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ordenblitz
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Priority Care aspirin boluses contain a small amount of urea as well as microcrystalline cellulose as a compression aid.
A better choice is to use their aspirin powder sold in one pound bags that is pure ASA.
http://farmvet.com/farmvet/shop/shopdisplaydetailfarm.asp?pr...
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quicksilver
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| Quote: | Originally posted by Rosco Bodine
One thing I am getting with methyl salicylate is a clear oily precipitate which contaminates the end product , and also there is a soapy detergent
like byproduct of sulfonation which results in a persistence to the foaming , at times the nitration is like trying to stir whipped cream or shaving
cream , which is very annoying and troublesome , making the additions go tediously slow to allow continued mixing . There are very significant
viscosity problems to manage
during the nitration , much worse than is the case for ASA . |
When you said that I just thought of something..... Salicylic acid with heat source converts to carbolic acid (phenol) and
carbon dioxide; (in presence of water from 98% H2SO4)
The formed phenol just sulfonates rapidly. The wintergreen oil would need to jump through hoops to get to that point.
-SO3H group will do as -NO2 or -OH groups in accelarating the evolution of CO2 at lower temps.....perhaps....the meer fact that one is dealing with
an "oil" would account for the soapy by-product...(?) Let's say that the sulfonation process is too fast (just a guess) and in a solid
with a closer phenol structure it's OK...but in a product like oil of wintergreen it takes a much longer time because we don't have
C7H4O2 + H2O --- C6H6O + CO2
-C7H6O3 -- C6H6O + CO2
to start from. (I hope I wrote that correctly: but you get the idea)...
I have used Indigo....had a lot of problems....so once I let it sit in H2SO4 for a full day (24hrs)....final product came out lemon - white yellow and
looked great. Used it in a reaction - it was the real thing. Of course I have yet to use horn or wool, or some damn thing....
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Mumbles
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Thats not pure ASA.
| Quote: | | 1 level tablespoon is approximately 1/2 oz. 1/2 oz. contains approxiamtely 7080 mg of Aspirin. |
1/2 oz is ~14g. 7080mg is only 7.08g. This puts it at 50% ASA.
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Rosco Bodine
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With alternative precursors in mind , it may be of interest that red gum may be nitrated to picric acid . I have never tried this method but it seems
worth noting for any who may wish to experiment with unconventional precursors .
P.S.
Damn ESPACENET for going to encrypted files which are more difficult to assemble and decrypt for saving and sharing , and the stupid new user
interface which they have substituted for the more functional one which has been recently removed from service . It adds 10 useless minutes of
difficulty to handling any .pdf file they offer compared to what used to be so straightforward . And besides that , anybody with half a mind can
recompile
the document in an unencrypted intelligent form ...so what have they accomplished really but to piss off their clients with their stupid new "
document wrapper " interface ????
Attachment: GB104352 Picric Acid from Red Gum ( gum accaroides ).pdf (307kB)
This file has been downloaded 1262 times
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quicksilver
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| Quote: | Originally posted by Rosco Bodine
Damn ESPACENET for going to encrypted files which are more difficult to assemble and decrypt for saving and sharing , and the stupid new user
interface which they have substituted for the more functional one which has been recently removed from service . It adds 10 useless minutes of
difficulty to handling any .pdf file they offer compared to what used to be so straightforward . And besides that , anybody with half a mind can
recompile
the document in an unencrypted intelligent form ...so what have they accomplished really but to piss off their clients with their stupid new "
document wrapper " interface ???? |
IT'S ABOUT TIME SOMEONE SAID THAT....I simply stopped working with British patents at that site because ESPACENET has become a vacuous shambles
of what it was supposed to be....Lord in Heaven! that site is a pain in the ass.
-=However; thank you for hasseling the file.=-
Please note that it needs to be renamed to "xxxxx.pdf" due to the above issues. But it IS a great example of the issues discussed.
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quicksilver
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| Quote: | Originally posted by Rosco Bodine
With alternative precursors in mind , it may be of interest that red gum may be nitrated to picric acid . I have never tried this method but it seems
worth noting for any who may wish to experiment with unconventional precursors .
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After reviewing the patent there are some very important issues discussed. First of all is temp that they mention; the use of 40C (104 F) and time of
nitration. This has been a real stumbling block for many. If the temp is raised, the nitration proceeds and if monitored can be successful but the
yield falls. If nitration temp raises to the point wherein the solution has a "Yellow Froth" (temp unk.) the tri-nitration usually results
BUT the trick is to MONITOR the solution for an overall orange colour NOT red! This colour issue is a real important one, I believe. It gives some
clues where resources are not available - EXCEPT for appearence.[We can't just stop and use an old fashoned NitroMeter] And the solution must
appear clear (as you mentioned). If cloudy and red the nitration has brought about the resultant "red-goo". This appears (to myself at
least) to be a temp vs time issue. One can go as high as 200+C but the solution MUST be monitored. I have heard it said that if time were not at issue
and one wanted to allow the synth to stretch over several days that 40C would be just fine (the patent points to this as well, in effect). But very
few folks want a lab to proceed over days and on a production scale it would be problematic. Therefore monitoring the solution for colour is
manditory.....due to a varience in ratio of temp vs. size of synth.
This has applied to BOTH my use of Indigo & plain old asprin.
I have worked with ounces (rather than grams) in my PA synths because I want to have a useful amount of reagent available after I'm all done. But
that involves monitoring the thing constantly as I have found out that the temp/colour issue will change when I am at 1 OZ vs 8 ounces.....etc.
The patent speaks of sulfonation at the 10 hour level. I believe at 30C... I have not kept it that low myself....but I have brought the the temp to
boiling (230C + or -) monitoring it constantly; I personally have had success but with a low yield. They mention 48 hours which leads me to believe
they are working with the multi- pound or Kg level of product perhaps.
As you have mentioned I ALWAYS let the solution set for 12 hours after nitration and allow the cooling off to proceed without any interference (or a
sudden plunge in cold) & my crystals have been fantastic!
On another topic therein they speak of purificication of the starting material. They mention purification in the cold! I have always done so. Even
when many have said to use heated alcohol....I have used cold etoh and the product has been excellent. I have found a useful little trick with asprin.
I use a solution of ethyl alcohol and acetone in my initial step of grabbing the ASA from the store bought material. I use 2/3 etoh to 1/3 acetone.
This has two important effects. The 1st is that the product appears to be MUCH purer and forms very strong well formed crystals (I am not sure why but
it is very different from using alcohol alone) and it also evaporates MUCH faster. The product is thus made has been THE BEST I have ever used. When
comparing mp and it's appearence under a microscope to mfg reagent grade PA from a major suppier; it appears to be the SAME! All in all the
patent agrees with what I have found experimenting over 6 months with PA alone. I have never seen this patent (due to the problems with that damn
patent web site) yet it tracks with what I have found by trial & error! All in all it is an important patent as it outlines what many have had to
learn by trial and error...IF...you know what you are looking for in both the patent and the synth itself.
[Edited on 23-9-2005 by quicksilver]
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ordenblitz
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Mumbles said:
__________________________________________________
That’s not pure ASA.
1 level tablespoon is approximately 1/2 oz. 1/2 oz. contains approximately 7080 mg of Aspirin.
1/2 oz is ~14g. 7080mg is only 7.08g. This puts it at 50% ASA.
__________________________________________________
Well actually it is pure ASA crystals.
Beside the fact I get quite pure TNP using it as received, I decided to alleviate any doubts...
I measured out 1 tablespoon, obviously a very inaccurate form of measure, and got 9.42 gm.
The package states:
Active ingredients - each pound contains Acetylsalicylic Acid (Aspirin)......1 lb.
To be sure I checked it on the FTIR.
(Kbr, transmittance)
Omnic full library search calls it as:
2-(acetyloxy)-Benzoic acid U.S.P
CH3COOC6H4COOH
This is definitely pure ASA crystals and the best $8.00 your going to spend.
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chemoleo
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Awesome your FTIR. You should create a thread on this, the uses of FTIR in amateur chemistry. While people submit either the methods or even the
samples to you for analysis.
Did you ever get round to comparing AP vs 'DPPP'?
Sorry that's way off topic, and please dont respond to this, Ordenblitz, except in the correct thread....
So much for being an example eh
Never Stop to Begin, and Never Begin to Stop...
Tolerance is good. But not with the intolerant! (Wilhelm Busch)
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ordenblitz
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Working from Roscoe's good old country recipe as was posted in another thread, I made some TNP this weekend.
The materials…
http://img58.imageshack.us/img58/9658/asacrystals7bj.jpg
http://img58.imageshack.us/img58/4581/h2so48hp.jpg
93.75 grams of ASA were sulfonated in 375ml 80º, ~96.5% H2SO4
http://img58.imageshack.us/img58/8198/hotsulfasa8lv.jpg
Strangely enough, upon cooling overnight the solution remained clear with no sulfonated material precipitating.
http://img58.imageshack.us/img58/6996/coldsulfasa4gw.jpg
The mixture was placed in a 1000ml flask and the temperature raised to 95º. The additions of granular sodium nitrate commenced. The NaNO3 was
obtained from a commercial fireworks chemical supplier and is of high quality but the actual purity is unknown.
http://img58.imageshack.us/img58/1463/beginnitra0wo.jpg
http://img58.imageshack.us/img58/9098/1stadd6oj.jpg
The solution began to slightly darken with each subsequent addition.
http://img58.imageshack.us/img58/627/3rdadd3sl.jpg
http://img58.imageshack.us/img58/9339/7thadd2jo.jpg
http://img58.imageshack.us/img58/2308/10thadd1uv.jpg
As the crystals of TNP formed the mix began to thicken and lighten again.
http://img58.imageshack.us/img58/5044/14thadd6gb.jpg
At this point there was considerable foaming upon the addition of the solid nitrate and the timing between same had to be greatly increased as was
suggested.
http://img58.imageshack.us/img58/6453/22ndadd9zj.jpg
Stirring was very difficult and the viscous mix moved but slowly with my poor 2" stir bar. Roscoe mentioned a big 3"oval stir bar and
It's surely needed! Next time I will use more sulfuric to lower the viscosity. No sense being stingy.
http://img58.imageshack.us/img58/6875/26thadd8se.jpg
Although it looks like foam, it’s a viscous crust of TNP sitting on the top of the acid. It was making the additions of the nitrate almost
impossible to work into solution. This was the final addition of the nitrate.
http://img58.imageshack.us/img58/5117/28thfinal9bd.jpg
An evil looking brew as 500ml of water was being added from a wash bottle as the dilution began.
http://img58.imageshack.us/img58/7987/startdilution9mq.jpg
Some ice and some time and viola'
http://img58.imageshack.us/img58/634/dilutedandcooling4nd.jp...
Filtering out the raw TNP crystals. I cooled quickly, so the result is a voluminous fine crystal.
http://img58.imageshack.us/img58/8335/filteringtnp2kq.jpg
The raw material was suctioned well and dissolved in 2200 ml of boiling water and then allowed to cool again.
http://img58.imageshack.us/img58/7097/recrycooling2uk.jpg
The first crop was dried and weighed in at 84.2 grams or 70.5% of theoretical.
http://img58.imageshack.us/img58/2767/firstcrop6ff.jpg
The mother liquor was boiled down to ~500ml and a second crop was obtained. After filtering and drying a further 24.16 grams was obtained.
http://img58.imageshack.us/img58/9192/secondcropcooling9df.j...
The remaining TNP in solution was neutralized with K2CO3 then chilled and the crystals of potassium picrate were collected. They were then
re-crystallized from acetone which yielded 3.56 grams, corresponding to 3.053 grams of picric acid in the final liquor.
http://img58.imageshack.us/img58/6001/ktnp7um.jpg
Final tally was 111.41 grams of C6H3N3O7, 93.38% based on ASA.
It was a good day. Thanks Roscoe.
Kinda perty aint she?
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Quince
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That's funny. The sulfonation makes my liquid a very dark color which clears up during nitration, nothing like your images.
\"One of the surest signs of Conrad\'s genius is that women dislike his books.\" --George Orwell
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Rosco Bodine
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Looks like the right stuff and the right yield . Before I had a magnetic stirrer ,
I used about 20% more H2SO4 for a thinner mixture so it could be manually swirled in a 1.5 liter glass tea kettle .
IIRC the product was not quite as good , but the process followed about the same general track otherwise and was workable .
The higher temperature of 115-118 for the sulfonation will produce the disulfonate which is much darker and will gel solid on cooling overnight to a
suspension of crystals in a gelled acid matrix , like dark red-black sand jello full of light colored sand . My acid isn't reagent grade so the
color is probably off , but the physical consistency should be the same . The disulfonate nitrates more easily and decarboxylates vigorously from
the start so it is better I think from a reaction management standpoint to use the higher sulfonation temperature and get the disulfonate ,
but whatever works for you ...the mono and the disulfonate both lead to picric acid
upon nitration , only the reaction proceeds a little differently and decarboxylation is finished later in the nitration for the monosulfonated ASA .
Personally , I like to get most of the effervescence over with early , while the mixture is thinner in the mononitration and dinitration stage , but
there is some overlapping of the reactions across the whole time of nitration , giving variations on a theme depending on temps and rates , stirring
efficiency , as well as the sulfonation state of the precursor .
Give the mixture some slow cooling time , with stirring continued , after the plain water quenching , and a bit larger crystals will come out of the
warmer mixture before it is cooled more quickly with the ice , and then discontinue the stirring as the ice is completely melted .
If you hit it just right the crude picric acid will all be like fine beach sand , microcrystalline a bit finer than table salt , and it will filter
quickly even without suction by a plain gravity filtration .
The filter paper has limited life wet with the diluted nitration mixture , a couple of hours is okay , but it shouldn't be left all
day or it will possibly disintegrate when
rinsing off the crude crystals into the flask for boiling and recrystallization .
ASA really does give a nice grade of picric acid in good yield by this method . I have made it from time to time for about 25 years using basically
the same old country recipe ...er , I mean synthesis
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ordenblitz
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Roscoe,
I followed your sulfonation profile fairly closely but the hold time at 118 was only about 5 minutes as I needed to do some other things. So I shut
off the hotplate and put the flask up for the night. I'm going to try that again with a longer hold to see if I get the change in color.
>Give the mixture some slow cooling time
>with stirring continued , after the plain
>water quenching , and a bit larger crystals
>will come out
My solution was so thick that the stir bar just quit working. I had to stir the last portion of nitrate in with the thermometer. I would like to try
your cooling profile but, I need to get a better bar!
[Edited on 26-10-2005 by ordenblitz]
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Rosco Bodine
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After the midpoint of the addition of the total nitrate , the viscosity gets a bit tricky
and practice makes perfect when it comes to adjusting the addition rate and temperature to find the range where the
mixture is least viscous and stirs fairly well . It looks to me as if the mixture stirs most freely just after a bit of nitrate is added and some
foam is helping to loosen the mixture , but if the foaming becomes greater then it decreases the stirring efficiency greatly . So you have to watch
for the good working volume and pace the additions of nitrate to keep it stirring freely . The progress of the reaction follows a sort of curve
instead of being linear , and you will get skilled at the manipulation of the conditions with some practice . Feel free to adjust the proportions and
test your own ideas , as the synthesis is not necessarily optimized , though it is pretty good and probably not far off the mark . It is a good
working method but good stirrer torque and a heavy stirbar is definitely needed , and the additions of nitrate can get tedious when hours are involved
.
If I was intending many experiments with this , I would likely get a stepper driven auger feeder for addition of the nitrate and automate the process
. A control program could be devised for large batches , if any large scale production was intended . About the limit for my own equipment and
manually done batches would be a 2 mole scale , and that would require my 12 liter Florence being nearly filled for the first crystallization
Not exactly microscale .
I have one dedicated electrical branch for the 1.6 Kilowatt hotplate to which that humungus flask is paired . When it gets to the point of needing
pouring cradles and pumps for emptying your reaction vessels , you know you have a serious experiment underway
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Joeychemist
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| Quote: | Originally posted by Rosco Bodine
Memory fails me on where I read it first , but I know later that Philou Zrealone also has mentioned that picric acid can exist in different forms
depending upon the pH of the solution .
A lower pH favors the less soluble and less colored form of picric acid , IIRC it is called an enol form , and I don't recall the other form .
I'll have to go with the pH sensitivity / enol formation idea , and wish I could learn more about this . A possible clue
is in the formation of different colored forms of ammonium picrate , one yellow and one red . This may be a different aspect of the same pH
sensitivity causing a different crystal form and color for a picric acid salt , while the effect is being manifested from the picric acid itself .
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I have been performing my own experiments with Picric Acid lately and have some very interesting findings to share.
Rosco touched on this a little a while back but more proof was needed for me to be sure.
I have had several 5g batches of Picric Acid (Which were recrystalized into very light yellow/white crystals and precipitated using HCl) sitting out
on and evaporating dish now for about two months and I have noticed that the Picric Acid crystals are clearly changing back into the brighter
“canary yellow” color that we all attribute to Picric Acid. The surfaces of the samples and crystals which are exposed to the air revert back much
quicker than the crystals at the bottom of the sample but the color change is still noticeable (It is very noticeable on the larger crystals at the
bottom of the sample).
These observations (Along with Rosco’s observations) lead me to believe that there is infact both an Enol and Keto form of 2,4,6-TNP like Rosco
suggested!
Mmmm….Keto-Enol tautomerisms
This is very interesting and is a giant step forward in my eyes. What do you guys think?
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Rosco Bodine
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The pH sensitive color transition is very real not only for picric acid but also for sodium picrate . And I believe it was the light colored form
which was gotten from the diluted nitration mixture , in a nearly insoluble form of fine crystals , which at
a partial dilution did not even really tint the supernatant spent acid , nor did the liquid stain the filter paper yellow when filtered . That is
definitely an observable difference when a strong dye has lost its ability to dye , presumably from residual acidity of HNO3 and / or HNO2 which can
be smelled on the damp nearly white crystals .
I would not use the HCl for the final crystallization , in any significant concentration , as the crystals do absorb
some of the HCl and you can smell it on the crystals for days of airing out . Use plain distilled water with very little or no HCl for the final
crystallization and the color is still very pale for the highly purified product .
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ADP
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I am also in the works of performing a Picric acid synth and my sulfonation produces a very dark colored liquid. I am using the following reagents:
10g of purifyed ASA
20ml of H2SO4 (ACS)
35ml of 70% HNO3 (ACS)
Do these quantities seem reasonable? I heated my ASA/Sulf acid mix at 100dC for 1 hour and it turned from yellow, orange, then red, to deep brown and
then a thin blackish color. It has now cooled to room temp and I intend on chilling it to 0dC, adding HNO3, stirring, and then heating once more.
| Quote: | Originally posted by Quince
That's funny. The sulfonation makes my liquid a very dark color which clears up during nitration, nothing like your images. |
I was just now doing some thinking and realized that my asprin from which I procured ASA has polyethylene glycol, starch, and polyproprylene glycol in
it. I used acetone as means of purification and am worried that what I thought was pure ASA may have glycols in it. Should I be worried about this?
How would these react with H2SO4?
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IPN
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The amounts look quite reasonable to me but I don't think you need to cool the sulfonated product so much before adding it to the nitric acid, room
temp should be fine. Then just add it slowly with good stirring keeping the temp below 40C-50C and heat to ~120C for about 30-45 minutes after
addition. That will finish the nitration.
Beware of the NOx gasses that develop during the reaction!
Oh, and 10-15min should be enough (at 100C) for the sulfonation part.
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ADP
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Many thanks IPN, I will post results later.
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ADP
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Sucessful Procedure
I used the following reagents in my procedure:
10g ASA (purifyed via acetone)
20ml H2SO4 (98% ACS)
35ml HNO3 (70%)
I added the sulfuric acid to a 250ml beaker and added the ASA at once. The mixture turned a deep wine color and then went black but remained thin and
easy to stir. (on a side note I wonder if my ASA had polyproproylene glycol in it? soluble in acetone?)
Allowed to sulfonate for 1 hour at 100dC. Cooled to room temp (at this point the phenol-4-sulfonic acid was visible from the thickness and color of
the mixture) and then ice bathed at 10dC added 35ml of HNO3 and stirred.
I brought this mix to room temp and put in a steam bath at 50dC for like 20 min. I then raised the temp to 90 and 100dC and the water was boiling and
heavy NO2 was produced and the mixture was starting to boil. I was kinda worried about this and only let the mix remain this hot for like 5min.
The color changed to a light milky yellow and I removed heat and brought to room temp. I could clearly see picric acid at this point and added 200ml
of ice water and stuck in fridge to cool to -5dC for least solubility. Filtered and set to dry; here are my pics...
My one question of improvement is: How do I nitrate the phenol mixture at 120dC for 30-45min if my nitric acid is boiling and decomposing? Is this
supposed to happen and will a runaway ensue? Thanks a ton.
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kABOOM!
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Yep...this is how I too made Picric Acid, ADP. I kept the temperature slightly lower...say 65C for a slower reaction but still I got the same product.
I got a fairly decent sized yield too.
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Quince
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| Quote: | Originally posted by kABOOM!
I got a fairly decent sized yield too. |
What the fuck does this mean? Ever heard of numbers, measurements? "say 65 degrees"?! Did you even use a thermometer, or
just stuck your finger in and it seemed warmer than your mother's twat? What made you choose that particular temperature? Why not 50, or 80? No,
wait, let me guess: it just 'felt right'. For fuck's sake, I thought this forum was about chemistry, not fucking medieval alchemy! This forum is
being taken over by the k3wls, it would seem! Hey, I've got an idea, let's just start mixing up random shit in proportions determined by the dice
roll/cards/stars!
So, your mood shows as awesome, eh? Is that due to the holidays, or did you taste one too many of your witch's brews?
Any moderator care to check the IP of this tool, to see if it's another incarnation of Hideki, or just a cretinous copycat?
[Edited on 27-12-2005 by Quince]
\"One of the surest signs of Conrad\'s genius is that women dislike his books.\" --George Orwell
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12AX7
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| Quote: | Originally posted by Quince
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Did you happen to read the part of the Sulfuric Acid bottle that says "Do not drink", Quince?
Tim
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ADP
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When using HNO3 for the nitration of the phenol-4-sulfonic acid, what is the best temperature and nitration time from experience? I feel that my
nitration would have been better had I held say 80dC for 30 or 40min.
I kept a lab journal and will reattempt the synthesis today for improvements. I havne't weighed my yield yet as it is still damp. I will do so
shortly. 
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Quince
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| Quote: | | Originally posted by 12AX7 |
Yo, whazaaap Timmy, haven't heard from you in a while.
| Quote: | | Did you happen to read the part of the Sulfuric Acid bottle that says "Do not drink", Quince? |
It said no such thing on the label.
\"One of the surest signs of Conrad\'s genius is that women dislike his books.\" --George Orwell
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chemoleo
Biochemicus Energeticus
Posts: 3005
Registered: 23-7-2003
Location: England Germany
Member Is Offline
Mood: crystalline
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Please back to topic. I am well-tempted to just delete this little useless episode. I might do so at a later time nonetheless.
Never Stop to Begin, and Never Begin to Stop...
Tolerance is good. But not with the intolerant! (Wilhelm Busch)
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