nitrostyrene help

2cman · Sun Jul 03, 2005 11:35 pm

hello all.
been a lurker here for quite some time, and im in a tight problem.
i folowed the ethylenediammonium route to 2,5-dimethoxy-nitrostyrene ala rhodium :
I took ethylenediamine (98% commercial) and dripped in it GAA.
once all done, and xtalization seemed complete, i vacuum filtered, washed with ether, and cold methanol, and vacuum dried.
then 9g of EDDA, 83.1g dimethoxybenzaldehyde (98% commercial) were placed in 400ml ipa and warmed and stirred gently to get a clear solution. the solution didnt get clear even after 1 hour, an i accidently scorched a bit (just a bit) since i forgot the hot plate was on, and placed the earlewnmayer straight on the plate at first.
anyway i said, that if not all dissolve then not all dissolve and i added 36g nitromethane and stirred for 1 hour.
after 1 hour i filtered a bit to try to get the unsolubles out, but the formed nitrostyrene (which is in oil form) isnt soluble in ipa either so i cant filter the unsolubles out.
How can i clean the nitrostyrene? do i must need to distill?
I will wait till all nitrostyrene xtalize, and then see what to do.
probably it is contaminated with the benzaldehyde (and soe scorched benzaldehdyde)....
please help with advise...

2cman · Mon Jul 04, 2005 5:37 pm

ahhh. bump? anyone? help?

Harmonia · Mon Jul 04, 2005 9:06 pm

http://www.erowid.org/archive/rhodium/chemistry/edda.html

2cman · Tue Jul 05, 2005 6:17 am

Harmonia, Ive followed the procedure quite nicely. and i also said that i left to xtalize, and will check it later on (after 36 hours like the writeup says).
Anyway, it did xtalize in a beutiful manner. i now understand the statement of "intense orange"!
anyway, i still think it is slightly contaminated with benzaldehyde, though probably just a small bit. I will prolly first rextalize from boiling ipa, then reduce the whole shebang, then try to to purify it further via acid/base. then ill see what happens.
The only thing i did which was differrent then the writeup is that not all of my benzaldehyde dissolved. If you think it takes more then 1hour to dissolve the benzaldehyde in slightly warm ipa, please say so.
Thanks for the help anyway Harmonia.

Vitus · Psychoscientist

Don't rub your nose with 2,5-DMNS on your hands Wink

Harmonia · Tue Jul 05, 2005 10:58 am

It can take some time for it to dissolve but probably not an hour if you use slight heating and magnetic stirring.

I doubt your nitrostyrene should be contaminated with any considerable amount of aldehyde if you recrystallise it. And I'm definately shure that any aldehyde won't follow through the reduction process with a good a/b workup (alternatively distillation of the freebase).

Ephoton · Tue Jul 05, 2005 2:12 pm

not sure about dimethoxy nitrostyrene but straight nitrostyrene crystalizes on its
own in the freezer and if it doesnt you can use a very cold metal object to
start crystalization usualy took me two days. maby the two ethers off of the benzene ring hinder this though I am not sure.
nitrostyrene can be distilled under reduced pressure and I would say this would
also be true for the dimethoxy nitro compound.

Harmonia · Tue Jul 05, 2005 7:27 pm

I would strongly advice not to distill nitrostyrene even under reduced pressure as it most likely would decompose. Recrystallisation is more than enough as purification.

2cman · Tue Jul 05, 2005 11:12 pm

for your viewing pleasure, some "intense orange" DMNS!
In the reaction vessel

And after filtering Very Happy

2cman · Tue Jul 05, 2005 11:18 pm

sorry for the huge pics in the post. dont know how to link the thumbnails to the original pictures... anyway enjoy!

Harmonia · Tue Jul 05, 2005 11:48 pm

Looks great!
I love the look of nitrostyrenes. Smile

Good luck with the reduction.

Ephoton · Wed Jul 06, 2005 3:02 pm

well as far as harmonia said on distillation this could well be the truth.
I have not personaly ditilled a nitrostyrene but have read of others recomending
it in the case of none crystalization.
do you think steam distill would pick up nitrostyrene without decompostion
harmonia

joe_aldehyde · huxleys associate

heating nitrostyrenes far beyond their mp. is not a good idea, and afaik most nitrostyrenes/propenes melt in the range of 55-75 deg.c
stirring them with water for a while and then putting them back in the freezer after decantation of the water layer helps sometimes. swim found out that in his first experiments, the nitropropenes wouldn't crystallize since the reaction wasn't finished.

icecool · Insistent Chemist

SWIM just made some 2,5-DMNS and here are the pictures, he's still waiting for 36 hours until the reaction is complete (at room temperature and no stirring).
After 50minutes spontanously crystals preticipated and it was already quite full of crystals.
Here are some pictures.