Anethole epoxide from oxone

[backburner70]

I found this scrawled on a piece of paper in the trash. Thought I should pass it on to the elder bees and see what they say.

"29.6 grams of anethole was subjected to treatment with oxone per standard procedures. The reaction proceeded in the exact fashion described in the writeup. After 5 hours the look and smell was perfect. The solution was acidifed with 125mls of 31% HCl and all solids were dissolved. Everything was loaded into the sep funnel and upon standing a few minutes separated into 2 components: urine yellow on top and a darker reddish/gold/yellow oil on bottom. The darker bottom layer was in proportion to the expected epoxide yield so it was decanted and saved. Subsequent DCM extractions (3x75ml) were quick to separate, only slightly discolored, and no emulsions formed with shaking. The DCM was distilled off and only a few more mls of epoxide were obtained. These extra few mls were added to the original decanted bulk.

All in all, it just seemed too damn easy.

So the question: Is this reddish gold oil ready for an H2SO4 bath? It seems like it should need a brine wash or something(!) first. Will it matter if some pot bisulfate or sodium bicarb get thrown in with it? This whole exercise is just for education, not for consumption. The bee in question isn't really concerned about yield or viability, just getting a feel for oxone."

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[pickler]

https://www.thevespiary.org/rhodium/Rhodium/chemistry/oxone.epoxidation.html

[Chromic]

If you buffered it as I wrote in my document, I would recommend that you carefully distill the epoxide at atmospheric pressure (skip the H2SO4 rearrangement and distill it, it worked beautifully for anethole epoxide).

Raise the temperature past 200C slowly! (or do the H2SO4 rearrangement, but it's more work than just distilling the epoxide)

You'll get anethole ketone which will react perfectly. Test it by: 1) adding a drop to water, watch it sink (anethole floats) 2) check by doing a bisulfite test 3) try aminating 5g of PMP2P per MM to get a feel for the reductions. Taste PMMA if you dare, don't do over 80-120mg, trust me, it doesn't get better with higher doses.

[humidbeing]

Does the atm distillation epoxide> (higher temps)>ketone
as well?

 This hasn't been made clear yet.
singel wite intejunt male

[Chromic]

Yes, I am 100% certain that it works.

I rearranged anethole epoxide to anethole ketone and got PMMA in good yields. I also rearranged isosafrole epoxide to isosafrole ketone and got MDMA in poor yields (I blame this on my technique during that specific run, I accidentally added aqueous base to the foil before it had completed amalgamating...)

[backburner70]

pickler - Seen that doc, read it numerous times, thanks though!

Chromic - Many thanks for the reply. That other oxone thread is getting crowded, so a few more questions if you don't mind.

>If you buffered it as I wrote in my document,
Yeah, 45g of bicarb slowly added, had an initial pH of about 6.8.

>I would recommend that you carefully distill
Do you remember what temps did you were seeing for the epoxide to distill over? I know you mention the 200 degree mark. Did you heat first, then distill? Or did you just slowly crank it up until the ketone started coming across?

>Taste PMMA if you dare
Dare seems an appropriate word here. That's why the comment was made above about not being concerned about yield. The bee in question might not even bother to aminate. Who really needs 10g of PMMA.HCl in their life?

This does bring up a larger question though: Psychokitty mentions trying to acidify the post reaction mix with H2SO4 instead of HCl. This naturally leads one to consider the possibility of a one-pot oxone/rearrangment (using iso-saf of course). After 5 hours of oxone, add sulfuric, reflux, extract with DCM, and distill. Although I guess if thermal rearrangement of iso-saf turns out to be viable it will be a moot point anyway. Just thinking out loud.

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[LaBTop]

I would be interested to see ANYBODY repeat that oxone isosafrole thingy with heating/distilling at normal pressure, and then aminating the obtained product the right way, to see real yield. JUST CURIOUS. LT/
WISDOMwillWIN

[humidbeing]

Chromic and terbium have said that they've done it, why
wouldn't it work?

I'm sorry, you said REAl yeild. What does that constitute?
I crave..I YEARN

[Sinistar]

Is PMMA deathly dangerous like PMA is?

[Chromic]

LT: me too.

Temperature for distilling anethole epoxide was well over 200C, likely around 300C. I don't have a high temperature thermometer (ie markings stop at 260C) so I can't tell you exactly. I don't think Terb's done the thermal rearrangement, but I do believe that Ueruma and twodogs have.

[LaBTop]

MDP2P boiling point at normal pressure should be around 281°C, IIRC. The epoxide, can't find any figures on that, practice must give them. LT/
IIRC=ifIremembercorrectly
WISDOMwillWIN

[uemura]

Chromic,

, but I do believe that Uemura and twodogs have.

Just for the bees who still don't want to believe! Yes, the anethol expoxide thermal arrangement works very well, it works also for the crude epoxide.

The temperature of the boiling epoxide/ketone was 265-270DegC. Vapour temp about 5DegC less.

Let uemura add another evidence test for anethole ketone: Put into the freezer (-20DegC), the ketone should cristallise after some time if it's pure enough.

Carpe Diem

[backburner70]

Uemura - thanks for the info! Will give it a try and report back.

Everybody - Nobody cares to comment on the one-pot rearrangement idea?

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[Chromic]

Backburner, the correct sequence, which I performed, and which succeeded is:

Perform buffered oxone reaction, extract with DCM, distill with no vacuum to get your ketone.

It's that simple.Cleaning your distilling flask will be a bit harder...

[backburner70]

Chromic - I understand that part perfectly. And SWIM will try it out on anethole epoxide. The end product will get hit with some bisulfite to see if it is legit.

For clarity, let me re-state what I am asking: Assume for a second that some bee decided to perform an oxone reaction with iso-saf, and that same bee was a little paranoid of scorching their precious MD-P2P with those high (281!) temperatures.  Further assume the bee is lazy and at the end of the oxone reaction instead of dissolving the solids back into solution with HCl, they decide to add an appropriate ammount of H2SO4. Since their mix is already in a decent sized flask fitted with reflux condenser and is sitting on a hot-plate stirrer, they decide to do the 2 hour reflux right then and there, without ever isolating the epoxide from the oxone reaction mix.

Realize that I am just asking. I have not done this, I do not advocate it, I doubt it will work, and it is probably just a Plain Stupid Idea (tm). Is it lazy? Well yeah. Is it really that difficult to isolate the epoxide? Well no. Even if it had a remote chance of working, wouldn't it require a fair amount of tinkering to get it right? Probably. But always strive for efficiency, whenever and wherever possible.

Necessity may be the mother of invention, but laziness is her half sister.

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[Chromic]

The huge volume will be a pain if you don't extract the epoxide.

[Vibrating_Lights]

For the  thermal rearrangement of the isosafrole epoxide to be high yeilding the epoxide must first be vac distilled to remove the impurities that catalize the polymerization at high temps.  with vac distilled epoxide there is only small ammounts of polymerization.

[twodogs]

What makes you say that?

[Vibrating_Lights]

observed trial and error.  why do you people quit doubting and try it your damn self.

[twodogs]

Vibrator, I have tried thermal rearrangement of isosafrole glycol (got 60% ketone) and isodillapiole epoxide (got about 50% ketone.) It is just that when I saw your post using words like "impurities that catalyse the polymerization" I thought oooh he's a scientist. So.. what were your results from distilling crude epoxide and what did you get after vac distilling?

[Chromic]

Twodogs, I agree. I have tried it myself as well!

Distill the crude epoxide at atmospheric temperature. No polymerization happens. If you have the monoformyl or monoacetyl glycol it will work as well (however, you will notice the smell of acetic acid or formic acid in the distillate).

[Vibrating_Lights]

Some bee will post pics soon.
VL_

[backburner70]

Chromic - re:volume efficiency, Doh! Yeah, I wasn't even thinking about the associated volumes. I was more concerned with the oxone byproducts and salts interfering with the hydrolysis. Still learnin...

While we are on the subject of thermal rearrangement, if H2S04 relfux yields are about 50-60%, and thermal rearrangement yields are about 50-60%, has anyone ever tried iso-saf epoxide with LiBr/LiI in ethyl acetate?  Not exactly as cheap and OTC as the others, but I am curious if it is as high yielding as with the 3,4-dimethoxy in the European patent on Rhodiums.

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[Chromic]

There might be other OTC methods to hydrolyze the epoxide... more experimentation is definitely needed in this area. I don't know who has tried the LiI rearrangement, a quick search with TFSE revealed nothing but talk...

https://www.thevespiary.org/rhodium/Rhodium/chemistry/guest.phenylacetone.txt

is a good read of a description of dimethoxypropenylbenzene epoxide being rearranged with LiI in EtOAc.

[Rhodium]

Search for a Ritter post. I believe he tried the LiI isomerization.

[Chromic]

In 228754 Ritter says:
>Rhodium,  (I have) never run the epoxide rearrangement with LiI.

A good read on the synthesis of LiI by Ritter is in

Post 228375

(Ritter: "Re: Ketones from Propenylbenzenes via the di-bromides", Novel Discourse). But, more importantly, there has got to be other salts (likely hard Lewis acid cation / soft Lewis base anion) that would affect the rearrangement in good yield.

[Osmium]

LiI is hygroscopic as hell, to make it completely anhydrous (and I think it has to be completely anhydrous) you will need a GOOD drying agent.

[Osmium]

Read the whole thread, the LiI synth by ritter doesn't work as posted, he later corrected himself!

[Rhodium]

The preferred method of drying LiI is to heat it over P2O5 in a vacuum dessiccator for 1h at 60°C and then 1h at 120°C. That is pretty vigorous conditions.

[Chromic]

Os, thanx for the correction. Point of my post being: the Pinacol rearrangement and the epoxide rearrangement are both acid (or heat) catalyzed... and there's got to be lewis acid catalysts that are weaker than sulfuric acid (which tears at the molecule in places we don't want it touching) but are stronger than LiI (which won't even rearrange a glycol).

[Flip]

I think i'm gonna take VL_'s back on the thermal ATM rearrangement issue as per the results of

Post 264485

(Vibrating_Lights: "Thermal isosafrole epoxide rearrangement trials", Methods Discourse).

[backburner70]

For what it is worth:

"25.5g of crude anethole epoxide was removed from the freezer and placed in a simple distillation unit that utilized a sand bath to provide heat. Stirring and heating to 200°C commenced. After about three hours and numerous cranks of the heating dial, nothing had distilled across so the bee went "insulation crazy". More sand was added to the bath and the still head was wrapped in rockwool. After about three more hours and numerous more cranks on the heating dial nothing had distilled across. The max temp had been reached on the hotplate, so the whole unit was shut down and allowed to cool. After cooling the bee expected to find a charred black mess in the distillation flask, but instead found that the red/gold epoxide had turned into an opaque black liquid.

The sand bath was replaced with an oil bath and vacuum distillation was commenced. The first fraction to come across was a mobile brown oil (ketone!) with the exact properties described elsewhere by Chromic. 9.3 grams of ketone, bisulfite tests confirmed this. The next fraction came across about 14° higher and was a pale yellow oil, similar in smell to the original epoxide, 2.9 grams that was assumed to be the glycol. (How does one test this?) 

The remaining contents of the flask would not distill across at higher temps.  This is primarily because of the fact that upon cooling, the distillation flask contents turned into a thick, black tar. Clean up was achieved by soaking in acetone and using conc. sulfuric to clean up the remainder. The magnetic stir bar used was toast.

Amination of the ketone was not attempted."

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[Rhodium]

Why use sand baths? They conduct heat very inefficient and uneven. You really risk breaking glassware using sand.

[uemura]

backburner70!


Did you check Uemuras first write-up on the anethole ketone in

Post 243262

(uemura: "Epoxide Rearrangement Example", Methods Discourse)?

Rearrangement
The crude! epoxide was loaded together with some boiling stones in a 250ml flask equipped with a small Liebig condensor. The flask is heated by means of an electric mantel. At 260DegC (760Torr adjusted) the epoxide starts to boil (measured inside the liquid). Some 'spurious explosions' caused by the bumping stones or epoxide happened without getting out of control. The reflux is continued for 90min, the inside temperature stayed at 263DegC.
After cooling down a normal pressure destillation setup was performed. The flask was heated again and between 255 and 275Degc (*) 19g of a clear yellow-green oil came over. Then the temperature dropped down, a red-brown liquid remained in the destillation flask (Temp liquid > 283DegC). This is a yield of 19g ketone from 30ml olefine, approx. 57% yield which isn't really good but isn't bad either. (**).
A bisulfite test with 1ml of the received destillate worked like a super-duper-easy confirmation, no oily precipitae, after 20sec shaking pure bisulfite compound (light yellow in white gel) appeared.

There was indeed a brown-red residue, likely the glykol. But not tar, neither had problems with clean-up later.

Here is a typical pic of the apparatus used for rearrangement (this time not a Liebig, but just an air cooled condenser)


The anethole ketone is a yellow oil which solifies in the freezer:

Carpe Diem

[Vibrating_Lights]

Vac distil your epoxide befoer attempting rearrangement and your flask for the rearrangement will clean easy.  godd luck cleaning the flask.
VL_

[backburner70]

Rhodium - Sand was used because an RB flask was the only one available at the time and peanut oil didn't seem a good choice.  No mantles here. The lab space isn't exactly "luxurious," think "ghetto".

Uemura - I did see that post, but I was following Chromics "just distill" advice. No big deal. I later found out that the hotplate is only rated for 260C, tops, and I don't think it actually even made it that far. This exercise was not meant to be exactly on the money, it was more for education.

VL - Conc Sulfuric did the trick (finally!). 24 hour soak in acetone, 2 hour soak in H2SO4.

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[LaBTop]

Why not use a bunsenburner open flame for the high temp atmospheric rearrangement??
Safes your hotplate, stirring seems not really important here, shaking will do. LT/
WISDOMwillWIN

[LaBTop]

I once thought about using soldertin as a heating bath for high temps.

Would like to see what happens when you can find out if soldertin which is mixed IN the flask, will interfere with the epoxide reaction. If not, then you for sure will distill all oil over at atmospheric pressure, leaving behind just fluid soldertin. Pour that out fast, and your flask will be as clean as a baby bumm. LT/
WISDOMwillWIN

[Vibrating_Lights]

in vl_,s dream a colmans camping stove was uses.

VL_