08-18-03 05:59
No 454276
Swim wants to distill off his solvent, xylene, but swim's pump is oil and too strong, so all the xylene would end up in the pump. Is atm distillation of xylene okay for the freebase (no decomposition)? Xylene bp is 138-144 C.
(tourbee)
08-18-03 07:04
No 454288
HEy now,
Ok!SOoo are you telling me you need to distill off your xylene,why not gas out your product?Or if need bee lower your rxn temperature.
Am I the driver,or the driven?Am I damned ,or will I bee forgiven? -GD
(Hive Bee)
08-18-03 07:09
No 454290
no gassing of product! swim has gassed before without distilling freebase and it was not...fun. so swim wants to distill this time.
(Chief Bee)
08-18-03 13:03
No 454329
(Rated as: good idea!)
Install a bleeding tube into your vacuum line, essentially a T-connector where you on the "side arm" put a short length of vacuum tubing, which you pinch almost shut with a tubing clamp, but not so much as to completely seal it. With this you adjust the amount of air leaking into your apparatus until you achieve the desired lowering of the vacuum power.
Hoffman Tubing Clamp
(Newbee)
08-18-03 18:33
No 454367
I dont know how your pump is but mine has a 1/4 female inlet for vacuum.
So I connected a stainless steel pipe onto to it. Then a T-connector, and I installed one valve on each sides. One side serves to connect to the vacuum line, the other is the bleeding line. I can fine adjust the vacuum by opening more or less the bleeding line.
This is all stuff from Home Depot. The valves are for water and they can take up to 600 psi of pressure, they work great. So a couple of stainless steel pipes the right size, a t-connector that goes with it, two valves is all you need. You will also need an adapter of some sort to connect the pump to your system with a vacuum tube, but you already have that probably
Hope this helps
(Hive Bee)
08-18-03 20:48
No 454394
Distilling Xylene is a pain the ass, why dont you do an a/b and use a lower boiling non polar? DCM is the best by far and has been replaced for sometime as a nonpolar in past experiments. You can remove 1L by rotovap in just a few minutes, or by simple distillation, in an hour. Then crank up the heat and distill your freebase
In the al/hg, if you skip the initial A/B and just gather your freebase, you will also be gathering any unconverted ketone, so when you go to collect your freebase by vac distillation, it may appear like you struck gold as a greater mass is there than expected, but remember, this is a mixture of freebase and ketone. No problems will come from gassing this mixture.. providing there is some actual freebase in the mix.
Add 8x anhydrous toulene to the collection and gas with faith.
Im trying to recal a way of recovering that unconverted ketone in a quick manner. Im sure theres somthing in fse on it. I think polysam or placebo once mentioned something about it..
90%
(Hive Bee)
08-18-03 22:05
No 454403
swim wanted to use dcm, but for some reason it didn't form any separate layers in the post al/hg. using xylene caused nice layers, and later in the combined xylene extracts another small layer could be seen - the initial dcm attempt. It was slightly less cloudy than the xylene layer.
(Hive Bee)
08-18-03 22:25
No 454406
it is true that you will run into emulsion, BUT if your not in a rush, let the two layers seperate and within 30 minutes or so there should be 2 very distinctive layers.
The first time this was done, a coat hanger was used to stir the emulsion bubbles every 5 minutes or so, and it helped alot in speeding up the process, but otherwise you can just let it sit for little while and when you come back, it should be seperated. In the long run, it will save time and allows easy recycling of non polar, even with the 30 minute wait times. Give it another try and be patient. Use that 30 minutes to clean up shop.
Trust me, this works great.
and if you think about it, it makes alot more sense to use DCM as the freebase sinks to the bottom of basified rxn contents. Where will the DCM migrate once added?? The bottom also! This means you just have to tap off the bottom layer, (then add more dcm for a 2nd collection) by the time the first dcm collection has been distilled, then 2nd collection will be ready to be tapped off and distilled. 2 collections is usually all you need as long as your not skimping on the DCM. If you don't have acess to ample amounts of DCM, then this may not be a good choice for you as you will loose some due to mechanical losses, evaporation, etc. Good ventilation is a must, and allowing the basified rxn contents to completely cool to room temp before adding the dcm will help conserve the solvent. Once you do it a few times you'll have a working system down and be thanking the DCM gods.
90%
(Hive Bee)
08-19-03 02:17
No 454425
Swim was going to distill off the DCM in the xylene extract but something else started coming over at 60-70 C that was cloudy. Eh?
(Chief Bee)
08-19-03 02:33
No 454427
Yes, and don't forget water, which is usually involved when you find cloudy non-polars.
(Newbee)
08-19-03 04:48
No 454448
Extract the run with xylene, do an A/B then re-extract with DCM.
That should work, cuts down on DCM losses and use(more expensive to me) since you can extract the freebase in the water with less np then the first extractions from the solvent(IMHO). You surely wont need 500 ml to extract the basified water solution!
Then dry, distill the dcm, and youre left with freebase, ready to distill.
I wouldnt use DCM to extract the freebase . Its too expensive compared to xylene which I find it much more convenient to work with. After the A/B would be a great time to use DCM, easier handling since the dcm sinks, faster distilling. Try that
(Hive Bee)
08-19-03 05:31
No 454459
Its too expensive
A gallon of DCM will run you 20 bucks and you reuse much of it over and over. How fast will you run through that xylene?? Let me guess, you recycle it.
compared to xylene which I find it much more convenient to work with.
You obviously have not tried it. How could it be easier to: remove the polar layer (basified rxn contents) to get to the nonpolar layer, then add the polar contents to the sep again, etc..
When using dcm, you just tap off the bottom collection, then add more dcm, tap off again, voila. If you can't find DCM for under 20 bucks a gallon then you aren't looking in the right places.
90%
(Newbee)
08-19-03 15:07
No 454520
A gallon is about 30 bucks. I pay about 40 bucks for 20L of xylene. These are from chemicals companies where I'm from.
What I meant was that using large volumes of solvent, I prefer Xylene. I know you have to sep off the water for the first extractions. But you will definitely loose more dcm then xylene when doing that extraction no?
And yes I try to recycle my solvents, which is why i was suggesting that. Out of the say 500 ml of xylene you would use to extract the basified rx content, how much can u get back? Almost all.
Now use 500ml dcm, wash, then do the A/B. How much DCM will you get back? 300ml?
And what about when u wash? You have to sep off the DCM, which you dont have to do when using xylene
So if you extract twice and wash twice its all the same except for costs and amount of dcm lost.
This is what I meant. And I said that because DCM is a lot more expensive to me, maybe not to you. I guess that depends where u live. And I guess cutting down on DCM makes you breath less of it.
(Newbee)
08-21-03 00:18
No 454749
To extract the basified rx content?
What I mean is do you filter the sludge before extracting?
I ask because I used to, but not anymore. So adding a np that floats makes more sense to me that way. The aluminium sludge would end up in the the DCM if you didnt filter right?
(Hive Addict)
08-21-03 05:33
No 454788
DCM forms horribly emulsions with basic solutions and tends to boil away when mix is even slightly warm.
For those about to synth,we salute you
(Newbee)
08-21-03 15:37
No 454860
I am running out of np and wont receive any before next week.
This is what I would do.
Extract with Xylene, then wash with 5% NaOH. Extract that with acidic water.
To wash, I would use DCM as it sinks, so easier handling.
Then basify till pH around 12(MDMA pka is 9.5). Now here is my question: If I use DCM here, will it still form a nasty emulsion? In the end it would be much easier to strip off the DCM then the xylenes for distillation. I ask because I've never used a basic solution with DCM. What do you think? Could the water layer be seped off(my freebase floats) as much as possible before adding the DCM? That should decrease the emulsion without any loss of freebase?