P2np Syntheses Ammonium Acetate Catalysis

[yuiopjkl]

This is my experience with ammonium acetate:
80ml benzaldehyde
80ml nitroethane
60g anhydrous ammonium acetate
70ml GAA

refluxed In a water bath, the temperature is close to boiling (I think 90°-95°) for 5-6h.

Shake the flask periodically

After 6h:

Let it cool to room temperature and place it in the freezer.
Yield is 78g.


note:
- If it does not crystallize, place a rod in the mixture.
-If you have ready-made P2np, put some of it in the mixture and it will crystallize immediately.

-Use dry ammonium acetate (My ammonium acetate was very wet and I dried it as much as I could with tissues, I think this is the reason for the low yield).
Thanks to the experts for the help
@G.Patton @HIGGS BOSSON

 

[Rabidreject]

I FINALLY actually got round to trying this, it’s under reflux now actually - colour is getting there for sure!
I fucking hate the smells you get from putting this rxn together…I really dislike that almonds cherry smell that this aldehyde releases, it’s gross - also is a really heavy liquid.

Mind you at least it’s legal here…is it not restricted in the states? I remember watching that ‘positive meth amphet‘ episode of Hamiltons show where he had was it uncle fester? It was def one of the chemists who has written lots of books on this subject and he was synthesising benzaldehyde or trying to at least - don’t see why he would try that if you could just buy it like here….might be wrong tho…either way it fucking stinks!

And yes. The ammonium acetate is a little bit of a bitch to work with -I honestly just got a knife, stabbed the 250g tub and then picked out whole chunks of it and prodded it into a funnel in the flask.
its weird stuff though, it actually really reminded me of ice…not meth-amphet’s street name but regular, cold snow balls type ice odd stuff but I was hoping it would all melt together when heated - I was correct Bug yeah I’d try and buy it anhydrous next time - even though I accidentally bought like a kilo and a half of the stuff by accident!

cheers for the guide anyway - seems similar-ish to the nitroaldol rxn I was doing on 2,5-DMOBA only using a mad catalyst and WAY MORE nitroethane than nitromethane, however, I guess that’s the trade off for not having any n-butylamine, I guess…I much prefferred having the correct catalyst tho - ethylenediamine in the case of the 2,5-DMOBA…

hopefully it shall work….no idea how ill go about reducing it even if I do manage to crystallise something and don’t end up with some shitty annoying oil…

by the way, I’m getting into the rxn now and no…total wrong colour…. Bright red! Bah!

 

[Rabidreject]

Ummmmm….weird colour - I’m highly doubtful over this

 

[OrgUnikum]

This is the worst way to run the Henry reaction to make P2NP from Benzaldehyde and Nitroethane. Lousy yields and a dark mess which is hard to workup. There is neither place nor reason for this crap to even be considered a useful candidate for this reaction.

Be warned! Stay away! A big waste of precursors and time, the only compound this synth produces in excellent yields is unhappiness.

 

[yuiopjkl]

Ammonium acetate is the best option if you cannot obtain cyclohexylamine.
The yield is not bad and the product is not very dirty. It only needs to be recrystallized once.
The last time I did the synthesis the yield was 100g from 90ml Nitroethane.
I haven't recrystallized it yet

 

[OrgUnikum]

No. Ethylene diamine as the di-acetate is the best catalyst. But Cyclohexylamine, Phenylethylamine actually any bulky phenylamine or diamine works great. it seems to be about how big the molecule is. Microwave not more then 60°C several times is pertfect, was done in 5 kg batches this way with 95% yield or more (on nitroethane). Shulgin did not have his best day when he wrote down the sodium acetate route, but he never intended this to be for big scale manufacture but only for some private enjoyment and so could afford this approach which in most cases leads to a black mess one has to painstakenly extract small amounts of P2NP fro
But hey, it is your money going down the drain not mine so do whatever you want, you have been warned though.

 

[OrgUnikum]

Take any bulky amine dissolve in a little IPA and add GAA until ph is acidic. This si your catalyst. Yes it will not be dissolved in the IPA but it does not matter. 10 g Amine per 100 ml Benzaldehyde is enough one can use less and get great yields just nuke two times more in the micro to 60°C max. Mix nitro and benzaldehyde and add a part of the catalyst, stir, nuke let cool down and repeat. I never had anything below 90% yield and I used a whole assembly of different amines. You must not look to get the one and only amine but you must look which amines you can get easily and then see which works best.

 

[Rabidreject]

Okay - I have triethylamine?

 

[Rabidreject]

This is very useful - I am going to just try to obtain the cyclohexylamine - given how much success I have just had performing the Nitroaldol reaction on 2,5-dmoba - when you actually use the correct catalyst….

iv just performed a couple of reactions using 2,5-dmoba, GAA, ethylenediamine and nitromethane - giving good yields of nice looking b-2,5-DMONS…

I have a decent quantity of the 3,4,5-TMOBA coming now so once iv re-x’d it, I do plan to get a bottle of cyclohexylamine from sigma.
Does anyone know if it can also be used in conjunction with nitroethane to form the TMA intermediate? Or is it just good for making the b-nitrostyrene intermediate?

sorry I sort of ended up with this thread more generally regarding the Henry rxn, I guess…but no - that initial report on here of 80ml benzaldehyde;80ml nitroethane just goes red - bright red…. I guess I’ll see but I’m doubtful!