Sciencemadness Discussion Board

I want some cyanide to play with!

JohnWW - 2-3-2007 at 12:08

Why do you want the stuff? Who or what do you want to kill with it?

garage chemist - 2-3-2007 at 12:26

There is a very extensive thread on this subject. I think it would be more appropriate to post your questions there.

evil_lurker - 2-3-2007 at 18:32

Probably so. However this thread dealing with conversion of the cyanide group into various salts whilst that thread involves creation of cyanide... but whatever.:)

And no, I'm not looking to kill anyone... I'm looking to making various aromatic nitiriles... hell if I was wanting to kill someone I would just add acid to the ferricyanide and be done with hit.

Bout the only thing I can find on liberating HCN is from this thread on orgsyn:

http://www.orgsyn.org/orgsyn/prep.asp?prep=cv1p0314

Unfortunately I don't have access to the reference for ferrocyanide.

DeAdFX - 2-3-2007 at 18:42

So I assume you were wanting to synthesize Acetone nitrile (methyl cyanide) out of sodium methoxide and hydrogen cyanide? If you neutralize with Sodium methoxide you will only end up with methanol and Sodium cyanide. There are other ways to acetone nitrile.

Convert acetic acid into acetamide and then dehydrate using acetic anhydride, P2O5, or some other sort of common dehydrating agent of similar power to those listed.

evil_lurker - 2-3-2007 at 19:20

No no no, I said aromatic nitriles as in phenylacetonitrile... I have a liter of acetonitrile already.

From what I've been reading, sodium (m)ethoxide is the way to go for neutralizing HCN as the salt precipitates out of solution and can be filtered off...

Nicodem - 3-3-2007 at 01:08

Quote:
Originally posted by DeAdFX
So I assume you were wanting to synthesize Acetone nitrile (methyl cyanide) out of sodium methoxide and hydrogen cyanide?

What is "Acetone nitrile"? Methyl cyanide is trivially called acetonitrile (the name is derived from the term "acetic" and has nothing to do with acetone except in that the name for acetone has similar origins).
Quote:
Originally posted by evil_lurker
No no no, I said aromatic nitriles as in phenylacetonitrile...

Phenylacetonitrile (PHCH2CN) is not an aromatic nitrile since the nitrile group is located on an aliphatic carbon.
Benzonitrile (PhCN) is a typical example of an aromatic nitrile.

garage chemist - 3-3-2007 at 05:24

Aromatic nitriles are made differently (e.g. Sandmeyer reaction) than aliphatic nitriles (e.g. from alkyl halide and NaCN). Benzyl cyanide is an aliphatic nitrile, just like benzylamine is and behaves like an aliphatic amine.

If you can simply buy ferro- or ferricyanide your best and least dangerous bet would be heating it to red heat under exclusion of air (stoppered test tube over gas burner will do fine). It decomposes into KCN, nitrogen, and iron and iron carbide. After this decomposition, KCN is the only soluble component in the resulting mixture.
Remember to not boil aqueous solutions of cyanides at normal pressure, they would hydrolyze to formates. Evaporation would have to be done under vacuum, if at all.

Boiling Ferricyanide + dilute H2SO4 will create HCN gas, but some, if not a lot, of the HCN may hydrolyze to formic acid due to the strongly acidic conditions that promote hydrolysis.
I think it would be the best procedure to boil the solution of ferricyanide under reflux while slowly dropping in the H2SO4 from a dropping funnel. That way the hydrolysis of the HCN should be kept to a minimum.
The HCN gas comes out at the top of the reflux condenser.

And please tell me, why methoxide? Do you want to waste sodium for this or what?
What you probably mean is alcoholic NaOH solution, which can be used to convert HCN into NaCN which precipitates.

If you have sodium, you can convert this to the amide with NH3 at elevated temperature and heat it with charcoal to obtain cyanide (Castner-Kellner process).

Dr. Beaker - 3-3-2007 at 06:04

If you have access to the corresponding aldehydes you can easily make nitriles. (you need I2 and amonia water (yes - the same reagents to make NI3). I used it to make 2-furanitrile from furfural and o-ethyl benzonitrile from o-ethyl benzaldehyde. for the 1st the rxn took about 5 min to complete, for the 2nd 3 hrs (sterics). high yields. cheap, and not highly poisoness reagents.

evil_lurker - 3-3-2007 at 20:26

That would be nice. Do you have a reference or name of the reaction?

Dr. Beaker - 4-3-2007 at 01:11

Talukdar, S.; Hsu, J.-L.; Chou, T.-C.; Fang, J.-M.. Direct transformation of aldehydes to nitriles using iodine in ammonia water. Tetrahedron Letters (2001), 42(6), 1103-1105