Sciencemadness Discussion Board

destruction of nitrobenzene

Jor - 10-5-2009 at 14:06

I have some nitrobenzene. I made this myself.
I have decided that I do not want to do the aniline synthesis (I have aniline), so i do not want to keep all (12mL) nitrobenzene. I have seen a few applications like preparing some dyes, and preparing the intermediate for dyes: benzidine. Unfortunately, benzidine is highly carcinogenic and it is one of the few substances, except for explosives and drugs, wich is forbidden to make. We have a small list here, wich makes the use, production, etc of the following substances illegal: benzidine, 2-naphtylamine, 4-aminodifenyl, 4-nitrodifenyl and 1,3-propansultone, all extremely potent carcinogens, especially for the latter wich is not even possible for research laboratories to use, law states 'no exceptions'.

So I see no use for it. It smells good so I'll keep a ml or so. The rest I will dispose off, it's not very pure anyways. I would like to simply 'destroy' it, without explosions (piranha)., Would H2O2/FeSO4 work (Fenton's reagent)? Or a boiling solution of KMnO4 in dilute sulfuric acid?
Any ideas?

kclo4 - 10-5-2009 at 14:19

Would it be practical for you to pour it in a fire? Perhaps soak a junk cloth in it and light it on fire?
It is probably fairly resistant to KMnO4. I think KMnO4 can oxidize aniline to nitrobenzene.

Magpie - 10-5-2009 at 16:49

I recommend you make aniline, and then from that, diazotize and make phenol. By doing this you will experience a great deal of practical organic chemistry. Then when you get to university level organic chemistry you can just coast while others are sweating things out. ;)

woelen - 11-5-2009 at 10:43

Jor, mix it with 30 ml or so of a highly flammable organic solvent (wasbenzine, aceton), soak a few paper tissues with the liquid and put the whole mix on fire. Beware, however, that this little fire will be fairly slow and sooty. The ashes can go with ordinary household waste.

[Edited on 11-5-09 by woelen]

Eclectic - 11-5-2009 at 11:34

I'm fairly sure it's been used as a "performance" additive for gasoline.

Jor - 11-5-2009 at 14:22

Magpie do not like to organic chemistry in my home lab, as in my experience sofar, there is too much waste produced. But I might give it a try later. However, I have some (250ml acros) aniline, so I can do the phenol synthesis someday.

Woelen, I have tried your method and it works well. I had the idea of burning before but was too afraid of an uncontrollable fire. I can't burn outside, as it would draw too much attention.
But with paper tissue it works great. I took 1,5mL of crude nitrobenzene and 3mL of ethanol, put the mixture in a porcelain cruucible, added some tissue (wich absorbed it) and lighted it. It burns slowly, albeit for a long time. It produces lots of black smoke, and because I feared these may contains considerable amounts of PAHs, I did this in my fume hood. When burning benzene, you get a LOT of black smoke.

DJF90 - 11-5-2009 at 14:45

Jor: magpie's point was not just about going from aniline to phenol, but from nitrobenzene to aniline to phenol. You'll learn a lot just doing one of the steps, but not as much as you'll learn doing both (stating the obvious here aren't I...)

I can't say I agree with what you are doing... You are WASTING a chemical that isn't particularly easy to come by for most amatuers, and this is made even worse because you have such a small amount (12ml) that keeping it hardly constitutes an additional hazard!

Ozone - 11-5-2009 at 16:27

Only 12.5mL?

Ummm. I suppose I would just pitch it onto some hot concrete on a sunny day. *poof*.

O3

benzylchloride1 - 11-5-2009 at 19:22

I would reduce the nitrobenzene to aniline, and form bromobenzene via the Sandmeyer reaction. The bromobenzene can be converted into the Grignard reagent. The Grignard reagent could be reacted with a multitude of different metal chlorides to produce interesting organometallic compounds. Tetraphenyl tin, lead, silicon and others. Also the Grignard reagent could be reacted with methyl benzoate to produce triphenyl methanol. Have fun, nitrobenzene is a very useful compound. Also nitrobenzene can be reduced to azobenzene with zinc and sodium hydroxide. The azobenzene has a reddish-orange color and exhibits cis and trans forms that can be isolated via column chromatography, see Vogals Textbook.

Jor - 12-5-2009 at 00:23

Quote: Originally posted by DJF90  
Jor: magpie's point was not just about going from aniline to phenol, but from nitrobenzene to aniline to phenol. You'll learn a lot just doing one of the steps, but not as much as you'll learn doing both (stating the obvious here aren't I...)

I can't say I agree with what you are doing... You are WASTING a chemical that isn't particularly easy to come by for most amatuers, and this is made even worse because you have such a small amount (12ml) that keeping it hardly constitutes an additional hazard!


The thing is with nitrobenzene, is that is a has a smell wich is very easily detected. It stays everwhere, just to indicate, the water bath used for heating the nitrating mixture/benzene was washed a few times with water, and put in my cabinet. After 1 hour there was still nitrobenzene smell coming from it. Also during the synthesis, even with fume hood, it was everywhere (probably coming from the exit of the hood). The smell is nice, but gets nasty after breathing it too much, and now I hate it. Besides it is very toxic and a possible mild carcinogen, wich is absorbed by the skin. :(
And why would I keep something I don't have uses for? For me it's not valuable, because if I really want I can make more from my benzene (wich idecided to keep) or just buy it (around 20 EUR per liter). My interest in organic is not as great compared to yours, especially in home setting. I'm much more focussed on inorganic synthesis, wich i do a lot. Recently I prepared [Co(NH3)H2O]2(C2O4)3.4H2O , that's what i really like doing.
However, the azobenzene synthesis got me interested. I like dyes a lot. Can you give me a procedure for the synthesis of azobenzen. I have zinc shavings, no powder, but it should work I think.
I will certainly not do Grignards at home (fire hazard). Sandmeyer synthesis are fun I must admit, I have done it once (synthesis of p-chlorotoluene from p-toluidine,). That's why I bought my aniline, I wanted to do soem Sandmeyer synthesis.

I'm sorry DJF90, it might look like a waste to you but getting chemicals here is quite easy, so it doesn't feel like a waste here. Therefore, I tend to remove chemicals wich I don't use anymore and see no future uses. Some examples of chemicals wich i am going to remove soon is calcinated PbO (they never told me it was, doesnt react with acids!), KClO4, and a few more.
This way I prevent a build up of too much chems.

[Edited on 12-5-2009 by Jor]

DJF90 - 12-5-2009 at 01:37

Azobenzene synthesis is in vogel's third edition IIRC; you'll find it in the SM library

[Edited on 12-5-2009 by DJF90]

Ozone - 12-5-2009 at 16:41

The heat and the sun will do that tiny quantity in.

A bit more is given in this discussion:

http://sciencemadness.org/talk/viewthread.php?fid=10&tid...

I did a Friedel Crafts synthesis in it once, and then ran a big column with it. Yep, it's poisonous...but smells delicious.

Cheers,

O3