Sciencemadness Discussion Board

aromatic amine acetates to amides

Templar - 8-10-2014 at 15:19


I was wanting to know if it would be possible to convert aniline to acetanilide using glacial acetic acid and possibly a dehydrating agent like polyphosphoric acid or just reflux in a solvent with BP above that of water?

I understand ammonium acetate can be dehydrated to acetamide, but I do not have any idea if this will carry through for aromatic amides.

A synthesis I saw used methyl aniline and glacial acetic acid to form the acetate salt, then refluxed for three hours at ~120C to yield an amide. But sadly it has no references and I cannot find any mention of this anywhere.

Does anyone have an idea if this could work? It would avoid the use of acetic anhydride, messy to make and difficult to source.

[Edited on 8-10-2014 by Templar]

forgottenpassword - 9-10-2014 at 05:10

It would take you 4 hours to find out if it's true -- less time than you have spent waiting for an answer.

Haber - 9-10-2014 at 05:44

Have you read about acetylsalicylic acid as an acetylating agent?
This thread might be of interest

smaerd - 9-10-2014 at 17:16

Hmmm I could be mistaken but I think someone on this forum performed this acetylation using aspirin in an alcoholic solution at slightly elevated temperature.

Templar - 10-10-2014 at 07:23

Quote: Originally posted by forgottenpassword  
It would take you 4 hours to find out if it's true -- less time than you have spent waiting for an answer.

Thanks fp, that's a really good idea. I'll just pause all my studies and go run synthesis for ~8hrs

If you have nothing to contribute to the thread, dont post

Yes smaerd I did see that acetylation using aspirin. I thought it was very clever and would be excellent for small sub 5g quantities. I think the biggest issue would just be getting enough bulk aspirin, which isnt very prevalent at all where I am.

I'll have to just give it a whirl when I have holidays. I thought somebody might have been able to chime in saying it does or doesnt work; vogel seems to think it does which is a pretty solid thing to go on.

The question is, what happens if you put OH or carboxylic acid groups on the same phenyl group? I wonder if this would adversely effect it.

hyfalcon - 10-10-2014 at 07:35

Go to a vet that deals with horses. You can get all the bulk, pure, aspirin you need. Buy it by the pound.

CuReUS - 13-10-2014 at 08:03

maybe you should try a different route
why not do a beckmann rearrangement of an oxime to amide
if you react n -phenyl hydroxylamine with acetaldehyde and then treat that with acid you will get amide
links for making n-phenylhydroxylamine
in the above orsyn page ,go to bottom of page and see under discussion for more methods of preparation
this caught my eye-the oxidation of anilinomagnesium bromide with an ether solution of hydrogen peroxide.-i could not find the exact reference but found this

all the best:)

[Edited on 13-10-2014 by CuReUS]

Templar - 15-10-2014 at 01:35

15g of n anthranilic acid was combined with 150ml of GAA and refluxed for four hours. Anthranilic acid eventually fully dissolved within an hour, and the whole solution went from clear to opaque light orange/yellow.

The mixture was flushed with 150ml of cold water at the 4 hour mark and left to cool. No crystals were observed even after sitting in the refrigerator for a couple of hours.

I dont think this works for anthranilic acid.

Interesting point there cureus, might well look into that. Cheers

CuReUS - 15-10-2014 at 08:02

anthranilic acid ,did you make it or you bought it
i thought it was a watched chemical:o

also ,i think acetanilide can be rearranged to give anthranilic acid but not the reverse.

could you please tell the name of the reaction that you have done i.e anthranilic acid-->(glacial acetic acid/reflux.4h) acetanilide