Author Topic: cl2 + koh + iso = mdp2p  (Read 11662 times)

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jacob019

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Re: cl2 + koh + iso = mdp2p
« Reply #20 on: October 09, 2001, 05:02:00 PM »
why all this distillation setup why not just mix some br2 and isosafrole at cold temps.
C10H10O2 + Br2 --> C10H8O2Br2 + H2
Is this not correct?

Osmium

  • Guest
Re: cl2 + koh + iso = mdp2p
« Reply #21 on: October 09, 2001, 05:14:00 PM »
There is no H2 released!

Yes, dissolve your isosafrole in your solvent of choice and add the Br2.

The Br2 can of course be prepared in situ, but since this means water is present the halohydrin will be the product. Which is no big deal at all, since it will produce the same intermediate in a shorter time during the KOH reflux.

That's what I would do if I wanted to go that route:
prepare a solution of NaBr in water, acidify with HCl or H2SO4, add the isosafrole dissolved in some DCM or chloroform or CCl4 or whatever, place in ice bath and switch on the stirrer. Then add H2O2 slowly, dropwise. This will generate Br2 which is extracted into the organic solvent where it immediately reacts with the alkene.
Once the required amount of H2O2 has been added let phases separate, wash organic layer with some water or diluted NaOH, remove solvent, and continue with the KOH reflux.

cilliersb

  • Guest
Re: cl2 + koh + iso = mdp2p
« Reply #22 on: October 09, 2001, 05:21:00 PM »
The distillation setup is to prevent having to isolate Br2 from the 48%HBr / H2O2 / H2O mixture with DCM extracts that are not as effective as one may think. That's if you consider the solubility of Br2 in the above mentioned mixture.

You'll notice that during that process the Br2 distills off as it is formed so you get very pure Br2 hitting your reaction mixture as opposed to the lesser purity of Br2 from the extract.

In spite of the initial setup of the equipment taking a bit more time and effort, it makes the isolation of Br2 and addition to the Iso a one step procedure.

I don't know, just seemed a good idea I guess!

otto

  • Guest
Re: cl2 + koh + iso = mdp2p
« Reply #23 on: October 09, 2001, 07:29:00 PM »
hi osmium,

do you have some refs for that the halohydrine would give MDP2P upon KOH reflux? I remember the epoxide being formed from halohydrins with alkali. will the epoxide give MDP2P under these conditions?
if so, you could theoretically use bleach on isosafrole to form the clorohydrine.
another question: can one use asarone in this procedure or is it too sensitive?

otto

jacob019

  • Guest
Re: cl2 + koh + iso = mdp2p
« Reply #24 on: October 09, 2001, 09:01:00 PM »
Ok here it is.  An improved workup of osmiums procedure. I've balanced the equations and calculated mass.  The equations I used were as follows.  I'm not sure if any of this is right but here it goes.  Oh and none of this is adjusted for water content and I don't use any excesses of anything. So I definately need imput.

1NaBr + 1HCl --> 1NaCl + 1HBr
2HBr + 2H202 --> 1Br2 + 2H20 + 2OH
1C10H10O2 + 1Br2 --> 1C10H10O2Br2
which when given mass values based off of 50g iso gives:
63.1g NaBr + 22.3g HCl (or 60g H2SO4) --> 46.9g HBr
49.6g HBr + 20.9g H2O2 --> 49g Br2
50g isosafrole + 49g Br2 --> 99g dibromoisosafrole

63g NaBr in 63g water was added to 22g HCl.  50g isosafrole in 50g DCM was added, and the mixture was placed in an icebath and stiring was initiated.  21g H2O2 was added dropwise over 10 minuites.  Stiring was contined for another 5 minuites.  The mixture was thrown in the sep funnel and the aquius layer was thrown out.  The organic layer was washed once with 150g water and once with 150g 15% NaOH solution.  DCM was distilled off.  Remaining solution was refluxed for 10 hours with 15% KOH.  3.2 times the mass of the dichloro was used.

Since I'm using 15% H2O2 I'll use 140g of it.

Would this procedure work on safrole to produce bromosafrole that could be used in agent smith's writup instead of the HBr gasser? Or would that produce a worthless dibromosafrole compound?

Rhodium

  • Guest
Re: cl2 + koh + iso = mdp2p
« Reply #25 on: October 09, 2001, 09:25:00 PM »
No, dilute aqueous HBr does not add effectively to safrole.

IudexK2

  • Guest
Re: cl2 + koh + iso = mdp2p
« Reply #26 on: October 10, 2001, 08:14:00 PM »

2HBr + 2H202 --> 1Br2 + 2H20 + 2OH




Isn't it 2HBr + H2O2 --> Br2 + 2H2O?

Could the diiodoisosafrole bee made by using I2 instead?


jacob019

  • Guest
Re: cl2 + koh + iso = mdp2p
« Reply #27 on: October 10, 2001, 08:59:00 PM »
That would make more sense.  Thank You.
So the amount of H2O2 should be cut in half.  But couldn't that be used in excess anyway?  I imagine I2 could be used, but to what advantage?  Some claim it's more reactive than Bromine, so maybe yields would be a little better.  But iodine is barely OTC, and bromine is cheap.  Also, I2 isn't liquid at room temp, although it would most likely go into solution.

Lem2

  • Guest
Re: cl2 + koh + iso = mdp2p
« Reply #28 on: October 10, 2001, 10:22:00 PM »
yeah, but if you could get it, iodine would be a lot nicer to work w/ than nasty Br2.

He who makes a beast of himself gets rid of the pain of being a man.

IudexK2

  • Guest
Re: cl2 + koh + iso = mdp2p
« Reply #29 on: October 11, 2001, 12:26:00 AM »
Also, I think reflux time w/KOH would bee significantly decreased. Also I2 is OTC here, while NaBr is not.

IudexK2

  • Guest
Re: cl2 + koh + iso = mdp2p
« Reply #30 on: October 11, 2001, 12:55:00 AM »
hmmmm but would I2 form the dihalopropenylbenzene compound less readily that Br2?

Rhodium

  • Guest
Re: cl2 + koh + iso = mdp2p
« Reply #31 on: October 11, 2001, 01:04:00 AM »
Yes, it would. It would also eliminate I2 easily, reforming the alkene.

jacob019

  • Guest
Re: cl2 + koh + iso = mdp2p
« Reply #32 on: October 11, 2001, 05:39:00 AM »
so does that mean that I2 is a lost cause for this procedure?  And IudexK2, what country do you live in.  In the states NaBr should be available both in the cleaning supplies of a hardware store, and in pool chemicals.  It was sited at super wallmart.

IudexK2

  • Guest
Re: cl2 + koh + iso = mdp2p
« Reply #33 on: October 11, 2001, 10:17:00 AM »
Yep, it would seem that Br2 is by far the best halogen to use in this case.

UK

boppesz

  • Guest
Re: cl2 + koh + iso = mdp2p
« Reply #34 on: November 10, 2001, 11:41:00 AM »
Where can I find more details aboutr this? I UTFSE but couldn't find the proper info

jacob019

  • Guest
Re: cl2 + koh + iso = mdp2p
« Reply #35 on: November 10, 2001, 11:59:00 PM »
I spent a lot of time trying to find details on this procedure.  I don't think you'll find anything else on rhodiums site or the hive.

Rhodium

  • Guest
Re: cl2 + koh + iso = mdp2p
« Reply #36 on: November 11, 2001, 12:18:00 AM »
We have our japanese friend Encopo who is currently trying to translate the original japanese patent into readable english.

AMINATOR

  • Guest
Re: cl2 + koh + iso = mdp2p
« Reply #37 on: November 11, 2001, 03:36:00 AM »
Boppez,  Check under username 'aminator' for otc mdma for beez with glass.

cilliersb

  • Guest
Re: cl2 + koh + iso = mdp2p
« Reply #38 on: November 12, 2001, 01:05:00 PM »
Has anyone tried the dihalo reaction, or are we all just asking Q's again?

Hansje

  • Guest
Re: cl2 + koh + iso = mdp2p
« Reply #39 on: November 12, 2001, 04:09:00 PM »

Isn't it 2HBr + H2O2 --> Br2 + 2H2O?



Not that it matters very much in the end, but when you make bromine from NaBr+H2O2+HCl there will be no HBr at all in your reaction mix.
There would be HBr formed if you used H2SO4.


Hansje high in proteine and fibre!