There are plenty of demonstrations of Grignard reactions on YouTube,

but in all our videos we haven't properly done one yet.

So we figured we'd do something a bit different, just for fun.

Yeah we've got some posh glassware here.

That's just because we're testing a theory out.

What happens if you use plain old ether out of the bottle,

dirty methyl iodide, and horrible old oxidized magnesium turnings?

Looks pretty good doesn't it?

We didn't even bother to dry the flask.

Got it out of the cupboard.

The magnesium is reacting with the methyl iodide in the ether to form methyl Grignard.

As we've shown in a previous video,

when it comes to methyl Grignard you can get away with quite a lot of bad practice.

Don't try this with more sensitive reagents though like benzyl halides or iodobenzene

as these require serious purity and dryness to work.

This test batch is getting towards completion now,

so let's try something you've probably not tried.

How do Grignard reagents react with water?

This isn't a very concentrated solution, but it should give us an idea.

So here's a bit of water in a small beaker.

Let's add some of the Grignard solution in ether.

There's a hissing noise and the ether is instantly boiled off with the heat generated.

And that's it.

That's a gelatinous precipitate of magnesium hydroxide remaining in the beaker.

Grignard reagents are very strong bases, and highly reactive.

The water in the beaker is now noticeably warm.

So it's a good cautionary indicator, treat these compounds with a little bit of respect and caution.

So with that in mind we're going to attempt to perform a Grignard reaction,

only with the exception of beakers we're not actually going to use any lab glassware.

An interesting challenge.

Ghetto style Grignard.

And yeah you've guessed it.

We're moving how soon so we've been drinking our way through the bottles and making rather a lot

of green pepper sauce. This is an empty bottle of brandy which we've washed out.

Look at that nice thin long neck. We'll be making the most of this later on.

Okay well we're going to need to at least make sure it's clean and as dry as we can get it.

So first of all we'll wash with a little bit of acetone.

The ant didn't make it. A little balancing act, just to get rid of as much acetone as possible.

And now we'll wash with a little bit of diethyl ether. The same as we'll use in the reaction.

Again, a balancing act to dry it. And while we're waiting for that,

let's look at our reaction ingredients.

And we're going to do this in a pretty ghetto style as well.

Here's our methyl iodide. It's been in storage for a whole year,

and it's got calcium chloride granules floating in it to keep it dry.

And there's been a small amount of decomposition into iodine, which is the yellow color.

It's dirty and nasty. Real dirty.

Oh yeah baby.

And if you think that's bad. Here's our magnesium.

These look like they've been roughly filed off a alloy sports car wheel while it was

stopped at the lights in a bad part of town at gunpoint.

In the rain. There's a lot of white colored oxide corrosion, and some black bits as well.

It's as dirty as you can get. Let's get these weighed out.

We'll use a rough kitchen scales to do this, so it's going to be rough.

First, 30g of our dirty methyl iodide.

Just under 15mL which is about right.

There's some calcium chloride particles in there as well by the looks of things.

We love it.

So now to our brandy bottle reaction vessel.

We're going to put some diethyl ether in here.

It's from a commercial bottle listed as reagent grade but we haven't dried it or done anything

special with it.

Let's see if that's good.

What does it taste like?

Do you mean, measure?

About 4 or 5 shots I reckon.

First we'll get our magnesium shavings in.

We've weighed out 10 grams of shavings.

This is about twice the theoretical amount needed, but we figure what the heck.

Awesome.

Okay so now we'll kick things off.

We'll add a little bit of the methyl iodide to the reaction bottle.

About one third added.

A shake for good luck.

And now we wait.

This is actually pretty dilute for a Grignard reaction so it might take some time before

we see anything happening.

It knows you're watching.

It's not going to do anything until you're not in the room.

So we leave it and wait.

After about 10 minutes, we see our first bubble coming off.

Something is happening, but it's slow.

So let's now get another crucial part of our apparatus set up.

Once this gets going, if it gets going, it's going to heat up and bubble.

Ether and methyl iodide are going to boil off.

So we need some sort of reflux condenser.

So we need some sort of reflux condenser.

Green yards.

Just do it.

Actually we don't know why these are in this bag, but what we've got here are some cold

gel packs.

We figure that we can assemble these, together with a couple of ice pack blocks, and make

a cooling device.

And here it is.

Held together with some tape.

There's two gel packs on either side, and then two blue ice blocks sandwiched in the

middle with a hole in the center.

beautiful hey we're going to try to turn that thin bottleneck into a DIY reflux

condenser it probably won't be very efficient but let's see what happens

back to the reaction about 20 minutes elapsed now still not much happening so

we'll add a little bit more methyl iodide

lots still left and this does it within five minutes of us adding this the

mixture suddenly turns orange and cloudy we've got lots of bubbling taking place

in one particular spot and this soon spreads and the whole lot starts to

react we'll soon find out if the condenser is any good look at that bad

boy go

pretty soon the color changes back to a milky white and we need to use a cold

water bath occasionally just to control the speed of reaction looking good time

for some more methyl iodide and immediately it kicks back off we don't

want to inhale ether or methyl iodide so time for ventilation

holy shit the cooling is actually working to some degree

we added all the methyl iodide and let it react for a whole hour after this

time the reaction had finished

still tons of magnesium in here so we're going to have to assume that we probably

lost some of the methyl iodide to пару there now let's do a final check of all methane Neighbor became an easy stopping忧 же

during the vigorous reaction so now to the next step we're going to

react our methyl Grignard with cyclohexanone so we've weighed out 10

grams of cyclohexanone which we prepared in a previous video this is half the

theoretical stoichiometric amount so hopefully will mean that the Grignard is

in excess you'd normally do this carefully in a reflux apparatus but

we're going to rock and roll and use a large beaker so in goes the

cyclohexanone and some more ether we've chilled our Grignard reagent in the

brandy bottle right down to zero degrees C the reaction is likely to be

exothermic so this will hopefully help let's rock

definitely a vigorous reaction and some yellow colored by-product being

generated okay let's stop pissing around

we'll use an ice bath for the last bit

we'll give this a stir now and make sure that everything has reacted you can

see the last traces of Grignard reagent on the bottle reacting with the air you

can also put a drop or two into a dish and evaporate the ether for fun

okay our reaction mixture is well stirred

so we're now going to work it up firstly by adding some water to destroy

any excess reagent we'll add this slowly to begin with

and now using some dilute 15% hydrochloric acid first we'll add a

couple of ice cubes as the magnesium hydroxide reacting with the acid will

give off some heat

and we've got a clear mixture of two layers and an engineering challenge how

to separate these without a separating funnel hmm a pastry piping bag

let's first check that the plastic doesn't dissolve in ether looks good to

go

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Too cool for our school.

So let's now evaporate this down and see what we get.

It's a warm day, so this goes outside for an hour.

There's clearly some iodine in here as that yellow color looks like iodine forming.

And here's what we get.

A slightly oils red liquid.

We figured we'd better first get rid of the iodine.

So we washed with a solution of sodium bisulfite.

And this got rid of most of the color, leaving us with an orange oil.

With an incredibly strong menthol and peppermint-like aroma.

Well, this is supposedly what 1-methylcyclohexanol smells like.

But it's not.

But it is supposed to be a solid at below 25 degrees C.

So we placed it in the freezer for a few days.

After only a few hours we could see crystals starting to form.

And here we are a few days later, with the white solid settled.

Here's a chilled sinter, so let's see if we can filter the product.

Here we go.

Here's 0.9 grams of a white crystalline and very intensely methyl and peppermint smelling

product.

And this is our crude 1-methylcyclohexanol, a tertiary alcohol.

As it's crystallized it does seem quite pure, but we're not going to bother to purify it

further because this is only a 4% yield on our starting cyclohexanol.

our starting cyclohexanol.

And frankly we're impressed that we got a crude product.

It does go to show that chemical reactions do respect care and attention, proper temperature

control, and good equipment.

So we really can't recommend this type of setup at all.

But it was a fun challenge.

Stay tuned.