulwakhiwo lwe-Pyridine N-Oxide

Izikhundla ze-Electrophilic zingabangela ukutshintshwa kwesimo se-pyridine kwi-2- okanye kwi-4-isikhundla ngenxa yempembelelo σ enamandla. Nangona kunjalo, iindlela zokulinga zingasetyenziselwa ngelixa zenza indawo ye-electrophilic endaweni ye-pyridine N-oxide. Emva koko kulandelwa i-atrojeni ye-ashogengenation ye-atrojeni. Ngoko ke, ukufakwa kwe-oksijeni kuyaziwa ngokunciphisa ubuninzi be-nitrogen kwaye kufakela indawo endaweni ye-2-isikhundla kunye ne-4-position-carbons.

Izixhobo ze-divalent sulfure okanye i-phosphorus e-trivalent ziyaziwa ngokuba lula kwi-oxidized hence zisetyenziselwa ukususa i-athomu ye-oksijini. I-Triphenylphosphine oxide yinkomfa eyenziwa emva kwe-oxidation ye-Triphenylphosphine reagent. Enye enye into engasetyenziswayo ukulahla i-athomu ye-oksijini evela kwenye into. Ingcaciso engezantsi ichaza indlela ukufakelwa kwe-electrophilic eqhelekileyo inabela ngayo ne-pyridine.

I-pyridine nitration ifuna izimo ezithile ezinzima, kwaye ngokungekho mveliso. Ukuphendula kwe-dinitrogen pentoxide kunye ne-pyridine phambi kwesodium kungabangela ukubunjwa kwe-3-nitropyridine. Iziphumo ezivela kwi-pyridine zingatholakala nge nitrate ye nitronum tetrafluoroborate (NO2BF4) ngokukhetha i-athomu ye-nitrogen ngokukodwa nangokukwikhompyutha. Isisombululo samacandelo amabini we-6-dibromo pyridine sinokubangela ukubunjwa kwe-3-nitropyridine emva kokususwa kwee-athomu ze-brom.

I-nitration ngqo ithathwa njengento ekhululekile kune-sulphonation ngqo ye-pyridine. Ukubilisa kwe-pyridine kwi-320 ° C kunokubangela i-pyridine-3-sulfonic acid ngokukhawuleza kunokubilisa i-acid ye-sulfuric kumaqondo afanayo. Ukongezwa kwento yesulfure kwi-athomu ye-nitrogen kungatholakala ngokuphendula iqela le-SO3 phambi kohlobo lwe-mercury (II) i-sulphate esebenza njengento yokubangela.

Ukuchlorwa ngokukhawuleza kunye nokubhena kunokuqhubeka kakuhle ngokungafani ne-nitration kunye ne-sulphonation. I-3-bromopyridine ingafumaneka ngokuphendula kwe-bromine ye-molecule kwi-sulfuric acid kwi-130 ° C kunye ne-pyridine. Kwi-chlorination, isiphumo se-3-chloropyridine ingaba sezantsi phambi kwe-aluminium i-chloride esebenza njenge-catalyst kwi-100 ° C. Ukuphendula ngokuthe ngqo kwe-halogen kunye ne-palladium (II) kunokubangela i-2-bromopyridine kunye ne-2-chloropyridine.

Izicelo zePyridine

Enye yezinto ezibonakalayo ezibaluleke kakhulu kwiifekthi zeekhemikhali yi-pyridine. Kwi-1989, i-total production of pyridine emhlabeni jikelele yayingu-26K itoni. Njengoko kwe-1999, i-11 ephuma kwii-25 ezinkulu ze-pyridine zindawo zokuvelisa zaseYurophu. Abavelisi abakhulu be-pyridine baquka iKoei Chemical, i-Imperial Chemical Industries kunye ne-Evonik Industries.

Kwii-2000 zakuqala, ukuveliswa kwe-pyridine kwandiswe ngumda ophezulu. Ngokomzekelo, ilizwe laseKhayini linye lithatha umlinganiselo wonyaka wokuveliswa kweetoni ze-30,000. Namhlanje, ukusebenzisana phakathi kwe-US kunye ne-China kubangela ukuveliswa kwe-pyridine ephezulu emhlabeni.

Pesticides

I-Pyridine isetyenziswe ngokubanzi njengophambi kwezinto ezimbini zokurhweba kunye ne-paraquat. Kwilungiselelo le-friticide-based fungicides, i-pyridine isetyenziswe njengesakhiwo esisiseko.

Impendulo phakathi kweZincke kunye ne-pyridine kwiziphumo ekuveliseni izixhobo ezimbini-laurylpyridinium kunye ne-cetylpyridinium. Ngenxa yeempawu zabo zokuxhatshazwa, izixhobo zombini zongezwa kwimveliso yonyango nangomlomo.

Ukuhlaselwa kwe-alkylating agent ukuya kwi-pyridine iziphumo kwi-N-alkylpyridinium usawoti, i-cetylpyridinium chloride ngumzekelo omnye.

IParaquat Synthesis

Solvent

Enye isicelo apho i-pyridine isetyenziselwa ukukhanda kwe-Knoevenagel, apho isetyenziselwa njengento ephantsi, esebenzayo, kunye nesiseko. I-Pyridine ikhetheke kakhulu kwi-dehalogenation, apho isebenza njengesiseko sokusabela ekupheliseni xa idibanisa i-hydrogen engenayo ukudala ityuwa ye-pyridinium.

Ngama-acylation kunye ne-esterification, i-Pyridine isebenza i-anhydrides okanye i-carboxylic acid halides. Eyona nto isebenzayo kule mpendulo i-4- (1-pyrrolidinyl) pyridine kunye ne-4-dimethylaminopyridine (i-DMAP), eyimveliso ye-pyridine. Kwindlela yokuphendula, iPyridine isetyenziswe njengesiseko.

Ukuqulunqwa kwe-pyridinium ngokusebenzisa ukusabela kokupheliswa kwe-pyridine

I-Pyridine nayo ibaluleke kakhulu kwimveliso yombumba. Ngaphandle kokuba kusetyenziswe njengoluhlu olwenziwe kwi-rubber kunye nedayi, isetyenziselwa ukukhulisa umthamo womnatha wekotoni.

I-US Yokutya Nezolawulo Zezidakamizwa ivuma ukongezwa kwe-pyridine ngobuncinane kwiindawo zokutya ukuze kubonelele ukuvumba.

Kwizisombululo, umgca wokubona we-pyridine ujikeleze i-1-3 mmol·L-1 (79-237 mg · L-1). Ukuba isiseko, i-pyridine ingasetyenziswa njenge-Karag Fischer reagent. Nangona kunjalo, i-imidazole isetyenziselwa ukuba ithathe indawo ye-pyridine njengoko yona (imidazole) inomsindo ocolileyo.

Precursor ukuya ePiperidine

I-Pyridine hydrogenation ne-ruthenium-, cobalt-, okanye i-nickel-based based catalyst kwiqondo eliphezulu liphumo ekuveliseni i-piperidine. Le yinqanaba le-nitrojeni ye-heterocycle eyinqaba ebalulekileyo yokwakha.

AmaReagents akhethekileyo asekelwe kwiPyridine

Kwi-1975, uWilliam Suggs noJacob Corey bavelise i-pyridinium chlorochromate. Isetyenziselwa ukukhupha i-alcohols yesibini kunye neetononi kunye neengqonge eziphambili kwi-aldehydes. I-pyridinium chlorochromate ifumaneka xa i-pyridine yongezwa kwisisombululo se-hydrochloric ne-chromic acid.

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

I-chromyl chloride (CrO2Cl2) ukuba yi-carcinogenic, enye indlela kufuneka ifunwe. Omnye wabo kukusebenzisa i-pyridinium chloride ukuphatha i-chromium (VI) i-oxide.

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

I-reactent ye-Sarret (ubunzima be-chromium (VI) i-oxide ne-pyridine heterocycle e-pyridine), i-pyridinium chlorochromate (PCC), i-reactent ye-Cornforth (i-pyridinium dichromate, i-PDC) kunye ne-Collins reagent (ubunzima be-chromium (VI) ne-pyridine i-heterocycle kwi-dichloromethane) zifana ne-chromium-pyridine. Ziye zifake izicelo ze-oxidation, ezifana nokuguqulwa kwamanzi asezantsi kunye noomgangatho oyisiseko kwi-ketoni.

I-Sarret ne-Collins reagents ayilona nje inkohliso ukulungiselela, kodwa nayo inobungozi. Ziyi-hygroscopic kwaye ziyakwazi ukutshabalalisa ngexesha lokulungiselela. Ngenxa yoko, ukusetyenziswa kwe-PDC kunye ne-PCC kunconywa. Ngelixa izibini zombini zisetyenziselwa kakhulu kwi-70 kunye ne-80s, aziqhelwanga ngokuqhelekileyo ngenxa yobunetyhefu kunye nokuqinisekiswa kwe-carcinogenicity.

Isakhiwo se-Crabtree's catalyst

Kwi-chemistry co-coordination, i-pyridine isetyenziswe ngokubanzi njenge-ligand. Ivela kuye, njengokuba iphuma kwi-2,2'-bipyridine, equka i-2 i-pyridine iamolekyu zihlanganiswe kunye kunye ne-terpyridine, i-molecule yee-3 i-pyridine izindandatho ezidibene kunye.

Isiseko esiphezulu sase-Lewis singasetyenziselwa ukutshintshwa kwegridine ligand eyincinci yesakhiwo sotsimbi. Esi sibonakaliso sisetyenziswa kwi-catalysis ye-polymerization kunye nokuphendula kwe-hydrogenation, usebenzisa, umzekelo, i-catalyst ye-Carabtree. I-pyridine iLingard ethatha indawo endaweni yokuphendula iyabuyiselwa emva kokugqitywa kwayo.

Ucaphulo

I-Nomenclature ye-Organic Chemistry: Iingcebiso ze-IUPC kunye namagama akhethweyo 2013 (iBlue Book). I-Cambridge: iRoyal Society of Chemistry. 2014. p. 141.

Anderson, T. (1851). "Ueber die Producte der trocknen Destillation thierischer Materien" [Kwiimveliso zengxube ezomileyo zengxaki yezilwanyana]. UAnalen der Chemie no Pharmacie. 80: 44.

USherman, AR (2004). "Pyridine". Kwi Paquette, L. I-Encyclopedia yeReagents ye-Organic Synthesis. i-EROS (i-Encyclopedia yeReagents ye-Organic Synthesis). ENew York: J. Wiley & Son.

Behr, A. (2008). I-Angewandte homogene uKatalyse. Weinheim: iWiley-VCH. p. 722.