Hexavalent - 4-5-2013 at 07:22
Attached below is a summary of my recent work involving the preparation of 5-sulfosalicylic acid from generic, household aspirin pills. As always, any
comments and suggestions are welcomed and much appreciated.
Attachment: sulfosalicylic acid.pdf (317kB)
This file has been downloaded 3492 times
woelen - 4-5-2013 at 07:46
Nice to read about this synthesis. It looks like an easy preparation, which can well be carried out by an amateur.
Magpie - 4-5-2013 at 09:02
Super! Using good technique, quantifying everything, and determining yield and purity provide the most satisfaction when doing syntheses, IMO.
[Edited on 5-5-2013 by Magpie]
Prometheus23 - 4-5-2013 at 09:26
Very nice write-up Hexavalent. You did an excellent job of not only preparing your products, but also purifying and characterizing them. It's
interesting that there was no detectable amounts of the 3-sulfosalicylic acid isomer, as although this isomer would be disfavored over the 5 position
I would think it would still be produced in small amounts.
Did you have to go through much trial and error before you were able to optimize the procedure? Or was your work based off of a published procedure?
Hexavalent - 4-5-2013 at 09:34
Thank you for your comments! 
The main sulfonation part of the synthesis came from a published article, which I have tweaked somewhat to optimize it. The rest of it I developed
myself, bearing in mind the needs of the amateur chemist beginning in organic chemistry: clarity, simplicity, and a "feel" for the compounds they
prepare.
I have run the sulfonation a few times, and have managed to get yields of up to 98% by modifying some elements of the procedure. The results I showed
here are based upon the first run I did of the reaction.
Prometheus23 - 4-5-2013 at 09:43
Did you try modifying the workup of the final product? This is just a guess, so take it with a grain of salt, but I think you might be able to find
better option than quenching with brine to precipitate the 5-sulfosalicylic acid.
Hexavalent - 4-5-2013 at 09:52
I tried quenching with ice-cold water as a variation, but to no extra avail - it seemed that less product crystallized out when I tried this. In
either case, however, I cannot stress the importance of adding the acid to the "quenching agent" slowly, and with stirring - the additions were both
very violent, somehow seeming more so than when diluting regular sulfuric acid.
Have you another suggestions for the workup?
Another point is that the current method is simple and easy to perform for the amateur chemist beginning in chemistry, but I guess a somewhat more
advanced workup vs increased yield is a good compromise.
Boffis - 4-5-2013 at 13:36
Nice write up Hexavalent!
Just one small point, the reference if Eur. J. Inorg. Chem. but the date is 1900; this journal didn't exist until about 1990! The nature of the title
however looks like 1900 vintage Berichte or is the date a typo?
Hexavalent - 4-5-2013 at 13:49
I'm not sure, as the paper was originally found via a Reaxys search. When I was writing the document above, I found the information I listed
about said reference here;
http://onlinelibrary.wiley.com/doi/10.1002/cber.19000330386/...
barley81 - 4-5-2013 at 16:20
Nice write-up, congratulations! I find it interesting that you were able to obtain crystals of the free acid (instead of the sodium salt) from a brine
solution. When I have time during summer break, I might try this with some of the salicylic acid I made (boiling aspirin tablets in dilute sulfuric
acid. Note --- the filler from the tablets turns to goo at the bottom of the beaker and little bits of the stuff get in the product; recrystallization
is recommended, as you described in the paper).
Boffis - 4-5-2013 at 17:18
Found it! On the Gallica website! The original paper is in Beritche 1900 p3238. When I tried to download it I got 1400+pages though! Does any body
know how to break it up into manageable ie individual paper, paper sized documant other than by printing it off and scanning it?
smaerd - 5-5-2013 at 05:14
Good work Hexavalent. Always a pleasure, keep it up!
gsd - 5-5-2013 at 18:18
@Boffis
It has been a while since I last downloaded anything from Gallica, however, IIRC there is an option by which you can download specific set of pages.
Gsd
Rosco Bodine - 7-5-2013 at 14:04
Here ya go, but crappy gallica scans as usual ...Wiley where are you 
Attachment: 5 sulfosalicylic acid Berichte 1900 3238-3243.pdf (571kB)
This file has been downloaded 1409 times
Hexavalent - 8-5-2013 at 09:45
Here is the original version I used - perhaps it is of somewhat higher aesthetic quality - (many thanks to DJF90, for sourcing it on
Reaxys).
Attachment: 19000330386_ftp.pdf (217kB)
This file has been downloaded 1037 times
Also, note that the original paper describes two procedures for workup: I chose the one seen in my article as I do not currently have the glass fiber
filter paper/fritted funnel needed to filter concentrated sulfuric acid.
[Edited on 8-5-2013 by Hexavalent]