Author Topic: Benzo Wacker impurities quantification  (Read 3589 times)

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Sunlight

  • Guest
Benzo Wacker impurities quantification
« on: March 02, 2004, 06:18:00 PM »
I've got the chance to perform recently a small benzo. My first surprise was the neon green color that had the crude ketone under UV. Fortunately, the distilled ketone was just yellow, without this neon green, but in the collecting flask appeared small white crystals, what has been mentioned in the Hive.
I wonder what the hell is that product, as well as the other impurities in the distillate that can react in a reductive amination. If the solids are some benzo or hydroxy benzo or something like that, it will form some kind of aniline that is a poison.
Otherwise, a TLC in toluene:ethyl acetate 10:2 shows a spot of safrol/iso on top , a spot of ketone in the middle and a third spot below the ketone. A shadow in that place appears even in a TLC of 98 % pure ketone when using a not diluted sample.
It seems that there are some bees with access to analytical equipment and may be some of them know the benzo wacker. It would be very educative for all us to know the composition of the ketone produced with the benzo, what are the solids and if that product can be removed just filtering and an estimation of other specially not interesting products such the aldehyde or the 1 ketone.
Anyone ?

Rhodium

  • Guest
Synthesis in desperate need of analysis
« Reply #1 on: March 03, 2004, 12:59:00 AM »
If the melting point of the crystals are somewhere around 35-40°C, they might be MDP1P from the oxidation of isosafrole formed in situ. I have also mentioned here several times that it should be next to unavoidable to perform a wacker oxidation on safrole without ending up with at least some "MDP3P" (the hydrocinnamaldehyde).

I definitely agree with you, this synthesis desperately needs an analytical investigation as it is so widely used.


Sunlight

  • Guest
Crystals
« Reply #2 on: March 03, 2004, 02:13:00 PM »
Crystals are soluble in ketone, so filtration mainly dissolves it. The precipitated crystals were about 100-200 mg in 100 gr (just an estimation) but may be there were mor solved.
I guess that the only thing that I've in my hands is to check the mp of the final product.

gsus

  • Guest
analytical equipment
« Reply #3 on: March 03, 2004, 10:28:00 PM »
mp is right. it may be that the only analytical equipment needed is a good thermometer and some inorganics. you know where im going with this: bisulfite, CrO3, KMnO4, Phhydrazine, Na, hydroxylamine(possible nitriles!) and more that we can think of, and can find the mp's of.
  if you dont have enough crystals to do micro-scale analyses of, then you'll just have to make more.

there is no simple answer

Sunlight

  • Guest
mp
« Reply #4 on: March 05, 2004, 01:38:00 AM »
So you say that the mp of MDMA prepared from the benzo way has been checked and it's ok, right ?

Sunlight

  • Guest
Mp confirmation
« Reply #5 on: March 07, 2004, 08:12:00 PM »
I can confirm that the mp of MDA made via CTH reductive amination and benzo ketone is perfect. It seems that the God of the alchemists  are with us.
Anyway the only advantage I see in this procedure is the save of time, the buffered performic one yields the same (from safrol) and uses innocent easy chemicals.