Sciencemadness Discussion Board

Bubbling dry HCl gas through a extract

dobeid - 21-9-2008 at 12:52

Can someone explain exactly what the process is for "bubbling dry HCl gas through an extract". I can not seem to find step-by-step instructions. If this process is posted somewhere, pointing me to the web site or explanation would be greatly appreciated.

Thanks

kclo4 - 21-9-2008 at 16:50

Well, what is it you are doing exactly, or are wanting to achieve?
Are you referring to precipitating an alkaloid salt from a polar solvent?

solo - 21-9-2008 at 17:33

I guess he wants to make a salt.....an HCl salt, so have some HCl in separatory funnel and drip it into some H2SO4....then have an exit from where all this is happening attached to a hose that runs through a drying tube and then into the solution you wish to chlorinate.......solo

Hulagu khan - 27-12-2019 at 11:13

Swim would like to know from the friendly Bees if he would need to boil/evaporate some of the solvent (ether) in the solution before doing the bubbling process mentioned above or will the HCL gas evaporate the solvent and turn the solution into crystals (pardon me if the question seems dumb, swim is still very wet behind the ears when it comes to different types of synthesis’ and he has been learning a lot from the posts on this forum from various Bees

Abromination - 27-12-2019 at 11:39

Sounds like cookery, but I could be wrong. Its cheapest to dropwise add hydrochloric acid to anhydrous calcium chloride, leading the gas thorough a washer full of 98% sulfuric acid or another suitable drying agent (maybe a bit unnecessary, the calcium chloride should remove most water) and from there bubbling into your “extract.”

It would of course help to know what that “extract” is though.

G-Coupled - 27-12-2019 at 12:28

Quote: Originally posted by Hulagu khan  
Swim would like to know from the friendly Bees if he would need to boil/evaporate some of the solvent (ether) in the solution before doing the bubbling process mentioned above or will the HCL gas evaporate the solvent and turn the solution into crystals (pardon me if the question seems dumb, swim is still very wet behind the ears when it comes to different types of synthesis’ and he has been learning a lot from the posts on this forum from various Bees


You want to generate 'dry' (as in no water) HCl gas, as detailed in multiple posts here already, and when this is bubbled through the solvent (Diethyl Ether?) containing the freebase of your desired product , the Hydrochloride salt of your product will form which is insoluble in the Ether so it will 'salt out' of solution in the form of many tiny crystals. You then evaporate/filter/recrystallise, or whatever.

You want to keep water out of the process as the salt form of your reaction product is almost certainly soluble in water, so you will lose product, the more water is present.

Hulagu khan - 27-12-2019 at 13:02

Abromination and G-Coupled, Swim is so grateful for your Superbee input and swim would like to clarify that he joined the forum a few hours ago and though a lot of posts on the forum have been helpful to swim but he just needed to know the missing piece of the puzzle that you just assisted with. Swim can’t find words to show his gratitude.

[Edited on 27-12-2019 by Hulagu khan]

Texium (zts16) - 27-12-2019 at 13:22

@Hulagu khan: I see that you are new here. Please read the forum guidelines: https://www.sciencemadness.org/whisper/viewthread.php?tid=19...

How you spend your personal time and what you use information here for is none of my business, but we don’t tolerate “swim” talk here. In the future please refrain from it, or you can expect to find your posts in Detritus.

Abromination - 27-12-2019 at 14:13

Quote: Originally posted by Texium (zts16)  
@Hulagu khan: I see that you are new here. Please read the forum guidelines: https://www.sciencemadness.org/whisper/viewthread.php?tid=19...

How you spend your personal time and what you use information here for is none of my business, but we don’t tolerate “swim” talk here. In the future please refrain from it, or you can expect to find your posts in Detritus.

I am not sure as to what “swim talk” is, anyone care to inform me? Either way I regret replying to this blatant spoon feeding in the first place.

Hulagu khan - 27-12-2019 at 14:15

My apologies @Texium, I assumed it was common for someone who is new to such a forum to refer to themselves as a swim. I appreciate the heads up, I saw it being used by some members who referred to themselves as being new members. I will go through the guidelines to ensure a similar thing never happens again.

G-Coupled - 28-12-2019 at 05:53

SWIM = 'Someone Who Isn't Me' - not so much to do with account newness, more it was used on forums as a kind of 'can't (legally) prove it was me' kind of thing.

Seemed to die out like a decade ago or so, but one might still come across it in old archived forum threads etc.

Yttrium2 - 28-12-2019 at 10:45

I've tried several methods out in the woods...


Hcl + sulfuric made a big cloud of hcl

Salt + sulfuric was more controllable


Al + HCL aq took off like a rocket..


Hcl + calcium chloride - I forget.


Hcl + calcium chloride from the dollar store is your best option .


Now for contraptions, I used to use a water bottle with a polypropylene hose in the center. I would add sulfuric acid and table salt. The bottle would be squeezed as I inserted the tube to the liquid to be gassed'

And retracted so fresh air could be sucked in


Squeezed again when inserting the tube.




In the future I'll use calcium chloride and hcl aq, though I don't remember how quickly this takes off. It's the cheapest route.



I wonder how much the moisture affects the yield, in addition...


Wear Goggles:D

[Edited on 12/28/2019 by Yttrium2]

morganbw - 28-12-2019 at 14:54

Quote: Originally posted by Yttrium2  
I've tried several methods out in the woods...


Hcl + sulfuric made a big cloud of hcl

Salt + sulfuric was more controllable


Al + HCL aq took off like a rocket..


Hcl + calcium chloride - I forget.


Hcl + calcium chloride from the dollar store is your best option .


Now for contraptions, I used to use a water bottle with a polypropylene hose in the center. I would add sulfuric acid and table salt. The bottle would be squeezed as I inserted the tube to the liquid to be gassed'

And retracted so fresh air could be sucked in


Squeezed again when inserting the tube.




In the future I'll use calcium chloride and hcl aq, though I don't remember how quickly this takes off. It's the cheapest route.



I wonder how much the moisture affects the yield, in addition...

Wear Goggles:D

[Edited on 12/28/2019 by Yttrium2]


Yields? Of what.
Be careful of those woods.

Hulagu khan - 12-1-2020 at 02:20

Quote: Originally posted by G-Coupled  
SWIM = 'Someone Who Isn't Me' - not so much to do with account newness, more it was used on forums as a kind of 'can't (legally) prove it was me' kind of thing.

Seemed to die out like a decade ago or so, but one might still come across it in old archived forum threads etc.


I highly appreciate the heads up G-Coupled and I have noticed some of the posts on the forum are +/-15yrs old. I appreciate your input.

draculic acid69 - 14-1-2020 at 16:04

Quote: Originally posted by Yttrium2  
I've tried several methods out in the woods...


Hcl + sulfuric made a big cloud of hcl

Salt + sulfuric was more controllable


Al + HCL aq took off like a rocket..


Hcl + calcium chloride - I forget.


Hcl + calcium chloride from the dollar store is your best option .


Now for contraptions, I used to use a water bottle with a polypropylene hose in the center. I would add sulfuric acid and table salt. The bottle would be squeezed as I inserted the tube to the liquid to be gassed'

And retracted so fresh air could be sucked in


Squeezed again when inserting the tube.




In the future I'll use calcium chloride and hcl aq, though I don't remember how quickly this takes off. It's the cheapest route.



I wonder how much the moisture affects the yield, in addition...


Wear Goggles:D
[Edited on 12/28/2019 by Yttrium2]



U forgot to try calcium chloride and h2so4 which provides twice as much dry HCl compAred to HCl +Al which equals wet gas.

BromicAcid - 14-1-2020 at 17:12

I ignored it the first time but since it was brought up again:

6HCl (aq) + 2Al ---> 2AlCl3 (hydrated) + 3H2

No hydrogen chloride

Edit: The exotherm of the reaction may volatilize some already there but you're not forming it.

[Edited on 1/15/2020 by BromicAcid]

draculic acid69 - 14-1-2020 at 18:05

HCl +Al = definitely large amounts of HCl gas whether or not it's just evolved bcoz of a thermal increase caused by the HCl+Al=alcl3+H2 or not it definitely releases HCl gas
Wet gas but gas none the less.lots of Al is left over after it usually.so the alcl3 formation is rather minor I'd say.i don't think any usable amount of hydrogen could be separated from the HCl gas no matter how much bubbling and scrubbing u put it through. It's predominantly HCl gas.

draculic acid69 - 14-1-2020 at 18:10

And yes I understand that it's not really forming HCL but that's not really a relevant point in this post.

BromicAcid - 14-1-2020 at 19:12

Relevant in this post? This is a chemistry forum. Ignorance like that should not be allowed to pass unchecked. In this case you might as well just heat the hydrochloric acid on a hot plate.

OldNubbins - 14-1-2020 at 21:21

Quote: Originally posted by draculic acid69  
HCl +Al = definitely large amounts of HCl gas


More like a soggy cloud of mist containing some HCL due to all the hydrogen bubbles. But I could be wrong because sounding confidently wrong is just..... silly....

Tsjerk - 15-1-2020 at 02:31

What works nicely without having to deal with any gas is adding concentrated HCl to ether with CaCl2 on the bottom. The HCl will sink to the bottom where the water is absorbed by the CaCl2. If done slowly all HCl will dissolve in the ether, qiving a solution of dry HCl in ether. It is a good as quantitive so you can calculate the amount of HCl needed, and the ether can be decanted or filtered.

draculic acid69 - 15-1-2020 at 04:23

Have either of you ever actually tried it.i have.it worked.so I don't really see how it could in any way be wrong.

draculic acid69 - 15-1-2020 at 04:32

Quote: Originally posted by BromicAcid  
Relevant in this post? This is a chemistry forum. Ignorance like that should not be allowed to pass unchecked. In this case you might as well just heat the hydrochloric acid on a hot plate.


U could just put it on the hotplate but it would be extremely ineffective compared to the Al foil method.and there'd be way too much water and way too slow.
Whether it's formed or evolved is not really something to give a shit about when gassing something
[Edited on 15-1-2020 by draculic acid69]

[Edited on 15-1-2020 by draculic acid69]

Abromination - 15-1-2020 at 07:31

Quote: Originally posted by draculic acid69  
Quote: Originally posted by BromicAcid  
Relevant in this post? This is a chemistry forum. Ignorance like that should not be allowed to pass unchecked. In this case you might as well just heat the hydrochloric acid on a hot plate.


U could just put it on the hotplate but it would be extremely ineffective compared to the Al foil method.and there'd be way too much water and way too slow.
Whether it's formed or evolved is not really something to give a shit about when gassing something
[Edited on 15-1-2020 by draculic acid69]

[Edited on 15-1-2020 by draculic acid69]

You dont evolve any extra gas through aluminium then by heating. The only reason HCl would be evolved through the reaction of HCl and aluminium would be through heating from the exothermic reaction.
If you want to explain your reasoning, we would here it.

[Edited on 1-15-20 by Abromination]

morganbw - 15-1-2020 at 10:24

The Al in HCl may not produce HCl gas, I get it, the chemistry thing:)
I do know that some shake and bake producers use this method for their gas.
Carried over in spite of the bad chemistry, I guess.

Good method, absolutely not, but they do get crystals.
Shake and bake, good method, horrendous from a chemist point of view, but they do get crystals.

SWIM - 15-1-2020 at 10:55

In PIHKAL, etherial solutions of alkaloids are often made into HCl salts by diluting with DRY ethanol (10:1 or so usually) and then adding the calculated amount of concentrated HCl.

This saves the need for a HCl generator set-up, and makes it possible to use the calculated amount of acid without a large excess, but does call for lots of dry ethanol.

I use sulfuric acid dripped on salt wetted with conc HCl when I need HCl gas.
The gas rises through a condenser (Ice water) packed with broken glass, or glass coils if I'm feeling fancy, then by tubing into an Erlenmeyer with a lot of drying agent in there.

Works well enough for most things.