What would be the most efficient way of extracting Paracetamol (Acetaminophen) from tylenol or other tablets. My guess would be to use rubbing
alcohol. Would this work?bfesser - 3-12-2013 at 08:03
Please be more specific. Rubbing alcohol is usually <em>either</em> denatured ethanol <em>or</em> propan-2-ol ('2-propanol',
'isopropanol', 'isopropyl alcohol'). Which do you mean? Also, it would help if you specified which tablets you intend to extract the acetaminophen
from. Some are coated and compounded with a lot of other things—making extraction more difficult—while others have only the
acetaminophen and a binder. Finally, did you try searching for an answer to this question on your own before posting? I don't mean to discourage
you, but this has been answered hundreds of times on other sites (and likely already on this one). Extraction of the active ingredients in pain
reliever tablets is a common undergraduate laboratory exercise.
[edit] Google search for <a href="http://lmgtfy.com/?q=acetaminophen+isolation" target="_blank">"acetaminophen isolation"</a> <img
src="../scipics/_ext.png" />...
[Edited on 3.12.13 by bfesser]TheChemiKid - 3-12-2013 at 08:27
I think I will use methylated spirits, as shorter chains can dissolve more. I am using extra strength tylenol. I was thinking of crushing up the
tablets for faster extraction. I UTFSE here, and I didn't know how reliable some of the sites I found were.
I think this would work, do you agree?Bot0nist - 3-12-2013 at 08:43
Follow bfesser's advice. A search pulled up many methods that utilize your.desired isolates solubility curve in water. Practicaly insoluble in cold
water yet pretty soluble in near boiling water... Used often to remove the highly soluble hydrocodone bitartrate from the APAP in a common pain killer
in the states. I imagine relativly pure tylenol can be recrystalized from boiling water after several cold water washes.
[Edited on 3-12-2013 by Bot0nist]
[Edited on 3-12-2013 by Bot0nist]Boffis - 3-12-2013 at 09:09
Yes. My experience is that the best way is to use pure isopropanol (ethanol and methanol also work). I use an excess of solvent, about 7-8ml per
tablet so that the paracetamol stays in solution when it cools. This allow you time to filter the suspension without it crystallising. Some
preparations are full of difficult to remove fillers so I usually find that for a packet of 16 tablets about 0.1 -0.2g of celite or kiesulguhr and a
little decolourising charcoal need to be added to aid filtrations and removal of a very fine almost colloidal material. I use a Buchner funnel and
water-pump for the filtrations and I often find that the first liquid to come through the filter is still slightly cloudy; if this is the case simply
return it to the filter a second time. Rubbing alcohol is 70% aqueous isopropanol so you may find that paracetamol is less soluble in the cold and you
may need to adjust the details slightly. Some of the fillers clog the filter paper very badly so gravity filtration is often not practical.
About 80+% of the isopropanol is distilled off (until the first hint of solids form) and the residue mixed with water (about equal to the volume of
alcohol distilled off) reheated (most of the white precipitate does not re-dissolve) and then cooled slowly to give a filterable white crystalline
material. Recovery is about 95%. The isopropanol in the aqueous filtrate can be recovered by distillation too and a little more paracetamol recovered
on cooling but its hardly worth it. Don't evaporate to dryness and use this material it may contain soluble fillers.
I have found it very difficult to recrystallize from water because of the low solubility in cold water and the fine fillers make even vacuum
filtration too slow and therefore it crystallises in the funnel. Particularly as the first few cc of filtrate are almost never clear and have to be
returned to filter.papaya - 3-12-2013 at 09:14
Most importantly I want to know where this compound can be used, any interesting thing you plan to do?TheChemiKid - 3-12-2013 at 12:29
I am planning to synthesize benzoquinone, and possibly other things with that.Hexavalent - 3-12-2013 at 14:49
I can vouch for the method outlined here, although I had success using half of the acetone they suggest using.
Boffis - 3-12-2013 at 19:22
If you oxidize it with excess conc HCl and sodium nitrate or sodium chlorite (80% NaClO2) etc. or aqua regia you can get chloranil in good yield.
You can convert this into chloranilic, nitranilic and iso or o-cyananilic acid by treatment with a hydroxide, nitrite or cyanide respectively and
numerous other compound by treating it with sulphur compounds, metabisulphite.
Nitranilic acid can be reduced to 3,6 diamino-tetrahydrobenzene from which many more compounds can be created including rhodizonic acid, croconic
acid, hexahydroxybenzene and even cyclohexahexone hydrate C6O6.2H2O!!!
most of these compounds form brightly coloured complexes with some metal or another. bfesser - 4-12-2013 at 06:00
I UTFSE here, and I didn't know how reliable some of the sites I found were.
<strong>TheChemiKid</strong>, <em>most</em> undergrad teaching lab guides on .edu domains can be trusted, as
well as anything from the <a href="http://www.rsc.org/" target="_blank">Royal Society of Chemistry</a> <img src="../scipics/_ext.png"
/> (RSC; <strong>Hexavalent</strong>'s link). In the future, I recommend <a href="http://scholar.google.com/"
target="_blank">Google Scholar</a> <img src="../scipics/_ext.png" /> for finding reliable information—at least for those
results which you can access. Finally, have a look at <strong>Nicodem</strong>'s <strong><a
href="viewthread.php?tid=19143#pid246116">The literature searching guidelines</a></strong> and <strong><a
href="viewthread.php?tid=19143#pid294917">Guidelines for critical thinking</a></strong>—admittedly, I haven't read through
them yet, but I'm sure they're excellent. I hope this helps.TheChemiKid - 4-12-2013 at 08:21
I used 300 mL of hardware store denatured alcohol and 40 tablets of extra strength tylenol tablets (500mg Paracetamol per tablet) After workup and
recrystalization, I got 16g of Paracetamol melting at 168 to 169°C. This corresponds to an 80% yield.
@bfesser Thanks for the help on telling me what is reliable.Hexavalent - 4-12-2013 at 11:47
Because you're not performing a reaction here, is is customary to state that you have made an 80% recovery, as you are indeed
"recovering" the p-amidophenol from the tablets.
[Edited on 4-12-2013 by Hexavalent]bfesser - 4-12-2013 at 11:58
If you're going to be anal(ytical) about it, don't forget that the tablets don't contain exactly the stated amount to begin with. The math can
quickly become overwhelming.DraconicAcid - 4-12-2013 at 12:53
If you're going to be anal(ytical) about it, don't forget that the tablets don't contain exactly the stated amount to begin with. The math can
quickly become overwhelming.
You'd think a company selling medication would be legally obligated to get it pretty damned close.bfesser - 4-12-2013 at 12:54
Yes. There's a tolerance, though.TheChemiKid - 5-12-2013 at 12:58
@Boffis Could you elaborate on the hydroxide reaction and the procedure for rhodizonic acid? Also, is cyclohexahexone hydrate toxic as it is a polymer
of carbon monoxide?
[Edited on 5-12-2013 by TheChemiKid]ScienceSquirrel - 5-12-2013 at 13:25
I used 300 mL of hardware store denatured alcohol and 40 tablets of extra strength tylenol tablets (500mg Paracetamol per tablet) After workup and
recrystalization, I got 16g of Paracetamol melting at 168 to 169°C. This corresponds to an 80% yield.
@bfesser Thanks for the help on telling me what is reliable.
A simple extraction should yield close to 100%.
But he recrystalised the product to get a very pure product with a spot on melting point.
Not a bad effort and feel free to publish your experimental details. TheChemiKid - 6-12-2013 at 05:49
To start, I added 40 extra strength tylenol tablets to a 500mL erlenmeyer flask, then added approximately 300mL of denatured alcohol. On low heat
(40-45°C), I stirred for approximately 5 hours. I had a reflux condenser to condense any fumes. After the five hours, I let the liquid cool down,
then vacuum filtered off the binders and such. I filtered once more to get any residual particles. I added the liquid to some beakers, then let
evaporate. I was left with some almost clear crystals (When crushed down they were white). I used boiling water to recrystalize. I weighed my final
product, and took its melting point. Finally, I added it to a airtight bottle for storage.TheChemiKid - 11-1-2014 at 08:20
Sorry I posted this so much later, but I can't edit my post, so here is a link to my video on this.vmelkon - 13-1-2014 at 15:43
I used 300 mL of hardware store denatured alcohol and 40 tablets of extra strength tylenol tablets (500mg Paracetamol per tablet) After workup and
recrystalization, I got 16g of Paracetamol melting at 168 to 169°C. This corresponds to an 80% yield.
@bfesser Thanks for the help on telling me what is reliable.
Wow, you lost 4 g of paracetamol. You should perhaps have washed the crushed pills a couple of times with fresh ethanol.
Put all the ethanol together in the end and then distill the ethanol away. (Personally, I would collect the ethanol and use it as fuel.)
How much does each pill weight? Perhaps there is practically no cellulose in it. I once bought 650 mg pills of aspirin and it weighted 650 mg per
pill. I guess it was nearly pure.
Good stuff.
[Edited on 14-1-2014 by vmelkon]TheChemiKid - 14-1-2014 at 07:57
I lost the 4g from the recrystalization. Also, the tablets aren't exactly 500mg each.
