Benzaldehyde and MEK - TwoDogs Method

[lalalander]

I was performing the aldol condensation between benzaldehyde and MEK by heating with aqueous HCl, then washing to neutral and vacuum distilling.

However, I cannot isolate the aldol product by vacuum distillation because my vacuum pump is broken.

It is easy to make sure that things are going well when I get a black oily liquid when heating, but because my reflux condenser is not efficient enough, HCl gas escapes.

So I stir it with aqueous HCl first at 0 degrees for 6 hours and then at room temperature for 24 hours and wait for the mixture to darken in color. But it doesn't happen. It's only a deep red color.

I cannot crystallize the resulting organic layer in any way.

Can anyone help?

Thanks.

 

[The-Hive]

An old fridge compressor are good for vacuum. You can source them from any junkyard.

 

[lamer]

2 köpek methodu he

 

[Osmosis Vanderwaal]

I think for under $15 i could build a venturi type asperator

 

[Field7]

Steam distillation

 

[lalalander]

Can unsaturated ketone be steam distilled? I didn't know. Thanks.

 

[lamer]

rojin napıo

 

[BayHyde]

When 10 grams of Benzaldehyde + 10 grams of MEK and 7 grams of 30.5% aqueous HCl are mixed for 24 hours at room temperature, I obtain an organic layer.

The reaction should be carried out in an inert reactor, and the mouth of the reactor should be sealed with an inert stopper (such as LDPE, Teflon, glass, etc.).

I wash the organic layer with NaHCO3 solution until it is neutral and put it directly into the freezer. No heating. I filter it using a vacuum cleaner motor. This separates the remaining residual Benzaldehyde and MEK. White crystals remains behind.

When I pour -18 degree methanol on it, I obtain completely snow-white crystals. In my last test, I used 50 grams of Benzaldehyde + 50 grams of MEK and 35 grams of 30.5% aqueous HCl. I obtained 46 grams of snow-white crystals.

Methanol must be cooled in the freezer. Otherwise a lot of crystal will dissolve in the washing step.

I also think you can use ice water when washing, but I haven't tried it yet.

I no longer have any problem with aldol condensation step.

Here is a picture showing the upper organic layer, the lower aqueous layer, and the crystals obtained after freezing, before washing with cold methanol, for anyone is interested;

 

[lalalander]

When 10 grams of Benzaldehyde + 10 grams of MEK and 7 grams of 30.5% aqueous HCl are mixed for 24 hours at room temperature, I obtain an organic layer.

The reaction should be carried out in an inert reactor, and the mouth of the reactor should be sealed with an inert stopper (such as LDPE, Teflon, glass, etc.).

I wash the organic layer with NaHCO3 solution until it is neutral and put it directly into the freezer. No heating. I filter it using a vacuum cleaner motor. This separates the remaining residual Benzaldehyde and MEK. White crystals remains behind.

When I pour -18 degree methanol on it, I obtain completely snow-white crystals. In my last test, I used 50 grams of Benzaldehyde + 50 grams of MEK and 35 grams of 30.5% aqueous HCl. I obtained 46 grams of snow-white crystals.

Methanol must be cooled in the freezer. Otherwise a lot of crystal will dissolve in the washing step.

I also think you can use ice water when washing, but I haven't tried it yet.

I no longer have any problem with aldol condensation step.

Here is a picture showing the upper organic layer, the lower aqueous layer, and the crystals obtained after freezing, before washing with cold methanol, for anyone is interested;

 

[lalalander]

I'm grateful to everyone who approaches my problems with the intention of helping, whether it benefits me or not. I'm just very tired. I'm sorry if my behavior was hurtful to you.

Thanks.

 

[layla]

hello how can i prepare peracetic acid for benzaldehyde and butanone method thank you

 

[HIT MONKEY]

The end result is P2P, right? And how many % purity is it? thank you

 

[lalalander]

No. It is 3-methyl-4-phenyl-3-buten-2-one. It is oxidized to the enol acetate ester of P2P and hydrolyzed to rearrange P2P.

 

[AKINCI]

Is this P2P?

 

[lalalander]

Are you serious? Someone else already asked this, and I already answered. Are you blind or something? It's 3-methyl-4-phenyl-3-buten-2-one.

 

[Newbee]

can anybody provide me receipt to it

• lalalander

 

[lalalander]

When 10 grams of Benzaldehyde + 10 grams of MEK and 7 grams of 30.5% aqueous HCl are mixed for 24 hours at room temperature, I obtain an organic layer.

The reaction should be carried out in an inert reactor, and the mouth of the reactor should be sealed with an inert stopper (such as LDPE, Teflon, glass, etc.).

I wash the organic layer with NaHCO3 solution until it is neutral and put it directly into the freezer. No heating. I filter it using a vacuum cleaner motor. This separates the remaining residual Benzaldehyde and MEK. White crystals remains behind.

When I pour -18 degree methanol on it, I obtain completely snow-white crystals. In my last test, I used 50 grams of Benzaldehyde + 50 grams of MEK and 35 grams of 30.5% aqueous HCl. I obtained 46 grams of snow-white crystals.

Methanol must be cooled in the freezer. Otherwise a lot of crystal will dissolve in the washing step.

I also think you can use ice water when washing, but I haven't tried it yet.

 

[LabPsycho]

The reaction was carried out: 53 g of benzaldehyde + 36 g of MEK + 36 g of hydrochloric acid (0.50 mol reaction). Temperatures: 115°C to 125°C degrees. Time: 4 hours.
The reaction was carried out: 82 g benzaldehyde + 55 g MEK + 55 g hydrochloric acid (0.76 mol reaction). Temperatures: 115°C to 125°C degrees. Time: 7 hours.

Those were washed with brine, pure water and neutralized to pH: 7.

The combined dark brown oil from both reactions was dried for some time with the help of mild heat and acetone, because both had still accumulated a little water at the bottom, and the substance had to be steamed a little cleaner so that the dark oil would eventually become an orange-colored crystal. The rest of the water was sucked out with a measuring syringe. A black colored oil remained.
There was 133.26g of oil (waste without a measuring cup) and it was put in the freezer for 12 hours, during which time everything had crystallized into orange crystals.

 

[LabPsycho]

After those reactions, I made peracetic acid and left 133 g of MPB in (almost neutralized, little "overflow..") peracetic acid at room temp, got 106,3 g of the acetoxy ester. So the yield was ~ 75% (molar). Little dissaponted, but hey, there is some product to be hydrolyzed...

 

[lalalander]

I can't get the peracetic acid and performic acid to work. Any suggestions?

 

[lalalander]

I think so too. When I treat it with base, the color becomes very dark orange. After 2 hours, I make pH 7 with acetic acid. The color turns yellow again. But I don't observe any change in smell. Now I'm going to steam distill it.

 

[lalalander]

I had done it like this: I added MPB directly into peracetic acid without using a solvent and left it on its own for two days without stirring, assuming it had failed. Later, when I added the MPB + peracetic acid mixture, which had been left to stand for 2 days, into an Oxone, methanol, and water mixture, my entire house was suddenly filled with this smell. Most likely, what I had added was not MPB + peracetic acid, but an ester. Oxone provided an acidic environment, which led to hydrolysis with the methanol + water mixture, directly yielding P2P. This is probably why I did not observe a change in smell during basic hydrolysis, because what I had already obtained was likely P2P.

 

[AKINCI]

Is this P2P?