Author Topic: Thermal isosafrole epoxide rearrangement trials  (Read 10022 times)

0 Members and 1 Guest are viewing this topic.

GlaseIs

  • Guest
Re: Thermal isosafrole epoxide rearrangement trials
« Reply #40 on: March 11, 2002, 05:08:00 PM »
Hope this doesn't sound stupid.. but would it be possible to nuke the distilled epoxide in a microwave to carry out the thermal rearrangement? And watch the reaction with a UV light?

On the 6th day God created man. On the 7th day, man returned the favor.

Vibrating_Lights

  • Guest
Re: Thermal isosafrole epoxide rearrangement trials
« Reply #41 on: March 11, 2002, 05:22:00 PM »
20 mins on high did nothing to epoxide.  Not saying it wont work but need to rig the microwave better before any thing else is attempted.
VL_

LaBTop

  • Guest
Isosafrole Epoxide Thermal Rearrangement Review
« Reply #42 on: March 11, 2002, 08:24:00 PM »
It's getting confusing in this thread, if I get it right, then noj's tests were not giving amine, V_Lights says he got some amine (or not, not really clear with those ultrashort reportings of him and the others, Flip etc), and I see only one method mentioned, which seem to give a consistent yield, Chromics on Rhodiums pages.

The thermal rearrangement tests (just heat the DISTILLED epoxide at 1 atm to 283-284C, keep it there 20 minutes, then it's ketone, or better, use vacuum at 9 Torr up to 140-145C and reflux with an aircondenser inbetween for approx. 2 hours to get the same ketone, then distill under vacuum to get pure ketone) seems questionable till now, still no real aminations?

Please give me any postnrs if there is one I oversee! I'm getting desperate from the overload of posts lately on the subject of thermal and catalytic (15% H2SO4) rearrangements, and they hop from one thread to another, why not start a new thread with all real factual testreports, and no blahblabla please from people who want attention.

Here's some reading stuff from the Search Engine :

Post 227831

(uemura: "Ketones from Propenylbenzenes via the di-bromides", Novel Discourse)
62 posts, Ketones from Propenylbenzenes via the di-bromides, Uemura's Höring refs etc. Novel forum. After Rhodiums

Post 232994

(Rhodium: "Re: Ketones from Propenylbenzenes via the di-bromides", Novel Discourse)
it gets again really interesting. ""I don't understand why noone has tested the hypochlorite or hypobromite route to the halohydrin, and then made the epoxide from that with a base. It is OTC, and very simple." I also don't understand, that's layed out in Uemura's starting post up there in this thread.

Post 218193 (missing)

(Ritter: "LiI catalyzed pinacol rearrangement possible?", Chemistry Discourse)
Li catalysed pinacol rearrangement possible? Chemistry forum.

Post 235999

(Chromic: "Asarone epoxidation by Oxone", Chemistry Discourse)
Chromic's Asarone epoxidation by Oxone.

Post 241293

(uemura: "Properties of some epoxides", Novel Discourse)
Properties of some epoxides, Epoxide Synthesis (described for anethole) and Asarone Epoxide Rearrangement both exellent write ups, wished everybody confirm to this kind of perfectionism and clarity!!!
And Rhodium's Asarone glycol distillation.
TLC techniques by Uemura and Osmium. Plus UV lamp recognision of spots on TLC plates.

Post 241585

(uemura: "Boiling Point Measurement", Chemistry Discourse)
Uemura's Boiling Point Measurement, epoxide thermal rearrangment.

Post 265056

(Osmium: "Re: Thermal isosafrole epoxide rearrangement trial", Methods Discourse)
Osmium's way of isomerization of an epoxide to the ketone under vacuum.

Post 264485

(Vibrating_Lights: "Thermal isosafrole epoxide rearrangement trials", Methods Discourse)
Same thread, Thermal isosafrole epoxide rearrangement trials of Vibrating_Lights (=Flip?):
""Yes only from the atm distillation of the un distilled epoxide the ketone from the crude rearrangement did not aminate.  however the ketone that was produced with the previously vac distilled epoxide did aminate in 66% yeild. (V_L)""
Noj however reports a failure to aminate: ""Ok, swim has some fluid in the freezer that won't freeze. The H2SO4 hydrolysis was done, then tried a bisulfite adduct, which failed. Tried to aminate anyway, and it failed.""
V_L tried a microwave: ""20 mins on high did nothing to epoxide.  Not saying it wont work but need to rig the microwave better before any thing else is attempted.""   Failed till today.


So, conclusion: who got a thermal rearrangement really working, and what yield of amine they got?
Only report is from V_L, 66%. No one else on Isosafrole. A bit meager result to bet your money on.
LT/

PS: And the latest thread

Post 243262

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

PSII:

Post 280823

(cheeseboy: "Re: mdp2p from oxone", Methods Discourse)
mdp2p from oxone thread, Cheeseboy claims success, but has not aminated yet, keeps us sitting on the tip of the chair untill he does!

WISDOMwillWIN

Vibrating_Lights

  • Guest
Re: Thermal isosafrole epoxide rearrangement trial
« Reply #43 on: March 11, 2002, 10:10:00 PM »
First off VL_ is not Flip. Vl used a computer that Flip had been using one day and accidently posted under his name!!!!!
Now
A mix of undistilled isosafrole epoxide/diol from an unbuffered oxone rxn subjected to thermal rearrangement resulted in polymerization and no ketone was produced although the mess of polymerized crap did smell of ketone.

Vac distilled Isosafrole epoxide from a buffered oxone run yeilded ketone. Which in turn yeilded amine.
Apparently in cheese's last unbuffered oxone run it . the 2 hr H2SO4 reflux was only enough to convert the diol to the epoxide.  how ever after distilling his epoxide he said he submitted it to thermal rearrangement and yeilded what he believed to be ketone.  Lets hope he up dates us on his amination. 
VL_

LaBTop

  • Guest
Re: Thermal isosafrole epoxide rearrangement trial
« Reply #44 on: March 11, 2002, 11:36:00 PM »
To clarify I include here again Chromics clear post from the "mdp2p from oxone" thread :

Well, 1-alkene (safrole) to 2-alkene (isosafrole) is obtained by heat and KOH. Then we go onto the oxidation with oxone:

If it's buffered (pH near 7): the 2-alkene becomes the epoxide
If it's unbuffered (pH acidic): the 2-alkene becomes the glycol
(The buffer when used is sodiumcarbonate or -bicarbonate, 85% oxone + 15% -carbonate.)

Then when that's extracted (better stripped of solvents by distillation) and put into the H2SO4 mixture, if it's the epoxide, then it's hydrolysized to the glycol (addition of water, which opens that little epoxide ring). Then the glycol is dehydrated and rearranged by H2SO4 to the ketone by H2SO4. 2hrs of reflux (with stirring) seems to be enough time, yields have always been pretty good.




Then I include your above post, again for clarity reasons, people could get mixed up:


A mix of undistilled (starting from isosafrole) epoxide/diol(=glycol) from an unbuffered oxone rxn subjected to thermal rearrangement resulted in polymerization and no ketone was produced although the mess of polymerized crap did smell of ketone.

Vac distilled (Isosafrole) epoxide from a buffered oxone run yeilded ketone. Which in turn yeilded amine.
Apparently in cheese's last unbuffered oxone run it (. the 2 hr H2SO4 reflux???) was only enough to convert the diol=glycol to the epoxide.  how ever after distilling his epoxide he said he submitted it to thermal rearrangement and yeilded what he believed to be ketone.  Lets hope he up dates us on his amination.


 

To clarify more, there seems to be a consensus between various testers at the moment, that there are 3 fractions observed when distilling crude oxonization product: a small forerun of glycol, a big run of ketone, and then a small afterrun of epoxide. Or the other way round.

Now here I can't follow you anymore, how do you know the experienced details of this :
""Apparently in cheese's last unbuffered oxone run it (. the 2 hr H2SO4 reflux???) was only enough to convert the diol=glycol to the epoxide.""
Are you a clairvoyant like Mrs Cleo? Or do you also use HIS computer?  :P  ;D

Don't take that too serious, you have earned it by multiple promisses of schocking writeups, up till now we have to seethe first one yet.
However, I appreciate your posts and work, don't get upset now suddenly, laddie, you'r prolly to busy to write anything more then short posts, go on pls. LT/


WISDOMwillWIN

cheeseboy

  • Guest
Re: Thermal isosafrole epoxide rearrangement trial
« Reply #45 on: March 12, 2002, 12:35:00 PM »
VL_ is cheeseboy main man. K Daddy?

Cheeseboy-a whiteboy with Soul Like a black guy without soul
May The Source Bee With You Always.

Vibrating_Lights

  • Guest
Re: Thermal isosafrole epoxide rearrangement trial
« Reply #46 on: March 12, 2002, 03:59:00 PM »
Vl_ friend swim has been having to deal with stupid personal BS including the loss of most notes and kitchen.  Till the dreams can be properly undertaken again a write up would be getto. A getto write up is worth shit.  Vl_'s internal trouble sensing unit thus saved him again.
VL_

uemura

  • Guest
Re: Thermal isosafrole epoxide rearrangement trial
« Reply #47 on: March 13, 2002, 02:48:00 AM »

Post 280991

(LaBTop: "Isosafrole Epoxide Thermal Rearrangement Review", Methods Discourse)



Thank you Daddy!


noj

  • Guest
Re: Thermal isosafrole epoxide rearrangement trial
« Reply #48 on: March 13, 2002, 05:34:00 AM »
I don't recall the amount used now PK. Whatever it was, it was slightly lower than the ratios chromic suggested in his writeup. I believe it was supposed to be something like 2300g oxone but I used 2000g. I may be wrong on that too, since I don't buy the small bottles of pool shock anymore and can't be certain if they were 1lb or 2lb.

The best yield SWIM got from the oxone reaction, was as Chromic suggested in his writeup, and using acid to redissolve the solids in the end. This required an excess of DCM to extract to epoxide.

The suggestion of using no methanol at all was visually accurate, but SWIM has no way to tell what has been made other than visual appearances. It LOOKED like epoxide, but as you stated, it must not have been. I have been frustrated by this reaction ever since I started playing with the amounts.

The main things I think would be helpful would be to mix the water, oxone and methanol together and then filter the precipitate, then proceeding with the isosafrole (buffer if needed).

I apologize if I misled anyone by these posts. I was excited at the time. Who wouldn't be with an OTC synth that was working! I'll leave the reporting to those more apt to do so. And from now on, I will keep notes in accordance with any professional bee. I just hate having incriminating evidence around. Not that I did anything illegal, these were just lucid dreams.

Everyone falls down. It's how fast you get back up that is important.

greeter

  • Guest
Re: Thermal isosafrole epoxide rearrangement trial
« Reply #49 on: March 13, 2002, 09:43:00 PM »
>I just hate having incriminating evidence around.

laptop + disk encryption software = secure lab notebook.

try it, you'll sleep better :)

-g

cheeseboy

  • Guest
Re: Thermal isosafrole epoxide rearrangement trial
« Reply #50 on: March 13, 2002, 11:04:00 PM »
Cheese's amination via cyano failed. No ketone. Some oil that looks yellowish green that smells like burned fruit, yet not ketone. Ummm wha? Should cheese try again, this time on a small 17gm batch just to have the exact ratios as the write up? Scaling up is dangerous it seems with this one and it seems that buffering is necessary to yield epoxide.unbuffered is a messy situation of tar like cCRUD that you lose your stirbar in FOREVER, until the H2SO4/HCl/acetone combo kicks it's ass. :-[  Faileure, but still lovin' it! now that's sportsmanship!! Thanks for the help everyone, including LabTOP for straigtening things out alot.

Cheeseboy-a whiteboy with Soul Like a black guy without soul
May The Source Bee With You Always.

wacko_reaco

  • Guest
LiI isosafrole epoxide rearrangement trial
« Reply #51 on: March 14, 2002, 05:59:00 AM »
Rhodium,
With the liI salt, is it imperivative to have it completely dr before you use it. I remember in another life we used to dry out PTSA covering it with benzene and then distilling the azeotrope, is ethyl acetate the required solvent to solvate the Li salt or to solvate the epoxide, because if the reaction could be performed in benzene then the hassel of drying the LiI could be overcome by simply distilling for a few minutes and then converting to reflux (no where did I leave that reflix head???)
Any ideas?
Can LiI be made by dissovling Li metal in HI??? (slowly of course)

wacka wacka wacka