Sciencemadness Discussion Board - 2,5-dimethoxyphenyl-2-nitropropene synthesis - 89.3% yield

2,5-dimethoxyphenyl-2-nitropropene synthesis - 89.3% yield

niobium - 25-1-2006 at 12:29

Hello boys and girls,
Picking up on Stoicheomtric Steve's tradition of posting extra good procedures for interesting compounds swin would like to report the following -
95ml IPA was placed in a 250ml open beaker, placed on the the hotplate/stirrer, and stirring commenced. 20g of 2,5-dimethoxybenzaldehyde was weighed and placed in the beaker, followed by the addition of 2.16g of EDDA (0.1eq). The stirred mixture was heated slightly until complete dissolution, and then 11.7g of nitroethane (1.3 eq) was added. Heating was turned on and stirring continued. The temp rose to 60-65degC, and the solution was left to stir for 1.5 hours. During which time the volume decreased by 20ml or so.
The beaker was then stoppered, and placed aside for crystalization to occur. After 4 days the solution (which was a thick slurry of xtals) was filtered, filter cake and the beaker washed with cold IPA. The xtals were placed back in the open beaker, 50ml methanol was added, and the mixture was heated on a water bath. Then beaker was stoppered again, and left to cool down. once cool, it was transfered to the fridge for complete crystal formation. After 12 hours the mixture (again looking like a semi solid xtal cake) was filtered, washed with cold methanol, and allowed to dry.
24g of clean 2,5-dimethoxyphenyl-2-nitropropene were collected in total, accounting for 89.3% yield calculated from the benzaldehyde.

As far as swin knows, this is the best reported synthesis of this compound, with reported yeilds varying from 50-70%. The ease of this procedure, combined with the high yield makes swin think this is the optimal catalyst and reaction conditions for this compound.

[Edited on 25-1-2006 by niobium]

CherrieBaby - 26-1-2006 at 03:25

EDDA?

stoichiometric_steve - 26-1-2006 at 06:34

Quote:

Originally posted by CherrieBaby
EDDA?

pff...Ethylene Diammonium Di Acetate

excellent work, Mr. N.

zooligan - 26-1-2006 at 07:21

Quote:

Originally posted by niobiumThe ease of this procedure, combined with the high yield makes swin think this is the optimal catalyst and reaction conditions for this compound.

Any idea if this would work equally as well when reacting with nitromethane instead of nitroethane?

-z

[Edited on 26-1-2006 by zooligan]

enima - 26-1-2006 at 09:33

Yea, it works better >95% yields

niobium - 27-1-2006 at 02:59

with to make 2,5-dmns it works exceptionally well, requiring usually less then 36 hours for full xtalization and with a yield like enima stated of >95%

100% yield

DNA - 17-10-2008 at 01:18

Just found this topic and wanted to report that *I* got an excellent 100% yield on the 2,5-dimethoxyphenyl-2-nitropropene.

2g of 2,5-dimethoxybenzaldehyde was dissolved in 10mL glacial acetic acid, after dissolving it 1,3mL nitroethane was added and after swirling 4mL of cyclohexylamine was added.
The mixture was heated at ~80*C for 3 hours. Then it was left to cool down, DCM was added and the nitropropene extracted. The DCM was washed with water once, after evaporation of the DCM there was left a yellow-orange oil, which overnight crystalized into dark yellow crystals which weighed 2,61g (116% yield).
Then this was recrystalized from boiling methanol (17mL), this crystalized overnight yielding fluffy bright yellow crystals. Which after drying yielded 2,30g (100% yield)!

[Edited on 17-10-2008 by DNA]

[Edited on 17-10-2008 by DNA]

<sub>Edit by Nicodem: How many times do I have to say that "swiming" is not allowed? This is the last warning before I start removing the whole posts instead of just editing.</sub> :mad:

[Edited on 20/10/2008 by Nicodem]

Dextrose - 20-10-2008 at 08:39

Nice yield, but i have seen/heards reports of people getting 85-90+% in this condenzation using methylamine acetate with a 75 minutes reflux on water batch - finished in less than 3 hours.

I don't mean to burst your bobble.

[Edited on 20-10-2008 by Dextrose]

stoichiometric_steve - 20-10-2008 at 09:39

Dextrose, i wouldn't be too sure of that. Methylammonium Acetate is a beautiful catalyst for the Henry reaction if unactivated aromatic Aldehydes are employed. At least with Nitromethane, activated Aldehydes give mostly polymerized product unless great care is taken.

chemrox - 20-10-2008 at 13:33

If you don't have EDDA on hand is there another agent (base I'm thinking) that would facilitate this? Cyclohexylamine?

BTW: the use of "swim" is discouraged here but thanks for the writeup-outstanding!

[Edited on 20-10-2008 by chemrox]

Nicodem - 20-10-2008 at 22:50

Quote:

Originally posted by starman
How about EDTA?Is there a difference between "tert acetic acid" and "tert acetate"?

The acronym EDTA generally stands for ethylenediaminetetraacetic acid which is not a primary or secondary amine and as such irrelevant to this thread topic. I have no idea what do you mean with "tert acetic acid" and "tert acetate" though.

jarynth - 20-10-2008 at 23:09

Quote:

Originally posted by starman
How about EDTA?Is there a difference between "tert acetic acid" and "tert acetate"?

The latter is the salt of the former. E.g. "EDTA sodium" is the sodium salt of EDTA (acid).

EDIT
Sorry steve, I didn't read the whole thread and wanted to complete Nicodem's answer. EDDA is related to EDTA as both have =N-CH2-CH2-N= in them ("ED"). Basically EDDA is the (ionic) salt of ethylenediamine with acetic acid, while EDTA is ethylenediamine where each aminic hydrogen is substituted with acetic acid.

2,5-Dimethoxynitrostyrene with EDDA

[Edited on 20-10-2008 by jarynth]

stoichiometric_steve - 20-10-2008 at 23:27

starman, jarynth, CUT THAT SHIT OUT PLEASE - it would be kind if you deleted your posts as they contribute absolutely nothing to this topic

DNA - 21-10-2008 at 02:12

Concerning the 2,5-dimethoxynitropropene apparantly the reduction of it with BF3.Et2O and NaBH4 (à la varma and kabalka), gives crude product 90% yield so it is stated in a still to be published article.

[Edited on 21-10-2008 by DNA]

Barium - 21-10-2008 at 03:45

Quote:

Originally posted by stoichiometric_steve .....activated Aldehydes give mostly polymerized product unless great care is taken.

In my experience, just switch from alcohol or nitroalkane solvent to acetic acid in order to avoid polymerisation.

stoichiometric_steve - 21-10-2008 at 09:32

Anybody ever tried out other conditions than what is laid out in PIHKAL (Ariadne) for the condensation of 2,5-DMBA with 1-Nitropropane? NH4OAc ain't my favourite...

edit: This is about the reactivity of 1-Nitropropane, not the manufacture of drugs.

[Edited on 22-10-2008 by stoichiometric_steve]

Nicodem - 21-10-2008 at 23:40

Warning!

I don't want to hear discussions about increasing the yield of anything by a couple of %. This is closely related to economy and has little to do with science. By discussing about such things you put a shadow on your intents and make it look like it is not about amateur science. This chemistry might not be about illegal drugs, but it is nevertheless about intermediates toward psychoactive drugs. Even though most of them are legal in the majority of world legislations, it is nevertheless inappropriate to discuss about them in the same context as a meth cook would. Either you discuss about new routes to old targets or any such scientific thing, or just move the yield maximization issue to a more appropriate forum. I find this thread acceptable but on the verge of acceptability. Once you cross this verge I will close this thread.

(If you have any objections with this warning use the U2U rather than the post reply button)

stoichiometric_steve - 22-10-2008 at 00:56

Quote:

Originally posted by Nicodem
(If you have any objections with this warning use the U2U rather than the post reply button)

Sorry, this should be read by everyone.

I beg to differ that this is about economy. This is more about ecology - less unreacted precursor, less waste...

What i am working on is easy/high-yielding/environmentally benign synthetic techniques.

I don't think this thread is anywhere near the standards of other forums where "meth cooks" meet.

Dextrose - 27-10-2008 at 21:36

Quote:

Originally posted by stoichiometric_steve
Dextrose, i wouldn't be too sure of that. Methylammonium Acetate is a beautiful catalyst for the Henry reaction if unactivated aromatic Aldehydes are employed. At least with Nitromethane, activated Aldehydes give mostly polymerized product unless great care is taken.

So true, so true...

I have a long time ago "burned off" too much of the aldehyde, in just 15 minutes... Beware of the amount of the catalyst !!!

Isomeric_Fred - 28-10-2008 at 00:28

I spoke to niobium, who said that EDDA is ethylenediamine diacetic acid salt.
Dextrose, i highly doubt a 75minutes reflux will yield well, niobium says it does not work well, and produces a red product, which once cleaned does give the yellowish 2,5-dmp2np but at lowered yields.
the Me.Am.Ac cat is good for other stuff, but less good for this one. Perhaps a shorter reflux period can yield well, or no reflux at all.

starman - 28-10-2008 at 03:53

Quote:

Originally posted by Isomeric_Fred
I spoke to niobium, who said that EDDA is ethylenediamine diacetic acid salt.

Yeah,thats what I thought,had seen these acronyms EDTA EDDA DPTA etc used in chelation complexes.
So I guess my post which I deleted as per request with all due chagrin wasn't so dumb after all huh?

Nicodem - 28-10-2008 at 04:53

Please stop with this nonsense. "EDDA" in this case stands for ethylenediamine diaacetate (H2NCH2CH2NH2 * 2AcOH), a well known catalyst for these condensations. It is not one of the ethylenediamine acetic acids used for cation chelation (which would have no function in this reaction anyway).

By not using acronyms all this confusion would be have been avoided. I repeated it several times to define all the acronyms used, but nobody listens.

Isomeric_Fred - 28-10-2008 at 05:19

Quote:

Originally posted by Nicodem
Please stop with this nonsense. "EDDA" in this case stands for ethylenediamine diaacetate (H2NCH2CH2NH2 * 2AcOH), a well known catalyst for these condensations. It is not one of the ethylenediamine acetic acids used for cation chelation (which would have no function in this reaction anyway).

By not using acronyms all this confusion would be have been avoided. I repeated it several times to define all the acronyms used, but nobody listens.

As far as I know, ethylenediamine diacetic acid *SALT* = ethyelendiamine diacetate. In any way, the correct compound here, is, as Nicodem pointed out, Ethylenediamine diacetate, CAS# 38734-69-9, NH2CH2CH2NH2 · 2CH3COOH.

hope this helps...
On another note, Nicodem, I think yield optimization is quite a worthy topic. Is it because this compound *MAY* lead to illegal compounds that this kind of talk is frowned upon?
Kind of dissapointing to see legitimate chemical discussion gets frowned upon here.
I agree if this was talking about how to make Heroin (or any other illegal drug) and its yield optimization it might be inappropriate, but for this, I find it hard to understand

starman - 29-10-2008 at 05:03

Quote:

Apologies Nicodem,having looked further it is a pretty silly assumption.Will pay more attention to seven star generals in future

jon - 31-10-2008 at 22:00

what's polymerizing? the aldehyde or the iminium intermediate? or, the nitro styrene?
if the former then it would make sense that a more nucleophilic amine like a primary amine and an acid catalyst like acetic acid would favor the formation of the imine hence better yeild, any input here on this? i know the positive side (the backside) of aldehydes and ketones in the prescence of bases tend to polymerize, when heated. Is this what your suggesting is taking place?

also what causes the resulting nitro styrene propene to polymerize? i know if it sits to long it does this, are there any conditions that favor this?
maybe staring at it the wrong way, for example?

[Edited on 1-11-2008 by jon]

quote:

have a long time ago "burned off" too much of the aldehyde, in just 15 minutes... Beware of the amount of the catalyst

unquote:

so it's acid base chemistry and heat huh?

is the nitro whatever polymerizing, or the aldehyde?
i know certain reductions of the nitro (whatever) go well in acidic solution so it may be the base, and heat, and long rxn time polymerizing the product nitro styrene.
occams razor.

[Edited on 1-11-2008 by jon]

[Edited on 1-11-2008 by jon]

Dextrose - 18-12-2008 at 21:10

Quote:

Originally posted by Isomeric_Fred
I spoke to niobium, who said that EDDA is ethylenediamine diacetic acid salt.
Dextrose, i highly doubt a 75minutes reflux will yield well, niobium says it does not work well, and produces a red product, which once cleaned does give the yellowish 2,5-dmp2np but at lowered yields.
the Me.Am.Ac cat is good for other stuff, but less good for this one. Perhaps a shorter reflux period can yield well, or no reflux at all.

I must admit that i was wrong.
I did this condensation a couple of years ago with 200'ish of the aldehyde.
Got a yield of 90+% after a terrible clean-up, where i found out that MeOH is THE solvent to rxtl this nitrostyrene in.

I didn't do my calculations right, and just added up the catalyst (Me-acetate) from previous notes (duh!), and the product suddently crashed out after not more than 15 minutes, and i immediatly removed the condenser, and cooled the RB under cool running water.
(Yes, not more than 75 degrees celsuis, using a water bath and heavy stirring!)

Though i remember that there were a lot of impurities, that only the MeOH could remove - but still, the product was bright orange, and a recently Al/Hg-reduction of the 3 year (or so) old nitrostyrene, let to that i saw that it's supposed to be bright banana-yellow. (I was bored)

I'm sorry 'bout the bitching! - Anyway the Al/Hg worked out to my surprise (crap yield but what the fuck...) - i'll clean up the leftover nitrostyrene as soon as i get hold of some MeOH... no rush though.

Actually i hate the Al/Hg... talking about enviromental "harm reduction" in high yields in this topic, it is really a toxic pain in the ass!

And last, i did a variety of condensations back then, and another one with the same aldehyde and catalyst (way too much!), caused 50g or so to polymerize in just about 15 minutes also.

I didn't use the salt, but 40% methanolic MeNH2 and GAA.

Dex

[Edited on 19-12-2008 by Dextrose]

brew - 19-12-2008 at 01:56

The argument, that we should be able to discuss this chemistry, albeit leading to the possibility of this said chemistry being used to manafacture illegal compounds. and what a shame it would be, to have to deny such discussions etc, etc, Well the Ist sentence pretty well sets the stage of how this thread appears, dont you think, Well swim thinks so. Wave the fucking flag or what. Thats how it appears when you first read it, albeit from 2006 to now. It really annoys the hell out of me. Good chemistry, and the use of slang/ swim, etc, and then a defensive attitude when this is somewhat pointed out, it degrades it to just another meth dribble.

[Edited on 19-12-2008 by brew]

stoichiometric_steve - 19-12-2008 at 10:12

brew, what the fuck?

brew - 19-12-2008 at 15:55

WTF? I suppose I could cut and paste, but really cannot be bothered.

DJF90 - 19-12-2008 at 16:39

brew has a valid point. Do you think that when Albert Hofmann first synthesised LSD he wrote in his lab book "swim made some LSD today"? Of course he didn't! Because he was a chemist, not a meth cook. I believe for interesting chemistry like this to be discussed, it should be discussed as chemistry, with the exclusion of terms like swim.

Such terms are in place to "decieve" others of your true intentions (you aren't fooling anyone!), and as chemists, our intentions *should* be honest (as we are only interested in the chemistry!). It does not matter that you made 2,5-dimethoxyphenyl-2-nitropropene, so long as you don't intend on finding an unsavoury use for it.

Dextrose - 19-12-2008 at 17:41

I don't get this... Are someone being flamed here, or did brew just had a bad day?

Where i am residing, none in this topic is illegal to practice in real life.

And... I'm not SWIMming anymore, and you shouldn't be either, since brew and DJF90 has a point about this.

DJF90 - 19-12-2008 at 18:02

I don't think anyone is being flamed, I just think that swimming is pointless and a term employed by those trying to decieve others of their true intentions. If drug manufacture is "your thing", this isnt the place to discuss it, and as swim is a term associated with cooks, using it when describing a procedure (eg synthesis of precursors such as the one this thread is about) only causes (due) suspicion by others.

EDIT: This is fairly interesting chemistry, so can we please talk about it as chemists?

[Edited on 20-12-2008 by DJF90]

Dextrose - 19-12-2008 at 18:49

Yeah, science instead of point-less discussions.

Anyhow, i will point out that if you read "2,5-dimethoxyphenyl-2-nitropropene" and associates it with drug-chemistry - that's your fucking dirty mind, just like a pedophile would think of sex if he sees a 6-year old girl... Extreme comparison, i know, but i think you get my point.

I agree with stoichiometric_steve about the enviromental aspect in high yields - something i've never really given a thougt about... I would like to see some topics about "Eco-chemistry"

And BTW, i just realized that all the time i've been talking about the nitroSTYRENE, not the nitropropene... sorry for bringing in the confusion.

No blaming,
Dex!

[Edited on 20-12-2008 by Dextrose]

DJF90 - 19-12-2008 at 19:39

What associates this thread with drug chemistry is the swimming on the first page, nothing to do with my mind. High yeilds are great, I agree, but tweaking a reaction to get a small % increase isn't going to benefit the environment much on this scale. If you are worried about making alot of waste then work on a smaller scale (Woelen is a good example of a chemist who works in an environmentally sound way - I'm sure there are others here but he is the first that comes to my mind).

And if you are accusing me of having a "dirty mind" because I see a thread about a precursor that involves swiming then I am very much guilty.

Dextrose - 19-12-2008 at 20:35

Like i wrote, no blaming, and no acusing - it wasn't directed at you, but at whoever might be reading this thread.
I'm sorry that it seems like it, it is merely a reply, but i hope you'll survive.

I've been swimming a lot, but drowned - and we ain't saints - or what?

[Edited on 20-12-2008 by Dextrose]

brew - 20-12-2008 at 14:45

I just read this, and wanted to clarify something. OUt of respect for the marjority of people who are into chemistry for the sake of chemistry, I wouldn't call myself swim. It not only redlights me, but it redlights this forum and I dare say many people want to be associated with this forum and for it not to necessarily infer that they are really cooks called swim. I am not against that chemistry or that particular compound as such, but when I see it written, and in particular for the type of compound it was referring to, and in this particular forum, I am going to react.

I really have no more to discuss on this matter, I wasn't flaming no -one in particular, Usually I dont say squat, but when I saw it , I reacted.

Nicodem - 22-12-2008 at 08:58

Deleted the last three posts of this useless flame war.
"Swiming" is not allowed on this forum anyway, so I see no point in this discussion. The only reason why the original post of this thread contains the word "swim", or variants of it, is because it was posted before the ban.

brew - 22-12-2008 at 18:39

Okay, but I thought it was current as from 2008, and as I read it, after all thats been said on the matter etc, and to do with this particular compound etc, I reacted. I meant nothing personal to noone.

tom_servo - 23-12-2008 at 06:42

Quote:

Originally posted by enima
Yea, it works better >95% yields

I was under the impression that nitromethane would cause this reaction to not work at all or to give smaller yields.
Have you seen this first hand?
If so what ratios were used?

Never mind i thought you were talking about 3,4-methylenedioxyphenyl-2-nitropropene from piperonal

[Edited on 23-12-2008 by tom_servo]