In this video we'll prepare potassium thalimide, the reagent we plan to use in a future video.

You might be put off making this from the literature because of the huge quantities of Fe all involved, but we'll show that there's a more efficient way.

To start we weighed out 17.5 grams of thalimide. Check out our other video for details of how to make this yourself from phthalic anhydride.

We're going to react the thalimide with potassium hydroxide, so we've added potassium hydroxide.

We've weighed out the 1.2 times molar excess of solid potassium hydroxide, which is 8 grams.

After our ethyl chloroacetate preparation we have a very funky looking stirred bar and it seems as though the discoloration is permanent.

We'll test it in this reaction and see if it really is permanently dyed black.

We've got the 200 ml beaker set up with the stirred bar in on a heating mantle.

And here's one more.

100 ml of ethanol.

We've also tried using slightly less ethanol and the reaction seemed to work just as well.

Now we add the potassium hydroxide to the ethanol.

And we crank up the stirring to get it to dissolve.

This takes a couple of minutes.

And the solution will heat up a little bit in the process.

We've covered the top of the beaker with film just to stop any splashes because alcoholic potassium hydroxide is quite corrosive and we don't want this all over the place.

While we're dissolving we've switched on some heat and we're going to get the mixture up to nearly boiling point.

The potassium hydroxide has now all dissolved.

And you can now see from the slight bubbling at the bottom that we're close to boiling point.

The temperature is around 75 degrees C.

So now we're just going to start adding the thalimide to the stirred potassium hydroxide solution.

A little at a time to begin with just in case the mixture decides to boil.

There's a few bubbles coming off but nothing too vigorous.

We keep on adding the thalimide until it's all in.

So it forms a suspension in the liquid.

We're now all in and you can see a very faint yellow color developing in the mixture.

We've covered the beaker with wrap again.

And we're just going to stir and keep at around 70 degrees C for the next hour.

The suspension first becomes thick and then more fluid as time goes on.

At the end of an hour it looks like this.

The texture of the solid in suspension has changed and is now a very fine powder rather than the fluffy thalimide crystals.

We allowed the mixture to cool down to room temperature and then set up for vacuum filtration.

We washed the beaker and the precipitate with a small amount of absolute ethanol.

Then let the powder dry on the pump.

This took a bit of stirring and mixing around as the solid seemed to form a gel with the ethanol.

But eventually we got it pretty dry.

Here's the product.

23 grams of potassium thalimide which is very slightly damp with ethanol.

But it's basically a quantitative yield from the starting thalimide.

It's a fine powder and with an interesting very faint yellow almost green tint to it.

Let's check there's no remaining thalimide in the product.

Here's a small beaker of water.

And some potassium thalimide product.

It dissolves forming a perfectly clear solution.

Thalimide on the other hand is pretty much insoluble in cold water.

Let's add a few drops of dilute sulfuric acid to this solution.

The hydrogen ions from the sulfuric acid reattach to the nitrogen in the molecule,

reforming thalimide again as an insoluble precipitate.

You normally would think of a nitrogen in an organic molecule acting as a base.

But in the case of thalimide it acts as an acid, being able to donate a hydrogen ion rather than receiving one.

We'll leave it to you to work out why.

Potassium thalimide can be used on the synthesis of primary amines.

Look out for this in a future video.