Kugwiritsa Ntchito Kosiyanasiyana kwa Sodium Cyanide mu Organic Synthesis

Introduction

Sodium cyanide (NaCN), yokhala ndi formula yamankhwala NaCN, ndi crystalline yolimba yoyera kapena ufa womwe umasungunuka kwambiri m'madzi ndipo umakhala ndi fungo losamveka, lowawa la amondi. Chifukwa cha reactivity mkulu, wapeza ntchito kwambiri mu osiyanasiyana organic synthesis zochita. Komabe, m’pofunika kuzindikira zimenezo sodium cyanide ndi poizoni kwambiri ndipo iyenera kugwiridwa mosamala kwambiri komanso motsatira ndondomeko zachitetezo. Nkhaniyi ikufotokoza ntchito zosiyanasiyana za Sodium Cyanide mu organic synthesis.

Mapulogalamu mu Organic Synthesis

Strecker Reaction

Chimodzi mwazodziwika bwino ntchito za Sodium cyanide mu organic synthesis ali mu Strecker reaction. Izi ndi njira yamphamvu yopangira ma α - amino acid. Mu Strecker reaction, aldehyde kapena ketone imakhudzidwa ndi ammonium chloride (NH₄Cl) ndi sodium cyanide. General reaction mechanism ndi motere:

1. Choyamba, aldehyde kapena ketone imakhudzidwa ndi ammonia (opangidwa mu-situ kuchokera ku ammonium chloride) kupanga imamine. Gulu la carbonyl la aldehyde kapena ketone ndilopangidwa ndi protonated, ndikupangitsa kuti likhale la electrophilic. Kenako, ammonia imaukira mpweya wa protonated carbonyl, wotsatiridwa ndi deprotonation kupanga imane.

2. Kenako, cyanide ion (CN⁻) yochokera ku sodium cyanide imagwira ntchito ngati nucleophile ndipo imalimbana ndi carbon carbon. Izi zimapanga α - amino nitrile wapakatikati.

3. Pomaliza, hydrolysis ya α - amino nitrile pansi pa acidic kapena mikhalidwe yoyambira imatulutsa α - amino acid yofananira.

The Strecker reaction imapereka njira yowongoka yodziwitsira gulu la amino ndi gulu la carboxyl (pambuyo pa hydrolysis ya nitrile) pa atomu imodzi ya kaboni, yomwe ndiyofunikira pakuphatikizika kwa ma amino acid, zomanga zamapuloteni. Mwachitsanzo, pamene formaldehyde (HCHO) imachita ndi ammonium chloride ndi sodium cyanide, yotsatiridwa ndi hydrolysis, glycine (NH₂CH₂COOH), amino acid yosavuta, ingapezeke.

Kukonzekera kwa Nitriles

Sodium cyanide imagwiritsidwa ntchito popanga nitriles. M'malo mwake, alkyl halides (monga methyl bromide, CH₃Br) amachitira ndi sodium cyanide mu polar aprotic solvent ngati dimethyl sulfoxide (DMSO) kapena acetone. Zomwe zimachitika zimapitilira njira ya SN2, pomwe cyanide ion imaukira atomu ya kaboni yolumikizidwa ndi halogen. Atomu ya halogen imachotsedwa, ndipo alkyl nitrile imapangidwa. Mwachitsanzo:

CH₃Br + NaCN → CH₃CN + NaBr

Aryl nitriles amathanso kupangidwa pogwiritsa ntchito sodium cyanide nthawi zina. Mwachitsanzo, pakusintha kwina - zitsulo - zochititsa chidwi, aryl halides amatha kuchitapo kanthu ndi sodium cyanide pamaso pa chothandizira ngati copper(I) cyanide (CuCN) kapena palladium catalysts. Izi zimapangitsa kuti gulu la - CN lizigwira ntchito pa mphete yonunkhira, yomwe imakhala yothandiza popanga mankhwala osiyanasiyana, agrochemicals, ndi utoto.

Benzoin Condensation

Benzoin condensation ndi njira ina yofunika pomwe sodium cyanide imagwira ntchito yofunika kwambiri. Pochita izi, ma aldehydes onunkhira (aldehydes okhala ndi mphete yonunkhira, monga benzaldehyde, C₆H₅CHO) amachita pamaso pa kuchuluka kwa sodium cyanide mu njira ya mowa. The reaction mechanism imakhala ndi izi:

1. Iyoni ya cyanide poyamba imawonjezera carbonyl carbon ya benzaldehyde, yomwe imakhala ngati nucleophile. Zowonjezera izi ndi cyanohydrin - ngati zapakatikati.

2. Mphamvu yoyipa pa atomu ya okosijeni ya cyanohydrin - ngati yapakatikati imatha kuwononga kaboni wa carbonyl wa molekyulu ya benzaldehyde.

3. Pambuyo pa masitepe angapo otengera pulotoni ndikuchotsa cyanide ion, benzoin (α-hydroxy-ketone) imapangidwa.

Benzoin condensation imapereka njira yopangira mgwirizano watsopano wa carbon - carbon pakati pa mamolekyu awiri a aldehyde, omwe ndi ofunika kwambiri popanga mamolekyu ovuta kwambiri. Ngakhale kuti m'zaka zaposachedwa, zoyesayesa zakhala zikugwiritsidwa ntchito m'malo mwa sodium cyanide ndi zinthu zowononga zachilengedwe monga mchere wa thiazolium kapena vitamini B₁, njira yachikhalidwe yogwiritsira ntchito sodium cyanide ikadali yofunikira nthawi zina.

Zowonjezera Zomwe Zimagwira Pamagulu Opanda Unsaturated

Sodium cyanide amathanso kutenga nawo mbali pazowonjezera pazamankhwala osapangidwa ndi unsaturated. Mwachitsanzo, pamaso pa chothandizira, amatha kuwonjezera ku α,β - unsaturated carbonyl compounds (monga acrolein, CH₂=CHCHO). Zomwe zimatsatira zimatsata njira yowonjezeretsa ya Michael, pomwe ayoni ya cyanide amaukira β - carbon ya α,β - unsaturated carbonyl compound. Izi zitha kugwiritsidwa ntchito poyambitsa gulu la cyanomethyl (-CH₂CN) paunsaturated system, yomwe imatha kusinthidwa kukhala magulu ena ogwira ntchito. Mwachitsanzo, zotsatira zake zimatha kupangidwa ndi hydrolyzed kupanga carboxylic acid kapena kuchepetsedwa kupanga amine.

Zilingaliro Za Chitetezo

Monga tanenera kale, sodium cyanide ndi poizoni kwambiri. Kukoka mpweya, kumeza, kapena kukhudzana ndi khungu ndi sodium cyanide kumatha kupha. Imalimbana ndi zidulo kupanga hydrogen cyanide (HCN), mpweya wapoizoni kwambiri. Pogwira sodium cyanide, njira zotsatirazi zotetezera ziyenera kutsatiridwa:

1. Gwiritsirani ntchito muvuvu lokhala ndi mpweya wabwino kuti mupewe kuchulukana kwa mpweya wapoizoni.

2. Valani zida zodzitetezera zoyenera, kuphatikiza magolovesi, magalasi, ndi jasi la labu. Nthawi zina, pangafunike makina opumira.

3. Sungani sodium cyanide mu chidebe chotetezedwa, cholembedwa kutali ndi zidulo ndi mankhwala ena ogwira ntchito.

4. Khalani ndi mapulani ndi zida zoyenera zothandizira pakagwa ngozi.

Kutsiliza

Sodium cyanide ndi reagent yosunthika komanso yofunikira mu kaphatikizidwe ka organic. Zimathandizira kupanga magulu osiyanasiyana ofunikira monga ma amino acid, nitriles, ndi α - hydroxy - ketones, ndipo amatenga nawo gawo pazofunikira za carbon - carbon bond - kupanga. Ngakhale kuti ali ndi poizoni, akagwiritsidwa ntchito mosamala kwambiri komanso motsatira malamulo a chitetezo, akupitirizabe kukhala chida chofunika kwambiri pakupanga zida za mankhwala opangira mankhwala opangira mankhwala osiyanasiyana, kuchokera ku mankhwala kupita ku mankhwala abwino. Komabe, zoyesayesa zopitilira kafukufuku zikuyang'ana pakupanga njira zina, zotetezeka kuti akwaniritse zolinga zopangira zomwezo.