synthetikal.com Forum Index


Performic
Goto page 1, 2, Next
Post new topic   Reply to topic    synthetikal.com Forum Index -> Essential Methods
Author Message
Soap

Joined: 26 Mar 2005
Posts: 86
2156.08 Points

Tue Mar 29, 2005 5:21 am
Reply with quote

Swim is making MDMA for his first time. Hes considering turning safrole to isosafrole then running the buffered performic (with dcm), using h2so4 to yeild the ketone, then al/hg. Swim is sure that this method is used by many people but he is finding very little information on the subject. Does anyone know of any walk throughs, similar to dr. drools or bright stars, but using the buffered performic? Swim also only has smaller beakers. all 24/40 glass one 3 neck 500ml rbf, 1 250ml rbf, 1 150ml rbf, and one 100ml rbf. i do not ahve a vigurex column but i have everything else. thanks for the help.
Back to top
IndoleAmine
Dreamreader Deluxe
Joined: 09 Feb 2005
Posts: 681
Location: Bahamas
18717.10 Points

Tue Mar 29, 2005 7:12 pm
Reply with quote

Everything you want can be found in the Rhodium archive under the entry "Peracid (Performic/Peracetic) oxidation of isosafrole to MDP2P (Review)" in the "Epoxide related" section at the very beginning....

Just replace the "Wacker oxidation" part of BrightStars writeup with a safrole isomerization using KOH and the performic oxidation described under the entry I gave you. Will work definately.


i_a
Back to top
Soap

Joined: 26 Mar 2005
Posts: 86
2156.08 Points

Wed Mar 30, 2005 5:54 am
Reply with quote

thanks for the help. any advice on a vacuum source? swim can not decide between an aspirator and 1/4 hourse power pump or spending a bunch ($100?) of money on an actual vacuum pump. thanks
Back to top
IndoleAmine
Dreamreader Deluxe
Joined: 09 Feb 2005
Posts: 681
Location: Bahamas
18717.10 Points

Wed Mar 30, 2005 7:37 am
Reply with quote

Depends on the water price and your location, a 1/4th hp (diesel?electro? Smile ) pump will make probably lots of noise, a membrane vacuum pump for laboratory use can pull as much as you will ever need (0.01mmHg is standard) as is silent - but DANG EXPENSIVE if you buy a new one.

Aspirators make some more gentle kind of noise; IMO its more some kind of "psycho-terrorism" rather than "noise": bshhhhhhhhhhhh (and it goes on and on the whole day......) Evil or Very Mad
(very cheap items though; you just need an extra tap running all the time, or a closed barrel with a water pump for continuous recycling of the water, combined with additional ice cubes added if the water heats up too much...)


i_a
Back to top
Spacemonkey

Joined: 14 Feb 2005
Posts: 29
759.14 Points

Wed Mar 30, 2005 8:02 am
Reply with quote

I'd recomend both. But you can make do with just an aspirator.

SWIM has a commercial reciculating aspirator and a 6cfm two-stage rotary vane oilbath pump good for <10 microns

You don't want to run corrosive/explosive vapors through a normal rotary vane pump. It'll contaminate the oil and eat the pump inside out. Hence the aspirator.

Swim would also like to get a teflon head diaphgram pump like IndoleAmine mentioned. These can do all that you'd do with both an aspirator and rotary vane pumps, and then some, such as pump liquids. But they are damned expensive and not as readily availible as other types.

The Rotary vane is quite loud even when it's pumping under vacuum. The aspirator station on the other hand makes a pleasing waterfall sound and barely anything than motor humming when it's pumping under vacuum.
Back to top
methyl_ethyl
Riedel De Haen
Joined: 18 Feb 2005
Posts: 107
Location: Estonia
7200.76 Points

Wed Mar 30, 2005 8:30 am
Reply with quote

Since the topic of this thread involves performics, I must note that if you decide to purchase a membrane / diaphragm pump I would highly reccomend you do your best to keep any and ALL condensable vapours out of that pump! It is my experience that when stripping formic acid and the like, that even solvent resistant membrane diaphragm pumps are not suited for such applications, even with cold fingers!

When it comes to performics, Leuckharts, or what have you I would recommend a rotary vane, with at the very least -50C in line condensation trap, also look into the gas ballast options. In my opinion it is easier to change the oil of a rotary vane pump immediately after stripping formic et al, than it is to deal with corrosion in a diaphragm pump. Perhaps this is just my inexperience surfacing. I will admit that I destroyed a diaphragm pump during a formic stripping procedure. Luckily the pump was given to me Laughing .

If you do decide to go with the membrane diaphragm pump purchasing a cold finger and some dry ice would more than likely be a wise investment.

All this being said I have never even seen an aspirator so I have no idea how useful this tool would be to you Crying or Very sad, or perhaps it will be the answer to your prayers! Laughing good luck regardless....

just_my_thoughts

methyl_ethyl
Back to top
IndoleAmine
Dreamreader Deluxe
Joined: 09 Feb 2005
Posts: 681
Location: Bahamas
18717.10 Points

Wed Mar 30, 2005 5:30 pm
Reply with quote

"A common device which makes use of the Bernoulli principle is the aspirator. When water is forced through a smooth constriction, the fluid velocity increases, lowering the pressure below atmospheric pressure. This can entrain air into the tube at the constricton and be used to partially evacuate the air from an attached volume."

http://hyperphysics.phy-astr.gsu.edu/hbase/fluids/aspirv.html#c1

and to keep it commercial (and to see how these things look like) Laughing :


BTW what about using two or three NaOH traps in line, together with a "woulff'sche bottle" against suckbacks, to deal with the performic vapors?


i_a
Back to top
icecool
Insistent Chemist
Joined: 16 Feb 2005
Posts: 268
8466.84 Points

Wed Mar 30, 2005 8:42 pm
Reply with quote

Indole do you also use an aspirator for all your vacuum or do you own a nice vacuum pump?
If so what did the vacuum pump cost and how low can you get the atmospheric pressure?
Back to top
Soap

Joined: 26 Mar 2005
Posts: 86
2156.08 Points

Thu Mar 31, 2005 11:53 am
Reply with quote

swim is convinced that i should go with the aspirator. the NaOH traps mentioned sound good since swim dosnt have a fume hood... how greatly is the vacuum effected by the temperature of the water? is there some sort of rule like 1 celsius degree = 1 mm Hg? Swim would rather not have to go through all that ice.. thanks everyone!
Back to top
icecool
Insistent Chemist
Joined: 16 Feb 2005
Posts: 268
8466.84 Points

Thu Mar 31, 2005 3:26 pm
Reply with quote

It's all about the water tension.
When the water is hotter there will be less vacuum pulled then with cold water.
you can calculate it with the law of bernouilli.
Back to top
IndoleAmine
Dreamreader Deluxe
Joined: 09 Feb 2005
Posts: 681
Location: Bahamas
18717.10 Points

Fri Apr 01, 2005 12:24 am
Reply with quote

Rule of thumb:

- room temp. water: 20 mmHg...

- hot tap water: 40 mmHg...

- cold tap water: 12 mmHg...


(this all is just relevant provided you are using silicone grease on all joints BTW!)

And I currently have no pump Sad , so the aspirator has to suffice. I HATE this thing! Evil or Very Mad (psshhhhhhhh)

greets


i_a
Back to top
ApprenticeCook
DILLIGAF
Joined: 12 Feb 2005
Posts: 162
Location: Australia
8486.38 Points

Fri Apr 01, 2005 6:03 am
Reply with quote

when my pump broke i didnt have the money to replace it so ive resorted to the aspirator... works ok as long as you keep the water temp stable and cold.... i have a fabric bag ontop of the resivour filled with ice cubes fromt he fridge.... it allows cooling without the risk of small ice cubes being sucked up into the pump. Just keep dumping ice cubes in as they melt... and make sure you have a overflow pipe to let away the excess water volume developed.
I hope to get my new pump soon, nearly there with the $$!!!

-AC
Back to top
anime

Joined: 13 Apr 2005
Posts: 131
Location: Planet Earth
3517.62 Points

Wed Apr 13, 2005 11:30 am
Reply with quote

Once you have your crude ketone form a bisulfite adduct with it. (Rhodium website/archive should have the details). Once you do this you can proceed to you asssspirator distillation. (Personally I recommend a vacuum pump YellowJacket all the way). Save up some cash, it is definitely worth it.
Back to top
IndoleAmine
Dreamreader Deluxe
Joined: 09 Feb 2005
Posts: 681
Location: Bahamas
18717.10 Points

Wed Apr 13, 2005 11:35 am
Reply with quote

Aspirator vacuum means 11-20mmHg, this is enough for distilling MDP2P.
Bisulfite adduct formation is necessary when you have only a shitty pump or no vacuum source at all...

And in this case pumps are nice (they're faster), but not essential for the first(?) distillation of ketone from a performic, and also not essential for further distillations to purify it...

Aspirators can't corrode, btw - they are't that bad at all... Wink


i_a
Back to top
anime

Joined: 13 Apr 2005
Posts: 131
Location: Planet Earth
3517.62 Points

Thu Apr 14, 2005 9:13 pm
Reply with quote

The do a good job for vacuum filtration, I personally haven't had much luck pulling a strong vacuum with the aspirator. I generally perform a bisulfate adduct post distillation to insure pure(r) ketone.

My recommendation on the bisulfite adduct being performed first was to reduce the amount of tar that would form in the flask during the distillation. From experience tar formation increases when a weaker vacuum (or a vacuum with nasty oil) is used as higher temps are needed to bring over the ketone. When performing the distillation try to let the oil bath temp get higher than 170C.

I'd also recommend using the HCl hydrolysis instead of the H2SO4, Its easier to work with and yields are higher. (HCl is more OTC than H2SO4, this helps too).
Back to top
Display posts from previous:   
Post new topic   Reply to topic    synthetikal.com Forum Index -> Essential Methods All times are GMT + 5.5 Hours
Goto page 1, 2, Next
Page 1 of 2

 



Powered by phpBB 2.0.11 © 2001, 2002 phpBB Group

Igloo Theme Version 1.0 :: Created By: Andrew Charron