Author Topic: cl2 + koh + iso = mdp2p  (Read 11660 times)

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jacob019

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cl2 + koh + iso = mdp2p
« on: September 25, 2001, 09:32:00 PM »
In the folowing text from the book of ecstacy is it necessary to extract with benzene or could one just distill

Piperonylacetone from the Dichloro Derivative of Isosafrole
Yuki[37] reports on piperonylacetone from 1-(3,4-methylenedioxyphenyl)dichloropropane and KOH.
Chlorine and the other halogens react readily with double bonds (like the one of isosafrole's) to form dichloro compounds in solvents inert to the halogens. The most commonly used solvents are CH2Cl2 (methylene chloride), CHCl3 (chloroform), and CCl4 (carbon tetrachloride). Running a stream of chlorine in a solution of isosafrole in one of these solvents from a cylinder or chlorine generator (see misc. chemicals chapter) will produce the appropriate dichloro compound. Use of bromine will generate the dibromo compound which could be used in place of the dichloro compound. Bromine reacts quickly in carbon tetrachloride. It is bromine in carbon tetrachloride that is used as a test for double bonds since the solution is clear red and the red color disappears as the bromine reacts. Chlorine will react slower. If water is present, a chlorohydrin will be formed which would probably react similarly to give the ketone. Experiment is king.




23.2 g (0.1 mole) of 1-(3,4-methylenedioxyphenyl)-1,2-dichloropropane is refluxed for 10hrs with 75g of 15% KOH (potassium hydroxide) solution. The mixture is cooled extracted with benzene. The benzene is removed in vacuum and the residue distilled to yield approximately 15.2 g of piperonylacetone (bp 149-151°C/10 mmHg). 85% yield from the dichloro compound.

Rhodium

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Re: cl2 + koh + iso = mdp2p
« Reply #1 on: September 25, 2001, 11:23:00 PM »
Extract with any non-polar solvent (like DCM, toluene, ether etc) but don't skip the step.

jacob019

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Re: cl2 + koh + iso = mdp2p
« Reply #2 on: October 03, 2001, 06:41:00 PM »
So let me see if I got this procedure right.
I searched the hive for a while, but couldn't find anything.
1. Mix isosafrole with DCM (50%/50%?)
2. Pump chlorine gas through the solution. (How much, how long?)
3. Distill off DCM. (is that sufficient or do I need to distill out the dichloro compound)
4. Take remaining dichloro compound and reflux for 10hrs with 75g of 15% KOH solution. (Could NaOH be used?, same concentration?)
5. Extract remaining solution with DCM. (How much should I use?)
6. Distill off DCM.
7. Distill MDP2P under vacuum.

This procedure looks great to me, because even though yeilds are small all I need to get from safrole to MDP2P in large amounts is KOH, DCM, and a Chlorine generator.

Oh and one more question, is the dichloro compound stable enough to store for long periods of time at room temperature.  That would be great because I could store it and be one easy step away from MDP2P.

Once I have the procedure and dream a bit, I'll post the results.

sunlight

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Re: cl2 + koh + iso = mdp2p
« Reply #3 on: October 04, 2001, 04:22:00 AM »
I would be fine, I'm asked myself if it's better than performic.

cilliersb

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Re: cl2 + koh + iso = mdp2p
« Reply #4 on: October 04, 2001, 01:56:00 PM »
Here's an idea

Setup your glassware for distillation. Add to the distilling flask a volume of 48% HBr. Add an equimolar amount of H2O2 to a pressure eq. addition funnel and fit this to the distilling flask. Take your IsoSassy and disolve in equal vol DCM. Place this in the recieving flask and place the recieving flask in an ice salt water bath on a magnetic stirrer.

While stirring the Iso in the reciever flask drip some (not much) of the H2O2 into the 48%HBr and bring your distilling flask to 59C and keep it there. Make sure that your condenser is efficiently cooled with ice water!!

Bromine should start distilling over as it is formed and drip onto the Iso. Control the rate of addition by controlling the rate at which H2O2 is added.

I'm not too sure how heat sensitive this reaction is, but it's probably a good idea to not let the Iso mix go above 25C.

I know, the bromine is very volatile and will interfere with your visual access to the reaction mix. I would also suggest a good mask or at least good ventilation or a fume cubby.

You'll probably need about a 20% excess of H2O2 and HBr beacuse of Bromine's solubility in water.

Dr. Hallucinator out. 8)

Agent_Smith

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Re: cl2 + koh + iso = mdp2p
« Reply #5 on: October 04, 2001, 02:04:00 PM »
cillers, that seems to me like a god synth for tar.  Doesn't iso brominate in the presence of Br2 just like safrole does?


blah blah blah something clever blah blah blah

jacob019

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Re: cl2 + koh + iso = mdp2p
« Reply #6 on: October 04, 2001, 04:33:00 PM »
Tdoesn't do much for me, because I'm not having anyluck getting HBr or H2O2 above 15% (food grade).  I could setup a bromine generator like in Agent_Smith's famous post for the glassless MDA with mothballs,  but that just changes chlorine to bromine, and doesn't really answer any of my questions.

cilliersb

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Re: cl2 + koh + iso = mdp2p
« Reply #7 on: October 05, 2001, 11:01:00 AM »
Agent, the way I understand it, with safrole the double bond is in the wrong place and it brominates incorrectly.

According to the first post (no refs??) the dibromo should form which makes sense if you look at the structure of Isosaf.

I'll do a nano and report back.

Lem2

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Re: cl2 + koh + iso = mdp2p
« Reply #8 on: October 08, 2001, 11:38:00 PM »
would anyone know if this would theoretically work on asarone?

Rhodium

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Re: cl2 + koh + iso = mdp2p
« Reply #9 on: October 08, 2001, 11:44:00 PM »
It would theoretically work on asarone if it does with isosafrole.

IudexK2

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Re: cl2 + koh + iso = mdp2p
« Reply #10 on: October 08, 2001, 11:49:00 PM »
I don't see why not  ;D

jacob019

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Re: cl2 + koh + iso = mdp2p
« Reply #11 on: October 09, 2001, 01:58:00 AM »
The original text says bromine would work.  I know from Agent_Smiths post that reacting safrole with HBr produces bromosafrole would reacting isosafrole with HBr produce dibromosafrole?  Could the rest of the procedure be done the same?  I still need imput on my original procedure.

IudexK2

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Re: cl2 + koh + iso = mdp2p
« Reply #12 on: October 09, 2001, 10:15:00 AM »
Reacting isosafrole with HBr would not produce dibromosafrole. The Q is, would reacting isosafrole wioth Br2 really produce a dibromosafrole that when refluxed w/KOH would give MDP2P?  ;D  Some wise bee please confirm or unconfirm this.

Many thankx,
IudexK

Osmium

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Re: cl2 + koh + iso = mdp2p
« Reply #13 on: October 09, 2001, 12:11:00 PM »
> would reacting isosafrole wioth Br2 really produce a
> dibromosafrole that when refluxed w/KOH would give MDP2P?

Yes of course.

cilliersb

  • Guest
Re: cl2 + koh + iso = mdp2p
« Reply #14 on: October 09, 2001, 02:27:00 PM »
This is kinda how I understand the literature too Os, now all we have to do is work out ratios / temps (Very cold    -10C to 10C Max)

A higher temp in the reaction / reciever flask (distill setup as mentioned before) would interfere with the bromine staying liquid and also probably favour side reactions and probably tar formation as mentioned by Agent Smith earlier.

I can't see why a normal Ice / Salt bath won't work perfectly fine.

48%HBr costs nothing and so does H2O2. Maybe some testing in this field is called for!! let's see what a nano (5g Iso) brings to the table.

The only thing that bothers me is that bromination of the ring may take place too, touch wood!

Will report back later.

Rhodium

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Re: cl2 + koh + iso = mdp2p
« Reply #15 on: October 09, 2001, 02:29:00 PM »
Osmium: I see the source of confusion here. We should probably call the reaction product between isosafrole and bromine "dibromoisosafrole" so that it is not confused with the dibromosafrole produced when adding bromine to safrole.

cilliersb

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Re: cl2 + koh + iso = mdp2p
« Reply #16 on: October 09, 2001, 02:53:00 PM »
I agree Rhodium, they are far from being the same and definitely not interchangeable.

Do you think that this reaction has much potential? To me that 85% eild of MDP2P with 15% KOH looks very attractive. All we need to do is make sure the formation of the DiHalo compound comes over in good eild.

How would you suggest getting the Dibromo comp out of the DCM / Br2?

IudexK2

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Re: cl2 + koh + iso = mdp2p
« Reply #17 on: October 09, 2001, 02:56:00 PM »
How about washing w/thiosulphate etc. to remove Br2, then w/dH2O, then dry DCM layer, remove DCM by distillation, and distil dibromoisosafrole under vacuum, or just use as is and do purification on ketone?

cilliersb

  • Guest
Re: cl2 + koh + iso = mdp2p
« Reply #18 on: October 09, 2001, 03:09:00 PM »
How about several washes with normal dH2O? with Bromine's solubility in water, three to four dH2O washes should remove Br2 enough to just distill off DCM and then pull the ketone over at the pump.

Remeber that Br2 should not be in large excess to begin with. If you use the right ratios and cooling there should be very little free Br2 in there after the reaction.

I do think that the Br2 need to be removed completely before distillation beacuse higher temps with Br2 in the mix will surely screw up the product.

Any idea if the H2O washes will work anyone? ;)

Osmium

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Re: cl2 + koh + iso = mdp2p
« Reply #19 on: October 09, 2001, 04:06:00 PM »
I wouldn't bother isolating the dibromo compound at all. Simply evap the DCM and proceed with the KOH reflux.

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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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!

Osmium

  • Guest
Re: cl2 + koh + iso = mdp2p
« Reply #40 on: November 12, 2001, 06:01:00 PM »
> when you make bromine from NaBr+H2O2+HCl there will be no
> HBr at all in your reaction mix.

?? Well, there will be H+ and Br-, which is just as good.

Hansje

  • Guest
Re: cl2 + koh + iso = mdp2p
« Reply #41 on: November 14, 2001, 10:06:00 PM »

Well, there will be H+ and Br-, which is just as good



...for oxidising the Br- into Br2, yes. For making Hydrobromic acid, no.
Admitted: that was not the topic. It was just all these NaBr+HCl ---> NaCl+HBr-like equations above that triggered my corrective instincts.
O well, I'm off now mixing vinegar with gypsum, cause I'm almost out of sulfuric... ::)


Hansje high in proteine and fibre!

FreeBee

  • Guest
Re: cl2 + koh + iso = mdp2p
« Reply #42 on: November 21, 2001, 05:14:00 PM »
Would sulfuryl chloride work for this reaction?  (It is a great chlorinating agent.)  Also, is it possible to just form the epoxide after the KOH reflux or would subsequent conversion to ketone be assured?

Finally, Is the ten hour reflux just a far worst case number?  Would a slightly higher conc. of KOH allow shorter times?

Thanks

Vibrating_Lights

  • Guest
Re: cl2 + koh + iso = mdp2p
« Reply #43 on: November 22, 2001, 06:41:00 PM »
What is the sensitivity to the ammount of Br2 in the Iso/Dcm mix.  Must the Br2 be added as it reacts or could it all be added at once.  can anyone see any adverse affects to having a large exess of Br2 in the solution so long as it is washed out before the solvent is removed.
2.  We all know that acedic conditions destroy the asarone molocule  but what about the affects of basic conditions. would the Koh reflux destroy the molocule.  if one was to suscessfully produce the asarone ketone, is the best way to TMA 2  via condensation with hydroxlamine then Al/Hg considering no NaBH4 is available.
VL_

Rhodium

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Re: cl2 + koh + iso = mdp2p
« Reply #44 on: November 22, 2001, 07:18:00 PM »
An excess of bromine in the solution would be bad, as then the benzene ring would probably be partly brominated in the 6-position. I don't believe asarone is as sensitive to bases as it is with acids.

zooligan

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Re: cl2 + koh + iso = mdp2p
« Reply #45 on: November 24, 2001, 07:00:00 AM »
Why do the majority of the posts in this thread deal with Br addition when the subject line s about chlorination?  What happenned to the chlorination routine after the third post from the top?  It seems to be completely forgotten.  what's up?


z


"And if we don't get some cool rules ourselves, pronto, then we'll just be bogus too!"

terbium

  • Guest
Re: cl2 + koh + iso = mdp2p
« Reply #46 on: November 24, 2001, 07:53:00 AM »
Yeah, chlorine gas is easier for the clandestine chemist to produce and handle than bromine. A good chlorination procedure could possibly give a more facile and OTC route to P2Ps than even peracid. The biggest question I see is: what could be used for a solvent other than CS2 and CCl4, both of these are not very OTC. Any chance that DCM would work?

Chromic

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Re: cl2 + koh + iso = mdp2p
« Reply #47 on: November 24, 2001, 09:09:00 AM »
DCM is fine for chlorination as free radical reactions have slower rates of reaction compared to forming the chloronium ion intermediate in halogen addition to alkenes. However, I personally think this route sucks... but to each their own.

Rhodium

  • Guest
Re: cl2 + koh + iso = mdp2p
« Reply #48 on: November 24, 2001, 01:09:00 PM »
Yes, DCM is perfectly fine for the halogenation reaction.

terbium

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Re: cl2 + koh + iso = mdp2p
« Reply #49 on: November 24, 2001, 08:08:00 PM »
However, I personally think this route sucks...
So, you are just going to leave me hanging? Why, pray tell, do you think this route sucks?

jacob019

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Re: cl2 + koh + iso = mdp2p
« Reply #50 on: November 26, 2001, 03:59:00 PM »
I tried this once with disasterous results.  At first I used amounts of everything as I had calculated above, but not all the KBr reacted so I ended up using a 50% excess of sulfuric acid and H2O2,  sulfuric acid worked better than HCl for some reason.  So first I mixed the sulfuric acid with the KBr.  That way it wouldn't be too acidic when I added the iso.  Would sulfuric hurt iso?  Then I mixed in the DCM and the iso.  I let this stir for a while and it turned yellow.  Then I started to drip in h2o2(15%) but there was no color change when it hit, so I just threw it all in.  It took a couple minuites to turn orange.  I had the worst time making sure it had all reacted.  I would let it stir for an hour in the future.  I played with it for the longest time, washed the water 3X with DCM, added all the DCM/dibromoiso together and weighed.  It was rediculously underweight, but I had played with the liquids so much that I could have lost a lot.  Anyway I decided to distill out the DCM.  I setup to distill and forgot about it. OOPS!!!  When I came back the room was so thick with bromine gas that I couldn't see, breath, etc.  I put on my gas mask, and proceded to the setup. I turned off the hotplate. And pulled out the stoppers.  A LOT of gas escaped and It was presurized.  ALL the glass had filled up with a tar.  Once it cooled it had the consistancy and color of charcoal.  The volume of the stuff must have increased 10 times at least.  It was rediculous.  The stuff was rock hard.  I tried cleaning it with everything.  HCl did nothing, DCM, toluene, and acetone did nothing.  Sulfuric reacted a little and loosened it enough so that air could go in one end and out the other and finally methanol dissolved it a little.  I setup for reflux with methanol and that cleaned out half the condensor.  I guess I'll distill a whole lot of methanol.  Anyway what happened?  I thought it would come over in the order of DCM/Br2?/dibromoisosafrole.  Insted the dibromostuff must have broken down.  Or was something else wrong.  I want to try this again.

Rhodium

  • Guest
Re: cl2 + koh + iso = mdp2p
« Reply #51 on: November 26, 2001, 04:01:00 PM »
Yes, sulfuric acid in the reaction mixture would definitely mess up isosafrole. You need to generate the halogen externally, not in situ.

jacob019

  • Guest
Re: cl2 + koh + iso = mdp2p
« Reply #52 on: November 26, 2001, 04:03:00 PM »
Time is a BIG problem for SWIM.  He hardly ever gets to his imaginary house with a lab.  He was wondering if it was possible to reflux undistiled sassafrass oil with KOH/NaOH for 4 hours at atmospheric.  Then distill out the iso.  That would save a lot of time.

Rhodium

  • Guest
Re: cl2 + koh + iso = mdp2p
« Reply #53 on: November 26, 2001, 04:07:00 PM »
Yes, that would be possible, but you would get lower yields, and as so many other things are present in the reaction mixture, you must distill carefully, preferably a slow fractional distillation to get pure isosafrole. Some unreacted safrole might also be present, so watch out for that fraction and save that for another isomerization.

jacob019

  • Guest
Re: cl2 + koh + iso = mdp2p
« Reply #54 on: November 26, 2001, 04:08:00 PM »
In response to Rhodium about my disaster:
If I only add enough sulfuric to react with the KBr then add the iso AFTER the reaction has taken place... could I test PH before adding the iso.  If so could it just be adjusted with NaOH?

Rhodium

  • Guest
Re: cl2 + koh + iso = mdp2p
« Reply #55 on: November 26, 2001, 04:22:00 PM »
You cannot measure pH correctly in such a mixture. You are welcome to try your suggestion out, but I don't think it will work well if you don't generate the halogen first, and then add it to the isosafrole solution. Perhaps you could mix your H2SO4/H2O2/KBr in a separate flask and then heat it slightly to lead the formed bromine that will boil off into the isosafrole solution (in dichloromethane, chloroform or carbon tetrachloride). Personally I'd think MnO2 would be safer to use than H2O2 in this reaction.

jacob019

  • Guest
Re: cl2 + koh + iso = mdp2p
« Reply #56 on: November 26, 2001, 04:33:00 PM »
Osmium said this earlier in this thread:
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.

So what your saying Rhodium is that this wouldn't work because the sulfuric would screw up the isosafrole.  The sulfuric would be in a different layer.  Could more water be added to make it more dilute.  Will the sulfuric not stay in the water layer?  Why couldn't the ph be tested?

Also,
could my problem with the tar be thermal breakdown of the dibromoisosafrole?  Should it be possible to distill the dibromo, or should it just be stripped of solvent and taken directly to the KOH reflux.  The only reason this reaction would be desirable is because it is so OTC. Is MnO2 OTC?
I hate extraction work, but could the KBr/H2O2/H2SO4 be extracted (Would 3X be necissary) into the DCM alone which would be mixed with the iso seperately.  And about the KOH refulux since there is water in the mix, is the original article suggesting that it be refluxed at 100°?

terbium

  • Guest
Re: cl2 + koh + iso = mdp2p
« Reply #57 on: November 27, 2001, 07:14:00 AM »
jacob019,

You should take your questions over to the Newbee Forum where they belong!

jacob019

  • Guest
Re: cl2 + koh + iso = mdp2p
« Reply #58 on: November 28, 2001, 03:30:00 AM »
thats not very nice terbium, nor does it help me.  I started this thread because I'm trying a not so well documented procedure, and I ran into some trouble.  I'm trying to figure out if the procedure failed because of thermal breakdown, or if it is as Rhodium suggests the sulfuric acid.  I was merely stating some ideas in the form of questions.  And If I'm reading the original articele correctly the reaction never goes above 100° until after the KOH reflux, and the bromine should be released during the reflux, decreasing the chance of thermal breakdown.  I would apreciate some advice but comments like yours don't contribute.

Aurelius

  • Guest
Re: cl2 + koh + iso = mdp2p
« Reply #59 on: November 29, 2001, 12:02:00 AM »
didn't uemura post a procedure for this just a couple weeks/months back?

reduction

  • Guest
Re: cl2 + koh + iso = mdp2p
« Reply #60 on: November 29, 2001, 01:00:00 AM »
i've been wondering about this procedure for a while
qi how much isosaassay to ghow much dcm and how manyt g'g of chlorine gaas should be aded ifd usinfg 100gf safrole.
2. then distrill off dcdm relux wirth aquous 15% koh for ? hours extract with dcm and dsistill mdp2p.
any ideasa
soundes verey orc to me
R

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DEA,FBI,CIA,NSA,ATF,DOJ

jacob019

  • Guest
Re: cl2 + koh + iso = mdp2p
« Reply #61 on: November 29, 2001, 02:46:00 AM »
Wow, that post by uemura is nice, it's not exactly the same, but uses br2 and isosafrole.  If anyone is wondering it's post

Post 236632

(uemura: "Re: Ketones from Propenylbenzenes via the di-bromides", Novel Discourse)
.  As far as developing the procedure using cl2, someone needs to balance out some equations.  Maybe later.

Rhodium

  • Guest
Chlorination with NaCl/H2O2
« Reply #62 on: December 10, 2001, 04:44:00 AM »
Phase Transfer Catalyst Promoted Halogenation of Alkenes with Hydrohalic and Acid Hydrogen Peroxide

Addition of molecular halogens especially that of gaseous chlorine, presents a potential environmental hazard and their quantitative utilization is often problematical. Chlorination of sulfanilamide with a mixture of aqueous hydrochloric acid and hydrogen peroxide has been reported, and recently the combination has been used for converting phenol to chloranil. These reactions might not have involved nascent molecular chlorine, but the in situ formation of a positive halogen species. In the light of this consideration, it seemed to be of interest to study the efficiency of the halogenation of olefins by this reagent system.

We wish to report the results of such an investigation using conditions similar to those of Lübbecke and Boldt. Furthermore, our investigations showed that the presence of a cosolvent (carbon tetrachloride) and catalytic quantities of phase transfer agent, such as benzyltriethylammonium chloride is beneficial, as the formation of chlorohydrins can be largely suppressed. These conditions are applicable to the preparation of dichlorides and dibromides, and give good, frequently better yields than the conventional halogen addition reactions.

It is noted that the ease of handling and regulation may render the method viable for laboratory halogenation, especially chlorination. Both gaseous chlorine and sulfuryl chloride could induce side reactions involving free radicals, which are not observed under our ionic conditions.

Halogenation of Alkenes; General Procedure:

To an ice-cooled, magnetically stirred suspension of the alkene (50 mmol), calcium halide (50 mmol), conc, hydrohalic acid (10 ml), carbon tetrachloride (10ml), and benzyltriethylammonium chloride (100 mg) is added dropwise 30% hydrogen peroxide (6 ml). The mixture is then allowed to warm up to room temperature while stirring is continued for 20 min. Dilution with petroleum ether, washing with water, drying and removal of solvent, gives the crude dichloride or dibromide which is devoid of starting alkene as shown by infrared spectral analysis. Purification of the product by vacuum distillation furnished by sample identical in physical and spectral properties to the authentic compound.

Chlorination: cyclohexene (76%), 1-octene (56%)

Bromination: cyclohexene (95%), 1-octene (92%)

Reference: Synthesis 676 (1977)

AMINATOR

  • Guest
Re: Chlorination with NaCl/H2O2
« Reply #63 on: December 10, 2001, 09:54:00 AM »
Aminator will committ to such meanial tasks. ;) 'tis good practice.
34.5% HCl = 1.1L/1mole
4.5% (chlorox)sodium hypochlorite=1.7L/1mole
2 HCl(aq) + NaOCl(aq)----->  Cl2(g) + NaCl(aq) + H2O(l)
:)

I hope the % solutions are correct.


Osmium

  • Guest
Re: Chlorination with NaCl/H2O2
« Reply #64 on: December 10, 2001, 03:21:00 PM »
Conc. HCl is more like 11-12mole/l.

gruns

  • Guest
bump
« Reply #65 on: July 06, 2002, 09:25:00 PM »
Has any more work been done with this?


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