acid.

First, we measured out 45 grams of solid sodium hydroxide into a beaker.

And now we've measured out 120 mils of cold water.

We're going to add the water to the sodium hydroxide and stir to form a solution.

The mixture will get hot, so caution.

Once dissolved, we need to get this chilled down to fridge temperature, so we placed into

a storage bottle.

Let it sit in the fridge for two hours to cool.

OK here we go.

Here's our starting material, 100 grams of chloroacetic acid.

Do know that this is not a very efficient reaction and to make nitromethane from chloroacetic

acid, which is quite hard to obtain, is not a very practical way to synthesize nitromethane

on any sort of scale.

Be careful with chloroacetic acid.

Has it's toxic?

Has it absorbed through the skin?

Wear gloves when handling, but you should be wearing them anyway, right?

We're going to mix the chloroacetic acid with 50 mils of water.

First we've got the chloroacetic acid in a large 600 mil beaker, and with a magnetic

stir bar.

And here's the water.

We place this in a larger container on top of a magnetic stirrer.

And now we've got about 120 grams of ice cubes.

And we add these to the chloroacetic acid in order to chill it right down.

We've also set up an ice bath in a container around the beaker using ice and cold water.

It's getting pretty chilly in there.

What we need to do now is use our cold sodium hydroxide solution we prepared to neutralize

the chloroacetic acid.

Doing this will release heat, but it's important we don't let the temperature rise too high.

Here's our chilled sodium hydroxide solution.

We add a small amount to the stirred chloroacetic acid.

The temperature increases slightly but quickly drops again.

So we add a bit more.

And there we go.

Now we're up to about 10 degrees C and most of the ice in the beaker has dissolved.

This is where we need to slow down with the addition.

It's important not to allow the mixture to go above about 20 to 25 degrees.

Towards the end of the addition we start to measure the pH of the mixture.

This is still on the acid side.

So we'll add more sodium hydroxide.

Let's see.

Let's check again.

Not strongly alkaline, but about pH 9.

This is where we want to be.

Here's our slightly alkaline sodium chloroacetate solution.

Let's get set up for the reaction.

We're going to use a liter flask.

The reaction produces some bubbles.

And if it gets too hot, they'll cause a flake.

There's a risk it will foam, so we want a flask with plenty of headroom just in case.

We've got a stopper in one of the outlets and a thermometer adapter and thermometer

in the other.

We add the sodium chloroacetate solution.

Now for our other reactant.

Reactions of sodium nitrite.

You will note that in contact with even weak acids, sodium nitrite reacts forming nitrous

acid, which is very unstable and rapidly decomposes to nitrogen oxides.

Chloroacetic acid will decompose the nitrite, hence the need to neutralize it before the

reaction using sodium hydroxide.

We're going to dissolve this in 70 ml of warm water.

.

As the salt dissolves, it will cool down, so dissolving takes a bit of stirring.

We're pretty much there.

First we've got our apparatus set up with the flask on a hot plate, and set up for simple

distillation without using the thermometer to measure the vapor temperature.

We've got a regular receiver and flask.

We're stirring the mixture slightly to get it to the right temperature.

a small stir bar and we've got a thermometer measuring the liquid

temperature in the flask. This is important as temperature control is

critical. We removed the stopper and placed a funnel in the flask neck and

now we add the sodium nitride solution.

There's no obvious change or change in temperature at this point. We left the

mixture stirring for a few minutes to react. What's happening now is the

formation of our intermediate nitroacetate compound in the solution.

Then after a few minutes we switched off the stirring and started to strongly

heat the bottom of the flask.

The procedure calls for a naked flame but

we're not too happy about flames and nitro-methane so we're using the hot

plate. The idea is to get the solution at the bottom of the flask hot. Once the

reaction kicks off, it's exothermic and should be self-sustaining but we don't

want this to get out of control. We're watching the temperature closely.

First thing we notice is a slight darkening of the solution.

To a yellow and then to an orange color and at around 55 degrees C we can see

the first tiny bubbles forming from the bottom of the flask. This is carbon

dioxide being produced as our nitroacetate decomposes. The mixture

turns more orange in color and at around 65 degrees C we can see more bubbles

forming throughout the solution.

Now at about 70 degrees and we've got some water condensing in the flask and at

about 80 degrees the bubbling increases rapidly to this point. We removed the hot

plate at this point to see if this would be self-sustaining. The reaction

increased slightly in intensity but felt very smooth with the temperature only

rising slowly.

After about 10 minutes the temperature was around 90 degrees C and we started to

get some distal bait coming over. To begin with this was slow but picked up

after a while.

The natural temperature reached a peak of about 95 degrees C at which point the

reaction mixture looked like this. We started to get two layers forming in the

receiving flask.

A slightly oily cloudy bottom layer with a faint yellow color. Once the reaction

appeared to die down slightly after about 40 minutes we bought a hot plate

back and applied gentle heat using an air gap. This got things back off to a

start and the reaction bubbled away vigorously but again without getting out

of control.

After another

16 minutes or so of gentle heating we put the flask back on the hot plate

directly and heated so that the temperature was around 100 degrees C. This

kept the mixture boiling. We dropped a sheet of indicator paper into the

reaction mixture to have a look at the pH. A byproduct of the reaction is sodium

bicarbonate and with the heat this decomposes into sodium carbonate which

is strongly alkaline.

This is supposedly the reason for the low yields encountered in this reaction as

the alkaline byproduct can decompose both the nitroacetate reactant and the

nitro marathane product. Interesting the mixture appears to be neutral or just

slightly acidic. After a few hours of distillation the layers are now much

more apparent. We kept this slow distillation going for a total of two and

half hours.

Once we collected around 150 mils of distillate we transferred this to a

separate container and then continued to distill. We collected about another 40

mils of distillate but there was no apparent oil coming off as a separate

layer so we stopped heating at this point. We did a final test of the pH of the

Here's the distillate.

About 180 ml in total with a pale yellow bottom layer.

We poured this into a separating funnel.

Then we added about 20 grams of sodium chloride salt in order to saturate the aqueous layer

and try to drive out any dissolved nitromethane.

After lots of shaking the layers separated, but the nitromethane is around the same density

as brine, so it took a while and a bit of tapping the funnel.

We then separated the bottom layer as best we could.

And then added some anhydrous calcium chloride granules.

.

We removed the bottom layer of saturated water using a pipette.

And then dried the liquid using some more calcium chloride.

Here's our product.

22 grams of nitromethane.

We could distill this for greater purity but it seems relatively pure as it is.

So we'll see how we get on with some subsequent reactions.

We'll see how we get on with some subsequent reactions.

This is a 34% yield on starting chloroacetic acid, which isn't really that bad and is about

the same as the larger scale morgescent reference that we used for the reaction.

Let's do a test to prove it's nitromethane, and combine this with a precautionary note.

Here's some solid sodium hydroxide.

Nitromethane has a special property in that it reacts extremely violently with strong

alkalis.

That was three drops.

So please don't get this anywhere near solid alkali or attempt this on a larger scale.

It could explode.

That's it.

Stay tuned to see what reactions we've got planned next.

Thank you for watching.