Lisebelisoa tse fapaneng tsa Sodium Cyanide ho Organic Synthesis

Selelekela

Sodium cyanide (NaCN), e nang le foromo ea lik'hemik'hale NaCN, ke kristale e tšoeu e tiileng kapa phofo e qhibilihang haholo metsing 'me e na le monko o monate oa almonde. Ka lebaka la reactivity ea eona e phahameng, e fumane tšebeliso e pharaletseng mefuteng e mengata ea synthesis ea manyolo karabelo. Leha ho le joalo, ke habohlokoa ho hlokomela seo sodium cyanide e chefo haholo 'me e tlameha ho sebetsoa ka hloko e kholo le ho latela melaoana ea polokeho. Sengoliloeng sena se hlahloba lits'ebetso tse fapaneng tsa Sodium cyanide ka organic synthesis.

Likopo ho Organic Synthesis

Karabelo ea Strecker

E 'ngoe ea likopo tse tsebahalang haholo tsa Sodium cyanide ho organic synthesis e ho Strecker reaction. Karabelo ena ke mokhoa o matla oa ho kopanya α - amino acid. Ho Strecker reaction, aldehyde kapa ketone e arabela ka ammonium chloride (NH₄Cl) le sodium cyanide. The general reaction mechanism ke ka tsela e latelang:

1. Taba ea pele, aldehyde kapa ketone e arabela le ammonia (e entsoeng ka har'a - situ ho tsoa ho ammonium chloride) ho etsa imine. k'haboneSehlopha sa yl sa aldehyde kapa ketone se na le proton, e leng se etsang hore e be le electrophilic haholoanyane. Ebe ammonia e hlasela carbonyl carbon e nang le proton, e lateloe ke deprotonation ho etsa imine.

2. Ka mor'a moo, ion ea cyanide (CN⁻) e tsoang sodium cyanide e sebetsa e le nucleophile 'me e hlasela imine carbon. Sena se etsa α - amino nitrile mahareng.

3. Qetellong, hydrolysis ea α - amino nitrile tlas'a asiti kapa maemo a motheo e hlahisa α - amino acid e tšoanang.

Karabelo ea Strecker e fana ka mokhoa o otlolohileng oa ho kenyelletsa sehlopha sa amino le sehlopha sa carboxyl (kamora hydrolysis ea nitrile) holim'a athomo e le 'ngoe ea khabone, e leng bohlokoa bakeng sa motsoako oa li-amino acid, li-block tsa protheine. Ka mohlala, ha formaldehyde (HCHO) e arabela ka ammonium chloride le sodium cyanide, e lateloa ke hydrolysis, glycine (NH₂CH₂COOH), e bonolo ka ho fetisisa ea amino acid, e ka fumanoa.

Tokisetso ea Nitriles

Sodium cyanide e sebelisoa hangata bakeng sa ho lokisa li-nitriles. Ka karabelo ea sebaka, alkyl halides (joalo ka methyl bromide, CH₃Br) e sebetsana le sodium cyanide ka har'a motsoako oa polar aprotic joalo ka dimethyl sulfoxide (DMSO) kapa acetone. Karabelo e tsoela pele ka mochini oa SN2, moo ion ea cyanide e hlaselang athomo ea khabone e hokahantsoeng le halogen. Athomo ea halogen e tlosoa, 'me alkyl nitrile e thehoa. Mohlala:

CH₃Br + NaCN → CH₃CN + NaBr

Aryl nitriles e ka boela ea etsoa ka ho sebelisa sodium cyanide maemong a itseng. Ka mohlala, phetohong e 'ngoe - karabelo ea tšepe-catalyzed, aryl halides e ka itšoara ka sodium cyanide ka pel'a sekontiri se kang koporo(I) cyanide (CuCN) kapa palladium catalysts. Karabelo ena e lumella ho hlahisoa ha sehlopha se sebetsang sa - CN ho selikalikoe se nkhang hamonate, se thusang ho kopanya meriana e fapaneng, lik'hemik'hale tsa agrochemical le dae.

Benzoin Condensation

The benzoin condensation ke karabelo e 'ngoe ea bohlokoa moo sodium cyanide e bapalang karolo ea bohlokoa. Karabelong ena, li-aldehydes tse nkhang hamonate (aldehydes tse nang le selikalikoe se monko o monate, joalo ka benzaldehyde, C₆H₅CHO) li arabela ka boteng ba sodium cyanide e ngata ka har'a tharollo e tahang. The reaction mechanism e kenyelletsa mehato e latelang:

1. Ion ea cyanide e qala ka ho eketsa carbonyl carbon ea benzaldehyde, e sebetsang e le nucleophile. Sehlahisoa sena sa tlatsetso ke cyanohydrin - joalo ka bohareng.

2. Tefiso e mpe ho athomo ea oksijene ea cyanohydrin - joalo ka ea mahareng e ka hlasela carbonyl carbon ea molek'hule e 'ngoe ea benzaldehyde.

3. Ka mor'a letoto la mehato ea ho fetisetsa proton le ho felisoa ha ion ea cyanide, benzoin (α - hydroxy - ketone) e thehoa.

The benzoin condensation e fana ka mokhoa oa ho theha setlamo se secha sa carbon - carbon pakeng tsa limolek'hule tse peli tsa aldehyde, tse bohlokoa ho kopantseng limolek'hule tse rarahaneng tsa organic. Le hoja lilemong tsa morao tjena, ho entsoe boiteko ba ho nkela sodium cyanide sebaka ka li-catalysts tse seng kotsi ho tikoloho tse kang letsoai la thiazolium kapa vithamine B₁, mokhoa oa setso o sebelisang sodium cyanide o ntse o sebetsa maemong a mang.

Lits'ebetso tsa Keketso ho Metsoako e sa Unsaturated

Sodium cyanide e ka boela ea nka karolo ho tlatselletsang karabelo ho metsoako ea unsaturated. Ka mohlala, ka pel'a mokelikeli, e ka eketsa α,β - metsoako ea carbonyl e sa tsitsang (e kang acrolein, CH₂=CHCHO). Boitšoaro bona bo latela mokhoa oa tlatsetso oa mofuta oa Michael, moo ion ea cyanide e hlaselang β - carbon ea motsoako oa α,β - unsaturated carbonyl. Boitšoaro bona bo ka sebelisoa ho hlahisa sehlopha sa cyanomethyl (-CH₂CN) ho tsamaiso ea unsaturated, e ka fetoloang ho feta lihlopha tse ling tse sebetsang. Mohlala, sehlahisoa se hlahisoang se ka tšeloa ka hydrolyzed ho theha asiti ea carboxylic kapa ea fokotsoa ho theha amine.

Mehopolo ea Ts'ireletso

Joalokaha ho boletsoe pejana, sodium cyanide e chefo haholo. Ho hema, ho ja, kapa ho kopana le letlalo le sodium cyanide ho ka bolaea. E kopana le asiti ho hlahisa hydrogen cyanide (HCN), khase e chefo haholo. Ha u sebetsana le sodium cyanide, mehato e latelang ea polokeho e tlameha ho lateloa ka thata:

1. Sebelisa ka har'a mosi o kenang moea hantle ho thibela khase e chefo.

2. Apara lisebelisoa tse loketseng tsa ho itšireletsa, ho kenyeletsoa liatlana, likhalase le jase ea lab. Maemong a mang, ho ka 'na ha hlokahala mochine o phefumolohang.

3. Boloka sodium cyanide ka sejaneng se sireletsehileng, se ngotsoeng hole le li-acids le lik'hemik'hale tse ling tse sebetsang.

4. E-ba le meralo le lisebelisoa tse loketseng tsa ho arabela maemong a tšohanyetso haeba ho ka tšolloa kapa ho hlaha likotsi.

fihlela qeto e

Sodium cyanide ke reagent e feto-fetohang le ea bohlokoa ho organic synthesis. E etsa hore ho thehoe lihlopha tse fapaneng tsa bohlokoa tse sebetsang joalo ka li-amino acid, nitriles, le α - hydroxy - ketones, 'me e nka karolo liketsong tsa bohlokoa tsa khabone - carbon bond - ho theha. Ho sa tsotellehe chefo ea eona, ha e sebetsoa ka tlhokomelo e feteletseng le ho latela melao ea tšireletso, e ntse e tsoela pele ho ba sesebelisoa sa bohlokoa ka har'a lisebelisoa tsa k'hemistri ea maiketsetso bakeng sa ho lokisetsa mefuta e mengata ea metsoako ea tlhaho, ho tloha ho meriana ho ea ho lik'hemik'hale tse ntle. Leha ho le joalo, boiteko bo tsoelang pele ba lipatlisiso bo tsepamisitse maikutlo ho ntlafatseng mekhoa e meng, e sireletsehileng ea ho finyella lipakane tse tšoanang tsa maiketsetso.