Talk:Nitration

Too specific

This article seems to specific in only discussing the nitration of aromatic compounds. Nitration can be performed on other molecules, such as alcohols. For example, the nitroglycerin page describes its synthesis as the nitration of glycerin.--24.16.148.75 21:15, 10 July 2006 (UTC)

• totally agree with your comment, nitration is much more than just aromatic nitration. I made a first effort to make the article more general. Thanks for your kind intervention V8rik 22:34, 10 July 2006 (UTC)

Perhaps the Aromatic nitration section could be improved slightly by mentioning activating and de-activating ring substitutents wrt selectivity?GreatMizuti 13:00, 20 July 2006 (UTC)

• • great idea, go ahead with it! V8rik 19:57, 20 July 2006 (UTC)

Heh, while I was just making a suggest I went ahead and tried my hand at doing an edit. I've discovered a few things; it's one thing to stand in front of a group of people with a whiteboard and pontificate on the subject but it's an entirely different thing to try and type out a viable explanation, no wonder so few people write textbooks, and that listing substituent groups is somewhat pointless, perhaps that section should just be ommitted in favour of a summary? Although anyone who isn't familiar with the terminology could be a bit baffled by anything less. I'm also thinking I should do a few diagrams. GreatMizuti 14:35, 21 July 2006 (UTC)

• one of the nice things in Wiki that many concepts have already been introduced, for example we already have activating group, deactivating group and the general article on electrophilic aromatic substitution so you only have to explain how these concepts affect nitration and not explain them again. Also in your edit most other concepts also have pages so you can link to them V8rik 16:13, 21 July 2006 (UTC)

I looked at those pages and noticed something about them both, they're stubs! They lack detail, accuracy (sorta) and depth! I mean, surely you can't imply that that's anything near a comprehensive list of activating/deactivating groups epecially since inductive effects are easily translated across conjugated system, oh and the absence of diagrams. Those articles are going on to my to-do list! (I need some practise using ISIS draw)GreatMizuti 12:58, 22 July 2006 (UTC)

full of errors

"Substituents such as other NO2 groups have an electron pair donor effect which deactivates the reaction"

Nitro groups are strong pi and sigma electron withdrawers. This sentence makes no sense at all. Donor should be replaced with withdrawer. Also one does not activate or deactivate a reaction, there is a mess up with the lingo too. You catalyze or retard a reaction. The author of this sentence should be familiar with the meaning of the latter word well enough.

Really? Are you sure? Here I was thinking that the use of catalysis in this example was erroneous because nitrating nitro-benzene was not the same reaction as nitrating benzene and thus we talk about activation and deactivation. As to your point of withdrawing effect vs donor effect, yes, that was an error on my part however (mercy be I am not infallible), as is indicated by the rather tidy diagram on the afore mentioned, linked page I already knew that. Thanks. Feel free to insult me in your retort, god knows I could use a laugh. :) GreatMizuti 15:55, 23 August 2006 (UTC)

"Nitration can be activated by substituents such as amino"

WRONG! Depends on the conditions. An amine (aniline) easily donates its lone pair to an electrophile (like nitronium) or and acid (nitric, sulfuric [avoid using harsh conditions for nitration of electron rich arenes], etc.) that's used for catalyzing the formation of nitronium cation. A thumb rule: amine groups NEVER activate a ring for nitration unless you play some tricks (and usually go through a non-amine intermediate [may be formed in-situ]). This holds true for other "activated" arenes, including phenols under more unlikely conditions. —The preceding unsigned comment was added by 81.213.65.144 (talk • contribs) .

These observations seem correct to me and I urge you to edit the article to reflect them. —Keenan Pepper 02:49, 23 August 2006 (UTC)

The statement was that amino groups can be activating substituents, well, I've never had to do that particular reaction either theoretically or in practise but there seems to be [|evidence a plenty] that you sir, are in error in that the statement is not wrong but simply not as anal as you would like it to be (although I'll have to give the matter further thought, my current thinking is that your line of logic forms a protonated and therefore positively charged nitrogen which is energetically less preferable than the substitution products). I honestly didn't know about amine substituents so I looked it up both in my notes and in the relevant texts and of course other wikipedia articles and there's a concensus: Amine groups can be activating groups. In fact, most references suggest that amine groups are strong activating groups.GreatMizuti 15:55, 23 August 2006 (UTC)

• interesting stuff, the nitration of aniline, checking internet resources (library closed). I think that both resources explain the confusion. I had to trim down some general explanation on activating groups and deactivating groups because these topics are already covered in the EAS page. Do we have citations on the topic of aniline nitration? V8rik 21:04, 23 August 2006 (UTC)

Amino groups most definitely activate an benzene nucleus towards nitration - the nitration of 2,4- or 2,6-dinitroaniline to 2,4,6-trinitroaniline(picramide) can be done under much milder conditions than those required for benzene or toluene. I also think the article should emphasise the difference between nitration, where a proton is replaced by NO₂, and nitrolysis, where other leaving groups (ie, COCH₃, C(CH₃)₃, Cl, Si(CH₃)₃ etc.) are replaced.

Error in the reaction scheme

The first scheme has an error in it.

I think the highest/top red arrow should be coming from the bond rather than going to the bond and ending at the oxygen. The way it looks now is suggesting it will form a double bond. — Preceding unsigned comment added by 94.214.148.76 (talk) 15:41, 29 November 2011 (UTC)

Last step

So in the last step the h2o comes and picks up the h, i dont think this is what happens, its the o-oso3h that does to form h2so4 because h2so4 was a catalyst and can't be consummed...Philoleb (talk) 21:30, 11 December 2011 (UTC)

Sulfuric acid is a strong acid and is essentially completely ionized in aqueous solution. The nitration mixture is typically a mixture of nitric acid (65 % w/w) and sulfuric acid, with no added organic solvent. --Rifleman 82 (talk) 22:27, 11 December 2011 (UTC)

ok theen would the so4 be the one that picks it up? and also when the No2 is attached to the benzene is it nitronium or nitrite Philoleb (talk) 22:31, 11 December 2011 (UTC)

btw french wikpedia shows nitration as i first said, http://fr.wikipedia.org/wiki/Nitration just look at the diagrams. Philoleb (talk) 22:34, 11 December 2011 (UTC)

The base can be sulfate, bisulfate or water. I'm not sure which one is preferred, but I don't suppose it really matters in the grand scheme of things. --Rifleman 82 (talk) 00:01, 12 December 2011 (UTC)

• I checked the scheme against Brown / Foote / Iverson / Anslyn (2010) that also shows water as the base. V8rik (talk) 21:45, 12 December 2011 (UTC)

Alternative Methods of Nitration

Is there enough research available to warrant a section devoted to the methods of nitration other than nitric acid/sulphuric acid mixtures?

Nitric acid/phosphoric acid mixtures look promising. There are also a few articles on nitrate salt/phosphoric acid mixtures.

http://jcsp.org.pk/index.php/jcsp/article/viewFile/1924/1357

http://pubs.acs.org/doi/abs/10.1021/ac60142a031

http://pubs.acs.org/doi/abs/10.1021/jo01034a063

http://www.springerlink.com/content/l736226872157485/

--SlapChopVincent (talk) 00:46, 4 June 2012 (UTC)