Kev siv ntau yam ntawm Sodium Cyanide hauv Organic Synthesis

Introduction

Sodium cyanide (NaCN), nrog rau cov tshuaj NaCN, yog cov khoom dawb crystalline lossis hmoov uas yaj tau zoo hauv dej thiab muaj ntxhiab tsw qab almond iab. Vim nws muaj zog heev, nws tau siv dav hauv ntau yam kev sib xyaw ua ke ntawm cov organic . Txawm li cas los xij, nws yog ib qho tseem ceeb uas yuav tsum nco ntsoov tias sodium cyanide muaj tshuaj lom heev thiab yuav tsum tau ua tib zoo saib xyuas thiab ua raws li cov txheej txheem kev nyab xeeb. Tsab xov xwm no tshawb nrhiav ntau yam kev siv ntawm Sodium Cyanide hauv kev sib xyaw ua ke ntawm cov organic.

Daim ntawv thov hauv Organic Synthesis

Strecker Reaction

Ib qho ntawm cov kev siv Sodium cyanide uas paub zoo tshaj plaws hauv kev tsim cov organic yog nyob rau hauv Strecker reaction. Qhov kev tshuaj tiv thaiv no yog ib txoj hauv kev muaj zog rau kev tsim cov α-amino acids. Hauv Strecker reaction, aldehyde lossis ketone reacts nrog ammonium chloride (NH₄Cl) thiab sodium cyanide. Lub tshuab tshuaj tiv thaiv dav dav yog raws li nram no:

1. Ua ntej, cov aldehyde lossis ketone reacts nrog ammonia (tsim nyob rau hauv - situ los ntawm ammonium chloride) los tsim ib qho imine. Pawg Carbon yl ntawm aldehyde lossis ketone yog protonated, ua rau nws electrophilic ntau dua. Tom qab ntawd, ammonia tawm tsam cov protonated carbonyl carbon, ua raws li deprotonation los tsim cov imine.

2. Tom ntej no, cov cyanide ion (CN⁻) los ntawm sodium cyanide ua lub nucleophile thiab tawm tsam cov imine carbon. Qhov no tsim ib qho α - amino nitrile nruab nrab.

3. Thaum kawg, hydrolysis ntawm α - amino nitrile nyob rau hauv acidic los yog yooj yim tej yam kev mob yields tus coj α - amino acid.

Cov tshuaj tiv thaiv Strecker muab txoj hauv kev ncaj qha los qhia ob pawg amino thiab pawg carboxyl (tom qab hydrolysis ntawm nitrile) mus rau ib qho atom carbon, uas yog qhov tseem ceeb rau kev sib txuas ntawm cov amino acids, lub tsev thaiv cov proteins. Piv txwv li, thaum formaldehyde (HCHO) reacts nrog ammonium chloride thiab sodium cyanide, ua raws li hydrolysis, glycine (NH₂CH₂COOH), qhov yooj yim amino acid, yuav tau.

Kev npaj ntawm Nitriles

Sodium cyanide feem ntau yog siv rau kev npaj nitriles. Hauv kev hloov pauv cov tshuaj tiv thaiv, alkyl halides (xws li methyl bromide, CH₃Br) hnov ​​​​mob nrog sodium cyanide hauv cov polar aprotic hnyav xws li dimethyl sulfoxide (DMSO) lossis acetone. Cov tshuaj tiv thaiv tshwm sim los ntawm SN2 mechanism, qhov twg cov cyanide ion tawm tsam cov pa roj carbon atom txuas rau halogen. Lub halogen atom yog hloov chaw, thiab ib qho alkyl nitrile yog tsim. Piv txwv li:

CH₃Br + NaCN → CH₃CN + NaBr

Aryl nitriles kuj tuaj yeem ua ke siv sodium cyanide hauv qee kis. Piv txwv li, hauv qee qhov kev hloov pauv - hlau - catalyzed cov tshuaj tiv thaiv, aryl halides tuaj yeem hnov ​​​​mob nrog sodium cyanide nyob rau hauv muaj cov catalyst xws li tooj liab (I) cyanide (CuCN) lossis palladium catalysts. Cov tshuaj tiv thaiv no tso cai rau kev taw qhia ntawm - CN ua haujlwm pab pawg mus rau lub nplhaib uas muaj ntxhiab, uas yog qhov tseem ceeb hauv kev sib txuas ntawm ntau yam tshuaj, agrochemicals, thiab dyes.

Benzoin Condensation yog qhov zoo

Lub benzoin condensation yog lwm qhov tseem ceeb cov tshuaj tiv thaiv uas sodium cyanide ua lub luag haujlwm tseem ceeb. Hauv cov tshuaj tiv thaiv no, cov tshuaj tsw qab aldehydes (aldehydes nrog lub nplhaib uas muaj ntxhiab, xws li benzaldehyde, C₆H₅CHO) hnov ​​​​mob nyob rau hauv lub xub ntiag ntawm ib tug catalytic npaum li cas ntawm sodium cyanide nyob rau hauv ib tug dej cawv tov. Cov tshuaj tiv thaiv mechanism muaj cov kauj ruam hauv qab no:

1. Lub cyanide ion ua ntej ntxiv rau carbonyl carbon ntawm benzaldehyde, ua raws li ib tug nucleophile. Cov khoom ntxiv no yog cyanohydrin - zoo li nruab nrab.

2. Tus nqi tsis zoo ntawm cov pa atom ntawm cyanohydrin - zoo li nruab nrab tuaj yeem tua cov carbonyl carbon ntawm lwm cov benzaldehyde molecule.

3. Tom qab ib tug series ntawm proton hloov cov kauj ruam thiab tshem tawm ntawm cyanide ion, benzoin (α - hydroxy - ketone) yog tsim.

Lub benzoin condensation muab ib txoj hauv kev los tsim cov pa roj carbon tshiab - carbon daim ntawv cog lus ntawm ob lub aldehyde molecules, uas yog qhov tseem ceeb hauv kev sib txuas ntawm ntau cov organic molecules. Txawm hais tias nyob rau hauv xyoo tas los no, tau siv zog los hloov sodium cyanide nrog ntau tus phooj ywg environmentally catalysts xws li thiazolium ntsev los yog vitamin B₁, cov txheej txheem ib txwm siv sodium cyanide tseem cuam tshuam rau qee kis.

Ntxiv Reactions rau Unsaturated Compounds

Sodium cyanide kuj tseem tuaj yeem koom nrog cov tshuaj tiv thaiv ntxiv rau cov tshuaj tsis txaus ntseeg. Piv txwv li, nyob rau hauv lub xub ntiag ntawm ib tug catalyst, nws muaj peev xwm ntxiv rau α,β - unsaturated carbonyl tebchaw (xws li acrolein, CH₂ = CCHO). Cov tshuaj tiv thaiv ua raws li Michael - hom ntxiv mechanism, qhov twg cov cyanide ion tawm tsam β - carbon ntawm α, β - unsaturated carbonyl compound. Cov tshuaj tiv thaiv no tuaj yeem siv los qhia cov pab pawg cyanomethyl (-CH₂CN) mus rau qhov tsis txaus ntseeg, uas tuaj yeem hloov pauv mus rau lwm pawg ua haujlwm. Piv txwv li, cov khoom uas tshwm sim tuaj yeem raug hydrolyzed los ua carboxylic acid los yog txo kom tsim tau cov amine.

Kev Txiav Txim Siab Kev Nyab Xeeb

Raws li tau hais ua ntej, sodium cyanide yog tshuaj lom heev. Kev nqus pa, noj, lossis kev sib cuag ntawm daim tawv nqaij nrog sodium cyanide tuaj yeem ua rau tuag taus. Nws reacts nrog acids los tsim hydrogen cyanide (HCN), ib tug heev toxic gas. Thaum tuav sodium cyanide, cov kev ntsuas kev nyab xeeb hauv qab no yuav tsum tau ua nruj me ntsis raws li:

1. Siv nyob rau hauv lub qhov dej-ventilated fume hood los tiv thaiv kev tsim ntawm cov pa phem.

2. Hnav cov cuab yeej tiv thaiv tus kheej tsim nyog, nrog rau cov hnab looj tes, tsom iav, thiab lub tsho tiv no. Qee zaum, yuav tsum muaj lub tshuab ua pa.

3. Khaws sodium cyanide nyob rau hauv ib lub thawv ruaj ntseg, sau tseg kom deb ntawm cov kua qaub thiab lwm yam tshuaj reactive.

4. Muaj cov phiaj xwm daws teeb meem thaum muaj xwm txheej ceev thiab cov cuab yeej siv nyob rau hauv qhov chaw thaum muaj kev sib tsoo lossis xwm txheej.

xaus

Sodium cyanide yog ntau yam thiab tseem ceeb reagent hauv organic synthesis. Nws ua rau muaj ntau yam tseem ceeb ua haujlwm pab pawg xws li amino acids, nitriles, thiab α - hydroxy - ketones, thiab koom nrog cov pa roj carbon tseem ceeb - carbon bond - tsim cov tshuaj tiv thaiv. Txawm hais tias nws muaj toxicity, thaum ua haujlwm nrog kev saib xyuas hnyav thiab ua raws li cov cai tswj kev nyab xeeb, nws tseem yog ib qho tseem ceeb hauv cov khoom siv hluavtaws hluavtaws rau kev npaj ntau yam ntawm cov organic tebchaw, los ntawm cov tshuaj mus rau cov tshuaj zoo. Txawm li cas los xij, kev tshawb fawb tsis tu ncua yog tsom rau kev tsim lwm txoj hauv kev, kev nyab xeeb dua kom ua tiav tib lub hom phiaj hluavtaws.