Good for nitration or not?

[SantasL.Helper]

Is it able to judge from a molecule's structure if a substance is nitrateable or not or if a substance can be turned into a nitrate ester? If so, how?

Other question, can a mixture of nitric acid and hydrochloric acid (aqua regia) be used for nitration?

[Dave Angel]

I'd recommend getting a good organic chemistry textbook and reading up on nitrations. The first question you ask requires quite an extensive answer. It relates, in some cases, to an aromatic ring's activation towards electrophilic substitution, depending on it's initial substituents, which also have directing effects. I'm not so sure how much nitro esters are covered in such texts, as I have never really looked into them.

I'm pretty sure aqua regia is not viable in most nitrations. Aromatic substitutions rely on formation of a nitronium ion, which is facilitated by concentrated sulphuric acid, but not hydrochloric acid. As hydrochloric acid will be at maximum 40% at stp, adding some to 95%+ nitric acid (for example) will actually be diluting your nitric with 60% water! Therefore this is not suitable for RDX synthesis.

There are some nitration procedures which can be carried out with hydrochloric acid. HDN can be made with HCl and a nitrate salt but the yields are poor compared to using say 70% nitric.

[Marvin]

In general, aromatic rings can be nitrated, alcohols can be esterified. What works well is a little bit of inspired guesswork and a lot of trial and error of the lost limbs variety. Looking back on other peoples experiments is the most valuable thing an explosives chemist can do. Attempting to make predictions based on the chemistry is something for qualified/experienced chemists only, as at best it only renders unsafe an experiment potentially suicidal.

In addition to the reasons Dave gave, Aqua Regia is destructivly oxidising with extremly toxic by products.

[SantasL.Helper]

Yea, i already have 2 organic chemistry textbooks but neither of em cover very detailed info about nitration... anyway, thanks guys...

[T_Pyro]

Another interesting method of nitration without using nitrating mix is to use an alkaline solution of nitromethane. The hydrogen atoms in nitromethane are quite acidic, and easily abstracted by hydroxyl ions from a strong base (KOH or NaOH). This gives the (CH2NO2)- anion, which can attack (among other things) the ketonic carbonyl group. 2-methyl1-nitropropan-2-ol, as well as 2-nitroethanol can be prepared in this manner.

[FUTI]

Dave is right about this. Do not try to nitrate alcohol with this, it's bad idea - not only the balance is that matters...but the fingers too...oxidative acid mixture + alcohol...nope I wouldn't do that. As for aromatic compounds...due to dilution it would do only on "activated" aromatics, and even then it will also chlorinate it in process (aqua regia contain also a chlorine and NCl3, not just starting acids) so you get fu*ked up no good product.
Let me clear something nitric acid is and can be used for esterification as in NG and similar explosives...but it can be used also for the oxidation of the alcohols...maybe I post something for non-chemist in education effort and for comparison, I'm little embarassed to wave with that in front of chemist :o