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Author: Subject: Preparation of cyanides
Myfanwy
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[*] posted on 28-10-2009 at 10:25


Hi im new in this forum and this is my first post :P

I also made Hydrogen cyanide by destilling K4[Fe(CN)6] with 25% Sulfuric Acid.
I condensed the Fumes with Ice-cold Water.My HCN was a little bit yellow, because of polymerization.
You can`t store it, if you don`t have H3PO4.

Now i want to make sodium cyanide in a different way.

Will Ammonium formiate and a ethanolic solution of sodium hydroxide will give some sodium cyanide?!
HCOONH4 + NaOH -> NaCN + 3H2O?

one weak ago i attemped to make Formamide by the decomposition of Ammonium formiate, but it mostly sublimes and decomposes to Ammonia and Carbon monoxide

Next weak i try ethyl formiate and ammonia! Ethyl formiate you get from sodium bisulfate and sodium formiate in ethanol.

If anyone have Urea, you can heat this with Formic Acid to become some Formamide.
This will produce a large amount of ammonia.
------------------------------------------------------------------------------

Ammonium formiate and sodium hydroxide won`t work to form cyanide.
It will form Ammonia, water and sodium formiate...

[Edited on 28-10-2009 by Myfanwy]
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JohnWW
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[*] posted on 29-10-2009 at 20:20


You were lucky to live to tell the tale!
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[*] posted on 4-12-2009 at 11:37


i was wondering if is posible to obtain liquid Hydrogen cyanide throught pigment PRUSSIAN BLUE ? (its easy to obtain pigment without any restriction) :p

and heat PRUSSIAN BLUE pigment up to 300 degress C or applying strong conc. H2SO4 on prussian blue and then fractional distillete it to obtain liquid HCN ?

what do you think ?
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Picric-A
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[*] posted on 4-12-2009 at 12:08


It scares me when new members ask questions regarding the preperation of 'liquid hydrogen cyanide'....
not to mention asking stupid questions which could be answered in about 30secs by google...
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[*] posted on 15-12-2009 at 07:41


Recently i have discovered info on other possible way to cyanides through weakly studied substance called Formaldoxime. Reference states the following:

"Our knowledge of this compound, the first member of the series of paraffinic aldoximes, is very limited, being in fact represented only by the observations made a few years ago br Scholl (Bey., 24, 573), who found that the chief product of the interaction of formaldehydeand hydroxylamine was a white amorphous solid, which behaved as a polymeride of formaldoxime. The aldoxime itself Scholl was only able to study as a solution, obtained by heating the polymeride withcertain liquids, and as a gas obtained by heating the dry polymeride. He showed that the substance in these two forms has a molecular weight corresponding with the formula CH2=NOH, that it is a powerful reducing agent, and in its other properties behaves as an aldoxime.

The authors have obtained formaldoxime as a colourless, highly refractive liquid, boiling between 84-85C, by extracting with ether a, warm, freshly prepared mixture of aqueous formaldehyde and hydroxylamine (hydroxylamine hydrochloride with the calculated amount of sodium carbonate), and then fractionally distilling the ethereal solution. All attempts to crystallise the liquid have failed.When cooled it quickly changes into the solid polymeride, and even at the ordinary temperature it cannot be kept for long without polymerisation taking place. It has a slight curious odour, which is difficult to describe, and it burns with a livid yellow flame, producing much hydrogen cyanide, CH2NOH = H2O + HCN. A determinationof the molecular weight of the liquid by Raoult's method,using acetic acid as the solvent, gave a result corresponding with the formula CH2=NOH.

Formaldoxime undergoes quantitative hydrolysis into formaldehyde and hydroxylamine when it is digested with cold concentrated hydrochloric acid, but when it is heated with dilute acids, formic acid and ammonia are also produced, owing to the previous conversion of some of the aldoxime into formamide, HCONH2, a mode of isomeric change which is characteristic of these aldoxirnes. Formaldoxime readily decomposes into its nitrile (hydrogen cyanide) and water when it is heated with aqueous alkalis, or when it is acted on by acetic chloride. It forms unstable derivatives with the alkali metals ; the sodium derivative, CH2NONa, is crystalline ; it explodes when heated, and very readily loses water, becoming sodium cyanide.

When warmed with aqueous solutions of salts of silver, gold, copper, and mercury, formaldoxime acts as a powerful reducing agent. With cold aqueous copper sulphate it furnishes a dark green solution, which soon deposits crystals of a remarkable copper salt,and these, when kept, spontaneously evolve nitric oxide.

When dry hydrogen chloride is led into the well dried ethereal solution of formaldoxime, the hydrochloride separates as an amorphous solid, which, however, may be readily crystallised from its solution in a mixture of alcohol and ether. When analysed, the well defined prismatic crystals (m. p. 136C) furnished data corresponding with the formula CH2=NOH*HCl.

This remarkable salt, which can easily be obtained pure, constitutes a convenient source for the preparation of pure formaldoxime. It dissociates into the aldoxime and hydrochloric acid when it is dissolved in water, and if the solution is neutralised, pure formaldoxime may be recovered by distillation. The salt dissolves when warmed with aniline, and the formaldoxime can then be distilled from the mixture. A similar crystalline hydrobromide, CH2NOH*HBr, m. p. 120°C, have been prepared."

Full version of ref from JCS is attached to this message.

Attachment: PL8941.PDF (1.5MB)
This file has been downloaded 1121 times

[Edited on 15-12-2009 by Engager]




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Engager
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[*] posted on 15-12-2009 at 08:07


Taking to account information from post above leads to idea to produce sodium cyanide by reacting formaldehyde with hydroxylamine, adding sodium hydroxide and subsequent evaporation off water to dryness. I'm sure that process will proceed through formation of sodium formaldoximate intermediate witch will loose water on heating to form sodium cyanide:

CH2=NONa => NaCN + H2O

Seems like this is a good idea to try, but regretably currently i don't have hydrohylamine available to try this prep. Someone up to try this?

Original article by Sholl from Ber. and US Patent for production of formaldoxime trimer are attached to this message.

[Edited on 15-12-2009 by Engager]

Attachment: Ber Formaldoxime.pdf (505kB)
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Attachment: US4680394 (Method of preparing formaldoxime trimer).pdf (330kB)
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Myfanwy
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[*] posted on 9-1-2010 at 05:49


To distill HCN from ferrocyanides you must take conc. H3PO4 ,instead of dilute H2SO4.
Conc H2SO4 will produce (CN)2 and dilute will hydrolyse the HCN in the boiling water to Formamide and Ammonium formiate.

Next week i will try with 75% H3PO4 and K4[Fe(CN)6] and post the results.
3K4[Fe(CN)6] + 6H3PO4 -> 18HCN + 4K3PO4 + Fe3(PO4)2
1692,96g on the left and 1693g on the right.

Okay, i will take 22,7g K4[Fe(CN)6], 15g 75% H3PO4, and distiling the resulting 10g HCN into an solution containing 15g NaOH. Then pour alcohol 96% into the solution and filtering the appeared crystals.

Theoreticly this will result 18g of Sodium cyanide.

EDIT :
But some Dicyane will hydrolyse to form sodium oxalate, whats non soluble in Ethanol.


[Edited on 9-1-2010 by Myfanwy]
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anotheronebitesthedust
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[*] posted on 10-1-2010 at 15:38


Does anyone know of any synthesis of Sodium Cyanoborohydride without the use of HCN?

I found this website:

http://designer-drugs.com/pte/12.162.180.114/dcd/chemistry/c...
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DJF90
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[*] posted on 10-1-2010 at 16:43


*That* site gives instructions using NaCN and also the reference from which they pertain. I suggest you open your eyes!
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crazyboy
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[*] posted on 10-1-2010 at 17:36


Quote: Originally posted by DJF90  
*That* site gives instructions using NaCN and also the reference from which they pertain. I suggest you open your eyes!


All the reactions detailed in that paper which use NaCN use diborane an extremely toxic, flammable, reactive gas which is also very expensive and nearly impossible to procure.

According to Wikipedia sodium cyanoborohydride can also be made by reacting sodium borohydride and mercury cyanide. Mercury cyanide can be made by reacting Mercury(I) nitrate and potassium cyanide. This path is also quite dangerous as mercury cyanide is also extremely toxic but not as dangerous as diborane and probably easier to handle than HCN.

It's up to you, pick your poison, (literally) just be sure to have adequate safety equipment and a backup plan in case something goes wrong.




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anotheronebitesthedust
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[*] posted on 12-1-2010 at 08:50


http://en.wikipedia.org/wiki/Mercury_cyanide
Quote:

It rapidly decomposes in acid to give off hydrogen cyanide. Samples also decompose when exposed to light, becoming darker in color. It reacts vigorously with oxidizing agents; fusion with metal chlorates, perchlorates, nitrates, or nitrites can cause a violent explosion.


It also mentions that Mercury(II) cyanide is one of the most toxic poisons, and requires quite stringent safety precautions according to http://www.analytyka.com.mx/tabla%20periodica/MSDS/Hg/mercur...

500 grams of Mercury Cyanide is only $388.19 at VWR. I wonder how much Sodium Cyanoborohydride could be synthed from 500 grams of Mercury Cyanide? Not that I would ever attempt an advanced technique, since I am such a chemical newbie. Not to mention my fumehood is not quite done.

50 grams of Sodium Cyanoborohydride is listed at VWR for $123.14 Speaking of which, if anyone knows of a cheap Sodium Cyanoborohydride supplier, I'd very much appreciate a lead in the right direction. I have accounts with most of the major chemical suppliers, but many of their prices can be way overpriced. I tend to use Chinese or Indian suppliers, but the Borohydrides are classified as flammables/explosives and most of my overseas suppliers refuse to mislabel what they consider to be dangerous/flammable/explosive chemicals.

[Edited on 12-1-2010 by anotheronebitesthedust]
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anotheronebitesthedust
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[*] posted on 12-1-2010 at 10:01


Some more quotes from Wikipedia which may deter newbie chemists from attempting dangerous syntheses involving Cyanide and Cyanide salts without professional equipment or at least some experience in a qualified lab.
Quote:

Cyanide salts are among the most rapidly acting of all known poisons. Cyanide is a potent inhibitor of respiration, acting on mitochondrial cytochrome oxidase and hence blocking electron transport. This results in decreased oxidative metabolism and oxygen utilization. Lactic acidosis then occurs as a consequence of anaerobic metabolism.

Quote:

Sodium cyanide is an inorganic compound with the formula NaCN. This highly toxic colourless salt is used mainly in gold mining.

Quote:

Because the salt is derived from a weak acid, NaCN readily reverts back to HCN by hydrolysis: the moist solid emits small amounts of hydrogen cyanide, which smells like bitter almonds (not everyone can smell it—the ability thereof is due to a genetic trait[6]). Sodium cyanide reacts rapidly with strong acids to release hydrogen cyanide. This dangerous process represents a significant risk associated with cyanide salts



But of course I'm preaching to the choir aren't I? Oh well, I figure it's better to err on the side of caution.

Ahh... The beauty of copy and paste. Nowadays anyone can act like lie an experienced expert with the use of Wikipedia. lol.

[Edited on 12-1-2010 by anotheronebitesthedust]
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Myfanwy
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[*] posted on 29-1-2010 at 06:34


well i try to make sodium cyanide this weekend by passing gaseous HCN (from H3PO4 and K4[Fe(CN)6]) into a concentrated lye.

if u have a good burner, try CO(NH2)2 with K2CO3 and C.
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mario840
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[*] posted on 29-1-2010 at 06:56


tell me more men :)

did it work??? how many g KCN you made ???
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mario840
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[*] posted on 29-1-2010 at 06:57


sorry NaCN :P :)
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Myfanwy
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[*] posted on 29-1-2010 at 07:21


:D
nope i tried it not yet.
i will make it tomorrow or so...

then i`ll tell you

[Edited on 29-1-2010 by Myfanwy]
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mario840
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[*] posted on 29-1-2010 at 08:02


ok i'll wait ... i hope for tomorrow :P:) as soon as you can :P
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mario840
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[*] posted on 29-1-2010 at 08:46


i have better idea ... if you want too .... make photos by your phone and past them into word document you know what i mean like in drug forum in pdf .... "scenario" of experiment and wirte the most important thing like for example ... to 100g ferrocyanide we add hmmm 45 ml of 60% H3PO4 .... many people doing that thing and make life easy to many users ... i will be very greatfully if you do that ... and pst here like or something ... it's just idea but i bet it will be fantastic work .... then no-one ask how to make cyanide ... just a few picture of most important part of experiment that's all
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Myfanwy
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[*] posted on 29-1-2010 at 09:29


mh i make a video + photos + description with my digicam and post it on youtube, if i dont die :D :(
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mario840
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[*] posted on 29-1-2010 at 09:41


yesssssssssssssssssssssss :)

please do that , but seriously ... i don't recomend youtube .. cyanide is higly poision as you know :) and Your movie will be very quick delete .... make photo past into word file or make pdf or whatever you like :) make video and paste this into hmmmm rapidshare you know some not "invigilated" servis and give here to us link :)

ohhh i'm sure you not die ... it's not that poision as there write ... :)
make in high resolution picts :P:) and of course make photo of final substance
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mario840
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[*] posted on 29-1-2010 at 09:54


ohhh it's very good :) so post it in youtube and send link
and as I said please do that experiment as soon as you can , finally i will be know 100% working synth of cyanide :)
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Myfanwy
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[*] posted on 29-1-2010 at 10:02


jop i make it definitively tomorrow, but im a little bit scared from this shit, because im a pussäy^^

mh but i think all HCN will be bond by the lye and not released into the air.
i use a 100ml roundbottom flask and a liebig condenser for the distilling.
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S.C. Wack
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[*] posted on 29-1-2010 at 10:03


Quote: Originally posted by Myfanwy  
you can make KCN directly from potassium hydroxide and formamide.


http://moronail.net/img/1156_Its_time_to_stop_posting_lolcat...

formamide can however be

DEHYDRATED

without P2O5 with copper gauze in a tube heated to 600C or any number of catalysts in the patent and etc. literature.

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mario840
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[*] posted on 30-1-2010 at 03:41


ok do your thing and remeber making photos during the reaction in the most imporant moments ... when you add acid when destill and when crystallize from ethanol .... i'll be waiting for results ... good luck ....
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Myfanwy
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[*] posted on 30-1-2010 at 06:13


ok i done the experiment. i made 64 pictures and movies.
i got about 10g of sodium cyanide (55,6%).

the yield could be better. i think to much HCN leaved the Flask gaseous and didnt react with the Lye. I done it outside. The smell of the bitter almonds was really amazing^^love it.

now i will make the movie. i think its ready in 3 hours.




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