Author Topic: OTC tosic acid rearrangement SUCCESS!  (Read 1959 times)

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Chromic

  • Guest
OTC tosic acid rearrangement SUCCESS!
« on: August 10, 2002, 09:33:00 PM »
Added 0.5ml sulfuric acid, 0.5ml water, 100ml toluene to a 250ml flask. Slowly refluxed for 4 hours with magnetic stirring and a dean stark trap attached between the flask and condenser. The mixture turned black and everything went into solution as 1ml of water was collected. Ran a 100mmol buffered peracetic in dcm on isosafrole (standard run). Added the tosic acid in toluene to the glycol. No exothermic reaction was noticed (unlike what Ritter said might happen). Refluxed with a dean stark trap for 20 mins. Washed 3x with 50ml 5% NaOH, then 50ml of water. Not too much crap was removed by the washes, unlike the 15% H2SO4 rearrangement. Distilled off the toluene.

0.2ml of the suspected ketone, 5ml of sat. bisulfite. One hour later after lots of shaking, a light yellow milkshake of bisulfite adduct precipitated!

SUCCESS! This method makes MDP2P just as the refs say, and just as Ritter stated!

This method is much faster and much easier than the 15% rearrangement, and I bet the yields are higher.  8)  8)  8)

Ritter

  • Guest
Exotherm
« Reply #1 on: August 10, 2002, 10:15:00 PM »
Good work Chromic!  Although you didn't detect much of an exotherm, you must realize that you were only working with  .1mol of substrate.  Scale that baby up 10-20 times and see what happens!

The reason I recommend very short reaction times is because I ran the reaction basically the same way as stated in your post only to find out that upon vacuum distillation, most of the "product" was actually tar.  But who knows, maybe it was a fluke on my part.  Please post yield post vacuum distillation ASAP!

Chromic

  • Guest
Ketone from this method
« Reply #2 on: August 10, 2002, 10:52:00 PM »
>most of the "product" was actually tar.

This was a very dark, but very free-flowing ketone with almost no smell. It was not nearly as viscous as normal post-15% H2SO4 hydrolysis ketone. I'm very encouraged by this method and suspect very little is tar. The ketone crystallized beautifully with bisulfite, impure ketone never does that.

>Please post yield post vacuum distillation ASAP!

I'm going to get an idea of the yield by going directly to forming the oxime. If the bisulfite crystallizes, I have almost no doubt in my mind that the oxime should crystallize as well. That way I'll get a good idea on the yield and, if I'm lucky, I can skip the vacuum distillation. My pump is long since toast, and I don't want to distill it without a vacuum as I fear that I'll only recover 80% of the ketone. Out of a possible 19.3g of ketoxime from 16.2g of isosafrole, I wonder what I'll recover.

I'll have the results in a few days if it crystallizes as I expect. The oxime takes many days in the dessicator to dry.

hCiLdOdUeDn

  • Guest
Good job Chromic! We need more people like you at ...
« Reply #3 on: August 10, 2002, 11:13:00 PM »
Good job Chromic!

We need more people like you at the hive  ;)

hcildoduedn

Chromic

  • Guest
Fuck, the oxime did not crystallize.
« Reply #4 on: August 11, 2002, 04:26:00 PM »
Fuck, the oxime did not crystallize. Sorry guys, although I'm willing to bet this is high quality ketone... but I've got no way to crystallize the oxime. I should have distilled.  :(

I've tried hitting it with a dilute mix of HCl, tried seeding it with 50mg of pmp2p ketoxime, tried the freezer, fridge & stirring / shaking. Any other ideas?

Rhodium

  • Guest
Do you have silica gel or alumina and a column?
« Reply #5 on: August 11, 2002, 05:09:00 PM »
Do you have silica gel or alumina and a column? Take a 1g aliquot of your impure ketone and flash chromatograph it through the column, then evaporate the solvent and weigh the purified ketone, then extrapolate the overall yield.

Do you perhaps have a phenylhydrazine or semicarbazide you could derivatize the ketone with?

If not, just wait for your new pump to arrive.

Chromic

  • Guest
Sorry
« Reply #6 on: August 11, 2002, 05:16:00 PM »
I'm in a very under-equipped & under-funded lab, and the answer to all those questions is no. I suppose I could run another batch, and quantify by bisulfite or attempt an atmospheric distillation. Selling mdma to finance my hobby really bothers me, if it didn't, this lab would be doing quite well.  :)

Chromic

  • Guest
More tosic acid making
« Reply #7 on: August 12, 2002, 07:37:00 PM »
2.5ml sulfuric acid, 2.5ml water, 125ml toluene in a 250ml flask with a 25ml dean stark trap. Refluxed for 3 hours. About 5ml (*) of water was collected in total and the toluene in the flask turned a homogeneous black color with some black crystals forming on the walls of the flask. About 20ml of toluene was also in the trap.

Now I can just use 20ml of this solution and 80ml of fresh toluene for each 100mmol isosafrole glycol (this works out to 1.8g tosic acid / 20mls, a healthy amount more than what's recommended, but since this is OTC stuff... I figure it's a good idea to up the concentration a bit). Beautiful.

I'll get around to running a 150mmol scale isosafrole bufferred peracetic in dcm followed by a rearrangement and do an atm distillation to get an idea of yields for all of you guys & girls.

(*) The toluene was distilled and reused from other runs. That likely explains why more water than the theoretical amount was collected.

hellman

  • Guest
tosic acid problems
« Reply #8 on: August 13, 2002, 05:41:00 AM »
I wonder what is going wrong with the formation of the tosic?
They should be beautiful white crytals?
I don't want to regurgitate the same ol stuff, but could it possibly be that you are in fact just not using HCL, as the recipe requires,.????

Could it be this simple?
You deserve to have these problems solved before introducing
bizarre variables compromising your levels of Success ,.


IQ is the rate of logic, as Wisdom increases logic, fear & compromise decrease to reveal objectivity