1-Phenyl-2-nitropropene (P2NP) Video Synthesis From Benzaldehyde and Nitroethane. Henry Reaction.

[Sitr1x]

My friend, we can never get nitroethane, is there an alternative to it in this case?

cyb3r0Just a heads up SWIM found out on the clearweb somewhere that particular 'paint brush saver' liquids contain primarily Nitroethane and isn't too much on the expensive side of things.

 

[wael gano]

Just a heads up SWIM found out on the clearweb somewhere that particular 'paint brush saver' liquids contain primarily Nitroethane and isn't too much on the expensive side of things.

Sitr1xWelcome
There is a thread on the forum for the synthesis of nitroethane

 

[HairyPoppins]

Hi s3v3n,

I did try this using benzaldehyde, nitroethane, and n-butylamine. As a template, I used 3,4-DMA from PIHKAL. Instead of the veratraldehyde and n-amylamine, I used benzaldehyde and n-butylamine, and adjusted the amounts accordingly.

The RM seems unchanged after a month. No solids have precipitated at all.

This was my last effort in a line of unsuccessful reactions with this nitroethane:

Nipron ®™ fuel enrichment additive cas 79-24-3 Pure nitroethane based, 100 ml.

This was supposed to be >98% nitroethane (NE). I didn't have any way to definitively check it, so it could be something other than NE or have high water content. Was expensive too - $125 for 100mL delivered.

I think this reaction (and I thought it was a Knovenagle reaction, not a Henry reaction!) would work, but there may be something about the unsubstituted benzaldehyde that requires different reaction conditions.

plancklongIve used the Nipron ®™ fuel enrichment additive cas 79-24-3 Pure nitroethane based, 100 ml with ammonium acetate and benzldehyde to produce p2np it seemed ok to me was just hard to crystalize. i just threw in a small cube of nitrogen to get it cold enough

 

[yuiopjkl]

Ive used the Nipron ®™ fuel enrichment additive cas 79-24-3 Pure nitroethane based, 100 ml with ammonium acetate and benzldehyde to produce p2np it seemed ok to me was just hard to crystalize. i just threw in a small cube of nitrogen to get it cold enough

HairyPoppinsCan you tell me all the steps of synthesis with ammonium acetate

How many ml of ammonium acetate did you use?

Did you use acetic acid?
Reflux time?
yield?

Thanks in advance

 

[yuiopjkl]

I can't get cyclohexylamine nor butylamine but I can get ammonium acetate.
I'm going to do 100ml benzaldehyde, 100ml nitroethane and 25ml acetic acid.
So how much ammonium acetate will I need?

 

[41Dxflatline]

I can't get cyclohexylamine nor butylamine but I can get ammonium acetate.
I'm going to do 100ml benzaldehyde, 100ml nitroethane and 25ml acetic acid.
So how much ammonium acetate will I need?

yuiopjklWhy can't you get them?

 

[41Dxflatline]

It is not available locally, and if you order it online, it will take more than a month to get here.
ammonium acetate i can get it today

yuiopjklAmmonium Acetate Catalysis in Excess Nitroethane

A solution of benzaldehyde (6.4 g) and ammonium acetate (1.0 g) in nitroethane (20 mL) was heated to reflux for 5 h. On cooling, after removal of the solvent, the residue was purified by column chromatography on silica gel 60 N (neutral; hexane-chloroform, 2:1, v/v), then recrystallized from hexane and gave 1-phenyl-2-nitropropene as a light yellow crystals weighing 6.2g (63%), mp 71-73°C.

 

[yuiopjkl]

Ammonium Acetate Catalysis in Excess Nitroethane

A solution of benzaldehyde (6.4 g) and ammonium acetate (1.0 g) in nitroethane (20 mL) was heated to reflux for 5 h. On cooling, after removal of the solvent, the residue was purified by column chromatography on silica gel 60 N (neutral; hexane-chloroform, 2:1, v/v), then recrystallized from hexane and gave 1-phenyl-2-nitropropene as a light yellow crystals weighing 6.2g (63%), mp 71-73°C.

41DxflatlineThank you. I have also read this method in previous replies.

And Someone in the replies said:

there is 4.4 times more nitroethane than benzaldehyde
hell of an excess for yield that's average at best.


im pretty sure if you add a solvent like glacial acetic acid, and instead of reflux you just heat to 60-80 you, wont need so much nitroethane and will still get similar if not slightly better yield.

The thing that I understood is that if I add acetic acid, I will not need a high temperature, and the synthesis time will decrease.


If I did the same amount as in the thread said
100ml Benzaldehyde
100ml nitroethane
25ml Acetic acid
?? Ammonium acetate

how much ammonium acetate will I need?




Experts need your help please @G.Patton @HIGGS BOSSON

 

[G.Patton]

Thank you. I have also read this method in previous replies.

And Someone in the replies said:






The thing that I understood is that if I add acetic acid, I will not need a high temperature, and the synthesis time will decrease.


If I did the same amount as in the thread said
100ml Benzaldehyde
100ml nitroethane
25ml Acetic acid
?? Ammonium acetate

how much ammonium acetate will I need?




Experts need your help please @G.Patton @HIGGS BOSSON

yuiopjklHello. Well, ammonium acetate work as other Lewis bases (like cyclohexylamine and butylamine). So, you have to take about 4 g in accordance with approximate molar ratio. I'm not sure in this amount. It's worth to check in smaller scale synthesis batch like 10g load.

 

[yuiopjkl]

Hello. Well, ammonium acetate work as other Lewis bases (like cyclohexylamine and butylamine). So, you have to take about 4 g in accordance with approximate molar ratio. I'm not sure in this amount. It's worth to check in smaller scale synthesis batch like 10g load.

G.PattonHow much ammonium acetate and GAA do I need to add to
10g benzaldehyde and
10g nitroethane

thanks in advance

 

[G.Patton]

How much ammonium acetate and GAA do I need to add to
10g benzaldehyde and
10g nitroethane

thanks in advance

yuiopjklyou can reduce amounts proportionally

 

[yuiopjkl]

I put 10ml benzaldehyde, 10ml nitroethane, 2.5ml GAA, and 4g ammonium acetate in a flask

Heating at 60-70 °C for 4 hours. After cooling to room temperature, there were two layers, at the bottom a yellow layer and at the top a white layer. I put it in an ice bath for 2 hours (I don't have access to a freezer right now) and there weren't any crystals, only the oily layer got thicker. The upper layer was discarded , 10 ml of distilled water was poured, and it was cooled in an ice bath for 5 hours. Nothing happened, only the aqueous layer became transparent.
The aqueous layer was discarded and 10 ml of IPA was poured. There are no layers, only one yellow layer.
It was placed in the freezer for 10 hours and there are no crystals .


Is there anything wrong with my method?
Sorry for my bad english

 

[UWe9o12jkied91d]

I put 10ml benzaldehyde, 10ml nitroethane, 2.5ml GAA, and 4g ammonium acetate in a flask

Heating at 60-70 °C for 4 hours. After cooling to room temperature, there were two layers, at the bottom a yellow layer and at the top a white layer. I put it in an ice bath for 2 hours (I don't have access to a freezer right now) and there weren't any crystals, only the oily layer got thicker. The upper layer was discarded , 10 ml of distilled water was poured, and it was cooled in an ice bath for 5 hours. Nothing happened, only the aqueous layer became transparent.
The aqueous layer was discarded and 10 ml of IPA was poured. There are no layers, only one yellow layer.
It was placed in the freezer for 10 hours and there are no crystals .


Is there anything wrong with my method?
Sorry for my bad english

yuiopjklHas it crystalized yet? The organic layer being at the bottom is good indication reaction has taken place esp. if you say it's yellow, if there was unreacted nitroethane it would float to the top of water.It might want more or less solvent.Another thing u can try is seeding with any crystal, NaCl for ex. after chill overnight. A small amount of finely crushed ice might also do it after a good chill.
For further reference primary amines can be obtained from commercially available amino acid supplements trough acid base extraction

 

[yuiopjkl]

Has it crystalized yet? The organic layer being at the bottom is good indication reaction has taken place esp. if you say it's yellow, if there was unreacted nitroethane it would float to the top of water.It might want more or less solvent.Another thing u can try is seeding with any crystal, NaCl for ex. after chill overnight. A small amount of finely crushed ice might also do it after a good chill.
For further reference primary amines can be obtained from commercially available amino acid supplements trough acid base extraction

UWe9o12jkied91d

if there was unreacted nitroethane it would float to the top of water.It might want more or less solvent

There was a little oil floating on top of the water
And there was a benzaldehyde smell

---

This picture after heating for four hours

Then separate the aqueous layer, pour IPA and Put it in the freezer for 10 hours

And this is after shaking

No crystals appeared, then I evaporated I PA at room temperature, added 2.5 ml of acetic acid, and put it in a water bath at 80°

I think I'll throw it away and try again
Should I put more acetic acid like 6ml
(10ml benzaldehyde,10ml nitroethane,6ml GAA, and 3g ammonium acetate)

 

[UWe9o12jkied91d]

There was a little oil floating on top of the water
And there was a benzaldehyde smell

---

This picture after heating for four hours
View attachment 17006

Then separate the aqueous layer, pour IPA and Put it in the freezer for 10 hours

View attachment 17007

And this is after shaking
View attachment 17008
View attachment 17009

No crystals appeared, then I evaporated I PA at room temperature, added 2.5 ml of acetic acid, and put it in a water bath at 80°
View attachment 17010

I think I'll throw it away and try again
Should I put more acetic acid like 6ml
(10ml benzaldehyde,10ml nitroethane,6ml GAA, and 3g ammonium acetate)

yuiopjklI think you should consider a traditional catalyst, like I said you can get it from aminoacid supplements.Also if there's an option I would go lower heat and more time rather than reverse.

 

[yuiopjkl]

I think you should consider a traditional catalyst, like I said you can get it from aminoacid supplements.Also if there's an option I would go lower heat and more time rather than reverse.

UWe9o12jkied91d

I think you should consider a traditional catalyst, like I said you can get it from aminoacid supplements.

Thanks I will look for that.


And if I can't be patient, I'll try the other option

Also if there's an option I would go lower heat and more time rather than reverse.

 

[G.Patton]

There was a little oil floating on top of the water
And there was a benzaldehyde smell

---

This picture after heating for four hours
View attachment 17006

Then separate the aqueous layer, pour IPA and Put it in the freezer for 10 hours

View attachment 17007

And this is after shaking
View attachment 17008
View attachment 17009

No crystals appeared, then I evaporated I PA at room temperature, added 2.5 ml of acetic acid, and put it in a water bath at 80°
View attachment 17010

I think I'll throw it away and try again
Should I put more acetic acid like 6ml
(10ml benzaldehyde,10ml nitroethane,6ml GAA, and 3g ammonium acetate)

yuiopjklHello, you shouldn't.

Should I put more acetic acid like 6ml

I would recommend to put a glass rod or something like that in the solution of p2np in IPA during crystallization. It makes centers of crystallization and may help you. Your procedure sounds correct.

 

[the money]

Nitroethane 1000 ml;

GhostChemistCan I use nitromethane instead of nitroethane?

 

[ACAB]

Can I use nitromethane instead of nitroethane?

the moneyNot for P2NP.

 

[ACAB]

After I have successfully carried out the synthesis as it was shown in the first video, I now have the final question:
What remains besides the product? How can I recycle it?
My mother liquor has two layers, a heavier dark red oily layer and an upper light yellow layer, I assume an IPA/water mixture, from which I could distill the IPA.
Is the lower dark red layer also still usable? Or just waste?

 

[UWe9o12jkied91d]

After I have successfully carried out the synthesis as it was shown in the first video, I now have the final question:
What remains besides the product? How can I recycle it?
My mother liquor has two layers, a heavier dark red oily layer and an upper light yellow layer, I assume an IPA/water mixture, from which I could distill the IPA.
Is the lower dark red layer also still usable? Or just waste?

ACABSounds like you have nitro left, mother liquid should be monophasic and if already red it is more than likely spent.You could add ipa to homogenize everything and toss in freezer

 

[ACAB]

Sounds like you have nitro left, mother liquid should be monophasic and if already red it is more than likely spent.You could add ipa to homogenize everything and toss in freezer

UWe9o12jkied91dOk, what if you've already done this twice and the gain in yield seems marginal?

 

[UWe9o12jkied91d]

Ok, what if you've already done this twice and the gain in yield seems marginal?

ACAByou toss it and react fully next time, what is the ratios you used?

 

[ACAB]

you toss it and react fully next time, what is the ratios you used?

UWe9o12jkied91dIt was a mother liquor of two syntheses, the first of which gave nice pure yellow crystals and the second rather so slightly impure. As if the P2NP had been stored too long. I definitely need to do a recrystallization before I can use it. The second synthesis has been heating for more than 6 hours and was not directly processed further. So I am assuming oxidation rather than an Incomplete reaction..
My ratio
75ml Cyclohexamie
375ml Benzaldehyde
150ml Acetic acid
375ml Nitroethan
6h @ 60°C
1.Yield:550g
2. need recrystallization

But my question was more in the direction of how I can recover something from it.
I can distill IPA from the upper water.
From the red oil too, or does it go directly into the waste canister for incineration?

 

[ACAB]

you toss it and react fully next time, what is the ratios you used?

UWe9o12jkied91dAny advise? I would hate to dump everything into the environment and keep waste to a minimum.

 

[UWe9o12jkied91d]

Any advise? I would hate to dump everything into the environment and keep waste to a minimum.

ACABabout disposal? if you are in germany or austria you can take in chemical waste no questions asked for free.
Waste solvents can also be dilstilled for reuse, check the thread.