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

[Fenster]

Hi just a quick question:
I did 100ml nitroethane
142ml benzaldehyde
And after re crystallising p2np with IPA got 149.2g after 2 days in a vacuum dessicator at full vac and 2 days air dried. Does that sound about right yied or could it be improved
Kind regards newb

Evilcarrot2You need to take the Molecular Mass of both Benzaldehyde and P2NP. 100g of Benzaldehyde is just under 1 mole, 100 grams of P2NP is around .7 of a mole. Meaning you got around 70% if theoretical yield.

 

[Evilcarrot2]

You need to take the Molecular Mass of both Benzaldehyde and P2NP. 100g of Benzaldehyde is just under 1 mole, 100 grams of P2NP is around .7 of a mole. Meaning you got around 70% if theoretical yield.

FensterThank you. I had 100ml of nitroethane and 1 mol=75g
So I increased benzaldehyde to be slight excess but I didn't know how to work out %yield.
If that was the case I did 1.333333 mols of nitroethane

 

[Evilcarrot2]

I tried to work it out but struggled.
So I used 1.3333333333 mols nitroethane
And 1.338107802487749 mols of benzaldehyde being a very slight excess. Does that mean the nitroethane is my limiting factor. So is it yied/1.333333333?
Sorry once I get this down I won't ask the question again

 

[Evilcarrot2]

I think I get it.
So it's 0.92 mol of p2np divide that by the 1.3333333 mols nitroethane and I get me %yield of 69.19%

 

[Fenster]

Yes. That's correct.

 

[Charlie3]

Hi is the cas number for the nitroethane 79-24-3?

Reaction scheme:

View attachment 1298 ​

Equipment and glassware:

• 10 L Flask;
• Retort stand and clamp for securing apparatus (optional);
• Reflux condenser;
• Funnel;
• Vacuum source;
• Laboratory scale (0.1-500 g is suitable) - optional;
• Measuring cylinders 1000 mL and 100 mL;
• Water bath;
• Glass rod and spatula;
• Filter paper;
• Laboratory grade thermometer;
• Buchner flask and funnel;
• Bucket 5-10 L.
• Freezer;

Reagents:

• Benzaldehyde 1000 ml;
• Nitroethane 1000 ml;
• Glacial acetic acid 250 ml;
• n-Butylamine 50 ml;
• Isopropyl alcohol (IPA) ~1000 ml;

Medium scale:

1. Benzaldehyde 1000 ml, nitroethane 1000 ml, glacial acetic acid 250 ml and n-butylamine 50 ml are placed into 10 L flask.
2. A reflux condenser is installed onto the flask.
3. The stirrer and heater are turned on. The reaction mixture is heated up to 60 °С.
4. The reaction is conducted during 2-3 hours with constant stirring at 60 °С.
5. The reaction mixture is poured into an empty 5-10 L bucket.
6. Isopropyl alcohol (IPA) 800 ml is poured into the bucket and stirred.
7. The bucket with mixture is put into a freezer for 12 hours, 1-phenyl-2-nitropropene (P2NP) is crystallized.
8. The product P2NP is filtered on a Buchner funnel (suction filtration procedure), washed be a small amount of cold IPA and dried on air (or in vacuum chamber, optional).​

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Equipment and glassware:

• Beaker 500 ml;
• Funnel;
• Vacuum source;
• Laboratory scale (0.1-500 g is suitable) - optional;
• Measuring cylinders 50 mL and 100 mL;
• Glass rod and spatula;
• Filter paper;
• Buchner flask and funnel;
• Freezer;
• Microwave oven 750 W;

Reagents:

• Benzaldehyde 100 ml;
• Nitroethane 100 ml;
• Glacial acetic acid 25 ml;
• n-Butylamine 20 ml;
• Isopropyl alcohol (IPA) ~150 ml;

Microwave (small) scale:

1. Benzaldehyde 100 ml, nitroethane 100 ml, glacial acetic acid 25 ml and n-butylamine 20 ml are placed into 500 ml beaker.
2. A rubber glove is put onto the beaker.
3. The beaker is put into a microwave oven.
4. The power of the microwave oven is set up on 750 W. Oven is turned on and the mixture is warmed until the boiling. The mixture is cooled down to the room temperature.
5. Step 4 is repeated several times. Minimum 6 times.
6. Next, IPA 100 ml is added, reaction mixture is stirred and put into a freezer for 12 hours. 1-Phenyl-2-nitropropene (P2NP) is crystallized.
7. The product P2NP is filtered on a Buchner funnel (suction filtration procedure), washed be a small amount of cold IPA and dried on air (or in vacuum chamber, optional).

1-Phenyl-2-nitropropene (P2NP) can be recrystallized from hexane, methanol, ethanol or isopropanol (IPA).​

William Dampier

 

[yin-yang]

Yes, that's the right cas.

 

[teodor]

can hexamine (methenamine) be used for the synthesis

 

[UWe9o12jkied91d]

can hexamine (methenamine) be used for the synthesis

teodorno, atleast not with acceptable yields. You could try to freebase amindoacid salts from supplements and such(just a theory). Or if you are in the EU I can ship some.

 

[Fenster]

I've even heard some have had such with GABA.

 

[G.Patton]

Cheers! New video is here!

 

[Mr.Blanks00]

Thank you. I had 100ml of nitroethane and 1 mol=75g
So I increased benzaldehyde to be slight excess but I didn't know how to work out %yield.
If that was the case I did 1.333333 mols of nitroethane

Evilcarrot2hello bad potato, are you using a cyclohexamine catalyst, or n butylamine.

 

[Evilcarrot2]

Hi I'm using butylamine.

 

[Mr.Blanks00]

Hi I'm using butylamine.

Evilcarrot2Oh ok friends,thanks .

 

[MadHatter]

Honestly, is there any advantage to any of the catalysts? Is n-butylamine better than cyclohexylamine or is it vice versa? Or better and better- do they modify the reaction in terms of yield, sensitivity or robustness in any way? Which one would our experts choose if they had both?

 

[UWe9o12jkied91d]

Honestly, is there any advantage to any of the catalysts? Is n-butylamine better than cyclohexylamine or is it vice versa? Or better and better- do they modify the reaction in terms of yield, sensitivity or robustness in any way? Which one would our experts choose if they had both?

MadHatterI'm no expert by any means but I've tried : n-butyl, cyclohexil, monoetanolo, NaOH, Dibutil. All primary amines worked great, everything else was not acceptable, so chose the least stinky primary amine I guess.

 

[Felix34-73]

Can methanol or ethanol be used instead of n-butylamine?
@G.Patton

Fenster​

 

[Marvin "Popcorn" Sutton]

Can methanol or ethanol be used instead of n-butylamine?

Felix34-73n-butylamine is a catalyst, it can be replaced by cyclohexylamine

 

[cjcb[eqhfkbyf]

Hello everyone!Too huge proportions Please tell me for 200 ml of benzaldehyde and nitroethane how much vinegar and isoproponal you need acetamide, if it is possible, how much to use?

 

[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