(empty)

I thought you were suppose to wet the filter, then make a slurry out of the Celite plus whatever solvent you will be filtering to pour into the funnel, vacuum running.
Yes, isn't this exactly what was described?

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Baseline Does Not Exist.

I misread that; thought it described pouring dry Celite onto filter, then pouring water over the top, which is not ideal...

My bad
 ~ PB

As a consolation, I will change my signature to more attractive blonde school-girl sounding format.  Once again, I sincerely apologize for my lapse in judgement...

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Like, if you listen,
they will never lie.
To achieve the answer,
you must hit a big orgasm.

I tried filtering the post-reaction of an Al/Hg with a shallow depth of celite (diatomaceous earth from a pool supply store)... with manganese oxide sludge the filtrate usually pours thru the celite at the beginning. With the Al/Hg sludge it was painful! There was just a very slow drip at the beginning that started to slow down right away...

Unfortunately celite didn't work well for me at this task. Bummer, I was really hoping. Oh well, at least it's easy to distill off some of the alcohol from a post-al/hg. Perhaps Osmium's alcohol extraction is the best way (I don't like it because it uses so much alcohol) or perhaps Ritter's sodium hydroxide basification is the best way (I don't like it because it uses so much hydroxide).

Does anyone have other tips and tricks for filtering?

Usually these slow filtrations is due to a thin gel layer forming on top of the Celite. Just scrape that gel off from the top of the celite with a large spatula, and when fresh celite surface has been exposed again, the filtration wil again go faster.

Place a fine filter paper on the buchner funnel and then a 1/2" layer of celite or D.E. Then place another COARSE filter paper on top. Somehow this makes filtration a WHOLE lot faster on post al/hg sludge.

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Sink or SWIM

i don't use buchner on post rx crap,too messy.I just flood with NaOH solution and let stuff settle,then pour off clear yellow liquid and then flood the sludge again with some denat alcohol.

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For those about to synth,we salute you

> i don't use buchner on post rx crap,too messy.I just
> flood with NaOH solution and let stuff settle,

But others do that. Because the amount of NaOH needed for a big Al/Hg batch would be excessive, and because some people want to reuse their MeNH2.

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I'm not fat just horizontally disproportionate.

by contacting the funnel with a sonotrode (60W@80khz) usually not filterable solutions/emulsions/sludges can be filtered. Not with ease but it works. Care has to been taken as some mixtures solidify with ultrasound, so test with a small amount not to get a sudden solid surprise.


ORGY

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now or never

I've found that it's possible to distill off a lot of alcohol without filtering the sludge. Although it's not ideal, it's possible to recover some of the methylamine laden alcohol... then you can add your aqueous base and extract with toluene as per usual.

HiddenCloud, are you filtering right after the Al/Hg is finished, or after you've basified the alcohol? I imagine the basified alcohol solution would filter quickly, but I couldn't get the regular solution to filter with any speed (is this because of my shitty aspirator, or because this post-rxn crap doesn't filter well?).

Yeah, I basifyed first, then I vacuum filtered. I would imagine if you didnt basify that it would be alot slower.

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Sink or SWIM

Oh yeah, and wash the dark filter cake with methanol to get out the rest of the freebase from the filter cake.

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Sink or SWIM

Damn, I was hoping it would be possible to remove the sludge before we basified to reduce the amount of base needed. It turns out to be a lot of hydroxide when you're talking about taking the reaction to larger scales.

I dont know yet. I havnt actually tried to filter right after post-al/hg before basification. This weekend swim will try a al/hg and see if he can filter it w/o basification.

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Sink or SWIM

I just now finished up an al/hg run using nitromethane/methanol without any ketone of some sort. I didnt basify this time but i vacuum filtered hot using filter paper/celite/filter paper. It filtered fast. I filtered about 1.4L of the solution in about 3minutes using aspirator vacuum.

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Sink or SWIM

Do not apply too much vacuum for too long, and do not filter hot! You will suck all the good stuff out of your solvent!

Just pour your room temp post reaction mixture into the Buchner funnel, apply some vacuum to the filtration flask, switch it off again after a few seconds and let the filtration take its course. If you use an aspirator, use a valve between the pump and the filtration flask. Coarse, fast filter paper (coffee filters?) will usually do, doesn't matter when some Al sludge gets sucked through if you intent to use the MeNH2 in MeOH for an Al/Hg amination.
 Who cares if it takes long?! Still better than all the fine methylamine product ending down the drain!

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I'm not fat just horizontally disproportionate.

>> and do not filter hot! You will suck all the good stuff out of your solvent!

Good point! The thought never crossed my mind that filtering when hot could result in loss of yield. Good advice!

The al/hg when filtered was about 35-40C. I dont think i lost that much methylamine...atleast i hope not

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Sink or SWIM

The guy at depot didn't have a clue.. "Celite? Huh? Whats it look like?"

I just stood there for a minute as the store became silent.. I didn't have a clue what it looked like, "I think it looks like perlite".

Needless to say the guy didn't know what perlite was either..

Not knowing what celite is, I tried to picture it visually from the info in this thread. I kept picturing Perlite, the white pourus volcanic material. Having used that in mushroom cultivation, I familiarized with it's properties and off to walmart I went. No deal, they were fresh out.. but I know they stock it certain times of the year, for a long while back I bought some there.

Well, no perlite, and for all I know it could be a totally different thing, but Im thinking perlite could work.

Empty handed, I thought I would try foil instead. If you tightly ball the foil up into little bb's!! Wait.. thats it! Could BB's work? A filter, with 1 even layer of bb's, then another filter on top?

Is Celite anything like Perlite? Educate me please.  

It sounds very similiar to perlite.

https://www.thevespiary.org/rhodium/Rhodium/hive/hiveboard/picproxie_docs/000384725-file_3vkw.jpg" title="View this image">

I'll try it, I found some in the garage minutes ago. I hate when that happens.. out at the store lookin for shit I already have.

Heres more info on it. It's not soluble in water at all.

http://www.perlite.net/