Sciencemadness Discussion Board

Nitrating toluene with KNO3

thebolter - 27-12-2013 at 17:43

I was wondering if it was possible to nitrate toluene with potassium nitrate instead of nitric acid.

My previous attempt resulted in a brown liquid which did not turn yellow. Toluene was slowly added to a stirred, over saturated solution of concentrated sulfuric acid and potassium nitrate at 20-30C.

Anyone ever try this before?

Zyklon-A - 27-12-2013 at 18:15

I'm quite sure if it is possible, everybody would do it/know about it.

Bot0nist - 27-12-2013 at 21:01

Yes, conc. sulfuric acid and KNO<sub>3</sub> will nitrate toluene. Mostly to the di nitrate. Some TNT likely results if some mild reflux is applied. Better to try the nitration in steps, then worry about seperation of the lower nitrated products and other crap. Including the potassium.

Oh, and dont use a suspension. Make a conentrated solution of the nitrate salt in the acid. Use gentle heat and stirring. Make sure the nitrate salt is very dry and fine. Try anhydrous sodium nitrate for better results.

Remember these nitrations create NOxious gasses and the products present a health risk. Skin contact is to be avoided.

Also check the physical data on MNT, DNT, and TNT, and mixes there of.

[Edited on 28-12-2013 by Bot0nist]

thebolter - 27-12-2013 at 22:23

I should have mentioned that my desired product is MNT.

Also, shouldn't heating be avoided to avert explosions?

Lambda-Eyde - 27-12-2013 at 23:25

Your toluene likely contains thiophene which results in a brown/black mess when treated with conc. sulfuric acid. I ran into the same problem a while back: http://www.sciencemadness.org/talk/viewthread.php?tid=17783

Quote: Originally posted by Bot0nist  
Mostly to the di nitrate. Some TNT likely results if some mild reflux is applied.

I was under the impression that TNT required oleum?

Bot0nist - 28-12-2013 at 05:36

Oleum and conc. nitric acid is the best way to get TNT. Some can be formed with conc. sulfuric, and anhydrous nitrate salt or strong nitric acid if a long enough reaction is carried out at the right temps. I have seen this on test tube scales, and quicksilver discussed it on many occasions, IIRC.

Elevated temps are needed. This isnt nitroglycerin, an ester. Its an aromatic nitration. Heat is required

[Edited on 28-12-2013 by Bot0nist]

Turner - 28-12-2013 at 08:49

Bot0nist, you always push your "UTFE" stuff, but could you post a link or a reference to the nitration from DNT to TNT w/out the use of Oleum but using harsher conditions? (more heat, more sulfuric acid, etc.)

I searched plenty, I've read the whole 8 page thread on TNT.

Turner - 28-12-2013 at 08:59

Does "Klean-Strip" Toluene contain thiophene?

Bot0nist - 28-12-2013 at 14:54

Turner, you have me at a loss. I searched a bit and cant locate what I know I have read and attempted. In the next two weeks I will try to recreate the experiance and post my results, as I have no notes. I can measure purity roughly with a rigged melting point apperatus and physical properties. I lack a few reagents and liquidity at the moment. Will update.

[Edited on 28-12-2013 by Bot0nist]