Sciencemadness Discussion Board

question about Amides

neo_90 - 2-8-2006 at 05:57

Hi! I've searched on the internet for some easy chem experiments, and I found that some amides are easy to make, ie Acetamide.
so, my question is:
can ammonium hydro carbonate be used instead of ammonium carbonate?
and what concentration dose the acetic acid need to be?

and one more, what other amides can be made from other carboxyl acids?

edit: spelling (;

[Edited on 2-8-2006 by neo_90]

not_important - 2-8-2006 at 09:32

yes, but using at least twice as much
as strong as possible - 99+ %

Besides ammonia, almost any primary or secondary amine could form an amide with almost any carboxylic acid, using various methods. As an exercise, you could list the combinations; the CRC handbook will give you a number of acids and amines as a starting point.,_esters,_ami...

TheBear - 2-8-2006 at 10:08

I've been thinking:

Could ethylenediamine be made in any practical way? I've searched the forum and the net but haven't found anything useful.

neo_90 - 2-8-2006 at 11:35

okey, thanks!
and thanks for the websites

is there a way to increase the concentration of acetic acid? some one said that distilling won’t work, why I don’t know. for me it looks like it would work, since it has a higher boiling temp then water.

not_important - 2-8-2006 at 12:24

The lower carboxylic acids tend to co-distill with water, even if they don't form an out and out azeotrope. As a minimum it takes a fractionating column.

What does "any practical way" mean?

neo_90 - 2-8-2006 at 12:32

okey, I can get 75% easy (without the need to buy for a specific amount of money), will that be enough? the amide is just for fun and I wont use it to anything specific

not_important - 2-8-2006 at 12:56

You are in effect dehydrating ammonium acetate to make the amide. If you start out with water around you make it that much harder.

And one problem is that you're dealing with weak acid and base, boiling solutions of such usually result in one or both of the parts boiling off as well.

Isn't there a thread that talks about making concentrate acetic acid?

As an aside, what is commonly called "ammonium carbonate" is not (NH4)2CO3, but rather the carbamate NH4OC(O)NH2 - an amide. It can do an amide exchange with the acid, or be considered a mild dehydrating agent; in either view it helps push the reaction along. Using the bicarbonate instead is much like starting with ammonium acetate, heating can dehydrate it; an excess of bicarbonate can help keep an excess of ammonia in the reaction mix, but it also supplies water. Your yields will not be very good.