phenyl2nitropropene

[Grignard]

Hello.. I was just dreaming about a high yilding and quick synthesis of phenyl2nitropropene. I mix 0,5 mol Benzaldehyde, 0,5 mol nitroethane and 10ml propylamine. The reflux time was about 1 hr. and the crystals come out very easily after col down after removal of water (8ml). I stop the rx when the solution turn deep orange/red. much quicker than cyclohexylamine!!!

[Vitus_Verdegast]

Wow, no crystallisation problems at all?
P2NP seems to be notorious for this.

What is your final yield?

[GC_MS]

Wow, no crystallisation problems at all?
P2NP seems to be notorious for this.

P2NP a la Barium: 1 mol benzaldehyde, 1.2 mol nitroethane and 15 mL diluted aqueous methylamine in 150 mL alcohol. Stirred and slightly heated for ca 4 hours. The reaction mixture is brought over into a beaker and cooled in the fridge (4°C). If precipitation doesn't commence at this point, water is poured in and the mixture put back in the fridge. The P2PN oil layer will slowly (or sometimes quickly) start forming a crystalline layer. If it doesn't, scratching the wall with e.g. a glass rod will help. If even this won't help, it means you probably fucked something up. The yields I have had using this "adaptation": 81% (iPrOH), 79% (iPrOH), 75% (EtOH) and 71% (EtOH) (yields calculated after crystallizing once; I store my crystals in the freezer and also recrystallize them prior to use).

[Grignard]

I havent dryed my product yet, but i rextallise from meoh and the yeld seems to be very good! The only thing i did prior to crystallation was to separate the water from the mixture by using a separatory funnel while the solution was still hot. I think the metylamine could be bether, but it`s difficult to get my hands on..  

[psyloxy]

Yet another P2NP preparation, but not the worst:

Post 459820

(APOPLEX: "Bawoosh....success !", Methods Discourse)

--psyloxy--

[Grignard]

[Antoncho]

This reduction has been performed by several HyperLab bees a la Antibody2 on both PNP and 2,5-diMeO-PNP. Each and every time the rxn was said to proceed exactly as stated, yields varying from 30% to 60% (the latter in case of 2,5-DMA).

In that latter report by Vitsh the purity also seemed to bee outstanding - the product was a clear yellow oil (which it usually is not).

[Grignard]

He he... Thank`s! Then i will give it a shot today.. Hope for a bether yeld than 30% , Do you think the yeld would be bether with Zn amalgame or Al amalgame?

[Vitus_Verdegast]

Reduce the double bond first with NaBH4, then reduce the nitropropane with eg. Al/Hg

UTFSE for posts made by Barium

[Grignard]

I dont manage to get LaH or Borohydride stuff.. But i got HgCl and NiCl.. I have just tryed the urushibura reduction but there seem to be something vrong about the reaction, Everything smelled very very amine but after addition of NaOH everything smells ammonia and there is no oily layer, and i dont understand how there cold appear to be two layers in a alcohol/water mixture? what to do with all this ammonia water, i will try to boil it in to the final drop, but could i extract it with toluene or ether??    and the pH is very high!! hmmmmm...

[Grignard]

The yield from the nitrostyrene reaction is about 60% or a litle higher after rextalisation from MeOH.. I think that`s ok since the reaction time is about an hour..

[Antoncho]

Post the details. Post the details. Post the detail.

You've achieved a max yield of all known thus far w/this rxn

[Grignard]

I got around 0,3 mol from a 0,5 mol aldehyde. But this is just an aprox.. I have not evaporated some of the MeOH from the rextalisation yet. Very unprecise! I will try this next week and i will do an exact report of the result.