1-Phenyl-2-nitropropen (P2NP) Video Synthese aus Benzaldehyd und Nitroethan. Henry-Reaktion.

[Chemdog010297]

If you have no ability to freeze precipitate the p2np, can u separate the alcohol layer and evaporate solvent or acid extract ?

 

[GhostChemist]

Evaporation is bad idea
Better is adding some portions of water

 

[GhostChemist]

"p2np oil or acidify to salt" - p2np can't be forming the stable salts, this is nonsense (we do not consider anion salts in this case)

1. p2np decompose upon overheating
2. In the presence of base or acid, this instability is amplified: base may trigger Michael-type polycondensation, while acid can cause isomerization or hydrolysis

 

[P2NP_SELLER]

i just found out for the microwave synthesis at least with 600ml IPA for 500ml Nitroethane and so on that if you take out the mixture of the microwave and let it cool down for 15min. . Than you can start crystallization immediately without waiting 12 hours in the freezer by just adding one single drop either of water or hand wash soap. Sounds crazy but when i washed my hands of from the soap a drop mistakenly got into the reaction mixture flask and it immediately started to crystallize. Don't know why!? Cause of the water or the soap on my hands.

You should add this info to the synthesis description you posted in the forum bro.

Do you have any idea what could have happened here? I cannot believe that one single drop of water or water with rests of soap in it completely could possibly have ruined my p2np mixture.... it looks 1 to 1 like straight p2np crystals i got here in my flask.

i used the amounts for the microweave description instead of using 800ml of IPA , not 500ml which would be right regarding to your description.

 

[GhostChemist]

This synthesis is classical Henry Reaction

 

[mile123]

Hello @GhostChemist

In the medium scale instructions there is used n-butylamine 50 ml
conducted during 2-3 hours with constant stirring at 60 °С

What if I use 50ml of nitroethane, how to scale down n-Butylamine since it is catalyst and does conduction time remain the same?

Reagent	Scaled Amount (for 50 ml Nitroethane)
Nitroethane	50 ml
Benzaldehyde	50 ml
Glacial Acetic Acid	12.5 ml
n-Butylamine	10 ml

I got confused since for Microwave (small) scale we have 20ml

• n-Butylamine 20 ml;

 

[GhostChemist]

In most processes, the amounts of reagents and catalysts change proportionally.
But what is a catalyst? A catalyst is a substance that speeds up a reaction.
The speed or time of the reaction will depend on both the process parameters (for example temperature or pressure) and the amount of catalyst. But there is a limit to the amount of catalyst after which increasing the amount of this catalyst does not affect the process. Our reports provide optimal and checked quantities of reagents.

 

[mile123]

This helped a lot. Thanks.