Preperation of 2,5dimethoxyphenyl-2-nitropropene

[Vibrating_Lights]

Let me start by sayin wow.  To this date this is the easiest synth i ever seen in my life, side from making Hg2I2.  From start to finish it takes about 4.5hrs. And it requires no lab glass at all.

Procedure

16.6 gms(.1mol) 2,5 dimethoxybenzaldehyde was finely powered and   dissolved in 40mls 99.9%MeOH at RT.  It took 30 mins stirring with a spatchula to get it all into solution. 

Then 7.1 gms 99% Nitroethane was added.

4gms of NaOH is dissolved into 20ml of H2O and placed into the icebath to cool.

The rxn vessel (Jar)  was placed into an ice bath until the 2,5dimethoxybenzaldehyde began to crash out. 
As soon as it began to crash out it was removed from the ice.

The NaOH solution was added with a syringe over the period of 10 mins. When all the NaOh was added the whole thing spontaniously crystalized to an yellow white color.   It did not heat up at all but still it was placed into the ice bath and stirred by hand for an hour.

100mls of cold H2O was added which did not change much at all.

1l of 2M Hcl was made.(200mlof 36%Hcl in 800mlH2O)

100 ml of the 2M Hcl solution was added into the solution.  when each drop hit it made a blue color that turned lime green after a few seconds.  When it all was added it bubbled for a few minutes and then was placed into the ice bath. At this point it was canary yellow.  the soution was yellow as were the crystals setting at the bottom.  I suspect there was more still in solution at this point.  the whole thing was put into a filter.
The filtercake was washed 3x with 50 ml of H2O
The crystals were air dried without rxtylization to a weight of 16.2 gms. 

 I say again wow. Now it is time to try with Nitromethane  
VL_

[Bandil]

Sounds awesome VL

How come you get such a tremendous yeild compared to the standard methods of preparing the nitropropenes? Is it the low temperature?

Anyway, when you add the final NaOH, you say that you make a litre and add 100 mL. You then proceed to say, that you add "the rest". Is that the rest of the 100 mL's or the litre(im pretty sure you meant the 100 mL's, just wanted to be sure).

Anyways: cheers!

Regards
Bandil

[Barium]

This is not meant to shoot you down but I have a very strong suspicion that you´ve actually made the nitroalcohol. If you read the litterature on the subject of making nitrostyrenes with NaOH as the catalyst you´ll se that the reaction mixture should be poured into the acid, not the other way around which you did. This little change makes a whole lot of difference in order to obtain the nitrostyrene or the nitroalcohol.

[Barium]

Check the melting point of you product. The nitroalcohols has much lower melting points than the nitrostyrenes.

[Vibrating_Lights]

I will check the MPs.  What is the mp of the nitroalcohol.  even better i will reduce it and brominate it.  It did howevre go through the color changes mentioned in the writeup on rhodiums pages.  I also will try it by addding it to the acid.
VL
 

[blasephilomath]

I hope your mp's match up how you want them to. 

Supposing that all went well with the above reaction, would you ever consider using 2,6-dimethoxybenzaldehyde,
3,5-dimethoxybenzaldehyde, 2,3-dimethoxybenzaldehyde, 3,4-dimethoxybenzaldehyde or 2,4-dimethoxybenzaldehyde as your starting material?

PIHKAL convers the trimethoxyamp's and 2C's rather extensively, but I have often wondered about the psychoactivity of their numerous dimethoxy cousins.

Just curious...

[yellium]

shouldn't 2,5-dimethoxyphenyl-2-nitropropene be more orange instead of yellow?

[Vibrating_Lights]

I have no idea. BUt i think it is nitrostyrenes hat are orange.  I have seen people mention the yellow color dissapearing during the AL/Hg part of the reduction so i assume all is well. 
VL_

[Vibrating_Lights]

The rxn waws run again this time adding the slurry to the acid.  the crystals that formed this time had more of an orange color to them.  Reduction of the first product went like this.

13 gms Suspected nitropropene was dissolved in 250ml MeOH. 2.5 gms of NaBH4 was added over a period of 30 mins. There was much H2 evolution.  then 50mls of 20%Hcl was added and the color went to a slight greenish like MDP2P from a benzo wacker. 6 gms of amalgamated Al was aded and dissolved in 1.5hrs.  the mix was basified with 100ml of 30%NaOH and extracted 2x100ml of xylene.  this was washed with NaCl and Bicarb. 4mlof 36%Hcl was mixed with 4 ml of H2O and added to the xylene.  this was evaporated to give a green oil.  I guess it did make the nitroalcohol. 

Now time to reduce the oranger crystals. ? though
These crystals yellow/orange are pretty quick to dissolve in MeOH is that normal.
VL_

[Antibody2]

MeOH is useless for that reaction, even if you had the nitrostyrene you would get nothing. So you have no conclusive results here at all. Don't you read? IPA or EtOH with THF or even Et2O as co solvents but NO MeOH!  this is painful.

[Vibrating_Lights]

What about this then.  Is it bunk.

https://www.thevespiary.org/rhodium/Rhodium/chemistry/dob.html

Can diethylether be used here.

If it is bunk then we really got to do something about bunk information being on Rhodiums page. 

And yes it is painful but at least someone is doing it.

As a note, the nitroproprne was a clear orange juice color
after 2x rxtlyazaton from MeOH.   During the NaBH4 addition the color went from orange juice color to a pale yellow.  When the first of the Al is added, the color goes to an amber brown color. 
VL_

[Rhodium]

BUt i think it is nitrostyrenes hat are orange.

You cannot make such a generalization, all nitrostyrenes/phenylnitropropenes show individual colors, 3,4,5-trimethoxynitrostyrene is canary yellow and 2,5-dimethoxynitrostyrene is pumpkin orange for example.

[Vibrating_Lights]

Can any one confirm that MeOH is a suitable solvent for this rxn???
VL_

[Rhodium]

Read

https://www.thevespiary.org/rhodium/Rhodium/chemistry/nitrostyrene.nabh4.reduction.html

- the use of MeOH is not reccommended as it decomposes the NaBH₄ too fast. I will add a note about that to the procedure written by Dr Gonzo.

[catastrophe]

Post 301717

(Antoncho: "2,5-diMeO-phenylnitropropene - the "cold" way.", Chemistry Discourse)
- also has a discussion about nitroalcohols.

[Sunlight]

"and 2,5-dimethoxybenzaldehyde is pumpkin orange for example"

A typo, 2,5-dimethoxynitrostyrene is pumpkin orange for example

[Rhodium]

Yes, of course... *bangs head against keyboard*  

I'll edit my post...

[Vibrating_Lights]

The road to suscess is paved with wasted purcursors

[Antibody2]

Can diethylether be used here IudexK reported sucess using t-butyl ether/IPA a couple years ago.

[Vibrating_Lights]

5gms Supposed 2,5 dimethoxyPhenyl-2-nitropropene Made Via MeOh NaOh Nitroethane then added to Hcl all at once.  Was added to [50mls toulene/10mlsEtOH/1.1gmsgms NaBH4]  at first addition of the nitropropene the solution was yellow orange like orange juice. Fter H2 fizzing had subsided 50 mls of H2O was added then 50 gms of Nacl .  This left a biphasic mixture..  There wa no color to the toulene layer. DIlute Hcl was added until there was no more fizzing.  This left the bottom layer a little greenish. The toulene was removed with a water asperator Leaving a brownish oil.  The temp during the removal of the toulene was around 150.c.  This was taken up in 150ml of MeOh and 20mls aa was added with 15mls of HgI2 solution.  14.8 gms of Al was added.  When the solution  came back to room temp it was filtered and worked up as usual.  Both phases at the extraction point were void of any identifying colors.  no amine was produced with Hcl.


WHat if weird here is that when this nitrostyrene was reduced with NaBh4 in MeOH/HCL the post Al/Hg rxn had a rust color to it that carried over into the the toulene. 
When The nitropropene was reduced today in the toulene EtOH it was clear.  also WIth the MeOh rdxn when i got to the AL phase the rxn never went to reflux.  With the rxn today it went all the way to reflux. To me that means that something was being reduced.  But why was there no amine.


Next step to make some nitropropene through the classic ammonium acetate method and see what the fuck is going on here. 
Just though I'd let yall know
VL_