[Strike]

Hello,

I'm having a little difficultly trying to figure out this question. It's a simple acyl chloride reacting with an amine but the is only 1 equivalent of each (Meaning there's no excess of the amine). I understand that I need excess amine for the reaction to complete.



My guess was the amine attacks and the Chloride leaves but the hydrogen remains on the nitrogen because a second amine group can't pick it up.

Prediction:

The chloride could come back and pick up the hydrogen again, but then why would I need an excess of the amine if I could do that? Apparently there are 3 organic compounds in the mixture as the final answer but I can't come up with more than 1.

[Telamond]

Do you get to memorize a lot of pKa values of organic molecules? There's a lot of things that can be protonated and deprotonated in your mixtures making a whole variety (2) of organic salts.

[Strike]

Only a few pKa's like alcohol/water is ~16-18, carboxylic acid is ~4, amine is ~35 and alkanes are ~50.

But in our answers we usually omit stuff like Cl-.

[qw098]

Well, you know Cl- is a base because HCl is an acid. So the Cl- can pick up the H to form HCl. As you know, HCl is a strong acid, so forming by-products such as these in a chemical reactions isn't always such a great idea. That is why in some reactions we will use excess amine so it is the amine that grabs the H and not the Cl-!

Hope this clears some things up.

[fledarmus]

You have plenty of amine when the reaction starts - what happens if the first amine attaches to the carbonyl and a chloride ion is eliminated? What would it form?

What would be left at the end of the reaction?

Is there a workup after the reaction is complete, or are you just trying to predict what is present when the reaction ends?

[Strike]

You have plenty of amine when the reaction starts - what happens if the first amine attaches to the carbonyl and a chloride ion is eliminated? What would it form?

What would be left at the end of the reaction?

Is there a workup after the reaction is complete, or are you just trying to predict what is present when the reaction ends?

Even with 1 equivalent of each starting material there's enough amine?

When the amine attacks and the chloride leaves, wouldn't that be my current predictions?

I also don't think there's a workup, just what happens when the reaction is complete.

[fledarmus]

In a reaction, you won't have every single molecule of starting material A reacting with every single molecule of starting material B all at the same time. It takes time for all of the molecules in the beaker to run into each other, bouncing off all the solvent molecules and everything else in the flask.

So suppose, right at the beginning of your reaction, you throw your amine and acid chloride together and start stirring. A molecule of amine runs into a molecule of acid chloride and adds to it. A chloride ion is released. What will happen to it? Remember, your beaker right now contains your amine, your acid chloride, your solvent, one molecule of product, and one chloride ion...

[AWK]

http://en.wikipedia.org/wiki/Schotten%E2%80%93Baumann_reaction